The Official AVS Antenna Topic! [Text View] - Page 25

paulstefano

07-19-07, 10:21 AM

The 8800 appears to be great a pulling in Digital signals, especially from a wide angle. I'm pulling in FOX while the antenna is pointed 175 degrees away from the towers. It's not really doing what I hoped it would, but I have a bit of a unique situation, with an overly strong signal, and I really didn't expect it to.

I probably need to stagger stack. One of the reasons I wanted the 8800 is that I can take them apart and use them as 2 separate 4 bays and stagger them.

As I said, you can't beat the customer service.

Update, I got my replacement PR 8800 from Winegard in the mail yesterday. It was in much better shape than the one I bought locally. Based on the paint and the packaging, I now think the one I bought locally, might have been a return, oh well.

So, I put it on my mast, 40 feet in the air, and hooked it up. Unfortunately, I had similar results. Good reception on WPMT analog (channel 43), Solid signal on Digital Channel 49 (some independent station, I had previously pulled in), and no Digital WPMT (Channel 47). The only difference was I could also pull in WBAL with a solid 60% signal. Weird since the tower is 180 degrees from where I was pointing.

The other bit of good news was there was no WBFF DT (channel 46) at all. It would appear then, the bulk of my problems are interference from WBFF Analog (Channel 45).

I tried this with both my HDP-269 pre-amp in the line, and without. The analog signal on 43, was much cleaner with the amp. It would appear, that the amp does help with the long runs.

paul

AntAltMike

07-19-07, 11:08 AM

...there was no WBFF DT (channel 46) at all. It would appear then, the bulk of my problems are interference from WBFF Analog (Channel 45)...

Things are not as they seem. The PR-8800 will have about the same gain and front-to-back characteristics on channel 46 as it does on channel 45. You have almost exactly the same ratio of channel 45 signal power to channel 46 signal power now as you did before, but for technical reasons, your receiver simply is unable to develop a lock on that defective channel 46 data stream and is generating a no-signal message. You are farther away from a solution than you think.
I tried this with both my HDP-269 pre-amp in the line, and without. The analog signal on 43, was much cleaner with the amp. It would appear, that the amp does help with the long runs..

Not necessarily. with channel 43, you are trying to sustain an analog channel at about 30 to 40 dB above the thermal noise floor. With channel 46, you may be trying to either boost this much weaker signal above the receiver's input threshold or to at least maintain a S/N ratio of 16dB without qualitatively degrading it through intermodulation distortion. While the preamp visibly improved the analog channel 43, it may be helping or hindering your reception of digital 47.

At this point, you either have to erect a hundred foot mast or try phase canceling. The quarter wave stack solution does not require any sophisticated test equipment to implement.

ChocoLab

07-19-07, 05:42 PM

CPCAT & RICK0725 About that 91GX you guys recommended.

When it arrived the box was not impressive, upon unpacking, it looked like a toy from K-tel (that was a long time ago). All those gold plastic looking elements, man ....I felt like Mr. T on a pole.
But all is well!!!!

It will not be mounted in its proper place until this week-end, but in it's present position it is very impressive. I am holding three Atlanta day time signals, and in the evening two more channels join the steady stream. These stations are 80 miles away. I have pretty good elevation and a cm 7777 in line. I am adding a rotor and going up another 10 ft this week end, hopefully I will not screw it up. Thanks for info on the 91gx.
Good info, Don, I hope you'll let us know how it works once you get it put up.

Yesterday I again was fiddling with my 4228 and once again, I was disappointed in its performance. An old Radio Shack U-75 (or whatever the $24.95 Yagi was called) does almost as well, and the XG42 I have seems to do better. I'd almost think something was wrong with the 4228, but it looks perfect -- nothing bent or anything of that nature.

I actually tried ordering that Jaycar version that's very similar to the 91XG, but the transaction failed twice. They may have finally caught on to that super-cheap shipping from Australia. I hate to pay close to $100 for a "tinkering" application, but if the XG91 is really that good, and really that much better than the PR-9032 from Winegard, I may do it anyway.

Rick0725

07-20-07, 08:56 AM

I prefer the 91xg over the pr9032 and would intall one anyway.

ToddUGA

07-20-07, 09:00 AM

Yep, I've been super happy with my 91XG. Much better for UHF than the CM 3671 I was using.

paulstefano

07-20-07, 03:49 PM

Things are not as they seem. The PR-8800 will have about the same gain and front-to-back characteristics on channel 46 as it does on channel 45. You have almost exactly the same ratio of channel 45 signal power to channel 46 signal power now as you did before, but for technical reasons, your receiver simply is unable to develop a lock on that defective channel 46 data stream and is generating a no-signal message. You are farther away from a solution than you think.
.

Not necessarily. with channel 43, you are trying to sustain an analog channel at about 30 to 40 dB above the thermal noise floor. With channel 46, you may be trying to either boost this much weaker signal above the receiver's input threshold or to at least maintain a S/N ratio of 16dB without qualitatively degrading it through intermodulation distortion. While the preamp visibly improved the analog channel 43, it may be helping or hindering your reception of digital 47.

At this point, you either have to erect a hundred foot mast or try phase canceling. The quarter wave stack solution does not require any sophisticated test equipment to implement.

Yeah, I'm working on a quarter wave stack solution. I'm going to try a Jointenna (that I already ordered) first, and if that doesn't work, I plan to pull apart my PR-8800, essentially making it 2 PR-4400s and stack them. I already cut the wires to the proper length, in preparation!

Don F.

07-21-07, 08:47 AM

[QUOTE=ChocoLab]Good info, Don, I hope you'll let us know how it works once you get it put up.

With a lot of help from my brother-n-law, the XG is in its new location. It continues to deliver good results. I wanted to get more height, and in order to do that, a lateral move of about 15ft. was needed in order to guy the new combo.. The combo includes the XG91, a Winegard YA1713, cm preamp, and cm rotor. With addition of another 10 ft. I had hopes of increasing signal strength, but none improved. I believe the original location is the sweet sport, but no way to guy the now heavy load. The XG is about 30ft. above gound.
Both TV fool and Antenna web indicate Atlanta would be a challenge in my area, so I am very pleased with the results. I live on one of several ridges that run through my county.
The YA 1713 ads NBC dt ch 10. Their signal strength is not the strongest but very stable, all the other stations are uhf, with signal swings depending on atmospheric conditions.
My previous attempt to pull in these stations was with a cm 4248, which resulted in two fairly steady signals. The XG91/YA 1713 combo gives me four daytime signals on a regular basis, and up to seven at night. Of course all are subject to break-up from time to time. That can be expected at an 80 mile distance.
I am sold on the XG91.

sjv

07-21-07, 03:28 PM

Dumb question here: :o Is it possible to combine a cable feed (sd & hd) with an antenna feed (HD), using a diplexer, to a single cable outlet to the TV?:confused:
Thanks

WJonathan

07-21-07, 03:52 PM

After many hours of experimentation with different models of indoor antennas, I wanted to mention that best low cost amped traditional style (loop & rabbit ears) antenna I tried was a $10 model at Big Lots. I tried a bunch of junk from Philips, an RCA, and a few other brands including a $40 outdoor Philips model, and the best one in terms of both reception and amplification clarity was the Big Lots model. It's a generic brand in a red and black box for $9.99, and I believe the amplification is 24 db. Anyone looking for a cheap indoor antenna to improve marginal local signals should give this one a go first. Hope that helps somebody.

holl_ands

07-22-07, 03:13 AM

Dumb question here: :o Is it possible to combine a cable feed (sd & hd) with an antenna feed (HD), using a diplexer, to a single cable outlet to the TV?:confused:
Thanks
NO!!!!! You would need to use an RF Switch.

Cable systems populate EVERY OTA channel position, which would swamp the weak OTA signal in the combiner.

There isn't all that much reverse isolation in the combiner, so the high level cable signals
could ALSO leak out via your OTA antenna, which is an FCC violation,
and could result in your neighbors receiving a duplicate, delayed version (i.e. ghosting).

And BTW, there are ALSO cable frequencies outside the OTA TV bands.....oops....
and the intermods and harmonics are EVERYWHERE....

The cable company would also be upset if you re-distributed their extra-cost analog tier.

Falcon_77

07-22-07, 08:25 PM

WJonathan

07-23-07, 09:06 AM

It looks like CC is dropping this antenna? If so, that is sad, considering how well it works for its size.

I have still been able to find it in Fry's, though it is harder to find in some of those as well. The San Marcos, CA store had a bunch when I drove by there last. Other than that, they have been very hard to find in any retail store.

I certainly hope it is still being produced. It is a very handy test antenna and works well enough as a regular antenna for a few locations.

Does anyone have insight on what is happening to the Silver Sensor?

It's agreat antenna, assuming your towers are lined up a few degress from each other. I know Philips still makes it, and even if CC drops it plenty of online retailers still carry it. A bunch of independent retailers still sell it on Amazon. I just bought the Zenith model brand new from soembody off ebay, so the Philips manufactured ones should still be in warehouses for a while even if LG/Philips discontinues them.

sjv

07-23-07, 11:12 AM

NO!!!!! You would need to use an RF Switch........
Thanks for your response. I'm showing my ignorance here but what's an RF switch? :o

jtbell

07-23-07, 12:24 PM

RF = Radio Frequency. It's a common shorthand for the signal from an antenna or cable. What you need is a box with two coaxial-cable inputs and one output (screw-on connectors), and a switch that selects the input you want to use. You can get a small manual switch at Radio Shack or Wal-Mart for a few dollars, or you can spend more for a remote-control switch.

dxernut

07-23-07, 01:59 PM

Good info, Don, I hope you'll let us know how it works once you get it put up.

Yesterday I again was fiddling with my 4228 and once again, I was disappointed in its performance. An old Radio Shack U-75 (or whatever the $24.95 Yagi was called) does almost as well, and the XG42 I have seems to do better. I'd almost think something was wrong with the 4228, but it looks perfect -- nothing bent or anything of that nature.

I actually tried ordering that Jaycar version that's very similar to the 91XG, but the transaction failed twice. They may have finally caught on to that super-cheap shipping from Australia. I hate to pay close to $100 for a "tinkering" application, but if the XG91 is really that good, and really that much better than the PR-9032 from Winegard, I may do it anyway.
I own a 4228 and a 91XG antenna. The 91XG Blows away the 4228 in my situation. Also very light. Have heard 2 91xgs side by side works great for mulitipath, but I have enough money invested in these antennas!

ChocoLab

07-23-07, 06:11 PM

Don F. and dxernut -- Thanks! :)

In a way, I'm almost disappointed because just late Friday afternoon, I found out that a local wholesale electronic outfit sells CM 4248s for 40-something dollars. After several internet/mail orders and road trips to Frys a hundred miles away to pick up different antennas, I couldn't believe that someone in my small city had some good ones right under my nose!

I was really tempted to try one, except that I guess the 4248 and 4228 are pretty comparable... Or at least, most posts I've read seem to think that. Is that what people here have found?

Hate to pay almost double the 4248's price, but if the 91 is that good, I guess I'll end up doing it...

By the way, Don F.: If you see see this post, how far away again is the channel 10 you're getting with the YA-1713? I have a far-off channel 11 I wish I could get, and that might be a cheap way to try it. (I'd love to try that huge Funke, but I'm not sure I have room for it.)

Thanks again, guys. Good stuff.

Neil L

07-23-07, 07:40 PM

Hate to pay almost double the 4248's price, but if the 91 is that good, I guess I'll end up doing it...The performance XG91 is excellent. Because of it's "X" directors, expect a couple of db more gain than the 4248 on the upper end of the UHF spectrum. But, those "X" directors add more weight and wind resistance.

The 4248 has a larger and wider corner reflector than does the XG91, so that could make the 4248 stronger on the low end of the UHF spectrum, but probably not by much, maybe one or two db.

Personally, I just like the looks of the XG91, but suspect it's performance to be very similar to other manufacturers high gain antennas.

Don F.

07-24-07, 09:57 AM

Don F. and dxernut -- Thanks! :)

I was really tempted to try one, except that I guess the 4248 and 4228 are pretty comparable... Or at least, most posts I've read seem to think that. Is that what people here have found?

Hate to pay almost double the 4248's price, but if the 91 is that good, I guess I'll end up doing it...

By the way, Don F.: If you see see this post, how far away again is the channel 10 you're getting with the YA-1713? I have a far-off channel 11 I wish I could get, and that might be a cheap way to try it. (I'd love to try that huge Funke, but I'm not sure I have room for it.)

Thanks again, guys. Good stuff.

I have no experience with the 4228, but many in my area use one with good results. The 4248 is not as heavy and data says it is better in the upper vhf range. I was pleased with my 4248 (I paid $70) and its ability to pick up the Carolina stations, but my "mission" was to receive Atlanta. Four counties here in N E Ga. are in the Greenville dma, which means if you use satellite your "locals" are Carolina not Georgia, and I have beaten that horse to death.
The XG has outperformed the 4248 in receiving the Atlanta signals, enabling me to actually view news, weather, & sports from my own state.
I would advise you to get the xg91, and put to rest any doubt that will be in your head, if you buy the 4248.
The ya-1713 is doing a good job with ch. 11, 80 miles away. A few daytime drop-outs on ocassion, but at sunset ch 11 (dt 10 ) becomes very steady.
Your location and terrain will of course be the deciding factor. Most of the transmitters in Atlanta are about 2-thousand feet above sea level, and my location is 1-thousand feet above, with two edges inbetween, so says tv fool.
Good luck....

Konrad2

07-25-07, 07:35 PM

I'm experimenting with signal levels, and increasing the signal level
(remove attenuators & splitters) helps some of the stations, both analog
and digital. But if I remove the last splitter then I get diagonal lines
on a low power analog UHF station (54). 54 needs about 6-8 DB of attenuation
(a 7.4 dB 4-way splitter is about right) to knock the lines down. But being
a weak station it is starting to flirt with snow. Another few dB (like a
3-way splitter) and there is significant snow. So I'm thinking it must not
be 54 that is too strong, this must be interference from the stronger TV
stations. I have the FM band trapped out, not using a preamp or dist amp.

Are diagonal lines a symptom of intermodulation distortion? Is there a way
to tell if reception problems on digital stations are from IMD?

Using the formulas on
http://en.wikipedia.org/wiki/Intermodulation
I wrote a shell script to see what stations would give IMD, assuming a general
case where any frequency within the 6 MHz band could do it. With NTSC it would
most likely be the carriers that do the damage, but half the stations are ATSC.

Output for three of the more problematic stations:

chan30 (566-572MHz) - chan33 (584-590MHz) hurts chan27 (548-554MHz) via 2f1-f2 IMD
chan33 (584-590MHz) - chan40 (626-632MHz) hurts chan27 (548-554MHz) via 2f1-f2 IMD
chan40 (626-632MHz) - chan5 (72-78MHz) hurts chan27 (548-554MHz) via f1-f2 IMD
chan40 (626-632MHz) - chan6 (82-88MHz) hurts chan27 (548-554MHz) via f1-f2 IMD
chan40 (626-632MHz) - chan54 (710-716MHz) hurts chan27 (548-554MHz) via 2f1-f2 IMD

chan2 (54-60MHz) + chan24 (530-536MHz) hurts chan33 (584-590MHz) via f1+f2 IMD
chan30 (566-572MHz) - chan27 (548-554MHz) hurts chan33 (584-590MHz) via 2f1-f2 IMD
chan40 (626-632MHz) - chan46 (662-668MHz) hurts chan33 (584-590MHz) via 2f1-f2 IMD
chan40 (626-632MHz) - chan48 (674-680MHz) hurts chan33 (584-590MHz) via 2f1-f2 IMD
chan43 (644-650MHz) - chan2 (54-60MHz) hurts chan33 (584-590MHz) via f1-f2 IMD
chan43 (644-650MHz) - chan54 (710-716MHz) hurts chan33 (584-590MHz) via 2f1-f2 IMD
chan46 (662-668MHz) - chan5 (72-78MHz) hurts chan33 (584-590MHz) via f1-f2 IMD
chan46 (662-668MHz) - chan6 (82-88MHz) hurts chan33 (584-590MHz) via f1-f2 IMD
chan48 (674-680MHz) - chan6 (82-88MHz) hurts chan33 (584-590MHz) via f1-f2 IMD

chan4 (66-72MHz) + chan43 (644-650MHz) hurts chan54 (710-716MHz) via f1+f2 IMD
chan6 (82-88MHz) + chan40 (626-632MHz) hurts chan54 (710-716MHz) via f1+f2 IMD
chan8 (180-186MHz) + chan24 (530-536MHz) hurts chan54 (710-716MHz) via f1+f2 IMD
chan40 (626-632MHz) - chan27 (548-554MHz) hurts chan54 (710-716MHz) via 2f1-f2 IMD
chan43 (644-650MHz) - chan33 (584-590MHz) hurts chan54 (710-716MHz) via 2f1-f2 IMD
chan48 (674-680MHz) - chan43 (644-650MHz) hurts chan54 (710-716MHz) via 2f1-f2 IMD
chan49 (680-686MHz) - chan43 (644-650MHz) hurts chan54 (710-716MHz) via 2f1-f2 IMD

2 is 100 KW NTSC
4 is 16 KW ATSC
5 is 2.7 KW NTSC
6 is 100 KW NTSC
8 is 316 KW NTSC
24 is 2690 KW NTSC
27 is 381 KW ATSC
30 is 741 KW ATSC
33 is 750 KW ATSC
40 is 839 KW ATSC
43 is 500 KW ATSC
46 is 1000 KW ATSC
48 is 200 KW ATSC
49 is 2950 KW NTSC
54 is 105 KW NTSC

But I also get hits for stations with very good reception.
48 comes in fine despite being adjacent to the strong 49.
Some digital stations come in better with more signal strength,
while others come in the same over a wide range. Some stations
frequently come in 100% perfect with a reported signal quality of
55%, while other stations consistantly have errors with a
reported signal quality of 95%.

One thing I'm trying to figure out is if I should use am amp to make up for
splitting the line several ways (at least 4 ways). But if the TV is getting
overloaded when not using a splitter, an amp would likely be overloaded
as well. Or would it?

Am I barking up the right tree? Or it it something else (not IMD) that is
creating the diagonal lines?

nybbler

07-26-07, 10:13 AM

Any chance that Qualcomm is broadcasting on channel 55 in your area? That's another possible source of intermod products.

If it's coming from channel 49, you could probably play games like using two Jointennas to split channel 54 out, amplify it separately, and join it back in. If it's channel 55 (adjacent), things get much harder (read: more expensive).

Tower Guy

07-26-07, 07:55 PM

Are diagonal lines a symptom of intermodulation distortion? Is there a way to tell if reception problems on digital stations are from IMD?

Am I barking up the right tree? Or it it something else (not IMD) that is
creating the diagonal lines?

Tracing intermod can be hard, but your detailed explanation of the symptoms suggest that you are up to the task. Eliminate one of the two signals in the list that you posted and look for the interference. If the lines are still there, the filtered out suspect station is not the cause.

The layman's method to trace the source is creative use of filtering. For instance, a VHF/UHF band Joiner/Splitter can be used as a low pass filter to eliminate the VHF signal from getting to the tuner. This could be used eliminate the possibility of VHF stations intermoding with the UHF stations. I saw that on my antenna. At different times I took out the low band VHF stations by using a 4228 UHF only antenna and again by using a AP-4700 UHF only preamp.

Difficult FM interference may take two FM traps. Channel 54 is the 7th harmonic of 101.5 through 102.3 and the 8th harmonic of 88.7 through 89.5.

A single channel filter is very useful for troubleshooting, but they are expensive.

It may be helpful if you were willing to post your distance from the transmitters or even your exact location.

Konrad2

07-27-07, 05:48 PM

zip: 97005
antennas: Winegard PR-8800 and YA-1713
coax: Philips RG6 quad shield
diplexor: Picomacom UVSJ
filters:
Picomacom HPF-54MHZ 54 MHz high pass no attenuation spec

3 95-108 MHz FM traps 20 dB each
http://www.mpja.com/prodinfo.asp?number=4252+TV

1 88-108 MHz FM trap no attenuation spec
http://www.mcminone.com/product.asp?catalog_name=MCMProducts&product_id=33-341&CMP=datafeeds&ATT=froogle

I suspect the FM traps are similar to
http://www.kyes.com/antenna/interference/fm/frqrsp.jpg
http://www.kyes.com/antenna/interference/fm/sfmtrap.jpg

ferrite sleeves to knock down common mode

splitter: Monster Cable 1 Ghz 4-way 7.4 dB

The antennas are in the attic, "looking" through wood clapboards.

Adding the 2nd 95-108 trap helped. I'm not sure if the third is
doing anything significant. But they didn't fix channel 6, so...

The 88-108 trap is to knock down KBVM 88.3 FM which interferes
with channel 6 audio. More than one of these damages channel 6
too much.

I removed the 4-way splitter and verified the return of diagonal
lines on chan 54. I disconnected the VHF-HI antenna and replaced
it with a terminator at the diplexor. The diagonal lines on chan 54
disappeared, there is a hint of snow. And/or possibly a form of
interference that looks similar to snow, like FM.

This diplexor isn't much of a filter. Channel 8 still comes in
perfectly, chan 10 and 12 have a little snow but are still pretty
good. The VHF-LO analogs are still there but very snowy. I didn't
check digital chan 4.

nybbler> Any chance that Qualcomm is broadcasting on channel 55 in your area?
nybbler> That's another possible source of intermod products.

The web says they are putting out 50,000 Watts ERP. What's the deal?
I thought they had to wait until 2009?

Tower Guy> Difficult FM interference may take two FM traps. Channel 54 is
Tower Guy> the 7th harmonic of 101.5 through 102.3 and the 8th harmonic
Tower Guy> of 88.7 through 89.5.

So the 7th and 8th harmonics are strong enough to worry about? If the 88-108
trap is also 20 dB minimum, then most of the FM band should be at least 80 dB
down. I suspect that at some point the amount leaking in past the crappy
F connectors and the epoxy sealed back will be as much as an additional filter
would help. The traps don't help with the common mode, hence the ferrite
sleeves. No specs on those but the FM interference on chan 10 (visual, unlike
chan 6) went away.

I have 8 FM traps (4 of each). Would it be worthwhile to try hooking up all
of them and running reception tests on the digitals?

My main goal is to get the digitals as reliable and error free as possible,
in preparation for the analogs going away. Even a minor glitch on digital
can be far more disruptive than a little snow or a faint ghost on analog.
I don't have a spectrum analyser, and diagnostic info on the digitals is
extremely limited, so I'm trying to use the analogs to find clues.

Some of the digital channels are sensitive to the signal level, others are not.
This would make sense if it were the powerful stations vs the weak stations,
but that's not it. Perhaps there is a clue here?

Rick0725

07-28-07, 07:56 AM

The 88-108 trap is to knock down KBVM 88.3 FM which interferes
with channel 6 audio. More than one of these damages channel 6
too much.

zip: 97005
antennas: Winegard PR-8800 and YA-1713
coax: Philips RG6 quad shield
diplexor: Picomacom UVSJ

you are 4 miles from the towers with a pr8800 and ya1713. are the antenna web results correct?

* yellow - uhf KOIN-DT 6.1 CBS PORTLAND OR 47° 3.8 40
* yellow - uhf KPDX-DT 49.1 MNT VANCOUVER WA 33° 3.4 48
* yellow - uhf KGW-DT 8.1 NBC PORTLAND OR 36° 3.5 46
* yellow - uhf KNMT-DT 45.1 TBN PORTLAND OR 47° 3.9 45
* yellow - uhf KATU-DT 2.1 ABC PORTLAND OR 47° 3.8 43
* yellow - uhf KRCW-DT 32.1 CW SALEM OR 47° 3.9 33
* yellow - uhf KOPB-DT 10.1 PBS PORTLAND OR 36° 3.5 27
* yellow - uhf KPTV-DT 12.1 FOX PORTLAND OR 36° 3.5 30
* yellow - vhf KPXG-DT 22.1 ION SALEM OR 47° 3.9 4
* red - uhf KOAC-DT 7.1 PBS CORVALLIS OR 184° 63.1 39

is fm really an issue at your home? you are using a uhf and ch7-13 antenna somewhat oversized for 4 miles and has minimal gain under 98 mhz (FM).

you need to determine which channels in your market you wish to receive ...analog/digital or both and start from scratch in your setup...ie. antenna choice, simplify your wiring setup, move the antenna outside and go from there.

you mention analog channels. you have analog VHF ch 2,6,7,8,10,12 in the mix. ch6??? the ya 1713 is not used for ch 2 and does not have appropriate gain for 6 and should not be used as a determining factor for your reception success on ch 6.

Time to step back and determine what you want to receive and design the system appropriately around that one step at a time.

your current setup is geared for ch 7-69. If you desire ch2-69 you may be better off with a combo vhf/uhf antenna like winegard hd7082P installed outside for example. But in 2009 you are only going to need uhf.

cpcat

07-28-07, 10:02 AM

Am I barking up the right tree? Or it it something else (not IMD) that is
creating the diagonal lines?

I don't know if IM distortion has an identifiable "signature" like say a ground loop or FM would have, but I can tell you that my LP locals have always looked crappy. They even tend to look crappy on my local cable system. It could be something inherent to the transmission and therefore beyond your control. IF that's the case, then any other reception issues you are having are independent of what you are seeing from the LP station.

Konrad2

07-28-07, 03:18 PM

> you are 4 miles from the towers with a pr8800 and ya1713.
> are the antenna web results correct?

> * yellow - uhf KOIN-DT 6.1 CBS PORTLAND OR 47DEG 3.8 40
> * yellow - uhf KPDX-DT 49.1 MNT VANCOUVER WA 33DEG 3.4 48
> * yellow - uhf KGW-DT 8.1 NBC PORTLAND OR 36DEG 3.5 46
> * yellow - uhf KNMT-DT 45.1 TBN PORTLAND OR 47DEG 3.9 45
> * yellow - uhf KATU-DT 2.1 ABC PORTLAND OR 47DEG 3.8 43
> * yellow - uhf KRCW-DT 32.1 CW SALEM OR 47DEG 3.9 33
> * yellow - uhf KOPB-DT 10.1 PBS PORTLAND OR 36DEG 3.5 27
> * yellow - uhf KPTV-DT 12.1 FOX PORTLAND OR 36DEG 3.5 30
> * yellow - vhf KPXG-DT 22.1 ION SALEM OR 47DEG 3.9 4
> * red - uhf KOAC-DT 7.1 PBS CORVALLIS OR 184DEG 63.1 39

That looks about right. I am not trying to get KOAC Corvallis,
since I have KOPB on 10 NTSC & 27 ATSC.

> you mention analog channels. you have analog ch 2,6,7,8,10,12
> in the mix. ch6??? the ya 1713 is not used for ch 2 or 6.

Yes, I know that the YA-1713 is VHF-HI. Our VHF-LO stations
are supposed to go away in 2009 and the YA-1713 has better
specs than a VHF 2-13 antenna.

The YA-1713 does okay on VHF-LO, not as good as on VHF-HI
but good enough to get by for a couple years. Even the low
power channel 4 comes in pretty well. If I only split 4 ways
channel 4 is still reported as 100% signal strength from
the digital tuner, with signal quality of 75%. Sometimes
it is received perfectly, although usually it drops a few
packets per hour. Channel 4 is supposed to move to channel 22
in 2009.

> But in 2009 you are only going to need uhf.

8 10 and 12 are currently analog, but will become digital in
2009. The VHF-LO analogs (2,5,6) go away in 2009. Channel 4
moves to channel 22 in 2009. So I will need VHF-HI and UHF.
So I bought the YA-1713 and PR-8800.

> move the antenna outside

Yes, I would probably get a better signal with the antennas
outside... until the next wind storm. High gain antennas
less than 5 miles from the towers looking through wood ought
to work okay. And for some stations they do. I chose highly
directional antennas to reduce multipath.

> is fm really an issue? you are using a uhf and ch7-13 antenna
> that has minimal gain under 98 mhz.

Adding the 1st 95-108 trap helped. Adding the second one
helped more. Adding the 88-108 trap knocked KBVM 88.3 FM
down enough that I can listen to the audio on channel 6 NTSC
without having KBVM superimposed on top of it. Adding
the ferrite sleeves appears to have reduced common mode FM
that messed up the picture on chan 10 NTSC. Like this:

http://www.kyes.com/antenna/interference/fm/13nofmfilter.jpg

The most problematic station is 33, it is 750 KW and is supposed
to remain at channel 33 after 2009. It usually drops packets and
always has decoding errors. The Cascade2 demodulator reports
100% signal strength and 95% signal quality. This is the best
reported signal quality of any station, but it has the worst
actual reception. (Actual reception meaning decoding errors.)
The reported signal quality does change with signal level.
If 33's signal strength is reduced to 75%, quality goes down to 55.
As opposed to channel 27 which reports a quality of 55-65%
regardless of signal strength.

Tower Guy

07-29-07, 12:22 PM

The most problematic station is 33, it is 750 KW and is supposed
to remain at channel 33 after 2009. It usually drops packets and
always has decoding errors.

Is there a pattern to the errors on channel 33?

Do they occur more on windy days? (possible tree issue)
Can you time them with a stopwatch? (possible datastream problem)
Is it more likely to occur on a hot or cold day? (possible antenna beam tilt at the station)
Is there an airplane in the path when the pixelization occurs? (You are aimed toward the airport)

If you notice any of these trends it may suggest a solution.

Rick0725

07-29-07, 12:50 PM

Konrad

you should consider a more "commercial quality" notch filter made to order from here.

http://www.cefilter.com

much deeper and tighter notch and really not that expensive. The filter can be tuned tighter at the company above so not to affect ch 6 as much if you explain the sitation to the technician.

suggest both a 50db notch full band barrel style fm filter and a filter tuned to 88.3 mhz (if the fm band filter does not do the job).

another option...try a tri shield rg-6 coax instead of quad shield. slightly better shielding for signal ingress. Like Belden 7915A with foil tape, 80% braid, and an outer layer of foil.

https://www.tselectronic.com/belden/7915a.html?tse_Session=cc7767b40d6b035a226cb10b50b3bf1d

I am not a big fan of the PR8800 UHF expecially with trees and troublsome reception. Think there is room for improvement in that area too.

Konrad2

07-29-07, 03:11 PM

Tower Guy> Is there a pattern to the errors on channel 33?

Not that I have noticed. I've mostly looked for patterns (temp,
street traffic, wind, time of day, ...) with KOPB 27, since reception
quality varies a lot on 27. 33 is always bad.

The only correlation I've found is with the show itself. If I have
bad reception of a show and they (OPB) rerun the show later that day, or
the next day, or 2 months later, it is likely to have a reception problem.
Which might make sense if they were transmitting exactly the same bits
each time, but sometimes their decoder goes out to lunch and I get a
black screen (except for the station logo) for a moment, And then when
it reruns I don't get the black screen, so they are obviously
decoding/encoding the show each time. But I usually get a reception
problem (at a different time within the program) every time for a
particular show. Strange.

Tower Guy> Do they occur more on windy days? (possible tree issue)

I've tried to figure this out, but wind is such a localized thing
that data from the airports probably isn't that useful. It doesn't
take much wind to move leaves around. There are a few trees in the way,
other than that I have a clear view of the transmitting towers.

Tower Guy> Can you time them with a stopwatch? (possible datastream problem)

What do you mean by "datastream problem"? Who needs a stopwatch when you
have software decoders that tell you the time down to 0.1 second and even the
exact frame number?

chan 33 2007_04_08 beginning at 4:55am

frame=23844 q=0.0 size= 2791875kB time=794.9 bitrate=28770.6kbits/s dup=22 drop=0
frame=36390 q=0.0 size= 4262109kB time=1213.6 bitrate=28770.7kbits/s dup=22 drop=0
frame=37394 q=0.0 size= 4379766kB time=1247.1 bitrate=28770.6kbits/s dup=22 drop=0
frame=61876 q=0.0 size= 7249570kB time=2064.2 bitrate=28770.8kbits/s dup=22 drop=0
frame=63385 q=0.0 size= 7425586kB time=2114.3 bitrate=28770.9kbits/s dup=22 drop=0
frame=64027 q=0.0 size= 7500820kB time=2135.7 bitrate=28771.1kbits/s dup=22 drop=0
frame=92725 q=0.0 size=10863867kB time=3093.3 bitrate=28771.0kbits/s dup=22 drop=0
frame=92920 q=0.0 size=10886719kB time=3099.8 bitrate=28771.1kbits/s dup=22 drop=0
frame=92936 q=0.0 size=10888594kB time=3100.3 bitrate=28771.0kbits/s dup=22 drop=0
frame=93513 q=0.0 size=10956445kB time=3119.6 bitrate=28770.9kbits/s dup=22 drop=0
frame=118002 q=0.0 size=13826016kB time=3936.7 bitrate=28771.2kbits/s dup=22 drop=0
frame=126502 q=0.0 size=14822109kB time=4220.3 bitrate=28771.2kbits/s dup=22 drop=0

chan 33 2007_05_03 beginning at 10:55pm

frame= 5200 q=0.0 size= 607031kB time=172.9 bitrate=28767.2kbits/s dup=33 drop=0
frame=14124 q=0.0 size= 1653281kB time=470.8 bitrate=28770.3kbits/s dup=33 drop=0
frame=14275 q=0.0 size= 1670625kB time=475.7 bitrate=28770.9kbits/s dup=33 drop=0
frame=15923 q=0.0 size= 1863633kB time=530.7 bitrate=28769.8kbits/s dup=33 drop=0
frame=36691 q=0.0 size= 4297500kB time=1223.6 bitrate=28770.6kbits/s dup=33 drop=0
frame=38280 q=0.0 size= 4483828kB time=1276.7 bitrate=28770.6kbits/s dup=33 drop=0
frame=39136 q=0.0 size= 4584023kB time=1305.2 bitrate=28771.0kbits/s dup=33 drop=0
frame=62977 q=0.0 size= 7378008kB time=2100.7 bitrate=28771.2kbits/s dup=33 drop=0
frame=65166 q=0.0 size= 7634297kB time=2173.7 bitrate=28770.9kbits/s dup=33 drop=0
frame=67253 q=0.0 size= 7878984kB time=2243.4 bitrate=28771.0kbits/s dup=33 drop=0
frame=68886 q=0.0 size= 8070234kB time=2297.9 bitrate=28770.9kbits/s dup=33 drop=0
frame=69074 q=0.0 size= 8092734kB time=2304.3 bitrate=28771.0kbits/s dup=33 drop=0
frame=69136 q=0.0 size= 8099648kB time=2306.2 bitrate=28771.2kbits/s dup=33 drop=0
frame=72560 q=0.0 size= 8500781kB time=2420.4 bitrate=28770.9kbits/s dup=33 drop=0

> Is it more likely to occur on a hot or cold day? (possible antenna beam tilt at the station)

Not that I have noticed. I'll check the next time we have an especially hot or cold day.
I had both perfect and horrible reception of KOPB 27 during a recent hot spell.

> Is there an airplane in the path when the pixelization occurs? (You are aimed toward the airport)

Airplanes are far enough away that I rarely hear them outdoors, much less indoors.
Wouldn't airplanes affect all the stations about the same, given that the transmitting
towers are all clumped together?

KATU 43 comes in perfectly recently, as does KPDX 48 and KPTV 30. KOPB 27 usually
comes in perfectly lately, but occasionally it is quite bad.

I've looked for a correlation with street traffic (some people have trouble with
trucks, busses, ... ), but haven't found one.

hdtvluvr

07-29-07, 07:07 PM

I purchased a Winegard HD7084P last year for 2 reasons. 1 to move my antenna outside and 2 for a combo antenna because some of my channels will revert back to 5 and 13 in 2009. I currently have a Channel Master CM 4228 in the attic. I get dropouts at times.

Well, I started the installation today. It is about 40 ft. above ground level. Making small adjustments to the direction it is pointing, I was able to get 90 on some channels and 0 to 17 on others. My current attic antenna (CM 4228) gets all channels with a reading of 70 - 90.

The channels that I want to receive are below. There is a 20 deg span at a range that varies from 10.3 to 18.3 miles.

Is the pickup beam on the HD7084P too narrow for my purposes? Please help! I'm getting discouraged.

Cable run to each TV is approximately 150 ft.

Antenna Call Sign Channel Network City State Compass Miles Frequency
yellow - uhf WPTY-DT 24.1 ABC MEMPHIS TN 163° 10.3 25
yellow - uhf WKNO-DT 10.1 PBS MEMPHIS TN 178° 18.3 29
yellow - uhf WPXX-DT 50.1 MNT MEMPHIS TN 176° 14.4 51
yellow - uhf WLMT-DT 30.1 CW MEMPHIS TN 163° 10.3 31
yellow - uhf WREG-DT 3.1 CBS MEMPHIS TN 180° 16.4 28
yellow - uhf WMC-DT 5.1 NBC MEMPHIS TN 163° 10.3 52
yellow - uhf WHBQ-DT 13.1 FOX MEMPHIS TN 183° 16.9 53

tyromark

07-29-07, 07:13 PM

hdtvlvr - With a long cable run ("each TV"? You have it split to several?), maybe a preamp would make a difference for you. Just a guess.

hdtvluvr

07-29-07, 08:30 PM

I have D* (HD Tivo) and I am combining the OTA signal to the dish signal.

afiggatt

07-29-07, 10:36 PM

I purchased a Winegard HD7084P last year for 2 reasons. 1 to move my antenna outside and 2 for a combo antenna because some of my channels will revert back to 5 and 13 in 2009. I currently have a Channel Master CM 4228 in the attic. I get dropouts at times.

Well, I started the installation today. It is about 40 ft. above ground level. Making small adjustments to the direction it is pointing, I was able to get 90 on some channels and 0 to 17 on others. My current attic antenna (CM 4228) gets all channels with a reading of 70 - 90.

The channels that I want to receive are below. There is a 20 deg span at a range that varies from 10.3 to 18.3 miles.
Is the pickup beam on the HD7084P too narrow for my purposes? Please help! I'm getting discouraged.
Cable run to each TV is approximately 150 ft.
Looking at the spec sheet for the HD7084P, the beam pattern does get narrow at the higher UHF channels and you have three stations at UHF 51 to 53. Any particular for choosing a long range antenna such as the HD7084P rather than the medium range HD7080P?

But your 150' cable run suggests you need a pre-amp. If you are running it through a diplexer, then you will have to place the power supply for the pre-amp ahead of the diplexer.

The CM 4228 should be fine for getting WHBQ-DT Fox 13 when it switches to VHF 13. WMC-DT NBC 5 is shown as in the FCC 1st/2nd round selection as going to VHF 5. But since you already have a good antenna, I would have recommended that you wait until it is confirmed by the final round of channel selections that WMC-DT will end up on VHF 5. The FCC is still working it's way to the final post transition digital channel assignments. You could have put up a full VHF/UHF antenna next year if WMC-DT was shown as still switching to VHF 5.

hdtvluvr

07-30-07, 07:57 AM

I thought I might as well get the biggest possible. However, it may be too directional (I didn't think about that). Would the medium range work (beam pattern wide enough)?

The antenna cable is connected to a 5X8 D* switch so the signal is injected in with the satellite signal and routed to the TV's. It won't be a problem to add the power supply. Is the pre-amp water proof and can go outside? Which pre-amp.

With the CM 4228, I get pixelation and dropouts at times. I was hoping to improve the signal by moving it outside and add VHF ability at the same time. Maybe I just need a pre-amp on the 4228 (until the FCC decides on 5)? I just realized that there is about 120 ft. of cable for the CM 4228 antenna.

Rick0725

07-30-07, 08:52 AM

The hd7084P should work fine and be more than enough antenna for the stations you describe in your market at your distances of around 10-12 miles.

I install a ton of the hd7084p's here in a market where the towers are around 20 degrees apart with stations on chs 47,54,56, and 68. if some of the station patterns are on the "funky side" at your home, you may need to compromise some and aim a tadd towards the weaker signal.

your issue may actually center around your use of diplexing and the longer runs of 150' and would not loose hope just yet.

I suggest the winegard hdp269 preamp for your distances from the towers. this amp should be enough to offset the line losses in your setup. you may need more gain tough to tell from here but the hdp 269 is a good start.

if the amp does not correct the situation you may need to think about running a separate line for off air. diplexed setups can be troublesome.

if at the end you are still not satisified you could use the hd7084p for vhf/fm and combine the cm4228 for uhf. this situation would offer the best of both worlds. you would combine the signals from each antenna with a cm 0549 vhf/uhf combiner then amplify the signal off the cm 0549 with the hdp269 preamp.

another thing to look at. the hd7084p. make sure the circuit board in the plastic housing is properly installed with the board properly seated and making adequate contact with the antenna elements. look out for shorting/touching, make sure the contacts are far enough apart, and at the same time make sure the 2 antenna elements are making adequate contact with the circuit board. if not you may need to bend the elements sightly till they do. I see this issue many times during service calls.

I would first purchase the hdp 269 preamp and wire the amp into your system and see what happens. if still not satisfied, you may need to take a look at your wiring setup. then explore the possibility of combining both antennas. fyi...for example, you could leave the cm4228 in the attic and the hd7084p outside run coax from the hd7084p inside and combine everything in the attic close to the cm4228 and integrate into your current setup. or you can install the cm4228 and hd 7084 on the same mast or separate ones outside.

you have plenty of options.

from my experiences, the hd7084p should be awesome and much more than enough antenna at your distances from the towers unless

-the elements are shorted in the plastic housing
-you are expriencing signal blockage from local geography or other factors
-inadequate wiring and signal distribution setup
-losses associated with diplexing and splitting

if you are experiencing loss of signal in the uhf channel range, losses from diplexing, splitting , and long cable runs can be the issue. adding an amp may be the bandaid and redesigning the setup may be better in the long run.

you have runs over 120' plus diplexing which adds even more losses.

150' = ~9 db loss ...then add the losses associated with diplexing and splitting. I bet the situation will improve tremendously if you clean up your wiring and signal distribution setup.

hdtvluvr

07-30-07, 09:59 AM

<<if the amp does not correct the situation you may need to think about running a separate line for off air. diplexed setups can be troublesome. >>

Are you suggesting a simple splitter?

>>if at the end you are still not satisified you could use the hd7084p for vhf/fm and combine the cm4228 for uhf. this situation would offer the best of both worlds.<<

The antennas are at opposite ends of the house and the cable run to combine them would be impossible.

>>another thing to look at. the hd7084p. make sure the circuit board in the plastic housing is properly installed with the board properly seated and making adequate contact with the antenna elements. look out for shorting/touching, make sure the contacts are far enough apart, and at the same time make sure the 2 antenna elements are making adequate contact with the circuit board. if not you may need to bend the elements sightly till they do. I see this issue many times during service calls.<<

Well, the antenna is now about 40 ft. off the ground on a telescopic mast. It was very hard to put up and now I may have to take it down to check the connections??? I wish there had been something in the instructions regarding this. What could be shorting/touching?

With the windload and the mast type / location, I don't think I can put the 4228 on the mast.

Regarding the winegard hdp269, I guess I should try it on the attic mounted 4228 first and see if that improves the UHF channels. If so, I can attempt to get 5 (VHF) if it reverts back to VHF later.

I could move both antenna's into the attic space over another part of the house, and combine them. How would I remove the UHF portion of the wingard? Part of the UHF elements are on the main antenna and the rest are on the added extension. Putting them in that part of the attic would still give me about the same length of cable runs.

I sure thought this would be easier. :(

Rick0725

07-30-07, 10:47 AM

if the amp does not correct the situation you may need to think about running a separate line for off air. diplexed setups can be troublesome. >>

Are you suggesting a simple splitter?

I am suggesting removing the off air distribution away from diplexing with satellite. separate lines with splitters...separate from satellite.

if at the end you are still not satisified you could use the hd7084p for vhf/fm and combine the cm4228 for uhf. this situation would offer the best of both worlds.

The antennas are at opposite ends of the house and the cable run to combine them would be impossible.

just run a coax from the hd7084p inside to the where the cm 4228 is and combine from there if you decide to. 2 hdp 269's would be suggested. 1 to amplify the vhf off the hd7084p and one for the cm4228. (you may not need to amplify the vhf since the losses per foot on vhf are much less than uhf over the longer distances and splitting)

Regarding the winegard hdp269, I guess I should try it on the attic mounted 4228 first and see if that improves the UHF channels. If so, I can attempt to get 5 (VHF) if it reverts back to VHF later.

I could move both antenna's into the attic space over another part of the house, and combine them. How would I remove the UHF portion of the wingard? Part of the UHF elements are on the main antenna and the rest are on the added extension. Putting them in that part of the attic would still give me about the same length of cable runs.

you would not remove the uhf portion of the hd7084p but leave the hd7084p intact. see pic.

the cm0549 vhf/uhf combiner will isolate the vhf and uhf signals enough and not create any issues. I combine a hd8200p for vhf/fm with a 91xg for uhf at my home for example using the hdp 269 preamp and cm0549. I have directv and do not diplex the sat with off air and instead distribute the off air signal separately at least 12 times around the home with no problems.

the entire installation may seem like a pain in the ass at first...but once completed satisafactorily you should receive great service for many years. as simple as off air seems, some installs can be a challenge for "do it yourselfers" if the coditions are not cut and dry.

hdtvluvr

07-30-07, 11:51 AM

I've ordered the winegard hdp269. I noticed that it appears to have an FM trap. Does it? Or is FM still passed but just not amplified? Not a real big deal but would like to know in case I try to replace my small FM antenna.

Will post back when I get / try the winegard hdp269

Falcon_77

07-30-07, 12:05 PM

Mloot

07-30-07, 10:56 PM

I just recently got back from a vacation in Oregon, and on the way up there, I saw a few of the larger type of antenna on some people's houses. I've never seen one before, so I was hoping someone could identify it for my curiosity's sake.

http://img295.imageshack.us/img295/171/p1010644se5.jpg

TIA.

paulstefano

07-31-07, 08:59 AM

I have Stagger stacking question.

For those of you who remember my situation, a quick update. I received my channel 47 Jointenna. For further testing I bought a Samsung DTB H260F. For the record, that H260F is much better at picking up local signals, but didn't help my situation at all. I may keep it just to use as a spare receiver, though.

Anyay, I put in my Jointenna, and got 0 help, as predicted here. I put it ahead of the pre-amp (please let me know if that was dumb) and then into my HDP269 pre-amp then to my 100 foot downlead.

I tried this 3 ways.

1. With pre-amp and attic mounted Winegard PR-8800
2. Without pre-amp in the attic
3. With pre-amp, with outdoor mounted Winegard PR-8800 on a 40 foot mast (thanks to the good people at Winegard, I now have 2)

Results: I got 0 picture on my DTV HR20, and Samsung SIRTS-160. and 1 signal bar on my H260F; in all 3 scenerios.

So, I'm off to stagger stack. I know I should buy a signal meter, but I can't bring myself to drop the coin on that (even though I've spent way more on supplies so far), so please humor me.

My question is this: If I mount the antennas on the same mast with a rubber or plastic sleeve under the U-Bolt, will that cancel out the conducitve properties of the mast enough for the antennas not to "see" each other?

MAX HD

07-31-07, 09:17 AM

Tower Guy

07-31-07, 09:21 AM

My question is this: If I mount the antennas on the same mast with a rubber or plastic sleeve under the U-Bolt, will that cancel out the conducitve properties of the mast enough for the antennas not to "see" each other?

The antennas should be stacked with sufficient distance between them. With such distance, there is no need to isolate the boom and the mast.

Rick0725

07-31-07, 09:23 AM

Anyay, I put in my Jointenna, and got 0 help, as predicted here. I put it ahead of the pre-amp (please let me know if that was dumb) and then into my HDP269 pre-amp then to my 100 foot downlead.

connection of jointenna is AFTER the preamps.

antenna to preamp module at the antenna
coax to preamp "to ant" input of preamp
tv out of preamp to jointenna

2 preamps work best. one for each antenna.

I usually run 2 coax inside from each antenna to 2 separate preamp power inserters. the tv out of each preamp is attached to the jointenna inputs (ch ?? and all channel input). the output of the jointenna is then sent to the tuners.

choice of antennas. would rather have seen you use 91xgs for your application. the pr8800's do not turn me on...though inexpensive you would be better off with something different.

paulstefano

07-31-07, 09:27 AM

connection of jointenna is AFTER the preamps.

antenna to preamp
tv out of preamp to jointenna

2 preamps work best. one for each antenna.

I usually run 2 coax inside from each antenna to 2 separate preamp power inserters. the tv out of each preamp is attached to the jointenna inputs (ch ?? and all channel input). the output of the jointenna is then sent to the tuners.

So you are saying that you don't put the Jointenna in until AFTER the power inserter?

Rick0725

07-31-07, 09:34 AM

So you are saying that you don't put the Jointenna in until AFTER the power inserter?

YES

choice of antennas. would rather have seen you use 91xgs for your application. the pr8800's do not turn me on...though inexpensive you would be better off with something different.

Falcon_77

07-31-07, 10:36 AM

I ended up picking up a pair of rabbit ears at Radio Shack. The results for 2 are only slightly better (I can almost see the makings of a picture).

It just seems that 80" rabbit ear dipoles just don't cut it for VHF-Lo. It is somewhat ironic, however, that these rabbit ears (this pair is w/o a UHF loop) work better for UHF than VHF. I am able to tune up to channel 62 with them, with far better results than 2-5.

Maybe one day I will understand what is so good about VHF. Are VHF channels really worth the monster antennas they require (such as the one just above)?

Rick0725

07-31-07, 11:57 AM

falcon

if you do NOT have reception issues impeding reception and live in an urban/suburban setting, rabbit ears can work for you.

BUT

the issues can be any of the following
-signal blockage from local geography
-noise from electric transformers, appliances, other outside sources, etc
-home construction

in general uhf can better "tolerate" some of this stuff but is still affected. the technical explanation is too broad to give explicit details and difficult to determine what exactly is causing your issues 3000 miles away in new york

most indoor rabit ears will give you results in the same general ballpark. vhf require larger antennas because of the wavelength transmitted on. I do not have a clue what will work reliably for you inside.

Konrad2

07-31-07, 02:11 PM

> http://www.cefilter.com
>
> much deeper and tighter notch and really not that expensive.

How expensive are they? I didn't find prices on their web site.
Custom sounds expensive?

I've thought of trying a notch filter instead of the 88-108 for
chan 6, but improving chan 6 isn't my primary goal, given that
it is going away. I'm trying to improve reception of the digitals.
Some sort of high-pass/low-pass/band-pass/band-reject filters to
eliminate all the non-TV frequencies would be a useful thing to try.

> another option...try a tri shield rg-6 coax instead of quad shield.
> slightly better shielding for signal ingress. Like Belden 7915A with
> foil tape, 80% braid, and an outer layer of foil.

I'm assuming that quad shield is two braid plus two foil? It is not
obvious how 3 would be better than 4 (thicker foil maybe?), although
I could believe that Belden is better than Philips.

There's only 3 feet of coax between the splitter and the digital tuners.
The filters and splitter are connected with F-to-F adapters, not cables.

However, the 50 foot run from the diplexor to the filters is near Ethernet.
Could picking up Ethernet hurt 27, 33 and 46 but not 30, 43 or 48?

> I am not a big fan of the PR8800 UHF expecially with trees and
> troublsome reception. Think there is room for improvement in that area too.

I can see where a different antenna could help with multipath, (e.g. put a
null where the multipath is coming from) but I don't see how it would help
with trees inline with the towers?

If you believe http://www.hdtvprimer.com/ANTENNAS/comparing.html
the only antenna with more net gain than the PR-8800 at channel 33 is the
CM 4228 and only by about 1 dB. Presumably this means that the PR-8800
is the 2nd most directional at chan 33 and the most directional at chan 27.
The PR-8800 has a flatter frequency response in the 27-33 range than the
CM 4228.

Holl_ands will disagree, pointing at Kerry Cozad's measurements. (Are these
available in a non-MS format?)

Konrad2

07-31-07, 03:11 PM

> Anyay, I put in my Jointenna, and got 0 help, as predicted here.
> I put it ahead of the pre-amp (please let me know if that was dumb)

It wasn't dumb, but it might not be the optimum setup.

If the preamp is not overloading, you would be better off having the
Jointenna after the preamp so that the signal doesn't suffer attenuation
before being amplified. If the preamp is overloaded, having the
Jointenna before the preamp would help keep the preamp from being
overloaded. If you have the Jointenna after the preamp you might
have to have it after the power inserter as well, since it might not
pass power. The instructions should say if it passes power or not.

IIRC you said that the analog station (43?) still has some noise (snow)
even with the preamp? So 47 might also be weak, even with the preamp.
If you have another amp sitting around, and the preamp isn't overloading,
you could try

antenna --> preamp --> power insert --> Jointenna --> 2nd amp --> power insert --> tuner

You could try this without the Jointenna and see what 43 looks like.
But without the Jointenna the 2nd amp is more likely to overload.
And it might overload even with the Jointenna.

Did you connect anything to the wideband antenna input of the
Jointenna? It might not perform properly with that input
open circuit? Try connecting a terminator. A terminator
doesn't cost much, it is just a 75 Ohm resistor in an F connector.
Or you could connect an unused tuner input (old TV or VCR, ...)
to terminate it.

The stagger stack is probably your best bet.

Rick0725

07-31-07, 03:27 PM

Konrad

Just got off the phone with the filter company and quickly described your situation.

contact Dave Dan at 1-800-882-1587 and explain your situation. He will out line your options. He works till a little after 4pm eastern time.

A barrel filter for 88.3mhz would cost $16.08 for example

this is how belden explaiins tri shield cable

Belden
7915A Duobond Plus® 3GHz RG6/U Tri-Shield Broadband Coax

Belden 7915A Duobond Plus® is a Belden innovation that features a three-shield construction consisting of Duobond II (foil tape) surrounded by 80 percent braid and an outer layer of foil with a unique shorting fold that creates the electrical effect of a solid metal conduit. The combination offers superior high frequency sheilding compared with traditional Quad shield designs.

Duobond® Plus foil shield ( Duobond II Foil + 80% aluminum braid + Duofoil tape with shorting fold).
18 awg solid bare copper center conductor , the best choice for baseband thru broadband applications
Sweep tested 5MHZ to 3GHz

paulstefano

07-31-07, 04:12 PM

Rick0725

07-31-07, 04:50 PM

paulstefano

07-31-07, 10:35 PM

terminating the port on the jointenna will make the unit a notch filter for the channel you had it tuned to. Is that what you want to accomplish...filter ch 47. keep in mind that the jointenna will filter 5 channels adjacent either side of center and there is a sizeable insertion loss.

thought you were using the jointenna to combine 2 antennas.

you have me confused with what you are trying to accomplish.

Are you trying to use 1 antenna to get reception of another channel from the rear hoping that filtering the more powerful signal with help the other lock.

going to be a challenge if that is the case...or you luck out.

keep us posted of how you make out.

I'm trying to pick up channel 47 at 3 degrees azimuth. Behind me, less than 5 miles away is WBFF on channel 46 at 187 degrees azimuth. I was trying to use the Jointenna to ALLOW channel 47. Can somebody clarify how to wire this thing to accomplish that? I wasn't even planning on using another antenna. I have all my locals from DTV, I just want channel 47, because it's out of market.

On another note, I tried a temporary stagger stack solution in the attic:

I took apart a Winegard PR-8800 and made it two 4 bays.

I pointed 1 at Channel 47 on a mast. I left antenna #2 on the ground floor of my attic. I then wired both to a BNC T connector with the #2's lead 1/4 wavelength longer. I then tuned to WBFF (virtual 45, actual 46). I picked up antenna #2 and started waving it around. After a while I discovered a sweet spot to completely cancel out 46. This spot turned out to be just in front and slightly lower than antenna 1 (probably the exact correct stagger distance had I measured and mounted it) Channel 46 was gone visually, and had Zero signal on my Samsung H260F. Then I tuned to channel 47, and still nothing but 1 signal bar. I did the same thing with my Winegard hdp269 amp wired in. Still no better.

This leads me to believe I am having issues with analog 45, also directly behind me less than 5 miles away. Either that, or I just can't get a strong enough digital signal from 47. The strange part is, I still get great analog reception on the same network at channel 43.

So, thoughts? I canceled out WBFF-DT succesfully, I think. Are there any options left?

thanks,

paul

Konrad2

08-01-07, 03:03 AM

> I still get great analog reception on the same network at channel 43

How much snow does 43 have?

How much power is 47 putting out relative to 43? And is 47 really
putting out that much, or are they limping along at half power
waiting for repair parts?

> I took apart a Winegard PR-8800 and made it two 4 bays.

If you use the two PR-8800s rather than splitting one in two
you should get about 3dB more signal.

You will probably get a stronger signal with the antennas up above
the roof rather than in the attic. (higher is usually better, and
no attenuation from the attic roof or wall) If your mast can handle
two antennas (weight and wind load). And you would need to fabricate
a mount for the stagger.

You can also try different locations within the attic, if there is room.
UHF can have hot and cold spots a few inches apart. That might make
finding the stagger distance by nulling 46 problematic. You might do
better setting the stagger distance with a ruler.

> I was trying to use the Jointenna to ALLOW channel 47. Can somebody
> clarify how to wire this thing to accomplish that?

Connect antenna to the single channel input. Terminate the all channel
input. Connect the output to your preamp.

BTW some splitters come with a terminator.

After reading
http://www.avsforum.com/avs-vb/showthread.php?p=10946969&&#post10946969
you might want the Jointenna ahead of the preamp even if the preamp
isn't overloading.

The Jointenna should allow you to use more amplifier gain than without.
If 43 has snow (*) you may need more gain for 47. In theory digital
doesn't require as much signal-to-noise ratio as analog, but in
practice it seems to.

(*) without the Jointenna attenuating it, and the stagger probably
(I haven't done the math to check) doesn't do 43 any favors either.

wildwillie6

08-01-07, 07:25 AM

Just to throw this into the mix, here's my case, in which a Join-tenna works just as intended: I have one signal on UHF 49 that comes from about 90 degrees apart from all my other signals.

I have a ChannelMaster 4221 getting that signal and sending it down through a 7777 preamp. All my other signals come from a ChannelMaster 4248 through a separate 7777 preamp. Downstream from both preamps, I put the signal from the 4221 in on the "Ch. 49 in" of the Join-tenna, then the signal from the 4248 in on the "all other channels."

Then I take the signal out from the Join-tenna to the TVs. And it works. (Previous testing with the rotator and the 4248 had shown it was hopeless to find a compromise angle to get all the stations with one antenna.)

I assume this is the obvious case in which the Join-tenna "should work," "ought to work," "of course it works," but there's the experience in case someone can benefit. :)

Rick0725

08-01-07, 09:46 AM

paulstefano

willie has some valid points. the jointenna is best used to combine 2 antennas with 1 antenna pointed to the station the jointenna is tuned to and the other for all channel use. the other application is for a 20 db channel trap for a specified channel.

the pr8800 is really not an antenna of choice for challenging reception situations. you may need to select a different antenna/ antennas for better results.

If I were going to take on the challenge here, I would use 2 antennas...one for the locals 5 miles away and one aimed at ch 47. the selection of antennas is very important because of the considerations of the adjacent channels and signal levels/distances involved in the combination. the jointenna setup is also going to be a challenge because they attennuate signal 5 channels either side of the center channel in your case ch 47 (your ch 45 and 46).

I also would suggest antennas that have the specs suitable for more accuracy. the gain of the antenna and the way the antennas match for the situation at hand is going to be important. for example, if ch 47 is weaker and farther away use an antenna with more gain for ch 47 and use an antenna of less gain for the stations close up so you can attemp to balance the signals better and minimize interferences.

amplification is also going to be an issue. amplification must be properly matched for the situation. amplification is not going to help matters because of the stations close by affecting or impeding reception of the stations far away. you may be better off without amplification and choosing appropriate antennas to compensate.

your set of circumstances may require a pro. you would need to try several alternatives...different antennas, amps, filters, instumentation, etc.

it is very difficult to offer concrete solutions to your problems from afar because to be honest there may not be any.

Don F.

08-02-07, 12:56 PM

Need some advise on how high to go with a radio shack pole.

I have a 15 ft. mast that sits in a mount on the roof of my porch. Seven feet up, the mast is anchored to the eve of the house, four ft. higher I have three-way guy wires, a foot above the wires is a cm rotor. Currently I have a 5 ft. mast in the rotor with an xg91, YA1713 and preamp. I think that is around ten pounds. I want to go up another 5 feet. If the addition is no problem, I would add a support bearing about 18 inches above the rotor and another set of guy wires at that point.
That would put the height of the xg91 at 16 to 17 feet above the eve of the roof, and about 8 ft. above the last set of guy wires.
Safe or not? Thanks

m_vanmeter

08-02-07, 03:23 PM

a suggestion would be to add the 5' section below the rotor and add another set of guy wires. Adding much more above the rotor, and unsupported, is almost a sure bet the next heavy wind will bend it at the least, bring it down at the worst. Your 5' above the rotor is enough for the CM rotor to handle.

MAX HD

08-02-07, 07:59 PM

Rick0725

08-02-07, 10:38 PM

I would still limit the length of the mast above the rotor to a trimmed 5' heavy duty mast. with the ya1713 as close to the rotor as possible (less than a foot) and the 91xg about 3.5' above the ya1713.

an alternatve to guys...try 1.25" emt conduit bent/molded to attach to the roof and below the rotor if you are able. extremely sturdy and something to hold onto when you are puttering on the roof.

I tried 7.5' above the rotor at my home earlier this year and the mast bent from the wind in less than 6 months and caused the rotor to bind. so I would not suggest that. had to replace and go shorter.

see pic for example.

Don F.

08-03-07, 10:26 AM

Rick, Max, & m_..... Thanks for the suggestions on the antenna height question.

I will temporally add 5 ft. from the bottom just to see if my signal improves. If there is no benefit, I will leave the antenna as it is today. If it helps, wish me luck. I have about 4ft. of separation between the ya1713 and xg91. I was concerned that was not enough, but acorrding to your info that should be good. The xg is at the top of the mast.
I have been very pleased with this combo, viewing stations 80 miles away on a regular basis.
Thanks again for your help!!

Boxcar74

08-03-07, 05:41 PM

Just to let you know, I am very new at this.

I live about 10 miles from most of the towers, and trying to get the digital broadcasts from my local stations. I live in a small condo so an outdoor antenna is out. I am currently using rabit ears and they just aren't cutting it. Does anyone have any suggestions for a good small indoor antenna?

tokerblue

08-03-07, 06:14 PM

I live in a small condo so an outdoor antenna is out. I am currently using rabit ears and they just aren't cutting it. Does anyone have any suggestions for a good small indoor antenna?
- I would go to the local HDTV forum and see what other people in your area are using. I've tried a lot of different indoor antennas and the only one I've had success with is the Zenith Silver Sensor. The biggest problem with it though is that it is very directional, so I was constantly moving it when changing channels.

I ended up with an outdoor andtenna because of this.

MLock

08-04-07, 08:40 PM

I posted this in the Indianapolis thread, but it may be more appropriate here.

I'm brand new to HDTV; just got a great television and am awaiting D* hookup. However, my local CBS affiliate is not carried on D* so I need to be able to pick it up OTA. This station is the ONLY one in Indy to broadcast its HD on a VHF frequency; all the others are on UHF.

Because I'm constrained (legally, I'm beginning to think) by Murphy's Law, I can get every single HD station that's on UHF quite well. I am using just a $20 antenna (VHF and UHF) I got at Circuit City, and my signal is upwards of 80 on every station.

Antennaweb tells me that this CBS affiliate should be the *easiest* chann for me to pick up -- but I don't get anything at all. No pixellation, no information -- it just isn't there at all.

I'm hoping I'm just doing something dumb. That would also, unfortunately, be quite common... but easier to fix!

Thanks for any help you can provide.

afiggatt

08-04-07, 09:25 PM

II'm brand new to HDTV; just got a great television and am awaiting D* hookup. However, my local CBS affiliate is not carried on D* so I need to be able to pick it up OTA. This station is the ONLY one in Indy to broadcast its HD on a VHF frequency; all the others are on UHF.

Because I'm constrained (legally, I'm beginning to think) by Murphy's Law, I can get every single HD station that's on UHF quite well. I am using just a $20 antenna (VHF and UHF) I got at Circuit City, and my signal is upwards of 80 on every station.

Antennaweb tells me that this CBS affiliate should be the *easiest* chann for me to pick up -- but I don't get anything at all. No pixellation, no information -- it just isn't there at all.
If you provide your zip code, we can look up how far you are from the CBS station. You may need a more substantial VHF antenna. Looking up Indianapolis, the station is WISH-DT 8 on VHF 9. Have you optimized the length of your rabbit ears for VHF 9 (186 to 192 MHz) with the ears extended to about 32" in total length? Also the open plane of the ears should be facing in the direction of the station.

MLock

08-04-07, 10:44 PM

Thanks for the offer. My zip is 46259.

I'll do as you say on the ears and report back.

jtbell

08-05-07, 01:28 PM

I'm looking for some advice about mounting a replacement outdoor antenna setup.

Here's a picture of what I have now (http://web.presby.edu/~jtbell/images/Antenna2.jpg), a Radio Shack VU-190XR combination VHF/UHF antenna on an old mast mounted at the side of my house. If you look closely, you can see the mast below the rotator is in three sections. The third section is shorter because about two years ago, my neighbor's tree trimmers knocked down my previous antenna, kinking the top few feet of the mast over sharply. I bought the RS antenna, which is somewhat larger than its predecessor, and the neighbor and a friend mounted it and the rotator on the stump left over after sawing off the kinked-over portion of the mast.

After this happened, I got into digital TV, and I now know that I don't need low VHF capability any more. Therefore I'd like to replace this antenna with a combination of Antennasdirect 91XG for UHF and Winegard YA-1713 for high-VHF, and replace the mast while I'm at it.

Would it be feasible to go with a three-section mast again? As you can see from the picture, the second section of the existing mast ends about a foot or so above the peak of the roof. The previous antenna was probably about 10' above that, but it was smaller than the one I have now. With the combination I want, it looks like I'd want the VHF about 1' above the rotator, and the UHF about 3' above that.

afiggatt

08-05-07, 04:05 PM

Thanks for the offer. My zip is 46259.

I'll do as you say on the ears and report back.
Looking at the antennaweb results for your zip code, you are on the outer edges or outside of what normally be considered viable for an indoor antenna in many places. The antennaweb results for your zip code and a antenna height of 150' under options to get a more complete lists shows the following digital stations:

* yellow - uhf WTHR-DT 13.1 NBC INDIANAPOLIS IN 337° 21.1 46
* yellow - uhf WRTV-DT 6.1 ABC INDIANAPOLIS IN 331° 19.9 25
* yellow - uhf WCLJ-DT 56.1 TBN BLOOMINGTON IN 208° 19.1 56
* yellow - uhf WFYI-DT 20.1 PBS INDIANAPOLIS IN 331° 19.9 21
* yellow - uhf WIPX-DT 63.1 ION BLOOMINGTON IN 207° 19.0 27
* yellow - vhf WISH-DT 8.1 CBS INDIANAPOLIS IN 330° 19.5 9
* yellow - uhf WXIN-DT 59.1 FOX INDIANAPOLIS IN 330° 19.3 45
* yellow - uhf WDTI-DT 44 PBS INDIANAPOLIS IN TBD 330° 19.3 44
* yellow - uhf WNDY-DT 23.1 MNT MARION IN 9° 34.2 32
* red - uhf WTTV-DT 29.1 CW BLOOMINGTON IN 208° 18.9 48
* violet - uhf WTIU-DT 30.1 PBS BLOOMINGTON IN 220° 44.3 14
* violet - uhf WHMB-DT 40.1 IND INDIANAPOLIS IN 6° 24.8 16

You have Indianapolis stations 19 miles to the NW and a CW station in Bloomington ~ 19 miles to the S. You have the one upper VHF station, WISH-DT on VHF 9. In February, 2009, after the analog shutdown, WTHR-DT NBC 13 will switch from UHF 46 to VHF 13. Since you are doing ok, with the indoor antenna, see if you can get better results putting it high up in a window or upstairs.

Since you are using D*, you might want to consider mounting a Channel Master 4220 two bay bowtie or CM 4221 4 Bay bowtie outside and using a diplexer to connect it to the D* STB or TV. The CM 4221 in the attic with a separate cable run is another option. Based on my results with the CM 4221, it has a good shot at picking up a strong VHF 9 station at 19 miles. If you got either antenna, I would experiment with the aim to try to pull in the stations in both places.

dotay

08-05-07, 05:40 PM

MLock

08-05-07, 08:36 PM

Looking at the antennaweb results for your zip code, you are on the outer edges or outside of what normally be considered viable for an indoor antenna in many places. The antennaweb results for your zip code and a antenna height of 150' under options to get a more complete lists shows the following digital stations:

<snip>

Your advice is all sound, and I think I will eventually put an antenna of some sort in my attic -- when it isn't 112 degrees up there. But for now, the resolution was oh so much simpler.

The TV I bought is a Sony KDS-55A2020. It has two auto-detect options, "Analog" and "Digital". (You probably already know what's going to happen) Of course, I kept telling it to auto-find digital channels (tuning directly to, say, 8.1 or 9 without doing the auto-find yielded nothing but snow), and it would find all of them I wanted except WISH (9, or 8.1). I, of course, just knew it was because my VHF antenna stunk.

Well, for the heck of it, this afternoon I ran a "full scan" which finds both analog and digital. Bingo. It found 10 analog and 24 digital. One of them is a 78-strong WISH-HD signal.

Apparently, to Sony, at least on this model, when you tell it to scan for "digital", it scans only UHF for digital. When you tell it to scan for analog, it scans both VHF and UHF for analog. If you tell it to scan both, that's the only time it'll find digital on VHF.

Thanks very much for your help. I'll be doing an attic installation but I won't be in such a rush now.

Tobias Ziegler

08-05-07, 10:09 PM

Does anyone know if TV stations adjust their transmission power around sunrise/sunset like many radio stations do?

Neil L

08-05-07, 11:00 PM

I don't know for sure, but I don't think TV stations ever adjust their power. However, sunrise and sunsets do provide the kind of temperature inversions that provide good dx'ing.

afiggatt

08-05-07, 11:18 PM

Apparently, to Sony, at least on this model, when you tell it to scan for "digital", it scans only UHF for digital. When you tell it to scan for analog, it scans both VHF and UHF for analog. If you tell it to scan both, that's the only time it'll find digital on VHF.
Wow. Who wrote that software? There are currently several hundred full power stations with digital VHF channels and we will have around 500 total on VHF after the analog shutdown. Are people going to have to "full" analog scans to get their stations after analog goes away? This is a big enough bug that Sony should be required to send out a firmware update to fix it.

Impressive that the indoor tabletop antenna works at 19 miles. Good luck.

afiggatt

08-05-07, 11:25 PM

I've currently got a Zenith ZHDTV1 silverstar antenna that worked great for a while but I've recently moved a little further away from the source so I am looking to go for an in attic model. I doubt I'll need anything powered since I'm still pretty close but I'm not sure what would best suit my needs.

Call Sign Channel Network City State Compass Miles Frequency
WANE-DT 15.1 CBS FORT WAYNE IN 335° 3.1 31
WISE-DT 33.1 NBC FORT WAYNE IN 338° 3.0 19
WPTA-DT 21.1 ABC FORT WAYNE IN 336° 3.7 24
WFWA-DT 39.1 PBS FORT WAYNE IN 333° 4.0 40
WFFT-DT 55.1 FOX FORT WAYNE IN 333° 4.4 36
What results are you getting with the Silver Sensor from your new location? If the antennaweb list is for your new location, you are only 3 to 4 miles, so the Silver Sensor is a good bet to work.

But for an attic antenna suggestions, all 5 of the digital stations are on UHF and will stay on UHF after the analog shutdown (which makes sense as their analog channels are all UHF). A Channel Master 4220 two bay UHF antenna is a good candidate for your location. Remember, that attics can have dead zones. My solution was to mount a CM 4221 on a flat piece of scrap wood using mounting bracket so I could slide the antenna around in the attic until I found a good spot.

Tobias Ziegler

08-05-07, 11:53 PM

I don't know for sure, but I don't think TV stations ever adjust their power. However, sunrise and sunsets do provide the kind of temperature inversions that provide good dx'ing.

Over the last few weeks I've been trying to determine the best antenna positions in my home for various tv stations, and I cant seem to nail it down because even local stations' strengths seem to change (from time to time) for no apparent reason. Tonite I noticed a drop in signal strength of my local stations over the half hour period that sundown occured. So it clicked in my mind. Maybe they're changing their broadcast strength the way radio stations do.

Falcon_77

08-06-07, 12:02 AM

Apparently, to Sony, at least on this model, when you tell it to scan for "digital", it scans only UHF for digital. When you tell it to scan for analog, it scans both VHF and UHF for analog. If you tell it to scan both, that's the only time it'll find digital on VHF.

Thanks very much for your help. I'll be doing an attic installation but I won't be in such a rush now.

Interesting info. Thank you for sharing this. Apparently somebody at Sony doesn't realize that there are some VHF digital channels, with many more coming in '09. I will have to watch out for this when the time comes.

holl_ands

08-06-07, 03:35 AM

Is there a small VHF antenna that would be good for testing purposes? I thought this was a simple matter of getting rabbit-ears but perhaps not.

I am currently trying an RCA ANT115 as a test antenna and the UHF loop does ok, but it is horrible at VHF, even with the dipoles fully extended.

I used this antenna to test reception in the Mystic CT area and I couldn't get hardly anything on WFSB 3 no matter what I tried. The result didn't surprise me considering what I was dealing with there. However, now that I am back in CA, with a mostly clear view of Mt. Wilson (from Irvine), I am having no luck getting KCBS 2. Channels 4 and 5 are very weak, though it improves a bit for VHF-High.

I had an older pair of rabbit ears that went missing. I seem to remember those working much better than this before I put up the CM4228. However, the old rabbit ears did not have a UHF loop and I had a balun attached. The RCA ANT115 just has a (very thin) Coax cable coming out of the base.

This seems like a silly question, but what is a good pair of test rabbit-ears? Perhaps it is as simple as finding another pair w/o the UHF loop combo.
The problem with Rabbit Ears is they aren't even CLOSE to the right size for low-band VHF....
and hence, the impedance is (cough-cough) "indeterminate".....

Here are instructions for building a DIY Folded Dipole (0 dbd gain), with optional Reflector (+3 dBd)
and Director (+5 dBd) elements to turn it into a single channel Yagi-Uda antenna:
http://www.wfu.edu/~matthews/misc/dipole.html
Note CH2 requires a Dipole element that is 2.5 meters long.....try THAT with Rabbit Ears!!!!

PS: A Folded Dipole is nominally 300-ohm, eliminating the lossy balun transformer.

Nitewatchman

08-06-07, 11:52 AM

holl_ands

08-06-07, 09:22 PM

while the "rod" antennas included with for instance, small portable TV's sometimes aren't even long enough to be a 1/4 wavelength vertical on low VHF, Most rabbit ears I've ever used are center fed dipole(therefore 300Ohms) and can be extended such that they are (more or less) a 1/2 wave dipole on channel 2, which is approx 8.5 feet.

http://www.kyes.com/antenna/rabbitear.html
Uhhhmmm......Center Fed Dipoles are nominal 75-ohm impedance at resonance:
http://en.wikipedia.org/wiki/Dipole_antenna
and should be connected to 75-ohm coax via a 1:1 Balun Transformer (balanced to unbalanced)....
(or equivalent).... which I bet most cheap Rabbit Ear Antennas simply omit....like in the wikipedia article!!!!

Folded Dipole is nominal 300-ohm:
http://personal.ee.surrey.ac.uk/Personal/D.Jefferies/rodres.html
And can be connected directly to 300-ohm Preamp or TV input and requires a
readily available 300:75-ohm Balun Transformer (or Quarter-Wave Stub Transformer per above article)
for connection to 75-ohm coax.

FYI: Fol. website claims to calculate Folded Dipole Impedance for arbitrary element
sizes and spacings:
http://www.n-lemma.com/calcs/dipole/

Nitewatchman

08-06-07, 11:28 PM

Uhhhmmm......Center Fed Dipoles are nominal 75-ohm impedance at resonance:/[/url]

Good point, thanks for the correction.

72 Ohms is actually what I remembered(but not well enough!) from "radio school", dunno why I was thinking of center fed rabbit ears as 300 ohms(it never worked that way for center fed dipoles for HF - such as "inverted vee's" ....) ...

Anyway, same info is also here in #2 section of below link, and I also wonder why they don't say anything about the typical impedance of your run of the mill "rabbit ears", given they do talk a lot about how to make the most out of them(rabbit ears) at their site ... :

http://www.kyes.com/antenna/antennatypes/antennatypes.html

And here's another graphic of a folded dipole made out of twinlead :

http://www.kyes.com/antenna/antennatypes/twinlead.jpg

which I bet most cheap Rabbit Ear Antennas simply omit....

I dunno, but other than comparing their performance with other antennas(such as folded dipole) expect you'd probably pretty much have to destroy them to find out .... i.e. just exactly what(if anything) is in that hard plastic between the "ears" ? ... It certianly does seem to usually be 300 Ohm balanced line coming "out" of that plastic ...... Of course, there are cheap rabbit ears out there these days with coax coming out of that plastic "stuff" as well .....

---------------

Update .... Hmmm ... here's perhaps another bit of an interesting "rabbit ear" read ..

http://www.ham-radio.com/k6sti/rabbit.htm

dotay

08-07-07, 11:59 AM

What results are you getting with the Silver Sensor from your new location? If the antennaweb list is for your new location, you are only 3 to 4 miles, so the Silver Sensor is a good bet to work.

But for an attic antenna suggestions, all 5 of the digital stations are on UHF and will stay on UHF after the analog shutdown (which makes sense as their analog channels are all UHF). A Channel Master 4220 two bay UHF antenna is a good candidate for your location. Remember, that attics can have dead zones. My solution was to mount a CM 4221 on a flat piece of scrap wood using mounting bracket so I could slide the antenna around in the attic until I found a good spot.

Thanks for the reply.

It's good at times but I have to point across the seating area and it seems very susceptible to any movement in front of the antenna. I suppose I could try this antenna in the attic as well and see what kind of results I get. Does anyone have any experience with the Silver Sensor in an attic? The antenna you suggested doesn't seem too pricey though so I might just pick one of those up to try it out.

Are there any general rules to try to stick to as far as placement goes, closer/further away from a wall is better?

lasko

08-09-07, 08:45 PM

I need to point in two diffent directions to get all my local HD channels. I do not want a large antenna and rotor. Found the Phillips MANT940 works really well and is small in size. Already have a roof mast mounted so I would like to combine them at the roof so I don't have to run another cable to the basement. Is there some sort of splitter/combiner that would work?

Neil L

08-09-07, 10:26 PM

lasko,
You might want to look into a Jointenna. Search this forum and this very topic for information.

videobruce

08-15-07, 09:29 AM

I know this has been brought up many times and I'm sure it works to some extent to eliminate the need for a rotor, but combining two antennas, pointing different directions, is it really worth while?

Using the 4228 copy cat DB-8 as example in one direction and a DB-4 in the other, considering the loss of the additional splitter, to combine both antennas, to me, all I see is additional loss on top of the issue of receiving reflections from the antenna of the opposite direction.

What do you guys think?

nybbler

08-15-07, 10:37 AM

What do you guys think?

I think those are DB-4 and DB-8. But yeah, combining antennas pointing in different directions without a Jointenna is probably not such a great idea. For instance, combining two 4-bays pointed in opposite directions gives you at best the same gain as one 4-bay with the screen removed.

jtbell

08-15-07, 05:07 PM

Tower Guy

08-15-07, 08:29 PM

The problem with combining two antennas pointing in different directions is that the antenna pointing in direction 1 still picks up a reduced signal from direction 2, and vice versa. When you add the two signals for the same channel together, they're time-shifted a bit with respect to each other, which gives you multipath interference.

True, but that could be almost eliminated by stacking the two bow-tie antennas above each other. (Yagi's are another matter) The other issue is reflections that could be picked up by the wrong antenna.

If the home has few reflecting surfaces in the main beam of either of the two antennas it much more likely to work with simple unfiltered combining than in a location surrounded by buildings.

christ1

08-15-07, 09:57 PM

I live in downtown Baltimore, MD and I am looking into receiving OTA HD stations from DC. Looking at antenna web, I get the following for DC stations.

blue - uhf WDCW-DT 50.1 CW WASHINGTON DC 238° 32.6 51
blue - uhf WJLA-DT 7.1 ABC WASHINGTON DC 240° 35.2 39
blue - uhf WUSA-DT 9.1 CBS WASHINGTON DC 240° 35.2 34
blue - uhf WTTG-DT 5.1 FOX WASHINGTON DC 241° 35.1 36
blue - uhf WRC-DT 4.1 NBC WASHINGTON DC 239° 35.8 48

A distance of 35 miles and a medium directional with preamp. My question is, can I receive these DC stations reliably from this distance, especially on Sundays for Redskins games? What would be the best antenna; people seem the like Channel Master? Also, do I need anything else besides an antenna? I have a HDTV with a built in tuner. Thanks.

AntAltMike

08-15-07, 10:15 PM

I live in downtown Baltimore, MD and I am looking into receiving OTA HD stations from DC. Looking at antenna web, I get the following for DC stations...

WDCW-DT 50.1...
WJLA-DT 7.1...
WUSA-DT 9.1...
WTTG-DT 5.1...
WRC-DT 4.1

A distance of 35 miles and a medium directional with preamp. My question is, can I receive these DC stations reliably from this distance, especially on Sundays for Redskins games?
There are tall buildings in downtown Baltimore. If any interdict your antenna path, they will make it impossible to reliably predict the reception quality at your location. If any are positioned so as to be the source of multipath reflections, they will also degrede your signal quality in a manner that we cannot predict.

The fact that channel 20.1 doesn't show up on your list is troubling. It could indicate that there is a hill between you and the Washington transmitters, or it just could be that the antennaweb data has not been revised to reflect the fact that channel 20.1 significantly increased its power about a year ago.

It's time to start experimenting. With antennas, bigger is better and higher is better, but of you are in an apartment and can't roof mount, you might as well start with something small but efficient that you can move around, like a Silver Sensor or a 2-bay bowtie. An amplifier will probably not help you and would probably be overloaded by your local UHF transmitters.

If you can't find a reliable, universal antenna position, your goal would be to find the spots where each station that provides unique programming can most reliably be received.

videobruce

08-16-07, 08:59 AM

nybbler; Yes you are right (previous post corrected). Those are the first DB4/8 antennas I have seen locally. They are such a copy cat (rip off) of the Channel Master design, at 2x the price, I can't see they are worth it.

christ1; since I have no idea exactly where you are, I came up with this starting point;
http://tiger.census.gov/cgi-bin/mapsurfer?act=in&infact=2&map.x=211&map.y=180&lat=39.30010&lon=-76.61071&wid=0.125&ht=0.125&iht=359&iwd=422&&on=CITIES&on=railroad&on=streets&tlevel=-&tvar=-&tmeth=i&mlat=39.30080&mlon=-76.61061&msym=redpin&mlabel=Baltimore__MD&murl=&conf=mapnew.con

That gave me this;
http://www.2150.com/broadcast/default.asp?latitude=39%2E2997513&longitude=%2D76%2E6107635&magnetic_north=%2D12&range=60&sort=distance&show_expired=True&show_construction=True&show_analog=False&show_low_power=False&action=Show+Stations

Those five 'locals' are just 3 miles away with another one 8 miles away. ANY amp (especially a preamp) will be overloaded with stations that close even though the Washington stations are SW of you and the Baltimore 'locals' are SE (with the reference chosen). Though they are 90 degrees apart which will help, I can't see how any amp would work. 35 miles isn't that far, but since I don't know the terrain and as the previous poster mentioned, tall buildings will be a major factor.

BTW; welcome to the forums.

christ1

08-16-07, 09:56 AM

videobruce

I don't have enough posts to put links in but I got pretty much the same result using the 2150 site for my specific location.

When you say amp, is this the same as the antenna? And you say "I can't see how any amp would work," does that mean that whatever antenna I get, the DC stations will be overloaded by the Baltimore stations? I guess I will just have to pay for NFL sunday ticket to watch Redskins games.

Mloot

08-16-07, 10:25 AM

I think videobruce is meaning something like a pre-amp, which is a device attached to the mast of an outdoor antenna and then plugged into a wall socket inside the home in order to amplify the signal coming from the antenna. It could also apply to any number of indoor antennas that have a built-in amplifier.

afiggatt

08-16-07, 10:40 AM

I live in downtown Baltimore, MD and I am looking into receiving OTA HD stations from DC. Looking at antenna web, I get the following for DC stations.

A distance of 35 miles and a medium directional with preamp. My question is, can I receive these DC stations reliably from this distance, especially on Sundays for Redskins games? What would be the best antenna; people seem the like Channel Master? Also, do I need anything else besides an antenna? I have a HDTV with a built in tuner. Thanks.
The key question is what is your view to the southwest in the direction of DC? Do you have tall buildings in the way? Also, do you want to get the Baltimore and other stations in the area as well as the DC stations? Are you in a condo/apartment or in a house/rowhouse where you have access to an attic or roof?

All of the digital stations in Baltimore, DC, and in the area are currently on UHF. But WJLA-DT 7, WUSA-DT 9, WBAL-DT 11, WJZ-DT 13 will switch their digital channels to their upper VHF channels after the analog shutdown in February, 2009. Check the first post of the Washington DC - Baltimore thread in the locals forum for digital channel assignments.

I get the Baltimore (43 miles), DC stations (16 miles), and several others from Sterling, VA with a Channel Master 4221 4 Bay bowtie in my attic. However, I recently added a Winegard YA-6713 upper VHF antenna to be prepared so I can get the more distant upper VHF stations in Baltimore after the analog shutdown.

You are probably too close to the Baltimore stations to use a pre-amp. But you should not need a pre-amp for pickup at 35 miles, depending on terrain and how long the cable run is. If you can provide us more information, then we can provide more help.

videobruce

08-16-07, 10:55 AM

But WJLA-DT 7, WUSA-DT 9, WBAL-DT 11, WJZ-DT 13 will switch their digital channels to their upper VHF channels after the analog shutdown in February, 2009. Where did you get that from? All those digital channels are UHF.

christ1

08-16-07, 11:25 AM

The key question is what is your view to the southwest in the direction of DC? Do you have tall buildings in the way? Also, do you want to get the Baltimore and other stations in the area as well as the DC stations? Are you in a condo/apartment or in a house/rowhouse where you have access to an attic or roof?

All of the digital stations in Baltimore, DC, and in the area are currently on UHF. But WJLA-DT 7, WUSA-DT 9, WBAL-DT 11, WJZ-DT 13 will switch their digital channels to their upper VHF channels after the analog shutdown in February, 2009. Check the first post of the Washington DC - Baltimore thread in the locals forum for digital channel assignments.

I get the Baltimore (43 miles), DC stations (16 miles), and several others from Sterling, VA with a Channel Master 4221 4 Bay bowtie in my attic. However, I recently added a Winegard YA-6713 upper VHF antenna to be prepared so I can get the more distant upper VHF stations in Baltimore after the analog shutdown.

You are probably too close to the Baltimore stations to use a pre-amp. But you should not need a pre-amp for pickup at 35 miles, depending on terrain and how long the cable run is. If you can provide us more information, then we can provide more help.
There are a couple of 7-10 story buildings about a mile to the SW and a couple of smokestacks. Other than that everything is only 2-3 stories in the immediate vicinity. I am in a 2 story rowhome so I have easy access to the roof. I will have Baltimore HD channels with Directv so I only want the OTA DC stations. I am not thinking about 2009 because by then i might be in a different place and a different TV setup. Correct me if I am wrong but the OTA UHF HD channels will not be affected by the shutdown or will all channels be moving to VHF before the shutdown? How high would I need to place the antenna? If I don't need a pre-amp, the antenna is the only thing to purchase correct? Thanks a lot.

Neil L

08-16-07, 06:47 PM

christ1,

After the analog shut-off, UHF channels 52-69 will no longer be used for TV. And almost no one wants to use VHF channels 2-6, so the FCC is deciding what to do about that. A lot of stations are using temporary UHF channels for digital right now, and still have their analog channels where they have always been. When the analogs are shut down, many stations will want to keep the same channel assignment they had for analog, so they will move from their temporary assignment back to the old assignment, whether that was UHF or VHF.

afiggatt

08-16-07, 07:34 PM

Where did you get that from? All those digital channels are UHF.
The FCC final channel selection list, which is an update of the list that was put out in 2006, is available at http://www.fcc.gov/dtv/. Read the document posted on May 18 under "Third Periodic Review of the Commission's Rules and Policies Affecting the Conversion to Digital Television" if you want to see some of the complex issues behind the digital transition.

A discussion of the final digital channel selection is at http://www.avsforum.com/avs-vb/showthread.php?t=823166. It has been established for some time that the four upper VHF stations in DC and Baltimore would be moving their digital channel from UHF to their analog channel after the analog shutdown. In fact, 517 full power stations (give or take a few final channel changes) across the US will be moving their digital channel to their current analog channel after the shutdown. As stated, the digital channel range will be from VHF 2 to UHF 51 after the shutdown, albeit with only 37 full power stations opting for low VHF 2 to 6. One of them is WPVI-DT ABC 6 in Philadelphia which will be a problem for anyone at further ranges from the station who put up a UHF only antenna for digital reception.

videobruce

08-17-07, 08:15 AM

In fact, 517 full power stations (give or take a few final channel changes) across the US will be moving their digital channel to their current analog channel after the shutdown. I understand some stations will revert back to VHF, but when I looked at a couple of the applications through the FCC database, they just showed UHF, no VHF was listed.

PA_MainyYak

08-18-07, 05:33 PM

Where did you get that from? All those digital channels are UHF.

Only temporarily. On February 9, 2009, the Washington-Baltimore DTV lineup will look like this:

Station______________(Old Analog)__(New DTV)
WJLA WASHINGTON............7__________7
WUSA WASHINGTON...........9__________9
WBAL BALTIMORE..............11_________11
WJZ BALTIMORE................13_________13
WETA WASHINGTON...........26_________27
WMBP BALTIMORE..............67_________29
WHUT WASHINGTON...........32_________33
WDCA WASHINGTON...........20_________35
WTTG WASHINGTON............5_________36
WMAR BALTIMORE...............2_________38
WNUV BALTIMORE..............54_________40
WUTB BALTIMORE..............24_________41
WBFF BALTIMORE..............45_________46
WRC WASHINGTON.............4_________48
WDCW WASHINGTON.........50_________50

The complete list is on the FCC web site:
http://hraunfoss.fcc.gov/edocs_public/attachmatch/FCC-07-138A2.xls

Falcon_77

08-20-07, 01:21 AM

Would it be practical to build an LPDA antenna for VHF-HI? What I'm thinking of is building a VHF antenna similar to what a Silver Sensor accomplishes for UHF. I suppose the lower frequencies (even for VHF-HI) doesn't make this practical, but thought I would ask why I only seem to find Yagi's for VHF-HI (other than rabbit ears).

Is there a construction guide for LPDA's?

If std. dipole lengths apply, The Silver Sensor appears to be made to support considerably higher frequencies than we need. As I understand it, the Silver Sensor was a UK imported design, so that might make sense. It also can be assembled in vertical polarization mode, which is rather useless here.

nybbler

08-20-07, 02:23 PM

Most full-band VHF TV antennas are LPDAs or log-cell yagis. Probably most VHF-Hi only antennas are straight Yagis because of the relatively smaller bandwidth needed, and the simpler Yagi construction.

Wade advertises a few LPDA VHF-hi antennas but they're CATV antennas and presumably priced accordingly.

Tobias Ziegler

08-20-07, 02:52 PM

Would it be practical to build an LPDA antenna for VHF-HI? What I'm thinking of is building a VHF antenna similar to what a Silver Sensor accomplishes for UHF. I suppose the lower frequencies (even for VHF-HI) doesn't make this practical, but thought I would ask why I only seem to find Yagi's for VHF-HI (other than rabbit ears).

Channels 14-51's center frequencies span from 473MHz to 693Mhz, while Channels 7-13's are 177MHz to 213MHz. This is pretty much a 3 to 1 ratio. So it might be worth a saturday afternoon to put together a SS clone that's scaled up 3 to 1 in size. I've no idea what it will do in terms of impedences, but the wavelengths should be right for the physical dimensions. Try it and let us all know how it works out.

AntAltMike

08-20-07, 04:48 PM

Buy yourself a copy of the ARRL antenna book. I bet you can find one on eBay for a few dollars. For your purposes, it won't matter how old it is. It should give you guidelines on building your own antenna that will be much better conceived than anything that you yourself could concoct experimentally.

Zero HD

08-20-07, 06:58 PM

lemmalone

08-21-07, 10:26 AM

Would it be practical to build an LPDA antenna for VHF-HI?

You might go to this thread. There are posts by serndipity and others on lpdas, and although I think he was aiming at higher frequencies, you might find some ideas. Also, some people made double-quad reflectors, and I seem to recall that they were aimed at VHF.

http://www.lumenlab.com/forums/index.php?showtopic=9613

MAX HD

08-21-07, 12:36 PM

Calaveras

08-21-07, 01:09 PM

I remember seeing a post recently on here,or maybe another forum,where someone built their own highband antenna and had it in their attic with nice pictures.The elements were fastened to a large board.IIRC,it was round a 10 element,or thereabouts.I'll poke around and see if I can find it.

This is weird. I never look at this thread but I did today. You may be referring to me. Here's the info:

http://www.aa6g.org/Lp/lp.html

If anyone is going to build it, build the 12 element version. It's better on channel 13.

Chuck

afiggatt

08-21-07, 08:28 PM

I have a Sammy 4661 with an ATSC tuner in it. I am on the 15th floor of an apartment building in Hamilton, Ontario that looks over the water all the way to Toronto (about 45 kilometers straight across. Up until now I was using a crappy philips powered indoor antenna but had to put it on my balcony to get the Toronto stations.

I am interested in getting an antenna that is a bit larger but not full sized, maybe one of the flat wall mounted ones that I could install on my balcony, any recommendations?
If the digital stations in Toronto are all on UHF, the Channel Master 4220 2 Bay bowtie should outperform the Philips indoor antenna. The CM 4220 is fairly new, but it a half sized CM 4221 4 Bay. The CM 4220 is sold by some vendors with a satellite dish type wall mount (http://www.pctinternational.com/channelmaster/0612/). See http://www.hdtvprimer.com/ANTENNAS/comparing.html for comparisions of some antenna models.

Falcon_77

08-22-07, 08:26 AM

http://www.aa6g.org/Lp/lp.html

If anyone is going to build it, build the 12 element version. It's better on channel 13.

Chuck

Thank you for the responses. It appears that even a VHF-HI LPDA will need to be fairly large.

I will see if I can find that book as well. Right now I have the 1998 "Practical Antenna Handbook" (Carr), which I have not found to be very practical with someone of my skill level.

I will see what I can come up with.

Thanks again,

99gecko

08-22-07, 02:04 PM

If the digital stations in Toronto are all on UHF, the Channel Master 4220 2 Bay bowtie should outperform the Philips indoor antenna. The CM 4220 is fairly new, but it a half sized CM 4221 4 Bay. The CM 4220 is sold by some vendors with a satellite dish type wall mount (http://www.pctinternational.com/channelmaster/0612/). See http://www.hdtvprimer.com/ANTENNAS/comparing.html for comparisions of some antenna models.

afiggatt,
Unfortunately ZeroHD is going after some very low powered stations. They range in power from CITY-DT @ 1.2 kW to CBLT-DT (CBC) @ 38 kW ERP. However, elevation is in ZeroHD's favour as most Toronto stations broadcast @ ~1000' to > 1600' HAAT, and there are no major obstructions (hills) since he/she is looking over Lake Ontario. As well, CITY-DT's pattern is directional to the North.
ZeroHD, I would recommend a CM4221, if there is anyway you could conveniently get it on your balcony. Some others apartment/condo residents, have placed the mast in a bucket of concrete/sand.

Yes all Toronto stations are on UHF.

hope this helps and good luck. :)

Don F.

08-26-07, 01:22 PM

MAX HD

08-26-07, 02:05 PM

Need advice again. I installed a cm 3020 for my niece a couple of years ago and she needs some improvement with uhf. She lives about 50 miles n e of Atlanta and is satisfied with most of her signals with the exception of ch 46. At this point she is still analog. I no longer use my cm 4248. Would it be worth while to remove the uhf section of the 3020, mount the 4248 a few feet higher on the mast, and connect it with the vhf portion? Thanks

The 4248 should be a little better.Use a CM7777 preamp dual-input and you're good to go.The antennas should be at least 3ft apart vertically.You dont have to remove the UHF section,but for windload factors you may want to.You could also reposition the 3020 for balance by drilling new holes for the ubolt clamp,plus it will look better :-)

Don F.

08-26-07, 05:23 PM

The 4248 should be a little better.Use a CM7777 preamp dual-input and you're good to go.The antennas should be at least 3ft apart vertically.You dont have to remove the UHF section,but for windload factors you may want to.You could also reposition the 3020 for balance by drilling new holes for the ubolt clamp,plus it will look better :-)

Should the current uhf section remain in the system? I have read where combined antennas should be the same make up.

Mloot

08-26-07, 05:40 PM

Should the current uhf section remain in the system? I have read where combined antennas should be the same make up.

Yes, that's fine. The CM7777 has two inputs, one for VHF and one for UHF. Hook up the 4248 to the UHF input and hook up the 3020 to the VHF input. The 7777 has band separators so that when the 3020 is hooked up to the VHF input, it amplifies the VHF portion that the antenna is picking up and dampens its UHF frequencies. Works like a charm.

cpcat

08-26-07, 08:45 PM

Should the current uhf section remain in the system? I have read where combined antennas should be the same make up.

I'm not sure exactly what you're asking, but separate uhf and vhf antennas will ALWAYS be better than a combo. This makes front end filtering possible (uhf/vhf filter, low/hi filter, FM trap whichever applicable) which cleans up the signal before amplification. It also obviously allows for an antenna to be designed for the specific band to be received. It makes no difference as far as performance to leave the uhf section (on a combo antenna used for vhf) as long as you are properly filtered.

MaxHD was referring to minimizing wind load and aesthetics which certainly can be significant but not from the standpoint of performance..

Identical antennas are necessary if combining on the same frequency, i.e. if combining two uhf antennas for increased gain and narrower bandwidth.

Don F.

08-27-07, 08:40 PM

[QUOTE=cpcat;11429649]I'm not sure exactly what you're asking, but separate uhf and vhf antennas will ALWAYS be better than a combo. This makes front end filtering possible (uhf/vhf filter, low/hi filter, FM trap whichever applicable) which cleans up the signal before amplification. It also obviously allows for an antenna to be designed for the specific band to be received. It makes no difference as far as performance to leave the uhf section (on a combo antenna used for vhf) as long as you are properly filtered.

Question is, in order to improve uhf reception, would it be worth while to remove the uhf section of a cm 3020 and replace it with a cm 4248 located a few feet higher on the mast, and wired to the remaining vhf section of the 3020? Funds may not be available for pre-amp. Thanks

cpcat

08-27-07, 10:21 PM

Question is, in order to improve uhf reception, would it be worth while to remove the uhf section of a cm 3020 and replace it with a cm 4248 located a few feet higher on the mast, and wired to the remaining vhf section of the 3020? Funds may not be available for pre-amp. Thanks

Sure you could do this. You'd need to combine the two with a uhf/vhf combiner. However, if your signals are weak a preamp may be mandatory (especially for uhf which will attenuate more quickly along the cable run).

Assuming you are 40+ miles out from the majority of your stations, your best first step may be simply trying the 3020 with a good preamp such as the CM 7777. The CM7777 is configurable for either separate vhf/uhf or combined input.

Don F.

08-28-07, 09:36 PM

Sure you could do this. You'd need to combine the two with a uhf/vhf combiner. However, if your signals are weak a preamp may be mandatory (especially for uhf which will attenuate more quickly along the cable run).

Assuming you are 40+ miles out from the majority of your stations, your best first step may be simply trying the 3020 with a good preamp such as the CM 7777. The CM7777 is configurable for either separate vhf/uhf or combined input.

Thanks guys for all the info. Sounds like the preamp is the most likely solution. Thanks again for the help.

Larrydalooza

08-28-07, 10:14 PM

35 miles from antennas in Chicago. Just made my $2.00 antenna out of solid copper #14 wire... 4 bowties ... I tuned 23 HD channels and 17 Analog just by leaning it against a wall. No reflector or anything, just the thing the guy on YouTube made.

Lar.

oraphus

08-29-07, 01:01 PM

Quick question...
on my set when i watch over the air HD material the sound is not synked with the picture. Like when you see peoples lips moving before the sound comes out.
AS far as i understand this is related to my HD signal.
I only see this with HD material, reg cable looks fine.
Is there anything i can do to sync the picture with the sound?

I notice that when i go in to menu and chancge to Antenna Vs Cable signal setting and then switch it back to cable the sound and the picture gets synked up, but then over time in the next 15-30 min they will again go out of sync.

videobruce

08-29-07, 01:06 PM

What TV?
What audio receiver/amp?
Internal or external speakers?

Is the audio ahead or behind the video?

oraphus

08-29-07, 01:22 PM

What TV?
What audio receiver/amp?
Internal or external speakers?

Is the audio ahead or behind the video?

TV- Vizio VP42HDTV
TV internal speakers
I believe the sound comes after the lip movement, so ahead... will have to check again.

Postmoderndesign

08-30-07, 11:56 AM

Posted on a local reception thread:
Has anyone tried the Kowatec antenna yet? There was a pretty good review in HT Mag. I think this could potentially solve the multidirectional issues I am having. Here is the site if want more information. http://www.kowatec.com/

I am also wondering about the effectiveness of this antenna. I contacted the company and got this reply:

"Thank you for your interest in our Antenna. The CS-102 is available only through Kowatec Corporation.

The price is $45. We accept Visa and Mastercard. You can either call me or I can call you to get your payment information. We have the item in stock and we can ship it to you right away.

Thank you once again for your inquiry.

Don't delay....Go Digital Today!

Best Regards,

[PERSONAL INFORMATION REMOVED BY REQUEST -Doc]

I don't need to be the first canary down this mineshaft because I am using two silver sensors and a roof antenna all on a combiner and getting all my local over the air stations. But if others find this antenna to get good reception I would give it a try.

Neil L

08-30-07, 05:51 PM

The Kowatec looks like it might be a double bow-tie inside a fancy case. If that is true, then we have a $10 antenna at best, selling for $40. I just don't see anything at all special about this one. FWIW.

fluffysheap

08-30-07, 06:22 PM

lemmalone

08-30-07, 09:20 PM

the DB2 is the best but I have to build my own stand
I can't seem to find the Silver Sensor anywhere locally (Seattle area) or I'd just go get one and try it out.

Will I need an amplifier? My current antenna has one built in but most of the amplifiers out there cost more than I paid for my whole antenna, so I must be missing something.

You could probably hang a db2 on the wall or in front of a window, and some people have success putting the antenna on the floor out of sight. You might also think about the Channel Master 4220, also a 2bay bowtie and much less expensive. Or you could make one, something that several of us have mentioned in various posts, which you might want to do if you have to build a stand for it anyway.

jnardone

08-30-07, 11:12 PM

Hi:
My antenna was damaged in storm and I replaced two parts that were obviously broken (the pre-amp & transformer - the piece on the antenna, not the voltage transformer) but I am still getting no signal to my HD box. Can I use a voltmeter to trace the signal from the antenna connector through the pre-amp to see if I have a broken cable or bad connection? What type of signal should I be looking for?
Thanks,
Joseph

afiggatt

08-31-07, 12:00 AM

I'm trying to get OTA HD reception. My zip code is 98040. I'm using the receiver built into my Mitsubishi 65732.

Right now I have a generic amplified loop antenna that I bought at Fry's. It's not bad, but sometimes I get dropouts on NBC, and Fox can get a little difficult to tune in from time to time.
The Silver Sensor is somewhat directional and you have stations in different directions. You need to think along the lines of a antenna that can get stations spread around in azimuth. The antennaweb results for your zip code for digital stations are:

* yellow - uhf KMYQ-DT 22.1 MNT SEATTLE WA 295° 5.0 25
* yellow - uhf KSTW-DT 11.1 CW TACOMA WA 295° 5.0 36
* yellow - uhf KONG-DT 16.1 IND EVERETT WA 291° 7.3 31
* yellow - uhf KTBW-DT 14.1 TBN TACOMA WA 249° 26.4 14
* yellow - uhf KING-DT 5.1 NBC SEATTLE WA 291° 7.3 48
* yellow - uhf KOMO-DT 4.1 ABC SEATTLE WA 290° 7.4 38
* yellow - uhf KBTC-DT 28.1 PBS TACOMA WA 196° 23.9 27
* yellow - uhf KCPQ-DT 13.1 FOX TACOMA WA 250° 27.0 18
* yellow - uhf KCTS-DT 9.1 PBS SEATTLE WA 295° 5.1 41
* yellow - uhf KWOG-DT 51.1 IND BELLEVUE WA 91° 12.9 50
* yellow - uhf KWDK-DT 42.1 DAY TACOMA WA 91° 12.8 42
* yellow - uhf KWPX-DT 33.1 ION BELLEVUE WA 91° 12.8 32
* violet - uhf KHCV-DT 44.1 SAH SEATTLE WA 91° 12.8 44

The last number on each line is the actual broadcast channel. All of your digital stations are currently on UHF. However, this will change in February 2009 when 3 of your locals - KCTS-DT 9, KSTW-DT 11, KCPQ-DT 13 - will switch their digital channel to their current analog upper VHF channel.

KBTC-DT Fox 13 is 27 miles so it is no surprise that you have problems getting it with an indoor antenna. If you can mount an antenna in the window or out on a balcony, I suggest you consider the Channel Master 4220 2 bay (~$20 plus shipping on-line) or maybe the CM 4221 4 Bay bowtie. Aim the antenna in the direction of the Fox station but shift it around to find a spot which gets you all the important stations. The better antenna may not need a pre-amp or amp at all.

EscapeVelocity

08-31-07, 12:50 AM

Those discontinued Radio Shack model 1880 Indoor Antennas are hard to find. But I found one! :)

rgharrin

08-31-07, 08:12 AM

How to protect preamp?
In the last 3 weeks 2 Channel Master 7777 preamps have burned out.
Both during storms. 1st storm knocked out neighborhood elect. The 2nd storm had little lightning. The antenna is not on the house but on a steel pole 100 feet from house. The pole is driven into the ground. RG6 runs along the ground to the house. The power supply end of the the preamp is plugged into a surge strip. Other things plugged into the strip, including computer were not affected.
Any ideas?

greywolf

08-31-07, 09:41 AM

That steel pole acts like a grounding rod. It needs to be connected to the main house ground with a 6ga copper wire to retain single point grounding (electrically), meet building codes and prevent damage from nearby lightning strikes. See http://www.cinergy.com/surge/ttip08.htm

fluffysheap

08-31-07, 04:29 PM

I don't really care about any of those stations to the east. I only care about the five networks (including CBS which for some reason is not on that list) which are all in more or less the same direction (at least, they're all to the west), so somewhat directional reception seems ok.

I can, theoretically, put an antenna on my patio under the "exclusive access" rule, but this will annoy my landlord, and I'd rather just keep it inside if I can.

Edit:
I found a Silver Sensor at Fry's, and it's better than the generic loop, but it's not good enough. All my other stations come in at 90% strength now and never have any dropouts, but I still can't get Fox unless I put it outside. Interestingly, when I do that, I get the best reception by pointing the antenna almost directly opposite where the station is - I guess I have a reflection that is louder than the actual signal! Which is plausible, actually, since I have a big hill between me and the station, and there's a pretty tall building behind me.

So, anyway, I guess next up is to try a 2 bay bowtie, and if I have to put it outside, well, tough. Sure would be nice if I could put it behind the sofa, though :)

I'm a little concerned about stations, especially Fox, moving to VHF. Do I have, basically, any hope of receiving this station after the switchover? It looks like rabbit ears will be about 8 dB worse than my current, already marginal antenna, so unless the transmitter power increases significantly, it seems like that station might become excessively difficult. And there doesn't seem to be much in the way of well-regarded indoor-capable VHF antennas. Maybe the Channel Master Smartenna? I don't really have a problem with using different antennas for VHF and UHF if necessary, I have two antenna connectors on my TV (both coax).

Thanks for your help :)

rgharrin

09-01-07, 08:17 AM

videobruce

09-01-07, 10:02 AM

fluffysheap; Using this as a reference point;
http://tiger.census.gov/cgi-bin/mapbrowse-tbl?lat=47.563149&lon=-122.226562&wid=.1&ht=.1&mlat=47.563149&mlon=-122.226562&msym=redpin&mlabel=98040+(Mercer%20Island)

I got this for your stations;
http://www.2150.com/broadcast/default.asp?latitude=47%2E56315&longitude=%2D122%2E22656&magnetic_north=17&range=90&sort=distance&show_expired=True&show_construction=True&show_analog=False&show_low_power=False&action=Show+Stations

You are on top of most of them so any antenna will work anywhere (assuming this is where you are). Since they are so close you can not use any type of amo or pre-amp because of overload.
Seven are NW and four are SSE of you.

greywolf

09-01-07, 01:26 PM

Greywolf,

Thanks for the information.
Run a copper wire from pole to house ground, in my case 150 ft.
Or does it take just a short copper wire connection from 75 ohm cable, where it
enters the house, to the common ground like the cable installers use?
The outside (as opposed to the copper wire) of the cable itself is a grounding connection?Since the pole is in the ground, it needs to be treated like a secondary grounding rod. That means a 6 gauge copper wire from the pole to the house ground is required. The cables also need to be grounded near where they enter the house as you have stated. Both types of ground connections are required. One doesn't replace the other.

http://www.mikeholt.com/mojonewsarchive/GB-HTML/HTML/GroundingSatelliteDishandLead-InCables~20020303.htm

http://www.mikeholt.com/mojonewsarchive/GB-HTML/HTML/2002NECGroundingCommunicationsSystems~20020701.htm

http://www.sadoun.com/Sat/Installation/Grounding.htm

AVSforum member Signal posted the following helpful sites. Dish and antenna masts have the same grounding requirements.

National Electrical Code - Search for "dish" http://forums.nfpa.org:8081/necfaq/necsrch.htm

The information there also applies to antenna grounding. In the 2002 code update, if a water pipe is used, it must be all metal and connected to the electrical panel within 5ft of where the pipe enters the building. The connection to the pipe from the lightning arrestor/ground block and from the antenna/dish mast must also be within 5ft of the pipe's entry.

Preventing Damage Due to Ground Potential Difference
http://www.cinergy.com/surge/ttip08.htm

fluffysheap

09-01-07, 02:46 PM

Videobruce: That 2150 site is nice! I like the extra detail about the transmitters.

You're right, I have very good reception on everything... except KCPQ Fox, which is 27 miles away, on the other side of Puget Sound, and apparently not very high powered. And on top of that, I'm in an apartment building behind a hill.

Why they put their transmitter there I can't say, but I have to live with it. And I can get it if I put my Silver Sensor on the patio. So, if my indoor antenna can get it outdoors, maybe an outdoor antenna can get it indoors! Failing that... I'll just put it on the patio.

revelstone77

09-01-07, 02:49 PM

afiggatt

09-01-07, 02:58 PM

Please forgive my ignorance. I am new to all this. Just got my first HD and don't want to pay the subscription mongers for service. I don't watch that much TV. Threw a small rabbit ear type i had laying around and managed to pick up a few stations. Very impressive. Went to antennaweb and determined i need a red antenna. I live in South Florida and am not aware of any electronics superstore like Fry's around here. Where the heck can I get an appropriate antenna. It obviously needs to be an outside antenna and as high as possible. Since I live a hurricane zone i would even like to have a rectractable mast if they exist. Any help anyone can provide will be greatly appreciated.
As always, please provide your zip code so we can look up your stations, the channels they are on and their distance & direction from your approximate location. If you have an attic and are not that far away, putting the antenna in attic can work provided there are no radiant barriers or construction material that blocks VHF & UHF signals.

ucladave

09-01-07, 07:06 PM

I too just recently bought an HDTV and am sick of paying directv for what should be free programming. I watch exclusively OTA broadcasts but would be watching more than just the primetime HDTV broadcasts.

I am in zip 90064. I am the top floor of a 4 story condo building and have no obstructions. However, there is a small general avaiation airport across the street. Without that airport, antennaweb says I need yellow for most stations, but with it it gives me red. I am not really sure it would affect anything but better safe than sorry I guess.

I currently have directv set up on the roof above my unit, with three 75 ohm cables coming down into the unit - a double cable for the tivo and a single for the bedroom. Ideally I would like to put an antenna (not too big!) on the roof and throw away the dish, connect two cables via a splitter to service both the bedroom and main room.

Questions:

1) will the splitter ruin the signal strength? If so I just wont use the bedroom one...

2) All the HDTV broadcasts are UHF, but during the daytime I would need VHF I think to receive regular programming (does this sound right, or do the digital stations broadcast regular def shows as well?)

3) I was looking at the terk HDTVs antenna because it is relatively small, and receives VHF as well as UHF stations. Is this a good bet, or can you guys recommend something better for my situation?

revelstone77

09-01-07, 07:28 PM

Sorry, the zip is 33418 but i am extreme northern end of that zip. i have a metal roof so i don't think an attic antenna will be of much use. seems like most of the stations are 192 -193 degrees. thx for the quick response. over in the reception forum i noticed a lot of people talking about measuring signal strength. How are they doing that?

fluffysheap

09-01-07, 08:05 PM

ucladave:
1) Yes, but you can get amplified splitters that will prevent it from being a problem.
2) If a channel has both analog and digital, they both broadcast all the time (broadcasting standard def programs via digital channel is no problem). For now, most stations are on UHF for their digital, and whatever their normal channel is for their analog. But in 2/2009, when analog goes away, many stations will move their digital back to VHF. So at that point you may need both.
3) You can start with a cheap $10 indoor loop/rabbit ears antenna and see how it does. Antennaweb is pretty conservative and you may find that a basic antenna is enough for you - if not you will have to look at stronger stuff. Most of Terk's antennas are not real good, an exception being the one based on the ubiquitous Silver Sensor.

ucladave

09-01-07, 09:44 PM

Thanks for the help there. Can you recommend an amplified splitter?

Also, I plugged in a set of rabbit ears and get quite a lot of stations. The digital UHF ones come in nicely, but the VHF ones come in pretty crappy I must admit. You can see picture but there is snow.

I would really like to go rooftop since the cables are already there and the antenna will be out of the way. If terk sucks, maybe you can recommend one thats decent but also small?

ucladave:
1) Yes, but you can get amplified splitters that will prevent it from being a problem.
2) If a channel has both analog and digital, they both broadcast all the time (broadcasting standard def programs via digital channel is no problem). For now, most stations are on UHF for their digital, and whatever their normal channel is for their analog. But in 2/2009, when analog goes away, many stations will move their digital back to VHF. So at that point you may need both.
3) You can start with a cheap $10 indoor loop/rabbit ears antenna and see how it does. Antennaweb is pretty conservative and you may find that a basic antenna is enough for you - if not you will have to look at stronger stuff. Most of Terk's antennas are not real good, an exception being the one based on the ubiquitous Silver Sensor.

fluffysheap

09-02-07, 02:17 AM

afiggatt and videobruce:
I bought a DB-8 that I found on craigslist and stuck it in a window I don't usually look out of, where it fits perfectly. Reception problems solved (with extreme prejudice). And most people would say the DB-8 is too big to be used as an indoor antenna! :)

ucladave:
I looked you up on that nice 2150.com site:
http://www.2150.com/broadcast/default.asp?latitude=34%2E029933&longitude=%2D118%2E435672&magnetic_north=17&range=90&sort=distance&show_expired=False&show_construction=False&show_analog=False&show_low_power=False&action=Show+Stations

So, you are getting nothing but static on channel Z, eh? :)

Looking at antennaweb, it seems like basically everything is in the same direction, so a highly directional antenna is probably what you want. But they are also relatively far away at 24 miles. I think, you'll probably do OK with most decent size Yagi-style antennas. http://www.antennasdirect.com/V10_vhf_antenna.html, just as a first guess.

I'm no expert, but:
The Channel Master CM-3043 amplifier (http://www.pctinternational.com/channelmaster/0612/amplifiers.html) seems like it is appropriate for your application. If you go with an outdoor antenna, on the other hand, you might want a mast mounted amplifier like the CM-7777, which will probably be strong enough that you don't need or want another amplifier in the splitter.

It seems likely (to me) that for now, you should be able to get all your channels on UHF, unless there is some particular one you want that is still VHF only and does not have a digital copy in UHF. Generally, VHF channels 2-6 require a different antenna style than 7-13 although lots of VHF antennas combine both styles into one unit. You might even be able to get 7-13 with your UHF antenna, if they are strong enough. However, low VHF is not going to be used much in the future. So you may not need that at all. Generally, the really long antennas are for upper VHF, and the really wide ones are for lower VHF.

The other thing to take into consideration is omnidirectional vs. directional. You can still use a directional antenna if you get a rotator to point it in the right place for your channels, I'd consider that inconvenient, but less so than futzing around with rabbit ears!

Really, though, you don't want my recommendations because I am pretty new at this myself. I don't know model numbers backward and forward like some people.

rgharrin

09-02-07, 09:08 AM

Greywolf,
Thanks for all the information!!

videobruce

09-02-07, 09:17 AM

I like the extra detail about the transmitters. That's what my 'sig' is about. fluffysheap; Too bad you aren't closer to Canada. One great thing about where I live, I am, and Canadian stations give you more choices and since they now have a cut off date (2011) they should be seeing more digfital stations in the next couple of years.
Your Fox station will require a outdoor antenna. It shouldn't be a problem.

videobruce

09-02-07, 09:27 AM

revelstone77; If this is you;
http://tiger.census.gov/cgi-bin/mapsurfer?act=in&infact=2&map.x=211&map.y=180&lat=26.8387012&lon=-80.1326523&wid=0.200&ht=0.200&iht=359&iwd=422&&mlat=26.838977&mlon=-80.132533&msym=redpin&mlabel=33418__Palm_Beach_Garde_

Here are your stations;
http://www.2150.com/broadcast/default.asp?latitude=26%2E8381443&longitude=%2D80%2E1326828&magnetic_north=%2D8&range=80&sort=distance&show_expired=True&show_construction=True&show_analog=False&show_low_power=False&action=Show+Stations

Looks as a bi-directional antenna would work since everything is either north or south of your location.
Are you trying for the Miami stations at 60 miles? You will have a problem with 49 & 59 being less than 8 miles away. They are to the north, so aiming south (no rotor) should drop their signal. Something with a good F/B (front to back) ratio would be in order
If not then try here;
http://www.wade-antenna.com/Wade/UHF.htm
SL-4BT 4-bay bi-directional (figure 8) antenna. over in the reception forum i noticed a lot of people talking about measuring signal strength. How are they doing that? By using what their TV reports. Problem is, that usually isn't a signal strength "meter", but a BER (bit error rate) indicator, which is better than nothing, but it isn't a level indicator. Unless you have a SLM (signal level meter) there isn't any way of knowing.
The easiest way is to use a analog station from the same location (as close as possible) and aim the antenna there looking for the 'best' image on the screen.

BTW, welcome to the forums.

ucladave

09-02-07, 11:30 AM

afiggatt

09-02-07, 11:33 AM

Sorry, the zip is 33418 but i am extreme northern end of that zip. i have a metal roof so i don't think an attic antenna will be of much use. seems like most of the stations are 192 -193 degrees. thx for the quick response.
Yes, a metal roof rules out the attic. The antennaweb results for your zip code, adding 150' to antenna height under options to get a more complete list, show the following digital stations:

* yellow - uhf WPXP-DT 67.1 ION LAKE WORTH FL 199° 18.1 36
* yellow - vhf WPEC-DT 12.1 CBS WEST PALM BEACH FL 199° 18.1 13
* yellow - uhf WFGC-DT 49 CTN PALM BEACH FL FCC Ext 223° 6.8 49
* yellow - uhf WFLX-DT 29.1 FOX WEST PALM BEACH FL 205° 19.4 28
* yellow - uhf WPTV-DT 5.1 NBC WEST PALM BEACH FL 200° 18.1 55
* yellow - uhf WHDT-DT 59.1 IND STUART FL 161° 8.8 59
* yellow - uhf WXEL-DT 42.1 PBS WEST PALM BEACH FL 205° 19.4 27
* yellow - uhf WPBF-DT 25.1 ABC WEST PALM BEACH FL 326° 24.9 16
* yellow - uhf WTCE-DT 38.1 TBN FORT PIERCE FL 354° 12.9 38
* yellow - uhf WTVX-DT 34.1 CW FORT PIERCE FL 327° 24.7 50
* violet - uhf WAMI-DT 69.1 TFA HOLLYWOOD FL 189° 59.3 47
* violet - uhf WSCV-DT 51.1 TEL FORT LAUDERDALE FL 189° 59.3 52

The last number on each line is the actual current digital broadcast channel. All of the stations are on UHF, except for WPEC-DT CBS 12 on VHF 13. A check of the FCC data, shows that after the analog shutdown in February, 2009, WPTV-DT NBC 5 will be switching from UHF 55 to VHF 12. The rest stay on UHF.

You have stations in different directions and need to cover UHF and the upper end of upper VHF, channels 12 & 13. The Channel Master 4221 4 Bay bowtie is a good antenna for your location. It has decent gain for VHF 11 to 13. You should be able to find a aim that picks up the major network stations without having to constantly rotate it. With a roof mount, I would recommend you get a rotator so you don't have to climb up and down to tweak the aim. For starters, I would aim the CM 4221 in the direction of the more distant WPBF-DT ABC 25 station and try to get the closer stations off in the sidelobes.

See http://www.hdtvprimer.com/ISSUES/erecting_antenna.html and http://www.hdtvprimer.com/ANTENNAS/cm4221.html.

afiggatt

09-02-07, 11:49 AM

Ok a new update that may shed some light on things for people. I found a pair of old rabbit ears and stuck them behind the TV set. I get every single UHF DTV channel in the area with full signal strength!

At this point I would love to stick something small and inexpensive on the rooftop just because the cables are already strung down into the unit AND into the back bedroom. The bedroom has a few reinforced walls blocking its "view" of the broadcast antennas, so I would like use just the one main antenna and split it to both TV's. Can you split rabbit ears?

Also, does anyone know if the los angeles stations will be changing back to VHF in 2009?
Yes, the upper VHF analog stations in LA will be switching their digital channels to their upper VHF channel in February, 2009 - channels 7, 9, 11, 13. Your zip code places you around 25 miles from the monster antenna farm on Mt. Wilson. Many people in the LA area pick up the digital stations with indoor or small antennas at long range because of the line of sight to the antenna farm at 6000' above sea level.

Simple rabbit ears may do the trick for the upper VHF stations in 2009. I assume your old "rabbit ear" antenna has a 8" loop UHF antenna which is what is picking up the digital stations, not the rabbit ears which are for VHF.
You can combine a VHF and a UHF antenna using a $10 or so combiner. One option is to put up a Channel Master 4220 2 bay bowtie (around $20 on-line, Fry's may carry it) which may have enough gain to get the upper VHF digital stations in 2009. If not, then a short dipole antenna may do the trick for upper VHF. Just leave room on the outdoor mounting mast for a small upper VHF antenna.

Yes, you can split the cable run from the antenna. If you have a long cable run or have to split it too many times, then you may have to add a pre-amp or distribution amp to boost the signal strength. Use RG-6 cable, not RG-59 for the co-axial cable run to the antenna.

revelstone77

09-03-07, 07:23 PM

scoobiesnackarff

09-03-07, 11:38 PM

afiggatt

09-03-07, 11:55 PM

Many thanks to Afiggatt and Videobruce! I am placing the order for the antenna tonight. I am going with a telescoping mast and rotator. Should I add an amplifier or should i wait to see what i get? I want to put a splitter in the attic so I can make a run into the bedroom also.
You are only 18 to 25 miles from the stations. You should not need a pre-amp or distribution amp unless you have a long cable run or split it multiple times. See if you can get all the stations without a pre-amp first. Oh, also be sure to use RG-6 cable for the co-axial cable., not RG-59, and to ground the antenna mast as well as use a grounding block on the co-axial cable.

videobruce

09-04-07, 08:09 AM

revelstone77; I wouldn't even consider a preamp with those two stations less than 8 miles away (even if they are off the back side of the antenna). A amp maybe (indoors out of the weather where you can get at it might be a option, ONLY if it had high input capibility (few do).

Falcon_77

09-04-07, 10:50 AM

afiggatt

09-04-07, 11:31 AM

I just purchased my first HDTV and like many here I would prefer to not pay my subscriber for the HDTV stations. My zip code is 99224 and its a townhome so upstairs and downstairs however there is no balcony nor do I have roof access. My TV is a Philips 1080P 47in ambi light, don't know if that would help figure out what I need but felt I would include it just in case.
You are around 9 miles from most of the digital broadcast stations in Spokane. The antennaweb results for your zip with 200' added to antenna height under options to get a more complete list (edited for just Spokane stations):

* yellow - vhf KXLY-DT 4.1 ABC SPOKANE WA 24° 26.5 13
* yellow - vhf KSPS-DT 7.1 PBS SPOKANE WA 97° 9.6 8
* yellow - uhf KREM-DT 2.1 CBS SPOKANE WA 89° 9.2 20
* yellow - uhf KSKN-DT 22.1 CW SPOKANE WA 89° 9.2 36
* yellow - uhf KHQ-DT 6.1 NBC SPOKANE WA 95° 9.6 15
* yellow - uhf KGPX-DT 34 ION SPOKANE WA 01-08 87° 9.1 34

KSPS-DT PBS 7 is on upper VHF 8, KXLY-DT ABC 4 is on VHF 13, the rest are on UHF. Antennaweb does not show a local Fox station for either analog or digital, although there is a KAYU-DT Fox 28 on UHF 30: http://en.wikipedia.org/wiki/KAYU-TV. The FCC database shows KAYU-DT has a licensed power of 335 kW on UHF 30, so you should be able to get it. There may be an error in the antennaweb database for KAYU.

You need upper VHF and UHF coverage. The KXLY-DT ABC station at 26 miles may be the challenge. For starters, try a cheap VHF rabbit ear and UHF loop table top antenna. It that doesn't work, then maybe an amplified indoor antenna, but stay away from the small UHF only models or models with silly amp numbers like 45 or more dB. Another option is a Channel Master 4220 2 bay bowtie (~ $21 plus shipping online) upstairs in a window or tucked up in a eave somewhere aimed at 30° to 50° NE.

Remember, when you hook up the antenna, you need to do a digital channel scan for it to build a map of the local stations. You will likely have to do multiple scans while tweaking the aim to get all the stations.

revelstone77

09-04-07, 08:55 PM

Once again, my thanks to Afiggatt and Videobruce. I'll be sure to post the outcome after i get everything in place.

TheKaz

09-05-07, 11:40 AM

DECdaze

09-05-07, 12:50 PM

... I KNOW local stations in my area broadcast in HD because I was able to pick up NBC in HDTV with a pair of rabbit ears (my signal strength topped out at 60/100)...
Typically any antenna that can pick up UHF will work well. However, you note:

...I am hoping that I can get these channels in my two story home (with the HDTV on the bottom floor) with an indoor antenna that can sit somewhere near the HDTV I have.
You may need an amplified antenna to boost the signal. You may also need a directional antenna to cut out some reflection. Finally, you may want to consider putting an antenna into your attic to try to reduce interference from other houses, trees and hills. Though a hassle, it may be the best bet to get a better signal.

...Is there a specific make/model of indoor antenna anyone can recommend that can accomplish this or am I out of luck? According to antennaweb.org, I see that I am 30 miles from most towers (I'm not sure how this affects my chances, however).
I use a Terk HDTVa. I hear the Phillips Silver Sensor does a good job.

Here's an article from a local TV station, which has pioneered HDTV OTA:

http://www.wral.com/wral-tv/story/1180264/

Hope that helps.

ceta123

09-05-07, 03:08 PM

Hi,

Try the CS-102 indoor UHF antenna. It has been tested by antenna expert Pete Putman and he has rated high in his article in Home theater magazine.www.kowatec.com

Tobias Ziegler

09-05-07, 05:26 PM

Hi,

Try the CS-102 indoor UHF antenna. It has been tested by antenna expert Pete Putman and he has rated high in his article in Home theater magazine.www.kowatec.com

Okay. I give up. How does a planar design make something omni-directional ?

Uni-directional, maybe. Bi-directional, certainly. Omni-directional?

Falcon_77

09-05-07, 09:04 PM

afiggatt

09-05-07, 09:13 PM

I KNOW local stations in my area broadcast in HD because I was able to pick up NBC in HDTV with a pair of rabbit ears (my signal strength topped out at 60/100).

This was the antenna I tried after buying it for 8 bucks at Walmart:

My problem is that I am specifically looking for CBS and FOX in HDTV more-so than NBC since the NFL season starts this Sunday. I have confirmed that the stations in my area for those networks DO broadcast in HD. My zip code is 29073.

I am hoping that I can get these channels in my two story home (with the HDTV on the bottom floor) with an indoor antenna that can sit somewhere near the HDTV I have.
You are 20 to 30 miles from your local broadcast towers, making an indoor antenna iffy. An indoor antenna might work if you can place it high up or on the 2nd floor, but you nay be prone to dropouts. You may have to consider putting the antenna in the attic or outside on the side of the house.

The antennaweb results for your zip code with an antenna height of 200' to get a more complete list of digital stations:

* yellow - uhf WACH-DT 57.1 FOX COLUMBIA SC 68° 29.0 48
* yellow - uhf WRLK-DT 35.1 PBS COLUMBIA SC 56° 20.9 32
* yellow - vhf WOLO-DT 25.1 ABC COLUMBIA SC 68° 29.0 8
* yellow - uhf WKTC-DT 38.1 MNT SUMTER SC 68° 29.0 39
* yellow - uhf WLTX-DT 19.1 CBS COLUMBIA SC 71° 28.5 17
* yellow - uhf WIS-DT 10.1 NBC COLUMBIA SC 68° 29.7 41
* red - uhf WAGT-DT 30.1 NBC AUGUSTA GA 231° 50.4 30
* red - uhf WRDW-DT 12.1 CBS AUGUSTA GA 232° 50.6 31
* blue - uhf WRJA-DT 28.1 PBS SUMTER SC 99° 54.2 28
* violet - uhf WJBF-DT 6.1 ABC AUGUSTA GA 231° 50.4 42

The last number on each line is the actual broadcast channel. WOLO-DT ABC 25 is on upper VHF 8, the rest are currently on UHF. WIS-DT NBC 10 will be moving in February, 2009 from UHF 41 to it's current analog channel, VHF 10. Your local CW station, WZRB CW 47, is analog only and has to wait to do a digital cut conversion to provide a digital signal (http://en.wikipedia.org/wiki/WZRB). The bottom line is that you need an antenna which can receive upper VHF and UHF. The Kowatec is UHF only, forget it. If you get a Silver Sensor UHF antenna, you need to get a model with VHF rabbit ears such as the Terk HDTVa.

If you insist on indoor, the Radio Shack #15-1892 "mushroom" antenna gets good marks. The Terk HDTVa might work. Another possibility is the Channel Master 4220 2 bay mounted up in the room. I suggest you buy something locally so you can return if it does not get all your locals (likely). See http://www.hdtvprimer.com/ISSUES/erecting_antenna.html for antenna info.

jtbell

09-06-07, 12:25 AM

Another question I have is how can an "omni-directional" antenna have gain? Isn't gain directly proportional to how directional an antenna is?

Think in terms of three dimensions instead of two. Making the antenna's reception pattern more pancake-shaped instead of spherical increases the gain, while still being omnidirectional in the horizontal plane.

holl_ands

09-06-07, 12:59 AM

Another question I have is how can an "omni-directional" antenna have gain? Isn't gain directly proportional to how directional an antenna is?

I also see the "DVB-T antenna" on the unit. I wonder which market it is designed for? I would think a UHF only antenna would be designed for the UK, but they usually call them "aerials."
A true "omni-directional" antenna has 0 dBi gain (relative to isotropic).
If it's a planar antenna, then it likely has nulls in the antenna pattern
along the plane of the panel....so "0-360 degrees (azimuth)"
would have significant losses in some directions.
The Kowatec's spec sez "4.35 dB gain", which is presumably dBi...or 2.2 dB dBd (relative to a dipole).
The latter number tells us that the antenna has more directivity than a dipole in some directions....
at the expense of NULLS in other directions....

A true "omni-directional" antenna can boost the gain by narrowing the response in the
vertical direction...
but this would be contrary to Kowatec's "0-90 degrees (elevation)" spec....
it is possible the Kowatec is including the nulls towards the top and bottom of the panel....

But of course, they never specified how consistent the gain was
in those directions....so let the buyer beware....

FYI: DTV broadcast antennas vertically stack multiple elements to achieve
narrow elevation angles with high "omni-directional" gain:
http://www.dielectric.com/broadcast/brochures/TF-batwing.pdf
But due to it's compact height, I doubt the Kowatec uses vertically stacked elements....

BTW: DVB-T is the European standard for digital television,
which has been adopted by many countries around the world.
The U.S. developed ATSC system was only chosen by a few "close" friends....

The VHF and UHF TV bands tend to be the same around the world,
so many of the same antennas can be used worldwide.
However, the quoted channel number specs typically don't
line up due to the use of 6, 7 and 8 MHz channel spacing....

PA_MainyYak

09-06-07, 08:43 AM

Hey all,

Completely new to the HDTV over-the-air thing. I just picked up a 42 inch Sharp HDTV and currently use DirecTV. Unfortunately, DirecTV does not offer the local channels in my area in HD so I think my only option at this point is to go the antenna route. I KNOW local stations in my area broadcast in HD because I was able to pick up NBC in HDTV with a pair of rabbit ears (my signal strength topped out at 60/100).

This was the antenna I tried after buying it for 8 bucks at Walmart:
http://www.amazon.com/gp/product/B000HKGK8Y/

My problem is that I am specifically looking for CBS and FOX in HDTV more-so than NBC since the NFL season starts this Sunday. I have confirmed that the stations in my area for those networks DO broadcast in HD. My zip code is 29073.

I am hoping that I can get these channels in my two story home (with the HDTV on the bottom floor) with an indoor antenna that can sit somewhere near the HDTV I have.

Is there a specific make/model of indoor antenna anyone can recommend that can accomplish this or am I out of luck? According to antennaweb.org, I see that I am 30 miles from most towers (I'm not sure how this affects my chances, however).

Thanks for all the help!

You can get a very good estimate of signal strength and coordinates by using the Signal Analysis Tool at TVFool.com/ (http://www.tvfool.com/). I checked it using your zip code and it appears an indoor antenna just might work for you. And, all the stations you are interested in appear to be in the same area northeast of your location. This tool allows you to enter your address or lat/long coords for a more precise estimate.
As for antenna recommendations, Antennas Direct (www.antennasdirect.com) is an excellent resource for your reception research.
Good luck.

gbynum

09-06-07, 01:07 PM

Another question I have is how can an "omni-directional" antenna have gain? Isn't gain directly proportional to how directional an antenna is?There are 2 considerations. First is the "reference" to which the gain is referenced. A "point source" radiates in a sphere and is used to make numbers look better (by, I think, 3dB). A vertical dipole covers half a sphere.

Directionality is the path to antenna gain; a pattern looking like a frisbee vs a half grapefruit results. Covering 18 degrees vs 180 might give 10 dB of gain ... Comment here ... most power boat antennas don't waste power up, sending all they can out ... mast antenna's on sailboats can have range reduced almost 10 times when sharply heeled with a typical power boat antenna ... and use height and a vertical dipole, usually.

Falcon_77

09-06-07, 03:35 PM

Ok, thank you for clarifying. It seems I have made the "Khan" mistake of not thinking in 3 dimensions. :o

I suppose Omni-Directional sounds better for marketing. Omni-Planar just doesn't sound as good, does it? :D

Tobias Ziegler

09-06-07, 04:24 PM

I still don't buy it. A frisbee standing on edge with pickup pattern that is omni directional in the horizontal plane? Uh Uh. If the frisbee was horizontal, maybe. But that's not what was pictured.

holl_ands

09-07-07, 09:13 PM

It's probably just a simple loop antenna inside the frame....
Which would resemble the bi-directional (0 dBd) response of a DIPOLE.....

If they've actually managed to obtain additional gain wrt a loop,
it's the result of NULLS in some direction(s)....
which would be contrary to their "omni-directional" claim....
But NULLS can help to reduce multipath....which is why the Silver Sensor works so well...

Don't expect any miracles....it's still a short range antenna like the
UHF loop in a set of rabbit ears....

nybbler

09-09-07, 11:33 AM

A full-wave loop does have some gain over a half-wave dipole... I could believe 2.2dBd. Nulls are in the plane of the antenna.

dgough

09-09-07, 02:45 PM

Hello to all,
I need some advice on what equipment will allow me to receive some OTA HD channels. First off my zip code is 79720 and my location is N32.2804 W101.5147. I currently have no ant. equipment so I am open to any and all suggestions (within normal monetary limits). The channels that I would really like to receive are KWAB-DT, KMLM-DT, KPBT-DT, KOSA-DT, KUPB-DT, KMID-DT, KPEJ-DT, and KWES-DT. From what I have read here I think that KWAB-DT is going to cause me all kinds of problems being so close. If I could reject KWAB-DT and receive KWES-DT instead that would be great because KWAB-DT will not show up on my DTV program guide but KWES-DT does. Antenna height would probably be ~40 feet.
Thanks in advance.
Danny

slightlysalted

09-09-07, 11:16 PM

Well at-least helpless at the time being. I went tvfool.com to check out where the HD channels where in my area. My zip is 47362 by the way. Though I am a little confused. I see that I will be able to pick PBS rather well. But the thing is the others that I want are in yellow. I live in the second story of a house that was converted into a apartment on the top floor where I live. So I don't see me being able to put up an outside antenna. I was reading that with yellow I would need a medium gained antenna. I'm not sure what that is. The only HD antenna I've been told about is the Zenith ZHDTV1. I have a feeling that won't work for me to get the other channels like ABC or CBS. Can anyone help me figure out how I might be able to get those channels over the air, even though I am in an apartment. Thanks for any help. Again my zip code is 47362, if that can help any.

RedStickHam

09-10-07, 11:59 AM

Typically any antenna that can pick up UHF will work well. However, you note:

You may need an amplified antenna to boost the signal. You may also need a directional antenna to cut out some reflection. Finally, you may want to consider putting an antenna into your attic to try to reduce interference from other houses, trees and hills. Though a hassle, it may be the best bet to get a better signal.

I use a Terk HDTVa. I hear the Phillips Silver Sensor does a good job.

Here's an article from a local TV station, which has pioneered HDTV OTA:

http://www.wral.com/wral-tv/story/1180264/

Hope that helps.

I just bought a Terk HDTV antenna and it works very well. It's the Terk that is a look alike for the Silver Sensor. I can pick up all of the local channels in my area(Baton Rouge, LA), including some I couldn't pick up on rabbit ears. I paid $70.00 for it, but I think it was worth it. The antenna is just sitting on to of a bookcase, pointed west towards downtown. They sell the antenna at Best Buy, give is a try!

RedStickHam

ChocoLab

09-11-07, 04:44 PM

Just came across this and thought I would point it out...

Antennacraft appears to have come out with a redesigned 4-bay and a brand new 8-bay. It will be interesting to see how people like them once they try one. Probably not much different than the Winegard or CM bowties, but as we know there will be some differences.

http://www.antennacraft.net/4%20&%208%20Bay.htm

new2hdtv07

09-13-07, 01:38 PM

HELP!
When I moved into my house, the previous owner left their attic antenna. I'm a newbie when it comes to understanding the ins and outs of getting the best antenna reception.

The antenna that is there is somewhat similar style to :
http://www.pctinternational.com/channelmaster/0612/3018.html
Its a uhf/vhf combo antenna. All the VHF elements (the long ones right?) are connected to what looks like an aluminum wire. All of the elements are insulated from the main trunk with some plastic. One of these element pairs inside the uhf "V" has the 300 to 75ohm transformer, but again what appears to be isolated from the uhf elements. Should I be seeing a point to connect to the UHF as well as VHF then use a combiner? Or does the V essentially reflect the UHF bandwidth onto the single VHF element pair inside the "V". I didn't see any other way the "V" would do anything for my signal.

Question 1: Can someone set me straight on this on whether I should get a combiner for my existing antenna or not?

And on a side note a few other questions to sneak in:

Question 2: The previous owner had the antenna sitting on wood in the rafters, if the element is touching even wood, would that impact the signal integrity? Do I need to install a mast in my attic for the antenna?

Question 3: I have a lot of devices in my house to hook up to the antenna. I have a home theater PC that records shows OTA, so that is up to 5 connections right there (3 analog, now 2 digital). I have 2 hdtvs and 2 analog TVs, and a couple AV amps that have a coax input for FM. All together that makes for about 10 devices. My antenna is approximately 50 feet from my distribution center. What would be the recommended distribution solution? Pre-amp and bunch of passive splitters? Is any old splitter addiquit, or do you have product recomendations? Right now I don't have a pre-amp, just a powered 4-way distribution amp that I split as needed with passive splitters.

Question 4: Are there any specific grounding schemes to use or ways to avoid ground interference or ground loops?

Thanks in advance for any help you can offer in making my signal quality the best it can be.
Justin

nybbler

09-13-07, 03:39 PM

The VHF part of the antenna is called a "Log periodic" antenna. This type of antenna has its elements connected together. The UHF part of antenna is a combination Yagi/Corner Reflector. In that sort of the antenna, the elements are not connected; they work by modifying the field in the air around the antenna. So the lack of connection between UHF elements is expected. The combiner should be integral to the antenna, but I believe different manufacturers implement it in different ways.

Ideally, the antenna shouldn't be touching anything. But then, ideally, it shouldn't be in an attic. If the wood is just touching the boom (what you call the "main trunk"), it's probably having little effect. If it's touching or in between the active elements, it could be more troublesome.

You should set up your system with a single device first, preferably one close to the antenna. Then try a single device at the distribution point. Then start worrying about amps.

Attic antennas don't need to be grounded, so they shouldn't have any effect on ground loops.

new2hdtv07

09-14-07, 11:11 AM

The combiner should be integral to the antenna, but I believe different manufacturers implement it in different ways.

Ok, so my vhf elements are all connected to the boom, but my uhf elements are insulated from the boom. There are NO boxes that connect them, so it is reasonable that the uhf part of the antenna is "combining" the signal by increasing the gain of the field of uhf frequencies around the first vhf element that is connected to my transformer and coax.

MEJHarrison

09-14-07, 02:45 PM

I've been asking about my problems over in the Portland, OR OTA thread, but thought I might have better luck with more eyes looking at the issue. The problem is I can't get decent reception with an indoor antenna even though everyone tells me I should be just fine. Here's the details.

I'm roughly 6 miles from the towers. They're due east from my house (maybe just a hair NE) and plainly visible from outside or from a second story window. There are no hills or large buildings (other than the neighbor's 2 story house) nearby. No really large trees.

My antenna is sitting behind my TV in the SE corner of the house. Being so close, I started with a cheap $10 antenna. I got a few stations very well (7-10 bars). A few I can't really get in at all (0-2 bars). Maybe a little if I fool with the antenna, but they go in and out. And the rest are somewhere in the middle. So I upgraded to a $40 powered antenna. Very little change. So I got one of those Silver Sensor antennas. That gave me the best results, but the overall results are about the same as the $10 antenna. It's just a little more reliable.

Last night I decided to try an experiment. I moved the antenna outside on our patio (about a 5' move to the south). From outside, I was getting about 8-10 bars on every single channel.

Now everyone tells me any old cheap pair of rabbit ears should work great for me given that I'm so close to the broadcasting towers. Yet I can't seem to get decent results no matter what I try. I've tried pointing the antenna, moving it to other parts of the room, lifting it higher (it's about 4' off the ground at this point), holding it up at the ceiling level. But no matter what I do, the reception barely changes. Only moving it outside did the trick.

So if anyone has any great ideas, I'd love to hear them. I'm upgrading my D* service on Monday and will finally have the ability to record OTA HD. So I'd love to get a stable setup. Unless someone can pinpoint my problem, I'm just going to have the installer run a third line from the dish (mounted outside on our patio roof) and I'll mount the antenna out there (under the patio roof obviously to keep it out of the weather). It would be nice to keep the setup simple, but I don't know what else to do at this point.

If it helps, my location is Beaverton, OR 97006. I can provide the exact address if that helps.

Falcon_77

09-14-07, 03:45 PM

Do your walls have stucco? Can you aim the antenna out of a window?

It sounds like it could be a multipath problem within the house itself. Perhaps an attenuator is needed within the house to cut down on noise/interference.

I also see that you have a digital station on physical channel 4. That is probably going to be tough considering what I've heard on VHF-LO DTV stations (see Chicago WBBM).

MEJHarrison

09-14-07, 05:23 PM

borekk

09-15-07, 01:30 AM

Quick question regarding receiving OTA HD signals. I'm going to blow my ignorance on this subject completely wide open (and I know this is a simple question), so please bear with me.

I just picked up a 50" Samsung plasma (HPT5054...on the advice of this forum, thanks!) today. I have never before tonight owned a device that can get HD channels. However, I'm unable to "see" any HD channels.

I do not have any type of HD antenna or anything of the like plugged in. I simply have the coax from my existing cable service plugged into the TV and those channels are coming in ok.

From the reading I've done here (and getting confused in a big hurry), it looks like all I need to do is purchase some kind of an antenna and hook it up to the TV in order to have it 'scan' to find the channels, is that correct? Is there a difference between a regular antenna and an HD antenna? Should I be looking for something specific when I go out tomorrow morning to buy one?

I hit up that antennaweb.org site and all of my local HD channels that I want to get are within 9 miles and yellow in color...evidently that means that they are the easiest to get?

Sorry if these are extremely base-line questions. I've read through several threads and it's obvious to me that I am light-years behind the curve of where I need to be to understand this comfortably right now. If anyone could offer me any advice, I would appreciate it.

Thanks in advance.

DECdaze

09-15-07, 04:51 AM

Quick question regarding receiving OTA HD signals. I'm going to blow my ignorance on this subject completely wide open (and I know this is a simple question), so please bear with me.
LOL! Been there, done that, got the T-Shirt, happy to pass on a few hints and tips, since you clearly are attempting to learn.

I just picked up a 50" Samsung plasma (HPT5054...on the advice of this forum, thanks!) today. I have never before tonight owned a device that can get HD channels. However, I'm unable to "see" any HD channels.
Yup. One of the big box stores has an advertisement, which points out you need an HDTV, an HD source, their installation team, a Swiss bank account number ... :)

I do not have any type of HD antenna or anything of the like plugged in. I simply have the coax from my existing cable service plugged into the TV and those channels are coming in ok.
Sounds as if you are like me, you have standard (analog) cable TV service. You could purchase digital TV service from your cable company. They would then give you a set top box. Additionally - for a mere second mortgage - you can get an HD set top box, which gives you several HD channels. What they don't tell you is that with only a few exceptions those are available free as over the air (OTA) digital TV broadcasts.

From the reading I've done here (and getting confused in a big hurry), it looks like all I need to do is purchase some kind of an antenna and hook it up to the TV in order to have it 'scan' to find the channels, is that correct? Is there a difference between a regular antenna and an HD antenna? Should I be looking for something specific when I go out tomorrow morning to buy one?
There is no difference between an antenna that can receiver digital TV OTA broadcasts and one that receives analog broadcasts. That being said, most of the digital TV broadcasts are in the UHF band. We are in a transition period, when the broadcasters are transmitting both analog and digital signals. In 2009 the analog broadcasts will end. When that happens, some stations will change their final broadcast station. You can check those in your area. However, some stations (especially stations with the lower VHF band channels) will stay with UHF band channels:

http://hraunfoss.fcc.gov/edocs_public/attachmatch/DA-06-1082A2.pdf

So, yes. You use the following URLs to search for stations in your area:

http://www.antennaweb.org/
http://www.tvfool.com/

Are they all UHF (channels 14+) or are some VHF (channels 2-13)? If they are UHF, then you don't need to worry about the VHF frequencies and you can focus on just a UHF antenna.

I hit up that antennaweb.org site and all of my local HD channels that I want to get are within 9 miles and yellow in color...evidently that means that they are the easiest to get?
Bingo. You can probably use a small indoor antenna to receive the UHF stations. Some of the antenna are omni-directional. The problem with that is that the signal can be reflected off nearby hills and buildings. On analog stations this can cause 'ghosts'. On digital stations it can cause enough of a drop in the signal strength to cause pixelation and sound loss.

So, many of the UHF antennas are directional. Some are amplified. Some are not. Some are the old classic circular loop and rabbit ear format. Some look like a modern sculpture.

Some are amplified many are not. Some HDTVs include a Low Noise Amplification circuit. With the stations only 9 miles away, you probably won't need an antenna with an amplifier.

Now, how well an indoor antenna will do will depend on several factors. Do you have a single or multi story house. Where is the antenna in relation to that? On the bottom story, the upper story may create more interference than if the antenna is on the upper story. Near a lot of trees? That can create a lot of interference. In a valley instead of a hill? You can get lots of multi-path reflection.

So, it's not just as simple as pick up 'x' antenna and away you go. However, that might be all you need. I wanted to see how well it work work, so I picked up a directional / amplified indoor antenna. It does pretty well. Well enough to convince me to try an attic mounted antenna to overcome some signal issues.

Sorry if these are extremely base-line questions. I've read through several threads and it's obvious to me that I am light-years behind the curve of where I need to be to understand this comfortably right now. If anyone could offer me any advice, I would appreciate it.
For further reading you might also want to try:

http://www.hdtvprimer.com/

barbie845

09-15-07, 06:44 AM

I do not have any type of HD antenna or anything of the like plugged in. I simply have the coax from my existing cable service plugged into the TV and those channels are coming in ok.

From the reading I've done here (and getting confused in a big hurry), it looks like all I need to do is purchase some kind of an antenna and hook it up to the TV in order to have it 'scan' to find the channels, is that correct? Is there a difference between a regular antenna and an HD antenna?

Call your cable company. Tell them you got a brand new toy and you need a HD box. If they want to charge you a billion $'s for it tell them you'll go elsewhere. D* is just about giving HD boxes away now.

As for an antenna if all your locals are in the same area/direction I recommend getting a inexpensive UHF directional antenna and if you have an attic, stick it up there somewhere and point it towards your locals. Something like this from Radio Shack should work fine for you...

http://www.radioshack.com/product/index.jsp?parentPage=family&summary=summary&cp=2032057.2032187.2032189.2032205&productId=2253765&accessories=accessories&techSpecs=techSpecs&currentTab=custRatings&fbn=Type%2FHDTV&custRatings=custRatings&f=PAD%2FProduct+Type%2FHDTV&features=features&fbc=1&support=support&tab=summary

Falcon_77

09-15-07, 11:43 AM

No stucco on the walls. It's a regular, plain-jane house from the early 90's with vinyl siding. I can put the antenna in the window on the south side (towers are on the east side) and give that a shot. But we always keep those blinds (aluminum) shut and the curtains closed since it's directly next to the TV and the sun shines on the screen otherwise. I'll give that a shot tonight.

Aluminum blinds? Have you tried reception with those pulled up? These are probably acting as screens and reflectors, which can hamper the signals.

Can you run a cable to another room with a view to the East, since it appears that the room in question doesn't have one?

So, where does one pick up an attenuator? I searched online at Radio Shack and Fry's since both are real close, but neither found anything searching for "attenuator". And would there be any difference having it hooked up to my TV (Samsung HL-S5687 DLP) today and hooking it up to the DirecTV HR20 I'll be getting on Monday? I thought I heard something about some receivers needing a stronger signal.

The easiest attenuators to find are splitters. Even a 2-way split will cut the signal by 3.5-4dB (just over half). If you have any 3 or 4 way splits, they will decrease the signal further. I have some attenuators courtesy of the cable company, but perhaps Fry's would have them as well. I will check my local store today.

My brother used to live in Beaverton, but we didn't know about DTV in those days ('02). I still remember the phrase, "Drive Slow in LO," from my trip.

Edit: My local Fry's didn't have any attenuators, so they appear to be harder to find than I thought. The splitter approach will probably have to do for now.

chnky18

09-16-07, 03:27 PM

barbie845

09-16-07, 04:04 PM

noob to all this but done my searching and reading so just want to check which antenna would be best...all my stations but 1 are in the green on tvfool.com. They come from the southside of my house where there is a window right next to the tv. So from reading an inside antenna will take care of me. Being in dfw, I need uhf/vhf. With that said, any recommendations on which antenna to get? Also, do i just place the antenna in the room, by the window, hang it in front of the window, keep the blinds up or is leaving them down fine? or does it matter? Then i run coax from ant. to "air" on my tv?

DO i need one with an amplifier?

good or no?
http://www.circuitcity.com/ssm/Philips-Indoor-HDTV-Antenna-PHDTV3/sem/rpsm/oid/158313/catOid/-15607/rpem/ccd/productDetail.do
http://www.circuitcity.com/ssm/Philips-Indoor-Antenna-MANT510/sem/rpsm/oid/158312/catOid/-15607/rpem/ccd/productDetail.do
http://www.circuitcity.com/ssm/Philips-Indoor-Outdoor-HDTV-Antenna-MANT950/sem/rpsm/oid/158307/catOid/-15607/rpem/ccd/productDetail.do

It all matters, blinds, window or no window, etc. But if you're going to buy your antenna from CC buy the least expensive one, try it, see the results, and if it doesn't work bring the antenna back and get the next best/more expensive..

There's NO hard and fast rules with these OTA antennas and signals. I live 65 miles from Albany NY and pick up every station but 1. I've read where other people live 25 miles from the transmitters and pick up nothing.

It's trial and error. But since it sounds like you live close to these stations, start cheap, point the antenna you get out your window, preferably without the blinds( they may cause signal degradation), and plug it into 'air' on your box or TV.

Grayson73

09-16-07, 04:59 PM

Can someone recommend me some indoor antennas to try, preferably something I can buy and return B&M (Best buy, Circuit City, Sears, Radio Shack, etc)?

yellow - uhf WUSA-DT 9.1 CBS WASHINGTON DC 152° 8.9 34
yellow - uhf WTTG-DT 5.1 FOX WASHINGTON DC 151° 8.5 36
yellow - uhf WHUT-DT 33 PBS WASHINGTON DC TBD 152° 8.9 33
yellow - uhf WJLA-DT 7.1 ABC WASHINGTON DC 152° 8.9 39
green - uhf WDCA-DT 20.1 MNT WASHINGTON DC 152° 8.9 35
green - uhf WPXW-DT 66.1 ION MANASSAS VA 214° 19.8 43
green - uhf WNVC-DT 57.1 IND FAIRFAX VA 200° 12.4 57
red - uhf WDCW-DT 50.1 CW WASHINGTON DC 136° 10.4 51
red - uhf WFPT-DT 62.1 PBS FREDERICK MD 345° 16.0 28
blue - uhf WFDC-DT 14.1 TFA ARLINGTON VA 155° 9.4 15
blue - uhf WRC-DT 4.1 NBC WASHINGTON DC 155° 9.4 48
violet - uhf WETA-DT 26.1 PBS WASHINGTON DC 176° 11.3 27

gbynum

09-16-07, 09:41 PM

I simply have the coax from my existing cable service plugged into the TV and those channels are coming in ok.

Nobody's lied much <g>, but they haven't mentioned how to get the "in-the-clear" channels that PROBABLY are there.

In your configuration, you can have the jack either look at ATSC-8VSB or at QAM ... this is called terrestrial (antenna) or cable in many sets. Select "cable" then let it scan ... will take about an hour ... and odds are good you will have "some" channels. It may find the encrypted ones but not have any picture. It may find the music. It may find others PPV watching of the moment.

Good hunting!

Falcon_77

09-17-07, 12:48 AM

I picked up a Channel Master Advantage 3020 today. The store (Fry's) also had a 3016, and a 3671, but they wanted far too much for the 3671 as well as the 2 and 4 bay bow-ties ($50 each). I already have a CM4228, so the new one is a test antenna of sorts.

I was surprised by how dirty and greasy the 3020 was. I had to wash my hands about a dozen times while putting it together and aluminum shavings were falling all over the place. This was quite a shock after the 4228, which being a steel antenna, had none of these problems.

As expected, the 3020 is quite large. Too large to put the VHF and UHF portions together in my family room. :D

Incidentally, I got this antenna to try my hand at getting San Diego stations w/o disturbing my 4228. However, it's VHF-HI performance isn't that great. I measured all the dipoles and found that none of them appear to be tuned for VHF-HI.

These are the measurements I took:

UHF:

6" Directors: 19 - these seem quite short... am I right that these are tuned for ~936 MHz?
17" Corner Reflectors: 4 top, 4 bottom (330 MHz)
14" Corner Reflectors: 3 top, 3 bottom (400 MHz)
11.5" Driven Element: 1 (488 MHz)

VHF:

55" Reflectors: 4
29", 32",38", 41", 47", & 53" LPDA elements: 2 each (53-96 MHz)

The VHF elements are swept forward. This seems to be counterproductive. They can be left more or less straight, which I may try.

Since it doesn't have any VHF-HI length dipoles, what would the effect be if I cut down the elements to form a VHF-HI LPDA instead? Has anyone tried this?

Does anyone know when Channel Master, Winegard and the like will start stocking 7-51 specific antennas. Especially on the high end, cutting UHF directors for channel 69 (or higher?) doesn't seem like a good idea anymore.

As for performance, both the UHF and VHF portions worked well enough separately, but I don't have enough room to combine them (no outside option here).

I also ended up ordering a Winegard YA1713, which I will be very curious to test. I wonder if it will be as greasy...

tyromark

09-17-07, 01:23 PM

MeowMeow

09-17-07, 01:45 PM

I've wondered about cutting the length of VHF-low elements on an older combo antenna many of us may have laying around. If the measurements were correct and cutting/crimping precise, is there any reason NOT to try this when we're trying to receive frequencies that may be no lower than VHF channels 7 (in my market, Ch. 10, actually) and up?

Hmm... I hadn't thought about that. It's an interesting idea. Unfortunately for me, none of my locals will be VHF until Feb 2009. On the upside, I have several antennas to test with.

Audioman1

09-17-07, 05:29 PM

I have the channel master 3020 and I can pick up stations 75 miles away when I turn the rotor that way, I have it about 40 feet in the air tho.

Nitewatchman

09-17-07, 06:48 PM

wmbjr

09-17-07, 06:55 PM

I live in zip code 29063. I have most of the main channels in one general direction. However, my ABC channel is VHF 8 and another will be moving to VHF 10 in 2009. Will a basic Channelmaster 4 bowtie such as the 4021 work to pick up all channels or will I need a separate UHF and VHF antenna? Thanks.

Neil L

09-17-07, 08:00 PM

TV Trey

09-17-07, 08:19 PM

I've wondered about cutting the length of VHF-low elements on an older combo antenna many of us may have laying around. If the measurements were correct and cutting/crimping precise, is there any reason NOT to try this when we're trying to receive frequencies that may be no lower than VHF channels 7 (in my market, Ch. 10, actually) and up?

Combination VHF/UHF antennas like the CM 3020 have the VHF elements cut to cover frequencies from 54 to 88 Mhz. Due to odd harmonics, these same elements will also work well for frequencies in the 164 to 264Mhz. Changing the length of the elements would not be advised. The elements are swept forward to reduce beam splitting.

wmbjr

09-17-07, 08:33 PM

wmbjr, a 4-bay bow-tie might work OK, but the Channelmaster 8-bay is much stronger on hi-vhf. My CM 4228 picks up channels 8 and 9 from about 30 miles just fine. I also get analog channels 10 and 13 very well from about 75 miles away.

My main concern is the fact I will likely end up with the antenna in my attic instead of outside. I am not sure I will have room for the 4228. I will certainly consider it though. If I end up going the smaller antenna route, any combinations of UHF and VHF that would work in an attic? Thanks.

Nitewatchman

09-17-07, 08:35 PM

Combination VHF/UHF antennas like the CM 3020 have the VHF elements cut to cover frequencies from 54 to 88 Mhz. Due to odd harmonics, these same elements will also work well for frequencies in the 164 to 264Mhz. Changing the length of the elements would not be advised. The elements are swept forward to reduce beam splitting.

From 2 posts above that :

As for the reason VHF elements on antennas like CM3020 are "swept forward", and "don't" have elements of ~1/2 wavelength on hi~VHF ... it involves a harmonic relationship between low VHF(and thus the lo-VHF "elements" on the antenna) and hi~VHF ... In other words, the "swept forward" low VHF elements are "used" for Hi-VHF reception as well ...

This is explained in more detail and accuracy here, specifically beginning in the 4th paragraph of the "comparision shopping" section(you'll probably want to read the rest of the article as well, however) :

http://www.tvtechnology.com/features/On-RF/antennas.shtml

Anyone want to find a 3rd way to say this ? ;)

edit: It probably wouldn't be a bad idea, because I've seen posts in local threads of people "getting rid" of the lo-VHF elements of their VHF/UHF combo+expecting them to still work well on HI-VHF ...

Falcon_77

09-17-07, 10:02 PM

So, it appears the Crossfire series is far different from the Advantage series. I can clearly see the VHF-HI elements on the pictures.

What purpose do the reflectors serve on the back of the Advantage? Behind a Yagi driven element is one thing, but behind an LPDA?

Well, I won't make any changes to it yet. I need to test it higher up to see how it compares with my ground level reception. If I put it in the attic, it might be even more fun than getting the 4228 up there.

Jigga Moog

09-17-07, 10:30 PM

My zip is 44142. I would like to put it in the attic of my ranch I have no obstructions. DB8 or 4228 or something else. I am undecided.

* yellow - vhf WKYC-DT 3.1 NBC CLEVELAND OH 109° 5.1 2
* yellow - vhf WOIO-DT 19.1 CBS SHAKER HEIGHTS OH 108° 4.8 10
* yellow - uhf WUAB-DT 43.1 MNT LORAIN OH 121° 3.7 28
* yellow - uhf WQHS-DT 61.1 UNI Cleveland OH 113° 4.5 34
* yellow - uhf WVIZ-DT 25.1 PBS CLEVELAND OH 158° 4.7 26
* yellow - uhf WBNX-DT 55.1 CW AKRON OH 111° 4.8 30
* yellow - uhf WJW-DT 8.1 FOX CLEVELAND OH 133° 4.4 31
* yellow - uhf WEWS-DT 5.1 ABC CLEVELAND OH 125° 4.0 15
* blue - uhf WEAO-DT 50.1 PBS AKRON OH 168° 23.3 50

afiggatt

09-17-07, 11:03 PM

My zip is 44142. I would like to put it in the attic of my ranch I have no obstructions. DB8 or 4228 or something else. I am undecided.

* yellow - vhf WKYC-DT 3.1 NBC CLEVELAND OH 109° 5.1 2
You are only 4 to 5 miles from the broadcast towers. Have you tried an indoor antenna? WKYC-DT NBC 3 is on VHF 2, so you need a VHF antenna to with a UHF antenna. I would start with a basic table top VHF rabbit ears and UHF loop antenna high up in the room or near a window if you have not tried an antenna yet. Extend the rabbit ears all the way for the long wavelength of VHF 2.

Jigga Moog

09-18-07, 08:25 AM

You are only 4 to 5 miles from the broadcast towers. Have you tried an indoor antenna? WKYC-DT NBC 3 is on VHF 2, so you need a VHF antenna to with a UHF antenna. I would start with a basic table top VHF rabbit ears and UHF loop antenna high up in the room or near a window if you have not tried an antenna yet. Extend the rabbit ears all the way for the long wavelength of VHF 2.

I have literally 30 year(the guy I bought the house from told me he put it up there) antenna in my attic and it does not get 25,50,or 55 so I was going to upgrade which I really don't mind doing. My TV is in the basement so I wanted to stay away from rabbit ears. What about that new ubh 22(I think that's the model #)that was mentioned a while back in this thread.

DECdaze

09-18-07, 08:57 AM

I have literally 30 year(the guy I bought the house from told me he put it up there) antenna in my attic and it does not get 25,50,or 55 so I was going to upgrade which I really don't mind doing. My TV is in the basement so I wanted to stay away from rabbit ears. What about that new ubh 22(I think that's the model #)that was mentioned a while back in this thread.
Since you already have the wiring in place, you may want to add a UHF antenna in attic and join them. Perhaps something like a Channel Master 4220 antenna and a Channel Master 0549 VHF/UHF antenna joiner.

Of course, I also bet the coax has not been replaced in those 30 years. That could result in signal loss as well. Those cables don't last forever. So, that might also need work at the same time.

afiggatt

09-18-07, 10:12 AM

I have literally 30 year(the guy I bought the house from told me he put it up there) antenna in my attic and it does not get 25,50,or 55 so I was going to upgrade which I really don't mind doing. My TV is in the basement so I wanted to stay away from rabbit ears. What about that new ubh 22(I think that's the model #)that was mentioned a while back in this thread.
Ok, the basement could be an issue for an indoor antenna. The old antenna may be fine, provided that it has a decent UHF antenna on it. The problem may be in the cable which at that old, may be twinlead or RG-59 coaxial. Co-axial cable does age and crack. If the cable is at all accessible, you should replace it with RG-6. Short of that, check the connection points for oxidization or corrosion.

If you replace the antenna, you need to get a full VHF/UHF short to medium range antenna to get WKYC-DT NBC 3 on VHF 2. BTW, WKYC-DT NBC 3 will be switching it's digital channel to UHF 17 in 2009 after the analog shutdown. The Winegard HD7080P or one of several shorter range Channel Master VHF/UHF antennas should do the job.

Jigga Moog

09-18-07, 11:31 AM

Ok, the basement could be an issue for an indoor antenna. The old antenna may be fine, provided that it has a decent UHF antenna on it. The problem may be in the cable which at that old, may be twinlead or RG-59 coaxial. Co-axial cable does age and crack. If the cable is at all accessible, you should replace it with RG-6. Short of that, check the connection points for oxidization or corrosion.

If you replace the antenna, you need to get a full VHF/UHF short to medium range antenna to get WKYC-DT NBC 3 on VHF 2. BTW, WKYC-DT NBC 3 will be switching it's digital channel to UHF 17 in 2009 after the analog shutdown. The Winegard HD7080P or one of several shorter range Channel Master VHF/UHF antennas should do the job.

How about the Winegard HD7084P would it be overkill. Is overkill such a thing in the antenna world? I plan on replacing the cable,about 50-75 feet,with RG6 quad. Do I need a pre-amp? I don't mind spending a little extra money if it helps me in the long run.

DECdaze

09-18-07, 01:39 PM

How about the Winegard HD7084P would it be overkill. Is overkill such a thing in the antenna world? I plan on replacing the cable,about 50-75 feet,with RG6 quad. Do I need a pre-amp? I don't mind spending a little extra money if it helps me in the long run.
Within 4 or 5 miles of the broadcast tower, I doubt you need the 84. The 80 should suffice. Besides the 84 is 11 foot in length! The 80 is only 7.5 foot. If the smaller antenna suffices you'll have less problems with it. (Larger = heavier = requires more bracing = harder to rotate if needed = too much of a good thing).

As to the preamp, well 100' of coax at upper UHF frequencies causes about 6dB signal loss. Not much if you are 4 to 5 miles away. The following URL helps you get a sense of the signal strength in your area:

http://www.tvfool.com/

Enter your address and check the strength (rx dBm). In the green range a small antenna - even with 100' of coax cable - should suffice without a preamplifier. By the way, I used this to compare the signal strengths in other areas around our metropolitan area. I plug in different ZIP codes to get a sense of how much distance impacts the signal strength.

By the way, from my reading, it appears old cable causes more signal loss in the UHF band than the VHF bands, so just the cable replacement can help. But 30 years old probably also suggests an antenna replacement and check of the mount while you are replacing the antenna.

Some good reading on this can be found at:

http://www.hdtvprimer.com/

Just my 2 cents.

holl_ands

09-21-07, 01:59 AM

Would imagine The spacing between the elements, as well as specifics involving different element lengths(for reflectors/directors/etc) is as important(or more) for broadband receive antenna design as it is for single frequency Yagi's.

In other words, I'm not so sure you can just "cut down" the elements of a broadband VHF(or VHF/UHF antenna) to be ~1/2 wavelength dipole on hi-VHF and expect it to perform well on Hi-VHF.

As for the reason VHF elements on antennas like CM3020 are "swept forward", and "don't" have elements of ~1/2 wavelength on hi~VHF ... it involves a harmonic relationship between low VHF(and thus the lo-VHF "elements" on the antenna) and hi~VHF ... In other words, the "swept forward" low VHF elements are "used" for Hi-VHF reception as well ...

This is explained in more detail and accuracy here, specifically beginning in the 4th paragraph of the "comparision shopping" section(you'll probably want to read the rest of the article as well, however) :

http://www.tvtechnology.com/features/On-RF/antennas.shtml
A little history: Back in the late 50's/early 60's, researchers at U. of Illinois (and elsewhere)
developed numerical calculation methods for a variety of log periodic antenna structures:
http://wwwold.ece.uiuc.edu/alumni/su04/antennas.html

This included the common LPDA, the swept forward LPVA (Log Periodic Vee Array),
the Triangular Trapezoid Log Periodic Array and the Spiral Log Periodic:
http://www.hdtvprimer.com/ANTENNAS/glossaryG.html#logperiodic
The LPLA (Log Periodic Loop Array) came later:
http://scholar.lib.vt.edu/theses/available/etd-080699-180221/unrestricted/ETD_LPLA.pdf

Once these numerical techniques were developed, it was possible to
model arbitrary arrangements of metallic structures.
Which led to complicated multi-band antenna structures, such as
a mixture of element lengths throughout the antenna, such as
CM Crossfire and some WG series:
http://www.winegard.com/offair/pdf/HD7084P.pdf
and LPDAs with Yagi-type reflector and director elements.

If you take the time to learn the NEC modeling program, you could
determine what happens when you shorten antenna elements.
However, bear in mind that you should ALSO be changing the
spacing between elements as well.
Simply hacking off elements can cause very strange results because
each element affects all of the other elements due to mutual coupling.
You might end up with deep nulls where you least expect them....

The pros perform thousands of trial and error runs (check out the
crazy antenna in Fig2):
http://alglobus.net/NASAwork/papers/Space2006Antenna.pdf
http://ic.arc.nasa.gov/people/jlohn/Papers/ices2001.pdf
http://www.stormingmedia.us/28/2807/A280744.html

Some example NEC models for LPDA/LPVA's:
http://www.cebik.com/lpda/teler.html
Lots of other examples if you follow the links at the bottom....

tyromark

09-21-07, 07:52 AM

=ahem= (clears throat) Yes, well, I see there ARE some good reasons for not cutting down the VHF-low elements on an old antenna. Thanks.

DECdaze

09-21-07, 08:23 AM

... The pros perform thousands of trial and error runs (check out the crazy antenna in Fig2):
http://alglobus.net/NASAwork/papers/Space2006Antenna.pdf
Wow! They look more like someone spending a few minutes bending a paperclip than the result of hundreds or thousands of hours trying to optimize an antenna for weight and signal reccption.

By the way, this is a great post. Informative at lots of different levels. The math is beyond me, but you include sources that allowed us to learn without being completely overwhelmed. Thanks for taking the time and effort!

Rick0725

09-21-07, 08:28 AM

How about the Winegard HD7084P would it be overkill. Is overkill such a thing in the antenna world? I plan on replacing the cable,about 50-75 feet,with RG6 quad. Do I need a pre-amp? I don't mind spending a little extra money if it helps me in the long run.

im my opinion there is no such thing as overkill unless you are not using an appropriate amplifier close up. If you want the best and it fits I have no problem with the hd7084p. I am 12-18 miles from towers and I use an hd8200p with no problems. The pictures are pristine and if I want to play and receive distant channels I have the flexibility.

To lessen overload potential I use an hdp269 preamp and only amplify the uhf and pass vhf/fm. If that interests you I can send you a diagram. I use the hdp 269 winegard preamp as a distribution amp mounted indoors at the distribution point. I get overload with the preamp mounted at antenna. The hdp269 is low noise and has only 12db gainwith much better specs than most distribution amps and a good match to give the higher frequencies a boost around the home. The vhf does not need to be amplified and I use the antenna for fm which I enjoy when I want to listen to music outside on the deck.

The hd7080p is ok but the hd7082P is a better matched antenna spec wise, only 18" longer, and only a few dollars more.

In regards to rg 6 coax. I have gone with tri shield cable with problem installs where signal ingress issues are suspect...no more quadshield and feel trishield works better. I use standard high quality rg6 otherwise since I have found that quad is not really necessary and requires special connectors. the standard rg6 connector works on trishield.

holl_ands

09-21-07, 03:45 PM

Finally found Cebik's NEC modeling article re LPDA ("log-cell") with reflector and director...
http://www.cebik.com/qex/lcy.pdf
http://www.cebik.com/logcell/logc.html
The best of both designs: the much wider frequency coverage of an LPDA
with the higher gain from the quasi-Yagi reflector and director elements.

He includes an analysis of the LPVA ("Vee") antenna:
http://www.cebik.com/logcell/logc4.html
For the chosen hybrid Log-cell Yagi design, Cebik didn't see any
advantage for the "Vee" over a straight Log-Cell Yagi.
But he didn't compare a pure LPDA to a pure LPVA.....

Note that he's only covering the narrow 10-meter amateur radio band,
so don't expect these high gains for an extremely wideband TV antenna.

Nitewatchman

09-21-07, 05:43 PM

holl_ands,

Thanks for the providing the detailed info+Links .... As others have noted, Excellent post, and fun reading.

Note that he's only covering the narrow 10-meter amateur radio band,
so don't expect these high gains for an extremely wideband TV antenna.

Perhaps however a ~6 element Hi-VHF(174~216MHZ) LPDA might offer "good enough" performance for many folks, while being significantly smaller than a winegard YA-1713 or the "homebrew" Hi-VHF LPDA mentioned farther below ...

It seems to no longer be on Winegard site, but Starkelectronics still shows this Winegard 6 element, (50" boom - maximum width 35") ch 7-13, what they call "broadband yagi"-* antenna on their site (Note : for reasons discussed before, personally I might view the winegard spec sheet info included at this link, especially perhaps the gain figures provided with a bit of a "grain of salt")

http://www.starkelectronic.com/wya6713.htm

* - Note - That's what it says, I didn't call it that ... I think many of these broadband TV receive antennas are probably usually more accurately defined as something that could be reffered to as "hybrid" design rather than something that is "strictly" say, a LPDA or yagi ....

Perhaps something along those lines may work for what falcon77 is looking for in a "smaller" VHF-Hi antenna(obvioulsly, it won't offer the gain/directivity of the YA1713 or the "homebrew" hi-VHF LPDA mentioned below).

For those who missed it earlier in this thread, Those interested in designs and info on a homebrew Hi-VHF LPDA receive antenna(12 or 13 elements, 92" boom length --for ch 7-13, 174~216MHZ) May want to see this post earlier in this thread by Calavaras + the info on it in URL provided in his post(also included below) :

http://www.avsforum.com/avs-vb/showpost.php?p=11370552&postcount=6130

http://www.aa6g.org/Lp/lp.html

.... However, bear in mind that you should ALSO be changing the
spacing between elements as well.....

..... Simply hacking off elements can cause very strange results because
each element affects all of the other elements due to mutual coupling.
You might end up with deep nulls where you least expect them....

Yep, Very well said ...

Also, along the lines of DECdaze's post -- Your excellent post+the info at links you provided should hopefully illuminate a bit the complex issues involved regarding designing such broadband receive antennas(especially relatively "small" ones), and involving the compromises usually necessary to design a product which will not only make it to market, but also achieve some success there ....

Given the situation regarding Lo-VHF and as it looks right now : Few full service DTV broadcasters in U.S. using it now, or for after analog shut off(unless we get a lot of "new" full service or potentially LP stations after analog shut off) : I do wonder if we will see more Hi-VHF+UHF antenna designs such as this one, discussed previously either in this or another antenna related thread :

http://www.antennacraft.net/HBU22.htm

Given that I expect for many folks there is a "lot to be said" for only needing one "all in one" antenna for TV reception, where only hi-VHF+UHF tv reception is required or desired, perhaps it would be good to see more hi VHF+UHF combo antenna designs like HBU22 available for folks ...

But, I think at least currently the best option for those who don't need/want decent lo-VHF or FM reception or the generally "larger" antennas involved, but do want or need good performance on VHF-HI and UHF in most circumstances would be to use seperate UHF and Hi-VHF antenna(such as Winegard YA-1713) along with VHF/UHF coupler such as CM #0549 or seperate VHF/UHF inputs on some preamps. Think this can also be advantagous in such situations w/o rotor where a single, desired HI-VHF station is in a different direction from desired UHF station, as then antenna can be aimed in different direction. Of course, a single channel Hi-VHF antenna would be a good option in this case as well, provided the station involved is going to "stay there" post analog shut off.

Of course, in addition to "for Hi-VHF" some of us also use either broadband VHF antennas or combo VHF/UHF antennas for FM reception and/or for lo-VHF TV/DTV ....

------------------

Falcon_77

09-21-07, 09:11 PM

Well, I guess I won't be cutting down on the 3020's VHF elements after all. :D

Thank you for the information, though it is a bit more than I can digest right now.

Actually, just the VHF elements on the 3020 are performing very well for me, but the size of the thing is making it a daunting task to mount anywhere. It also performs well enough for most of the UHF channels, probably for the same reasons it does ok in upper VHF.

I assembled the Winegard YA-1713 last night. Unlike every other antenna I have tried, this is a very narrow band antenna. As predicted 7-13 come in well, but it is more bi-directional than I thought it would be. Maybe it is just a case of strong signals, but 9 came in just as well from the back-end as far as I could see.

In general, I have found the front-to-back ratios on most antennas to be overly forgiving. On the UHF portion of the 3020, the back-side can still pick up a great deal of signal.

Perhaps I should have stated my goal for the current project a while back. I'm trying to pick up San Diego stations from my attic. :eek:

I have only been able to pick up analog 8, 10 and 15 from San Diego thus far. The 4228's back side gets 8 & 10, but only on occasion, when enhancement is good.

Up to this point, the 1713 hasn't improved 8 and 10, but I haven't put it in the attic yet. Oddly enough, 15 came in from the VHF part of the 3020.

There are absolutely no signs of any digital signals from San Diego, but I am only using a 10dB distribution amp and not the CM7777 as yet.

Perhaps I should mention that San Diego is obscured by a few hills and I have to look through another unit's 3rd floor as well (My attic is on the 3rd floor). The 4228 is mounted where it cannot be rotated and faces Mt. Wilson, so I'm trying others to point to San Diego.

It makes for a fun project, that's for sure.

Jigga Moog

09-22-07, 07:23 PM

What kind of cable should I use with winegard 7082? Is there a drawback using RG6 quad?

JJPP

09-23-07, 12:15 AM

I live in Howell near Pickney zip 48843. I was hoping to get away with a cm 4221 or at most cm 4228. I am looking for an antenna to use in my attic or indoors for Detroit/Lansing hd/dtv. I currently am using a Radio Shack 15-1892 with so so results. I would like a more stable picture. I don't want to invest a lot of $$$ because when my Dish contract is up I am changing to Directv w/hd. I refuse to pay Dish's upgrade prices and new contract. Most store antennas are junk and if I order one off the internet I don't want to try to return it.

Dan Kolton

09-23-07, 10:13 AM

Try phone: (800) 528-9984

http://www.dennysantennaservice.com in Ithaca,MI. Denny is pretty knowledgeable, and he gives you a full year return priviledge. I'm in Southfield. He sold me a CM4221 for my attic, and it works great after moving it around a few times, but I'm a lot closer to the broadcast towers than you.

afiggatt

09-23-07, 11:49 AM

I live in Howell near Pickney zip 48843. I was hoping to get away with a cm 4221 or at most cm 4882. I am looking for an antenna to use in my attic or indoors for Detroit/Lansing hd/dtv. I currently am using a Radio Shack 15-1892 with so so results. I would like a more stable picture. I don't want to invest a lot of $$$ because when my Dish contract is up I am changing to Directv w/hd.
All of your locals are currently on UHF and scattered around in azimuth, so the CM 4221 is a reasonable choice in that regard. Complicated list of digital stations in different directions that are up to 44+ miles away. Checking the FCC data, I see 2 stations switching to upper VHF in Feb., 2009: WJBK-DT Fox 2 will switch from UHF 58 to VHF 7 and WJRT-DT ABC 12 in Flint will switch from UHF 36 to VHF 12. The CM 4221 may not get the WJBK-DT Fox 2 on VHF 7 in 2009 at your range of some 44 miles. You might need to add a upper VHF antenna at that time.

You are pretty far from some of the stations for a CM 4221. I do get stations out to 43+ miles in different with a CM 4221 and a CM 7777 pre-amp in my attic. The CM 4228 (I assume that is what you meant) has more gain, but is more directional, so you may have to use a rotator with it. Your closest station is 17 miles, so a pre-amp won't be a problem.

You could try a CM 4221 combined with a CM 7777 pre-amp. The CM 7777 pre-amp has switchable separate inputs for UHF and VHF, so you can add a VHF antenna to it later. You could try the CM 4221 without a pre-amp and get the pre-amp later if you decide you need it.

If you put the antenna in the attic. my advice is to mount it to a piece of flat wood or a movable stand. Attic have dead zones, so you want the flexibility of moving the antenna around in the attic until you find a good location for receiving the weaker stations. You will have to experiment with the aim of the CM 4221 or 4228 for best overall results. Start by aiming it at the more distant stations and see if you can pick up the closer stations in the other directions in the backlobe. Taking the reflecting back-screen off of the CM bowties is an option to make the antenna fully bi-directional.

Geo05

09-23-07, 04:26 PM

AntAltMike

09-23-07, 05:34 PM

Based on info from this thread (thanks!), I installed a CM4221 in the attic of my ranch home. The NY broadcast stations are ~26 miles away. The main digital stations of interest are coming in with good reception (signal strength ~80).
However, Ch 13 (VHF, green) comes in but is a bit fuzzy. The problem is worsened due to the fact that my TV requires separate analog and digital signal inputs. If I use a splitter, signal strength drops by ~10.

Any suggestions on how I may improve Ch 13 reception?

I take it you mean that analog 13 is fuzzy (PBS?). Doesn't its digital channel carry the same programming? That should be pristine.

The 4221 is designed for UHF channels 14-69. You can sometimes get away with using it on digital channels 7-13 because you can also sometimes get them with a coathanger.

There are people here who will tell you that the CM4228 is better on VHF highband channels 7-13, but analog channels require flatness across the channel more-so than do digital channels, so you might be dissatisfied with analog reception of channel 13 even if digital reception of channel 13 in other markets has been satisfactory.

If you are trying to get a good looking analog channel 13, then you can buy any small VHF highband antenna, commonly called model 6713, meaning 6 elements, ch 7-13, for which you will pay less than $40, and couple it using something called a UVSJ, which you can find on the internet for three bucks.

Is your channel 13 now coming from the same tower as the other NYC channels?

Geo05

09-23-07, 06:03 PM

MeowMeow

09-24-07, 09:35 AM

Thanks, AntAltMike.
Yes, its PBS (WNET) I'm interested in. For some reason, the WNET-DT has a different program schedule. Yes, you are right, the digital version is indeed pristine. But it shows "Rick Steve's Europe", when I want the "News Hour".
Not sure if the "News Hour" is bradcast in digital, or how I may find out...

Most PBS stations run PBS-HD as their big waa-hoo and then run the local station's analog programming as a sub channel. For example, my nearest PBS runs HD on 3.1, it's regular analog signal on 3.2 and PBS World on 3.3.

Geo05

09-24-07, 08:05 PM

Most PBS stations run PBS-HD as their big waa-hoo and then run the local station's analog programming as a sub channel. For example, my nearest PBS runs HD on 3.1, it's regular analog signal on 3.2 and PBS World on 3.3.

Unfortunately not in my case. There are sub channels: 13.1 is 13-HD (different), 13.2 is kids-13 and 13.3 is a latino family entertainment channel in Spanish.

I am not sure about a separate VHF antenna, since I will nevertheless have to use a splitter at the TV and lose quality of both analog and digital signals. Would a pre-amp help? If it compensated for the spltter and gave a slight additional boost, I expect to be in good shape!

MeowMeow

09-25-07, 12:57 AM

Unfortunately not in my case. There are sub channels: 13.1 is 13-HD (different), 13.2 is kids-13 and 13.3 is a latino family entertainment channel in Spanish.

I am not sure about a separate VHF antenna, since I will nevertheless have to use a splitter at the TV and lose quality of both analog and digital signals. Would a pre-amp help? If it compensated for the spltter and gave a slight additional boost, I expect to be in good shape!

Actually, the CM 7777 preamp can act as a VHF-UHF combiner and might help some of your problem.

As for your digital subs, you need to ask your PBS station what they plan to do after the shutdown. What happens to your truly local programming? Is it done for? Kapput?!

The PBS channel out of Pittsburgh, PA, for example, bends over backwards to make as much local programming available as possible, with one of their subs dedicated to purely local programs and nothing else and another sub with mixed national and local stuff. The Penn State PBS station also lays on a pretty good coat of PSU-oriented local/propaganda programming on it's one sub. Both carry the HD channel.

Without local programming, one of the more significant contributions of PBS goes to waste.

Rick0725

09-25-07, 06:47 AM

Awww..you purchased a cm4221 and can not receive vhf to your satisfaction.

jk870

09-25-07, 09:53 PM

Falcon_77

09-25-07, 10:36 PM

I have checked the VHF-Low analog channels on my CM4228 just to see what it can do for that band. It does a bit better on 2 than 4 and especially 5. However, the picture quality is abysmal compared to the VHF-High performance.

I would not call my 4228's performance on channel 4 as "watchable," but I'm at 51 miles and it's in my attic. If you want to add a 4228 now, you are probably better off getting a VHF/UHF combiner so that you can still use the VHF part of the 3016. Is the 3016 not getting it done on UHF?

The rated spec of the 3016 for Lo-VHF might be +1.2dB, but the 4228 is reported at -11dB at best (Channel 2) and it gets much worse from there.

You may want to look at Using a UHF antenna for VHF on this site:

http://www.hdtvprimer.com/ANTENNAS/comparing.html

jk870

09-25-07, 11:06 PM

xlr231

09-25-07, 11:54 PM

Is there anything I can do to boost daytime reception of stations about 60-70 miles away? The channel I am trying to get is Fox 28 in HD out of South Bend IN. When I am watching football during the day I only get about 1-2 (out of 10) bars of signal and frequent drop outs on my receiver's signal meter. At night I get 9-10 bars on the same channel.

I have a Channel Master Spartan 3 amp, I don't remember the exact model, but I think it is UHF only. I recently switched from a Radio Shack 40" 17 element UHF antenna to an Antennas Direct 91XG. My daytime signal stayed about the same but I get much better signal at night. With the old antenna I only got about 4-5 bars with occasional dropouts.

My amp only has a 300 ohm input so I am using an 75-300 ohm adapter from the antenna to the amp. Could that be hurting my signal strength? Do you think a better amp would help or is there nothing I can do because of the distance to the tower and atmospheric conditions?

Also should I run a separate ground wire for my antenna mast or is just running the coax through a grounding block ok?

DECdaze

09-26-07, 08:05 AM

... My amp only has a 300 ohm input so I am using an 75-300 ohm adapter from the antenna to the amp. Could that be hurting my signal strength? Do you think a better amp would help or is there nothing I can do because of the distance to the tower and atmospheric conditions? ... Also should I run a separate ground wire for my antenna mast or is just running the coax through a grounding block ok?
First things first. Yes, do ground both the antenna mast and the coax. If lightening strikes the mast, your house and not the coax would be the next path for it to reach ground.

Next, the 75-300 ohm balun (adapter) can cause signal loss. If you are using a Channel Master balun, I doubt it will be all that much. See:

http://www.hdtvprimer.com/ANTENNAS/basics.html

The Spartan 3 has a 23db gain on UHF, so should do fairly well.

However, a caution. UHF going over 50 miles, you probably will always contend with fading:

http://www.hdtvprimer.com/ANTENNAS/glossaryA.html#fading

Plus, beyond 50 miles you are in the deepest fringe, and reception will always be a bit dicey:

http://www.hdtvprimer.com/ANTENNAS/glossaryA.html#fringe

A Channel Master 4228 might help, as well as a Channel Master 7775 or 7777 pre-amplifier. But that's pretty much a complete overhaul.

w0en

09-26-07, 10:43 AM

Great info, thanks!

The 3016 only receives 1 of the 3 digital UHF channels. I am looking to change to a CM 7777 preamp and noticed the UHF/VHF inputs, but frankly I hadn't been able to get to the 3016 to see how involved it would be to remove the UHF section.

The CM7777 should rolloff any weak UHF signal from the 3016 on it's own by taking it apart and moving the input switch to separate and plugging it into the VHF. No need to hack up the 3016. At least it has worked that way for me, YMMV.

My own experience with low VHF channels on the 4228 has been dismally snowy analog performance on 2,4,5 analog even with a CM7777 at 42 miles. 9 & 11 analog on VHF high were watchable.

nybbler

09-26-07, 10:47 AM

My amp only has a 300 ohm input so I am using an 75-300 ohm adapter from the antenna to the amp. Could that be hurting my signal strength?

If you open up the plastic box where the coax goes in on the 91XG, you'll find a 75-300 ohm balun. Remove both your balun and that balun and run twin lead directly from the amp to the antenna, and you could get a dB or two.

Falcon_77

09-26-07, 10:55 AM

The 3016 only receives 1 of the 3 digital UHF channels. I am looking to change to a CM 7777 preamp and noticed the UHF/VHF inputs, but frankly I hadn't been able to get to the 3016 to see how involved it would be to remove the UHF section.

Are the UHF channels of interest further away than channel 4, noted at 33 miles above? If you can provide your ZIP code, it will help us make a more accurate assessment of your needs.

As for taking the UHF part off the 3016, it may not be necessary as I would expect the VHF input on the 7777 to filter it out. Perhaps someone else who has tried that can comment.

Judging from my 3020 test antenna, it shouldn't be too difficult to remove the UHF part, but it's a bigger pain when it's already mounted on the roof.

mglass1646

09-26-07, 02:39 PM

quote from xlr231: Is there anything I can do to boost daytime reception of stations about 60-70 miles away? The channel I am trying to get is Fox 28 in HD out of South Bend IN. When I am watching football during the day I only get about 1-2 (out of 10) bars of signal and frequent drop outs on my receiver's signal meter. At night I get 9-10 bars on the same channel.
I have a Channel Master Spartan 3 amp, I don't remember the exact model, but I think it is UHF only. I recently switched from a Radio Shack 40" 17 element UHF antenna to an Antennas Direct 91XG. My daytime signal stayed about the same but I get much better signal at night. With the old antenna I only got about 4-5 bars with occasional dropouts.

I sometimes watch DTV from Terre Haute, about 77 miles away. I have found the same as you. It is hard to get a decent signal during the day, but no problem at night. I have two 91XGs stacked together at 35' AGL for TV DX. Most DTV stations within 50 miles are no problem if they have a decent amount of power. WSJV-DT only has 220kw which is 1/5 of the max allowed on UHF. Go to TVFool.com to find out what they think your reception should be.

Mike

reign80

09-28-07, 05:56 PM

So My tv set has a QAM tuner in it and it is picking up the HD version of these channel.
FOX, NBC, ABC and CBS. I am looking for a nice Antenna so that I could make these HD channel a little clearer and when I do buy this antenna do I plug it into the slot that as AIR instead of CABLE is that correct?

Thank You

Neil L

09-29-07, 09:11 AM

...when I do buy this antenna do I plug it into the slot that as AIR instead of CABLE is that correct?Yes, that is correct. Seems so obvious, doesn't it? Almost like it's too easy.

Rick0725

09-29-07, 10:33 AM

Hi guys,

I have a CM 3016 mounted on a chimney, currently with a cheapo 10db mast-mounted amp I bought on Ebay, and roughly 75' of RG6 cable. It appears as though the VHF-Low gain is very low on this model (~1.2db), but I am getting perfect reception on analog channel 4 (I also have unobstructed LOS at 33 miles).

My question is this: I completely understand the CM 4228 is not intended for VHF, particularly low VHF, but would the gain really be any worse than the 3016 on Ch 4? Is anyone having any luck at all with low-VHF on the 4228?

After 2009, analog 4 moves to 7, where its digital channel is now, but my other channels are 13, 16, and 29. I'd like to move to the 4228 now to get the bulk of the other channels, as long as I might still be able to get 4's analog signal.

Appreciate any insight!

Combine the cm 3016 for vhf with the cm4228 for uhf with a cm7777 preamp set to separate.

if you currently only have a single input preamp and you are happy with the performance, combine the 2 antennas with a cm0549 vhf/uhf combiner (.5db insertion loss, $10) and amplify the combined signal with the preamp. The length of coax between antennas is not an issue. you can run 2 separate coax inside and combine there if you want. therefore mounting the 2 antennas in separate locations outside is not an issue. Would not want to mount both antennas on the chimney and you need to allow at least 3.5" spacing between antennas.

http://www.starkelectronic.com/cmjoiner.htm

In 2009 you can remove the cm3016 if the hi band vhf of the cm4228 is satisfactory. My quess is the cm3016 hi band vhf should outperform the cm4228 hi band a tadd.

I would never use the cm4228 for ch 2-6 vhf...waste of time and money. You may also want to think about replacing your current preamp with the much better performing cm7777.

Neil L

09-30-07, 09:14 AM

I will echo what Rick said. I'm using a 4228 and can say it won't work for low VHF, except for channel 2 (but it is very,very weak on 2). It will pick up upper VHF, but it is weak there also, not as good as an antenna designed for those frequencies.

The Hound

10-01-07, 12:46 AM

So My tv set has a QAM tuner in it and it is picking up the HD version of these channel.
FOX, NBC, ABC and CBS.
Thank You
You mean an ATSC tuner.
Right?

MorningHill

10-01-07, 02:18 PM

Problem - breakup of picture on digital channels. The channels I want are digital except for PBS which has some programs I want only on analog. Signal strength on digital channels ranges from around 33% on CBS to 88% on FOX and CW.
Location - 22 miles NE of Portland OR
Antenna Web shows all the transmitters I want are within 4 degrees of one another, 22 miles from here, and should be OK with a yellow coded antenna.

ABC ch 2.1 freq 43
CBS ch 6.1 freq 40
NBC ch 8.1 freq 46
PBS ch 10.1 freq 27
FOX ch 12.1 freq 30
CW ch 32.1 freq 33

History - Have been using an attic mounted CM Crossfire antenna since 1998. This did fine for the analog channels feeding an older NEC CRT analog TV, SD only. Now have a 2004 Sony DHG HDD500 DVR-Tuner feeding a 720P Panasonic Plasma monitor. The Panny is monitor only, no tuner. Have heard the Sony doesn't have a great tuner.

CW and FOX are stable, ABC, NBC, and PBS sometimes stable, CBS rarely stable. Solid Signal and Antennas Direct both recommended a DB8 style antenna. Looked at this at local RS but wont fit through attic access. Tried a CM 3021 (DB4) but this is much less effective than the Crossfire, so doubt the DB8 will do the trick.

I'm looking at the 91XG from Antennas Direct. Comments? Other suggestions?

wsuetholz

10-02-07, 12:11 PM

Hello, I'm in the Milwaukee, WI market around 10 miles from the various broadcasting antennas for the major stations here. In the 53051 zip code.

I'm using a Terk TV-55 antenna mounted to my chimney. It's at least 6' higher than the top of the chimney, and most stations come in fine without turning on the onboard preamp via the power injector. I have a Samsung TV with a built in HDTV tuner that seems to work ok for all the stations, there are issues with Channels 18 and 6 HD sometimes. I recently got a HDHomeRun network digital tuner, and it has the ability to monitor not just signal strength like the TV, but also two other levels, that indicate the noise on the signal being received.

For Channel 6 I get no signal strength at all on the device unless I turn on the preamp on the antenna. But when I turn on the preamp the signal quality drops 2 bars on all the other stations I think that means 20%.
Which makes a couple of the stations that were good become marginal, more signal dropout.

I looked at the maps of the TV stations antenna at www.2150.com and noticed that TV6 has a much more focused spread then the others, which is probably the problem.

I tried turning the antenna, and I found that I can't point it the direction I thought it should be pointing, but instead it is turned a bit north... Instead of pointing E-SE (mostly east) It's pointing E-NE.

Ok, now for the questions..
1) IS channel 6 going to beef up their transmitter, and have the broadcast be more widespread?
2) Would getting a ChannelMaster or Winegard preamp introduce less noise to the signal.. Keeping in mind that I'd rather not have to preamp, since the only station that is helped by the preamp is CH6, all the others are hurt by the preamp.

I hope it isn't a problem that I posted this message in the Milwaukee thread as well, I thought that this would be a better forum for the preamp questions.

Thank you,

new2hdtv07

10-04-07, 01:00 PM

I am debating if it is worth while for me to buy a pre-amp for my antenna(uhf/vhf combo) for hd signal reception. I have an attic antenna in a single story house on a hill, with about 50 or 60ft of RG6 that runs to a 4-way distribution amp in the basement purchased from the local home depot.

I am soliciting for any speculation as to whether I would notice an improvement by adding a preamp to my situation. I see some dropouts here and there, especially when recording CBS.

Here are my station locations (I'm not so worried about 39 since I get ABC on 20).

netwk orient miles freq
NBC 134° 23.1 7
FOX 135° 22.2 19
ABC 143° 30.2 20
CBS 143° 24.7 2
PBS 343° 4.5 11
ABC 359° 28.5 39

If a pre-amp won't help me a lot over my distribution amp, then if I had a $50 budget to improve my signal, what would you recommend?

Tower Guy

10-04-07, 01:42 PM

I am debating if it is worth while for me to buy a pre-amp for my antenna(uhf/vhf combo) for hd signal reception.

CBS 143° 24.7 2

If a pre-amp won't help me a lot over my distribution amp, then if I had a $50 budget to improve my signal, what would you recommend?

Your performance on channel 2 is limited by the indoor antenna. I'd spend 20 bucks on an eave mount and a mast. Antenna height helps more on channel 2 than you would expect.

If outdoor isn't an option, a bigger attic antenna might help.

mlmahon

10-04-07, 02:35 PM

new2hdtv07

10-04-07, 03:10 PM

it's always best to amplify the signal as close to the antenna as possible before any loss occurs. Amplifying after line loss does little good and increases noise.

I'd go for the antenna preamp.

How many times can I split a pre-amped signal before needing a powered distribution? 4way, 8way?

I have the following setup:
Jack 1: CRT Tv + VCR
Jack 2: DFP Tv
Jack 3: DFP Tv + Computer tuner + FM amp
Jack 4: CRT Tv
Jack 5: Digital Tuner + Digital Tuner

I would think then I'd be advisable to use a passive 4way ( and a 2way to split jack 2 and 4), then use 2 and 3 way splitters as needed in the rooms. So worst case I'd expect about a 18db loss (from splitting and cable lengths) to the devices on Jack 3, is that correct? Is that enough to stay passive after a pre-amp?

Where would anyone recommend getting some good quality brand of passive splitters to look for? Maybe on ebay?

holl_ands

10-04-07, 03:54 PM

Preamp near antenna primarily determines overall sensitivity.
Sensitivity loss due to additional attenuation AFTER the Preamp
is reduced by the amount of gain in the Preamp.
So you should be able to tolerate quite a bit of loss in cable
and RF Splitters....so try it with ONLY the Preamp.

However, since you are very near PBS tower, the low gain,
very high overload W-G HDP-269 is your only option---
everything else will overload.

And you still might need a small amount of loss
(e.g. 3 db or 6 dB pad) between antenna and Preamp.

If you decide a distribution amp is needed, be sure to have
a significant amount of cable/RF Splitter loss between the
Preamp and the Distro Amp--otherwise you'll overload it's input.

=================================
Another alternative solution (presuming VHF is not a problem):
Use the existing antenna for VHF and use a separate, better UHF
antenna (e.g. CM-4228). Only use Preamp on UHF antenna and
use a VHF/UHF Combiner to feed the coax downlead, such as fol:
http://www.picomacom.com/specs/pico/C/C24.pdf
BTW: The UVSJ will filter out VHF signals coming from CM4228,
leaving only the unamplified VHF from your existing antenna.