The Official AVS Antenna Topic! [Text View] - Page 27

MAX HD

01-15-08, 02:58 PM

I live in the boon docks, about 50-60 miles from the towers I want, however, they lie in all directions - yes, 60 miles in all directions. I have an antenna on the roof (20 foot peak with a 10 foot mast-stand combination), with a new rotator (CM9521a). I need a good one size fits all directional antenna that can receive both UHF and VHF all the way down to channel 3, since there is a pretty even mix of both in the area. The digital signals don't seem to be only broadcasting in UHF. I don't want to overload my mast with two antennas, because we occasionally get some pretty high winds.

Can anyone give me a recommendation on the best deep fringe UHF/VHF antenna? I realize that a combination of something like the VIP-306 (or another yagi) and a CM4228 would produce the the best signal (when combined with a Titan 7777), but I don't think it would be wise to add onto the mast (since most of that 10 feet is stand, only about 3 feet is mast) and hike up a CM4228 on a rotator (I hear the wind resistance to that thing is pretty high). I think the wind would rip down the stand and a portion of my roof in the first strong storm.

Might help if you would reveal your general location/markets you're wanting to pick up.

afiggatt

01-15-08, 03:16 PM

I live in the boon docks, about 50-60 miles from the towers I want, however, they lie in all directions - yes, 60 miles in all directions. I have an antenna on the roof (20 foot peak with a 10 foot mast-stand combination), with a new rotator (CM9521a).
Your zip code would provide a better understanding of your location, terrain, what frequency bands the stations are on and whether any will move from UHF to VHF high or even low next year.

Shade00

01-15-08, 07:25 PM

All of your stations are in the same direction, so a directional antenna is fine. Is the "tiny old RCA antenna" a UHF loop (~8" in diameter) and rabbit ears for VHF tabletop antenna? WLBT-DT NBC 3 is on upper VHF 9. WJTV-DT CBS 12 will be moving it's digital channel from UHF 52 to VHF 12 by Feb. 17, 2009. So you need an indoor antenna to get UHF and upper VHF.

First, have you tried different locations and aim for the RCA antenna? Raised it higher up in the room, placed it in a window facing SW in the direction of the stations? Tweaked the aim of the rabbit ears and shortened them to ~ 32" long to try to get WLBT-DT NBC? If it has a UHF loop, aimed the open face of the loop towards the stations?

If that does not work, a Silver Sensor UHF antenna combined with rabbit ears for VHF is a good next step. Hate to recommend Terks, but they are available at local stores. The Terk HDTVi is an unamplified version, but is not widely carried by the chain stores. The Terk HDTVa has a built-in amp and is rather overpriced at $50, but can be found at many local stores. Another option is a 2 Bay bowtie such as the Channel Master 4220 mounted on a mast facing a window or outside on a deck if you have one.

This is some great information. I really appreciate you taking the time to answer me in such detail.

The antenna I have is a UHF loop and rabbit ears - I put the antenna up as high as could, got no real improvement, and played a little bit - I guess I should hook it up again and see if I can make it work better.

I will take a look at the other antennas you mentioned. I wish I could go with a CM antenna, but my complex frowns on ugly things hanging outside on our patios.

chemboy007

01-15-08, 07:52 PM

Of course...
I live in 49412...Michigan.

It's somewhat hilly, but not horribly, and I'm near the top of one of the small hills. Mostly farmland. I have a few medium size deciduous trees nearby, but they're not usually a problem.

I currently have an 8 foot antenna of unknown make, probably 20-50 years old with approximately 100 foot run of RG-11 leading to the one (very pretty 47" Philips 1080p) TV.

My reception is mediocre, currently, and I hope that upgrading to a deep fringe will give me the Southern Grand Rapids and Cadillac stations without the drop out problems I periodically get, now (even in seemingly ideal weather).

Oh, and my one wish is for World Peace...B-)

Antenna suggestions?

Falcon_77

01-15-08, 08:49 PM

I live in 49412...Michigan.

antennaweb.org list the following stations for your ZIP code. I have set the antenna height at 500' to overcome antennaweb's very conservative estimates.

* yellow - uhf WZZM-DT 13.1 ABC GRAND RAPIDS MI 175° 10.9 39
* yellow - uhf WCMU-DT 14.2 PBS MOUNT PLEASANT MI FCC Ext 66° 41.8 56
* green - uhf WTLJ-DT 54.1 IND MUSKEGON MI 181° 35.2 24
* lt green - vhf WOOD-DT 8.1 NBC GRAND RAPIDS MI 162° 58.2 7
* lt green - uhf WWTV-DT 9.1 CBS CADILLAC MI 38° 55.3 40
* red - uhf WXMI-DT 17.1 FOX GRAND RAPIDS MI 163° 57.7 19
* red - vhf WGVU-DT 35.1 PBS GRAND RAPIDS MI 180° 35.0 11
* blue - uhf WOTV-DT 41.1 ABC BATTLE CREEK MI 163° 66.4 20
* blue - vhf WWMT-DT 3.1 CBS KALAMAZOO MI 165° 61.2 2
* violet - uhf WMKG-DT 38 FMN MUSKEGON MI TBD 220° 18.0 38
* violet - uhf WZPX-DT 43.1 ION BATTLE CREEK MI 145° 70.2 44

WWMT/CBS 3 (DT 2) is going to tough to get, due to this station being on Low-VHF. 2 and 3 are especially hard to receive. However, WWMT will be moving to High-VHF 8 next year, which should be considerably easier to pick-up.

Western Michigan has quite a few VHF DTV stations as compared to the rest of the country.

WGVK/PBS 52 (DT 5) is slated to remain on Low-VHF 5, so if you have a need to receive that station. Note that antennaweb would not show it even at 500', but there appears to be an outside to be able to receive it.

If you can receive WWTV for CBS and WCMU for PBS, then you may not need to worry about Low-VHF.

WZZM/ABC is not very far at all, at 10.9 miles. This will cause problems, especially with a pre-amp as it will likely overload most pre-amps when the antenna is pointed in that direction.

If you are looking for a VHF/UHF combo and still want to have Low-VHF capability, then you may want to look at something like a Channel Master 3671 or a Winegard HD8200P. ...oh my, the HD8200P has been discontinued by Winegard?

http://www.solidsignal.com/prod_display.asp?PROD=HD8200P

Tower Guy

01-15-08, 09:21 PM

..oh my, the HD8200P has been discontinued by Winegard?

There is a replacement that is UPS shippable!

http://www.solidsignal.com/prod_display.asp?PROD=HD8200U

emddvm

01-16-08, 12:21 PM

Shade00

01-16-08, 02:10 PM

All of your stations are in the same direction, so a directional antenna is fine. Is the "tiny old RCA antenna" a UHF loop (~8" in diameter) and rabbit ears for VHF tabletop antenna? WLBT-DT NBC 3 is on upper VHF 9. WJTV-DT CBS 12 will be moving it's digital channel from UHF 52 to VHF 12 by Feb. 17, 2009. So you need an indoor antenna to get UHF and upper VHF.

First, have you tried different locations and aim for the RCA antenna? Raised it higher up in the room, placed it in a window facing SW in the direction of the stations? Tweaked the aim of the rabbit ears and shortened them to ~ 32" long to try to get WLBT-DT NBC? If it has a UHF loop, aimed the open face of the loop towards the stations?

I toyed with the antenna some more using your advice. I had just unplugged it and put it in the closet after having unsatisfactory results before. I am now able to get 9 digital stations (ABC, CBS, PBS, FOX, their substations, and another that I'm not sure of). Signal strength is excellent. My tuner does not even find NBC (3.1), though. This is with a US Digital standalone tuner - I will try my television's built-in ATSC tuner later. I am very happy to get HDTV now - Comcast here does not give us any freebie QAM stations. :(

rbarbier

01-16-08, 02:12 PM

Ok..

I live at zipcode 92571 and my local Digital channels are from Los Angeles. I am about 55 miles from Mt. Wilson and live in an apartment. Currently, I recieve all my local channel (except 13 but I don't need this) by using the Square Shooter ss-1000 with the CM-7777. What I am worried about is in 2009, channels 2-5 will stay on UHF (good) but 7,9,11,13 will be on the High Band VHF. Will this setup still work for me or do I need to change my antenna? Also, what would be a good antenna for my situation (apartment on the second floor with a balcony facing towards Mt. Wilson).

Thanks.

Falcon_77

01-16-08, 03:15 PM

What I am worried about is in 2009, channels 2-5 will stay on UHF (good) but 7,9,11,13 will be on the High Band VHF. Will this setup still work for me or do I need to change my antenna? Also, what would be a good antenna for my situation (apartment on the second floor with a balcony facing towards Mt. Wilson).

The Square Shooter is probably not going to get it done. For now, the best way to tell is to look at the analog VHF reception. If it is poor or worse, you will probably need to make a change or add a VHF antenna in '09.

Until recently, we did not have a local VHF DTV station, but KFLA-LD is now available on channel 8. However, it is a low power station and as such is probably not strong enough to pick-up in Perris.

Falcon_77

01-16-08, 03:55 PM

The coax cable is ran through an amplifier inside the house and split off to two tv's.

Have you tested the reception without the amplifier? There are some strong stations at ~22 miles, which may overload an amp.

How is WPXX coming in on analog 50? Since the problem stations are in the 50's as well, this may give an indication of the problem. Higher frequencies tend to have more problems with trees.

chemboy007

01-16-08, 06:47 PM

* yellow - uhf WZZM-DT 13.1 ABC GRAND RAPIDS MI 175° 10.9 39
* yellow - uhf WCMU-DT 14.2 PBS MOUNT PLEASANT MI FCC Ext 66° 41.8 56
* green - uhf WTLJ-DT 54.1 IND MUSKEGON MI 181° 35.2 24
* lt green - vhf WOOD-DT 8.1 NBC GRAND RAPIDS MI 162° 58.2 7
* lt green - uhf WWTV-DT 9.1 CBS CADILLAC MI 38° 55.3 40
* red - uhf WXMI-DT 17.1 FOX GRAND RAPIDS MI 163° 57.7 19
* red - vhf WGVU-DT 35.1 PBS GRAND RAPIDS MI 180° 35.0 11
* blue - uhf WOTV-DT 41.1 ABC BATTLE CREEK MI 163° 66.4 20
* blue - vhf WWMT-DT 3.1 CBS KALAMAZOO MI 165° 61.2 2
* violet - uhf WMKG-DT 38 FMN MUSKEGON MI TBD 220° 18.0 38
* violet - uhf WZPX-DT 43.1 ION BATTLE CREEK MI 145° 70.2 44

WWMT/CBS 3 (DT 2) is going to tough to get, due to this station being on Low-VHF. 2 and 3 are especially hard to receive. However, WWMT will be moving to High-VHF 8 next year, which should be considerably easier to pick-up.

Western Michigan has quite a few VHF DTV stations as compared to the rest of the country.

WGVK/PBS 52 (DT 5) is slated to remain on Low-VHF 5, so if you have a need to receive that station. Note that antennaweb would not show it even at 500', but there appears to be an outside to be able to receive it.
If you can receive WWTV for CBS and WCMU for PBS, then you may not need to worry about Low-VHF.

WZZM/ABC is not very far at all, at 10.9 miles. This will cause problems, especially with a pre-amp as it will likely overload most pre-amps when the antenna is pointed in that direction.

If you are looking for a VHF/UHF combo and still want to have Low-VHF capability, then you may want to look at something like a Channel Master 3671 or a Winegard HD8200P. ...oh my, the HD8200P has been discontinued by Winegard?

I hadn't noticed the 8200U...I had been considering the 8200P when they canceled it. I was not happy. I don't understand the mix of UHF and VHF, does anyone have any idea why the stations are laid out the way they are? Is there a preference for one band over another? Is that important to the digital signal?

I've never gotten WCMU, WOTV or WZPX; but WGVU has three stations at 35.1, 35.2, and 35.3, Channel 8 runs an 8.1 and an 8.2 (the non cable version of the weather channel - all local satellite all the time). Channel 17 runs a 17.1 and a 17.2 (where they play music videos - usually 80s and 90s. I enjoy the nostalgia). I can see all of the others, but the issue is how well and how often.

When a broadcaster is using multiple channels, like 35.1, 35.2, and 35.3, do they use the same band and just squeeze more info into it, which the tuner then separates?

btw...thanks for the help finding an antenna. I think the 8200U is the perfect choice!

Intheswamp

01-16-08, 08:41 PM

I currently have an old Radio Shack antenna mounted on a two story house. Height of the antenna is probably 25 feet or so. I live in a wooded area south of Memphis with big trees about 200 feet away from the house in the direction of the towers. I cannot receive channels 5.1 or 13.1 with this setup. The other digital channels come in pretty good, more so in the winter with leaves off the trees. The coax cable is ran through an amplifier inside the house and split off to two tv's. Below are the antennaweb results. Zip is 38651. Can someone recommend an antenna to try and improve the reception on these two channels? Thanks. Mike
<snip>
Mike, a couple of things come to mind. Beware, I'm not one of the regular experts here...just a tinkerer. ;)

1. Take the amplifier out of the circuit and see what happens.

2. If you can get to the antenna without much trouble slightly flex all the elements that you can...over a period of years oxidation and corrosion will cause high-resistant connections or even cause completely broken connections. While you're at it check the coax connections. I've done the "exercise" procedure on some older antennas and was quiet pleased with the results.

3. It looks like the two stations that you are interested in are (for now) in the upper UHF frequencies. If your antenna is a big, long, triangular shaped antenna it is probably predominately for VHF. A UHF antenna would probably help tremendously. I personally use an 8-bay Channel Master 4228 with a 7777 pre-amp and 100' of RG-6 coax. I really like the CM4228. They also make a 4-bay, the CM4221. You could also tinker with building one by checking out this link....diy antenna thread (http://www.lumenlab.com/forums/index.php?showtopic=9613).

My stations range from 21, 40, and 67 miles from me...these all come in consistently with my setup. I've got a couple of stations in the 20-40 mile range that I *can't* receive though :( ...these are still running low-power with their antenna still at a low height, once they go full-power they will come in fine. You might need to check and make sure that the stations that you can't receive have adequate power and antenna height for you to receive them. Being as WMC-DT is at the bottom of the listing but it isn't the most distance station it makes me think it hasn't gone full-power or maybe it's antenna isn't that high.

It's still interesting that the two problem stations are in the upper UHF range. How does WPXX-DT 50.1 (ION) come in? It's close to the same frequencies as the two others. ????

Out of curiosity I checked...looks like WHBQ is running low-power of only a couple of kilowatts. WMC is putting out a touch under 400kw which really isn't too shabby. You can go here (http://www.2150.com/broadcast/default.asp) and enter your lat/long and see the distances/power/etc.,.

Just some thoughts,
Ed

afiggatt

01-16-08, 09:18 PM

When a broadcaster is using multiple channels, like 35.1, 35.2, and 35.3, do they use the same band and just squeeze more info into it, which the tuner then separates?
All of the sub-channels are part of the same digital broadcast channel signal. An ATSC broadcast is a constant 19.4 Mb/sec data rate which can be divided into separate SD and a HD sub-channel. In this case, WGVU-DT 35 is broadcasting digitally on VHF 11 with 3 sub-channels.

emddvm

01-17-08, 11:25 AM

Intheswamp and Falcon77
Thank you for the replies. I have used the amplifier for several years and had to replace it a year or so ago. Without it I had trouble getting any reception on the TV that is farthest away from the splitter. I can try and remove it again though and see what happens.
As far as channel 50.1, I don't receive it either and had never considered it, so you all may be right that there is a problem with the upper UHF channels. The radio shack antenna I have is a VHF/UHF. I don't really know how to describe it but it is long with two smaller parts that come off the top and bottom of the front part that is aimed towards the towers. It is at least 15 years old. I have tried moving it around some on the direction it is pointed but it hasn't improved anything. I started to check the coax connection not too long ago but didn't since it seemed to have a covering that had kind of "melted" and I was afraid I might not be able to get it back together if I took it apart.
I would like to keep the VHF analog channels for now so if I do replace the antenna should I get something that does UHF and VHF? It looks like the CM4228 is primarily UHF. I will try things without the amplifier again and may try and check the coax/antenna connection. I just hope I can get it back together...
Thanks again.
Mike

miztahsparklez

01-18-08, 01:56 PM

Apparently we have a large TERK antenna inside the conference room that is adjacent to the room that I am working in. I have been informed that it does work, but I have not verified that myself. The setup seems to be an outdoor antenna, a few feet in length, maybe the diameter of a small coffee can. It happens to be just leaning against the wall in the room with all the wires. Luckily, the side of the building the antenna is working in faces at least two of the major broadcast locations.

Assuming that your building composition is cooperative, then I have a few questions:

1) Is this a temporary setup or long term?
The setup is long term

2) Are you interested in all digital channels or just one?
The more channels the better. However, there's no real specific channel needs to get to.

3) Can you access the space above the drop-ceiling?
Sure can, but it's preferable to keep the wire running within the same section of the room, as the building likes to have any extraneous wiring run by the electrician. I will have to double check to see what is acceptable by building policies.

4) Are you willing to ask for roof access (sometimes it's easier than you think)?
I think we are looking to minimize the complexity here. Roof access would be too much trouble for what usage the antenna would actually get. ( we already have DirecTV and the like)

5) Are there any constraints on antenna visibility/appearance?
It would be nice to have something we can hide away in a corner somewhere.

Thanks for your replies :)

Falcon_77

01-18-08, 03:59 PM

I started to check the coax connection not too long ago but didn't since it seemed to have a covering that had kind of "melted" and I was afraid I might not be able to get it back together if I took it apart.

Melted? :eek:

It sounds like the antenna has a UHF corner reflector, but it appears that something in the cabling may be hindering the higher frequencies.

Which analog stations are you able to receive?

I would like to see a picture of that melted connection if possible.

mlcarson

01-18-08, 10:48 PM

Any suggestions for an antenna here?

55:PBS 48deg, 7.6miles
59:CBS 61deg, 8.6miles

38:FOX 210deg, 12.9miles
51:ABC 180deg, 14.4miles
57:NBC 191deg, 13.1miles

I'm looking for an antenna (either outdoor or in attic) which could be fixed. All of these stations are close but they are in different directions. Was wondering if a round channelmaster 3002 smartenna might do the trick. I also have a 4221 uhf antenna in the attic that I might try taking the screen off from since it'll only work for 38,51,57 or 55,59 but not both at the moment. My main outdoor antenna is a dual 4248 horizontal mount combo that I was experimenting with for very distant stations -- this will work if pointed in between the stations but I'm now looking for something a bit smaller for just the local stations rather than the out of area ones.

Results:
Took the screen off the 4221 and pointed it toward 190 deg (the results are good enough). 55 didn't seem to lose signal or pixelate at all.
55:PBS 48deg, 7.6miles (53-58%)
59:CBS 61deg, 8.6miles (87%)

38:FOX 210deg, 12.9miles (100%)
51:ABC 180deg, 14.4miles (75%)
57:NBC 191deg, 13.1miles (100%)

mlcarson

01-18-08, 11:47 PM

No idea what 55,57,59 are transitioning to. If they went to their old VHF frequencies, it would be 23,10,6 respectively. They should just stay where they are -- or is that not an option? Smaller antenna for high freq UHF versus huge VHF antennas (especially for low vhf).

I'll probably try the screen removal on the 4221 and see if that will work. If it doesn't try one of the radio shack antennas... Hoping to find a solution which will work in the attic.

mstasko

01-19-08, 12:16 AM

I have been eyeing the DB4 Antenna. Nice and compact & reviews that I have read on the web give it high marks.

mlcarson

01-19-08, 02:09 AM

Not sure where you got the new channel numbers but thanks.
Ch 36 will conflict with neighboring WJRT unless they are also transitioning since that's their current digital channel. And yay - channel 57 has to be different and go VHF requiring everybody to use 2 antennas.

holl_ands

01-19-08, 10:31 AM

DTV Channel Elections (per Aug2007):
http://hraunfoss.fcc.gov/edocs_public/attachmatch/FCC-07-138A2.pdf

Falcon_77

01-19-08, 12:01 PM

Ch 36 will conflict with neighboring WJRT unless they are also transitioning since that's their current digital channel. And yay - channel 57 has to be different and go VHF requiring everybody to use 2 antennas.

WJRT is going back to their analog channel (12) in 2/09.

There are quite a few areas that will only have 1 VHF full power station after the analog shut-off. So much for making it easy for the viewer.

bernieoc

01-19-08, 03:16 PM

My Roanoke PBS will be on Ch 3. You know how big that antenna must be!

Falcon_77

01-19-08, 07:13 PM

My Roanoke PBS will be on Ch 3. You know how big that antenna must be!

WBRA may regret not going back to their analog UHF channel (15). I see that they are currently on VHF 3 for DTV, how much of a problem that has been so far?

Looking at Roanoke, the next PBS station appears to be WVPT (11), but it seems to be out of range. WSBN (32) is too weak and much too far.

johnstonamerica

01-20-08, 11:13 AM

Just wanted to thank everyone again for the help - I now have the 91XG mounted on the top of my mast for UHF and the 3671 below for VHF. The 7777 acts as the filter to separate the UHF from VHF. I have also installed a rotor and am able to receive the Hartford stations along with the Albany ones.

This forum made it easy for me to find the equipment I needed and I am extremely pleased to report that I am receiving all of these staions with no problems at all!

Thanks everyone who helped!!

Now my next task is finding the perfect recliner to fall asleep in when I watch TV :)

Konrad2

01-20-08, 12:16 PM

> Now my next task is finding the perfect recliner to fall asleep in when I watch TV

http://www.ekornes.no/us/stressless/stressless_recliners/

http://relaxtheback.com/massage-recliners-subcategory-6389770

http://www.brookstone.com/sl/home-gifts/chair-recliner

cpcat

01-20-08, 02:22 PM

jtbell

01-20-08, 03:45 PM

No idea what 55,57,59 are transitioning to. If they went to their old VHF frequencies, it would be 23,10,6 respectively. They should just stay where they are -- or is that not an option?

It's not an option. Channel 52 and above are required by law to be vacant after the transition, so they can be sold off for other uses. Some stations got stuck with pre-transition digital channels in that range because it wasn't possible to give all stations two channels (analog and digital) without causing a lot of interference in some places.

In my area, NBC, CBS, ABC and FOX are currently on digital 59, 53, 56 and 57 respectively, so they all have to move for the final transition. NBC doesn't want to use its current analog channel (4) because it's low-VHF which is very problematical for digital signals, so it's moving to 36. The others are moving to their current analog channels (7, 13 and 21 respectively).

Konrad2

01-20-08, 05:30 PM

holl_ands

01-20-08, 08:09 PM

FYI: Summary of On-Air Tests for VHF vs UHF Impulse Noise:
http://www.mstv.org/docs/techinfo.pdf

A lot depends on how close you are to VHF impulse noise sources....

johnstonamerica

01-20-08, 10:18 PM

Good work J! Let's see a pic!

will snap a pic tomorrow :)

thanks for the links to the chair sites Konrad.. that massage chair looks awesome but may be a bit out of my price range atm :)

Falcon_77

01-21-08, 01:52 AM

FYI: Summary of On-Air Tests for VHF vs UHF Impulse Noise:
http://www.mstv.org/docs/techinfo.pdf

A lot depends on how close you are to VHF impulse noise sources....

Thanks for the article. It seems to me if that Low-VHF will remain in the "core," that the ERP levels allowed will have to be increased significantly.

I have seen other analysis confirming the high relative noise levels for Low-VHF. That, coupled with the fact that larger (unsightly) antennas are needed, I am still baffled that the US is clinging to channels 2-6.

It seems to me that Low-VHF stations are only effective in the least populated markets.

PA_MainyYak

01-21-08, 08:30 AM

> NBC doesn't want to use its current analog channel (4) because
> it's low-VHF which is very problematical for digital signals,

VHF gets through trees and walls much better than UHF. Impulse
noise is supposed to be a problem with VHF-LO, but don't assume
that VHF-LO will be worse than UHF, because it isn't always.

I have a low power ATSC channel 4 which is much *less* problematical
than several of my high power UHF ATSC stations, even though
(A) I'm using a VHF-HI antenna to get it, and (B) I chose the
UHF antenna (8 bay) specifically for the higher gain (and more
importantly higher directivity) in the problematic frequency range.
The VHF-LO analogs have various problems with this antenna.
(The VHF-LO stations are all scheduled to go away, which is why I
didn't bother getting a good VHF-LO antenna.) I suspect I may have
*more* trouble with this station when it moves to UHF.

VHF-LO remains part of the TV spectrum post-transition, although by my count only 38 stations have elected channels 2-6 as their permanent digital home, compared to 456 on VHF-HI (7-13), and 1,330 on UHF (14-51). The FCC had expressed it's strong desire to clear the VHF-LO band, but that has not happened. In some cases (for example WPVI-6 in Philadelphia) there are simply no other channels available. On the other hand, it appears the majority of stations that will inhabit channels 2-5 elected their old NTSC channel, which the FCC has blessed with the proposed final DTV Table of Allotments.

kycubsfan

01-21-08, 09:40 PM

Thanks for the article. It seems to me if that Low-VHF will remain in the "core," that the ERP levels allowed will have to be increased significantly.

I have seen other analysis confirming the high relative noise levels for Low-VHF. That, coupled with the fact that larger (unsightly) antennas are needed, I am still baffled that the US is clinging to channels 2-6.

It seems to me that Low-VHF stations are only effective in the least populated markets.

As I've said elsewhere, I'm thrilled that my nearest FOX affiliate (WDKY) has elected to stick with VHF 4. At nearly 90 miles out, I'm going to enjoy a pristine Super Bowl feed. This station's network peers on UHF might as well not even exist.

VHF-LO is perfect for situations like that seen in Lexington, a metro area whose TV market reaches well beyond the city and across huge swaths of mountainous terrain. I just wish other Lexington stations had followed suit, but I know full well that reception in far-flung, often impoverished Appalachia is not a priority for these guys.

For me, the bigger (and more unsightly) the antenna the better.

holl_ands

01-23-08, 03:06 AM

Nearly all of the analog stations with "K" followed by two digit channel number
are either low power special interest stations (religious/community/etc) or are
low power REPEATERS for a more distant station (no, I don't know what's what).

Low power/repeaters are NOT required to shut down analog by Feb2009.
In fact, until Feb2009 analog shutdown opens up a bunch of channels,
they have (until recently) been discouraged from seeking digital assignments.

So don't expect most of the nearby analog stations to go digital until some
period of time ON or AFTER Feb2009.

=======================
www.antennaweb.org (above) only found one DTV station (KMCC-DT in Laughlin).

www.tvfool.com finds KMCC-DT plus three more DTV stations with
STRONGER, line-of-sight signal strengths:
KMOH-DT on CH19 (Independent),
K35JA-D on CH35 (owned by Smoke & Mirrors),
K28EU on CH28 (KVVU-DT L.V. FOX repeater) and
K25HD on CH25 (reportedly goes digital Feb2009).
The last three "low power" stations probably go digital on or shortly after Feb2009....

=========================
Tvfool also predicts five Las Vegas stations with low to very low signal levels:
CH2 (NBC-HD), CH7 (CBS-HD), CH9 (FOX-HD) and CH11 (PBS-HD).
And there are other L.V. stations with extremely weak signal levels....

However, since Bullhead City is also transmitting on CH2, CH7 and CH9 it would
be very difficult to sufficiently suppress these strong line-of-sight stations.
[It would even be a challenge for a staggered antenna nulling system].

BTW: Post Feb2009, KMOH-DT and KMCC-DT as well as the listed Las Vegas
digital stations will remain on their current channel assignments.
Most "low power" stations will probably try to stay on their current assignments.
However, K63HJ and K57FY will have to move out of the new "700 MHz Band".

holl_ands

01-23-08, 03:36 AM

Before we can recommend an antenna, you need to determine which stations
you want to receive...and/or could live without....now and post-2009
Where can we draw the line wrt decreasing signal strength???

BTW: If you can receive analog station now, you'll probably receive digital when
they change post-2009.

Mister B

01-23-08, 09:46 AM

I used to live in small towns in New Mexico and depend on rural translators for TV reception. They are not always reliable although most of the Albuquerque stations were good about taking reports about reception problems. It is alway good to have a back-up for the same network form another small town even if it is not as strong of a signal.
If I were in your situation, I would first get a rotor so as to be able to turn the antenna and note which channels are receivable. You could up-grade to a better UHF antenna, many of which are discussed on this forum and add separate VHF high band or even low band antennas later.

Falcon_77

01-23-08, 09:27 PM

VHF-LO is perfect for situations like that seen in Lexington, a metro area whose TV market reaches well beyond the city and across huge swaths of mountainous terrain. I just wish other Lexington stations had followed suit, but I know full well that reception in far-flung, often impoverished Appalachia is not a priority for these guys.

For me, the bigger (and more unsightly) the antenna the better.

Thank you for the info. I have a few questions.

What antenna are you using?

How does WDKY (4) compare with the upper VHF stations in the area: WLJC (7), WYMT (12) and WKYT (13). WKYT appears to be about 10 miles behind WDKY. The others are closer, is it easy to receive them?

The power levels on the VHF Lexington area stations are quite high at between 26.5 and 50kW, which no doubt helps reception. WDKY is listed as the 4th most powerful low VHF-station for 2009, after KYES (AK), WCES (GA) and KVBC (NV). The median Low-VHF power is around 7kW.

dmiller1971

01-24-08, 08:36 PM

Hi everyone. I'm new to this so turning to the pros for help! I live in Charlotte NC (28278) and installing an antenna (dropping cable altogether). Thinking based on the results from Antennaweb that the CM4221 will work for me fine (although appreciate any comments - my info is below). My question is related to install - I have a locked time warner box on the back of my house and will continue to use TW for internet. How do I connect my antenna to the existing cabling throughout the house so that I have antenna reception on all the TV's being used? There appears to be one coax connection outside of the box that is not being used but can't tell if it is "in" our "out". Take it easy on me with responses - I'm new to terminology here!

My antennaweb results.
yellow - uhf WBTV-DT 3.1 CBS CHARLOTTE NC 336° 21.5 23
yellow - uhf WJZY-DT 46.1 CW BELMONT NC 340° 20.6 47
yellow - uhf WCNC-DT 36.1 NBC CHARLOTTE NC 336° 20.0 22
yellow - uhf WCCB-DT 18.1 FOX CHARLOTTE NC 57° 18.8 27
yellow - uhf WSOC-DT 9.1 ABC CHARLOTTE NC 59° 18.9 34
green - uhf WMYT-DT 55.1 MNT ROCK HIL SC 340° 20.6 39
red - uhf WMYT 55 MNT ROCK HILL SC 340° 20.6 55
red - uhf WAXN 64 IND KANNAPOLIS NC 59° 18.9 64
red - uhf WAXN-DT 64.1 IND KANNAPOLIS NC 59° 18.9 50
red - uhf WUNG 58 PBS CONCORD NC 56° 28.1 58
red - uhf WUNG-DT 58.1 PBS CONCORD NC 56° 28.1 44
red - uhf WTVI 42 PBS CHARLOTTE NC 58° 21.3 42
red - vhf WTVI-DT 42.1 PBS CHARLOTTE NC 58° 21.3 11
red - vhf WSOC 9 ABC CHARLOTTE NC 59° 18.9 9
red - uhf WCNC 36 NBC CHARLOTTE NC 337° 20.0 36
red - uhf WJZY 46 CW BELMONT NC 340° 20.6 46
red - vhf WBTV 3 CBS CHARLOTTE NC 336° 21.5 3
red - uhf WCCB 18 FOX CHARLOTTE NC 58° 18.6 18
red - uhf W52CW 52 TBN CHARLOTTE NC 65° 20.3 52
blue - uhf W38CN 38 TBN CHARLOTTE NC 336° 20.0 38
blue - uhf WNSC 30 PBS ROCK HILL SC 191° 17.8 30
blue - uhf WGTB-LP 28 FMN CHARLOTTE NC 38° 14.4 28
violet - uhf WNSC-DT 30.1 PBS ROCK HILL SC 191° 17.8 15
violet - vhf WFMY 2 CBS GREENSBORO NC 57° 84.0 2
violet - uhf WUNE 17 PBS LINVILLE NC 331° 82.1 17

johnstonamerica

01-25-08, 08:21 AM

cp and others.. sorry I haven't put pics up yet, still having problems..

lost all my channels completley a few days agao, and after scrambling all over the roof in freezing weather checking my connections over and over determined the problem was with the power supply to the CM7777 right in my livingroom! I could wiggle the connections (hard) and sometimes get a signal for a second.

I replaced the power supply and voila, had everything back again!
Then, after a few hours away, I checked again, and am now missing my UHF completely while still getting my VHF fine. So crazy.

I noticed when I put the 91XG together the connection on the black box (balun?) seemed to move way too muc (in and out). Could it be that I have a faulty balun and that is why I lost UHF and not VHF.

Man this is getting more and more frustrating :) Every time I think I have it, victory is snatched out of my hands again and again!

Any thoughts would certainly be welcomed!

johnstonamerica

01-25-08, 09:24 AM

Thank you so much for the advice and encouragement Rick!

It has to be something wrong with the connection between the 91XG and the preamp, right? Otherwise why would I still be getting VHF?

Also, I keep wondering why the heck I got UHF fine when I first replaced the power supply. Plugged the new supply in and watched UHF for about 2 hours, no problems at all. Then a few hours later, absolutley nothing. Why the heck would it work fine first, then just stop when nothjing has changed? Coule the power supply be overheating or something?

I'm assuming the plastic housing on the balun comes off easily?

Appreciate the reply, I'm learning more about antennas than I ever thought was possible ;)

donnyjaguar

01-25-08, 09:46 AM

w0en

01-25-08, 09:56 AM

miztahsparklez

01-25-08, 01:22 PM

mangokm40

01-25-08, 03:31 PM

Hello.

I'm a neophyte looking for ideas. :) The following is the information I get when I type my address at antennaweb.org:

yellow - uhf 69.1 TFA 32° 20.1 47
yellow - uhf 4.1 CBS 29° 18.3 22
yellow - uhf 33.1 MNT 31° 18.5 32
yellow - vhf 10.1 ABC 31° 18.4 9
yellow - uhf 44 IND 35° 21.1 44
yellow - uhf 35.1 ION 32° 20.1 26
yellow - uhf 51.1 TEL 32° 20.1 52
yellow - vhf 7.1 FOX 31° 18.2 8
yellow - uhf 2.1 PBS 32° 17.9 18
yellow - uhf 6.1 NBC 29° 18.3 31
yellow - uhf 17.1 PBS 33° 19.6 20
yellow - uhf 23.1 UNI 29° 18.3 24
lt green - uhf 46.1 TBN 35° 21.1 46
red - uhf 39.1 CW 29° 18.3 19

My rabbit-ear test picked up everything (and more!) on UHF. However, I can't make the dipoles pick up the 2 VHF channels. Since they are going to stay VHF (8 moves to 7 and 9 moves to 10) next year, whatever solution I get will likely continue to work. I was going to get a Winegard GS1100 because they can be had for < $20, including shipping. I'd like to get something that will work in bad weather, though. I'd appreciate any thoughts.

Thanks for your time.

Falcon_77

01-25-08, 03:56 PM

My rabbit-ear test picked up everything (and more!) on UHF. However, I can't make the dipoles pick up the 2 VHF channels. Since they are going to stay VHF (8 moves to 7 and 9 moves to 10) next year, whatever solution I get will likely continue to work. I was going to get a Winegard GS1100 because they can be had for < $20, including shipping. I'd like to get something that will work in bad weather, though. I'd appreciate any thoughts.

It appears that you are in the Miami, FL area?

I'm guessing that multi-path interference is hampering your VHF signals. A real outdoor antenna like Rick suggests above would be good, as staying with an indoor solution may be problematic.

I have not had much success coming up with an indoor VHF directional antenna, which would help multi-path. Physics dictate that a directional VHF antenna will have to be larger.

How big would a "bow-tie" high-VHF antenna need to be I wonder... 4x as big as a 4228? It's no wonder I haven't seen one and that VHF relies on boom types.

johnstonamerica

01-25-08, 04:06 PM

does it matter if the coax from my 91xg passes right by the 3176 on the way down to the preamp? could that be the reason I'm getting no UHF?

it may even touch it at times when the rotor turns...

johnstonamerica

01-25-08, 04:52 PM

thanks Rick - yes the tuner is swithed to off air correctly. I have taken apart the 7777 and everything looks to be OK inside.

Now I have the mast back off the roof (a real pita in the cold!) and have the balun apart from the 91XG.

Connections look good there too
I have no clue.. guess I'll double check all connections as suggested tomorrow am..

holl_ands

01-25-08, 06:22 PM

Hi guys. I'm considering stacking 4 UHF yagis vertically on one pole. What's the best way to feed this kind of rig? Right now I'm leaning towards joining the equal lengths of 300Ω twinlead at a common point connected directly to the coax. I'll then use a current balun on the 75Ω coax. This is what the ham guys do. I've not tried it myself (due to weather in NE) so I thought I'd see how others were doing it. RF savvy on this end so no need to laymanize response.

Ta

Ham Radio bands are narrow and hence quarter-wavelength combiners are
usable across the entire (narrow) band.

However, UHF TV covers 2:1 in wavelength so you need to use RF Combiners.

A conventional 4-Way Splitter/Combiner will have about 1 dB of insertion loss
(and 6 dB combining gain) if all of the signals arrive with same signal strength
and phase (unlikely) and the antenna elements are "matched" so that the
various signals have the same signal energy and phase (possible, but small
variations degrade the matchings). Mismatches are dissipated in an internal resistor.

The Triax 841/UHF Stripline Combiner (and Lindsay 4WCU 4-Port Combiner)
use modern microstrip technology to avoid this matching problem, resulting
in an inserion loss of only 0.2 dB irrespective of poor input "matching":
http://www.triax.co.uk/?alPage=&rkPage=&articleId={CD3E79AC-C7F3-40F1-BC26-4B524F03A2CB}
See page 59 in Triax Catalog.

Since Lindsay (Ottawa Canada) was bought out by Wade/Taco/Delhi, I've
been unable to locate a source (if any are left).

kycubsfan

01-26-08, 10:16 AM

Thank you for the info. I have a few questions.

What antenna are you using?

I'm using a Terk TV-36 mounted at the peak of my single-story home's roof.

How does WDKY (4) compare with the upper VHF stations in the area: WLJC (7), WYMT (12) and WKYT (13). WKYT appears to be about 10 miles behind WDKY. The others are closer, is it easy to receive them?

I get WLJC-7 without fail. I've never been able to tune WKYT-13.

WYMT-12 is available only intermittently, but I attribute this to man-made obstructions in my immediate area which block my view toward Hazard. I plan to mount a Wade VIP-307/AD XG91 combo on a 60 ft. (or higher) tower to clear a shot to Hazard, as well as give me a chance at the UHF digital PBS (WKHA-35) and post-transition VHF digitals in Knoxville (WBIR-10) and Johnson City (WCYB-5.)

The power levels on the VHF Lexington area stations are quite high at between 26.5 and 50kW, which no doubt helps reception. WDKY is listed as the 4th most powerful low VHF-station for 2009, after KYES (AK), WCES (GA) and KVBC (NV). The median Low-VHF power is around 7kW.

Interesting. I assume this was done with the challenges of the Lexington DMA in mind.

Mister B

01-26-08, 10:44 AM

Since no one else has answered this question I looked up some information today. It is a bit unusual to have major broadcast stations from three different directions. You have 5 channels from roughly 60 degrees and another 4 from about 335 degrees. As the PBS station at 182 is the third in your market, possibly you could do without that channel.
I looked up channel assignments for February 2009 and none of yours are going to change, also unusual. Your PBS station, WTVI is the only VHF frequency being on 11. I usually do not recommend trying to get VHF with a UHF antenna, however it is up to you if you would like to try depending on how important this channel is to you and there is the PBS affiliate WUNG on 44.
Pointing one UHF antenna half way between the two transmitter sites may or may not work. The 4 and 8 bay "bowtie" units do have a wider degree of signal capture range than Yagi units, so you could give it a try. If the signal is not sufficient then you would have to resort to either a rotor or two antennas with one pointed in each direction and select between them with a switch. As you have indicated that you are interested in connecting more than one TV, a rotor or switch does not allow all TV's to have access to all of the channels at once. Be aware that "omni-directional" antennas seldom perform well and you can not just tie two antennas of the same frequency range together with a coupler.
As for tapping into the existing cable line to distribute the signal throughout the house, if having Internet service also means keeping basic cable TV the frequencies would overlap, especially that channel 11. It would be far more preferable to run separate cable for the antenna system and keep the number of taps to a minimum. Again, you could experiment and try to use the existing cable but it may not work.
This is probably a more complicated answer than you had hoped for, but as I stated above, you are in a rather unique situation.

mangokm40

01-26-08, 06:33 PM

Thank you for taking the time to reply. I guess I knew the answer but hoped for some 'magic bullet'. :) I guess I'll get the 7694 and try it in the attic first. If that doesn't work well, I'll bite the bullet and put it where it belongs. :)

Thanks again.

Nicolae

01-27-08, 05:32 PM

Hey guys, I've recently re-done my HTPC setup, and am now using a Silicondust HDHomeRun. However, when trying to split my current antenna's signal to go to both tuners, I'm no longer able to reliably watch some of the stations that come in just fine without the splitter. The antenna itself is starting to fall apart (just like the last one I had, it's a silver sensor clone from Philips) and I've been looking into getting a new one but I'm kinda lost.

I'm outside of Richmond, VA, 21 miles from all but one transmitter, and I'm 17 miles from that one. Right now, I've got the SS pointing out a window on the back of my house, which works well with some slight issues picking up the local Fox station (anything that makes the antenna vibrate, even slightly, causes it to break up).

I figure going for an outdoor antenna is best, even if I have to crawl under the house to run the cable. I'd prefer something I can just mount on the side of the house (for now), and I was looking at both the Antennas Direct DB2 and the ChannelMaster 4220, which seem to be similar. However, I will need something that can pick up VHF channel 12 come 2009, as the local NBC affiliate will be going back to their current analog station then.

My other question is whether I'll need a preamp or amp for this, for splitting it into 2 (and possibly 4 down the road).

No idea if it'll be helpful, but I've attached my TV Fool "Radar" map. I'm only interested in the first 6 stations, the CW would be nice but I'd have to deal with my neighbor's backyard jungle to get a signal.

Falcon_77

01-28-08, 12:55 AM

Dan Kolton

01-28-08, 11:08 AM

I presently have an attic antenna, and would like to try it outside, but don't want to go on the roof. I'm right on top of most stations (3-6 miles) but have big problems when it gets at all windy. Is it possible to mount on the side of the house at, say, 10 or 12 feet above the ground and expect any improvement? What about lighting protection?

Ben98gs

01-28-08, 11:46 AM

Looking into setting this up with my tax check, but do not really know where to start.

I would prefer to have the antenna in attic (I think there might be something in the neighborhood association rules about antennas... But I thought I read somewhere that it was against the law for them to try and limit you on where you can mount them... Maybe someone can chime in on that too), but would possibly be willing to go with a roof mount if it was small enough in size that I could "hide" it on the back of the house (I am the first house you see coming into the housing addition).

Here is a list of the local stations from antennaweb (I live at zip code 46055 at approximately N 700 W and Pendleton Pike/SR67)

yellow - uhf WTHR-DT 13.1 NBC INDIANAPOLIS IN 288° 13.4 46
yellow - uhf WRTV-DT 6.1 ABC INDIANAPOLIS IN 279° 14.0 25
yellow - uhf WXIN-DT 59.1 FOX INDIANAPOLIS IN 276° 14.1 45
yellow - uhf WNDY-DT 23.1 MNT MARION IN 4° 18.5 32
green - uhf WFYI-DT 20.1 PBS INDIANAPOLIS IN 279° 14.0 21
green - vhf WISH-DT 8.1 CBS INDIANAPOLIS IN 276° 14.3 9
red - uhf WFYI 20 PBS INDIANAPOLIS IN 279° 14.0 20
red - uhf WIPX-LP 51 ION INDIANAPOLIS IN 240° 14.0 51
red - vhf WISH 8 CBS INDIANAPOLIS IN 276° 14.3 8
red - uhf WIIH-CA 17 UNI INDIANAPOLIS IN 276° 14.3 17
red - uhf WBXI-CA 47 IND INDIANAPOLIS IN 276° 14.3 47
red - uhf WDTI 69 DAY INDIANAPOLIS IN 261° 13.0 69
red - uhf WDTI-DT 44 DAY INDIANAPOLIS IN TBD 277° 14.3 44
red - vhf WRTV 6 ABC INDIANAPOLIS IN 279° 14.0 6
red - uhf WXIN 59 FOX INDIANAPOLIS IN 276° 14.1 59
red - vhf WTHR 13 NBC INDIANAPOLIS IN 288° 13.4 13
red - uhf WNDY 23 MNT MARION IN 4° 18.5 23
red - uhf WHMB 40 IND INDIANAPOLIS IN 277° 14.3 40
red - uhf WALV-CA 50 IND INDIANAPOLIS IN 288° 13.4 50
red - uhf WCLJ 42 TBN BLOOMINGTON IN 203° 34.9 42
red - uhf WCLJ-DT 56.1 TBN BLOOMINGTON IN 203° 34.9 56
red - uhf WTTK 29 CW KOKOMO IN 2° 31.6 29
red - uhf WHMB-DT 40.1 IND INDIANAPOLIS IN 349° 9.5 16
blue - uhf WTTK-DT 29.1 CW KOKOMO IN 2° 31.6 54
blue - uhf WIPB 49 PBS MUNCIE IN 61° 35.2 49
blue - uhf WIPB-DT 49.1 PBS MUNCIE IN 67° 32.3 52
blue - vhf WTTV 4 CW BLOOMINGTON IN 203° 34.7 4
blue - uhf WTTV-DT 29.1 CW BLOOMINGTON IN 203° 34.7 48
blue - uhf WIPX 63 ION BLOOMINGTON IN 202° 34.8 63
blue - uhf WDNI-LP 65 IND INDIANAPOLIS IN 255° 12.3 65
violet - uhf WIPX-DT 63.1 ION BLOOMINGTON IN 202° 34.8 27
violet - uhf WLFI 18 CBS LAFAYETTE IN 318° 50.0 18

There are no real stations that I need, but would like everything red, yellow, and green (could care less about the blue and violet, but if I can get them, I would not complain).

I currently do not have anything, so what OTA box and antenna would your recommend for me.

holl_ands

01-28-08, 12:12 PM

bozey45

01-29-08, 05:25 PM

My antenna will be on a high gable near center of the house. My ground wire run is about 30 feet to roof edge then down 20 feet or so, to an existing ground rod. Question is can I run this through a metal gable vent trough that starts right below the antenna mast? There are holes ever so often to attach the wire to the trough so it would not be loose on the roof. The wire is #10 copper insulated; it would go off the roof edge gently curved downward down the side of the house through a long plastic cable hider like cable and satellite companies do to hide their cables. The antenna mast has to go this location on the house because of trees at a gable end that would be too close to the antenna and also I wanted it as high as I could get because of a stand of trees about 300 feet south of me towards the towers in Riverview, FL. The other way i could run the ground wire is down a short 8 foot or so of gable down to an added on metal sun room roof then a run of 12 feet to it's edge and down to a ground rod, this run somewhat shorter (about 25 feet), would only have to drive a ground rod at this location; I know its preferred to have the ground wire run short but the reason I was thinking of that first run is that it goes to an existing ground rod for the house. The ground rod stuff is new to me, never grounded an antenna mast at my other house that was up for 25 years, just never did it; this time I'm trying to do it correctly; any suggestions about these 2 choices of runs are appreciated.

mlmahon

01-30-08, 12:50 AM

Hey, anybody know the recommended spacing for stacking 2 91XG's vertically??

bozey45

01-30-08, 04:41 AM

All the recommendations I see say 4 to 5 feet spacing between antennas.

donnyjaguar

01-30-08, 10:44 AM

Run the ground wire as short and straight as you can. I personally would use a separate 10ft ground rod for the antenna. There is a potential to cause ground loops if your collective AV system is in any way grounded to the other (power) ground in your house. These problems are not insurmountable though. Basically you want to keep a direct hit out of your house. Tying the antenna to a ground shared with your electrical outlets does provide a path into your dwelling.

bozey45

01-30-08, 04:55 PM

Yes, glad you said that, I did choose the separate path that is shorter and has the separate ground rod; got that done today; the only deviation of the ground wire from straight from the antenna mast is where it goes over the edge of the sun room roof, actually a gutter edge down to the rod. From the gable mount I have it going thru 3 standoffs down the gable to the sun room roof.

hdtvluvr

01-30-08, 08:48 PM

bozey45
According to most electrical codes, any extra ground rods must be bonded with the main electrical ground. This means that a wire must connect both ground rods. I believe code says 10 ga. solid copper is the minimum.

Having a separate ground can cause a ground loop which can cause electrical interference with your electronics.

It should be evident that grounding the antenna is not for providing a path from the antenna to the ground when lightning hits it. The ground wire is there to remove any buildup of electrical charge (due to wind, etc.) which can actually draw a lightning strike. Lightning most likely will destroy the wire from your antenna to the ground should your antenna take a direct strike. I've heard that some insurance companies will look for non-bonded grounds when claims are made for lightning problems such as house burning, electronic failures, etc. and deny claims if any are found.

Call you local electrical code enforcement office and see what is required. You can call anonymously if you desire.

scsiguy72

01-31-08, 11:50 AM

Let me make it swim some more. A good website with HD and antenna information is:

http://www.hdtvprimer.com/

If you could provide your just zipcode, we might be able to provide more detailed suggestions.

By the way, at those distance you will want to preamplify the signal.

No doubt others can provide more detailed responses.

I want to thank all the people on this forum that helped me out with this.

Yesterday I put up a VU-120RX (Radio Shack $29.00) and a 5 foot mast strapped to my Chimney pointed the unit without a compass due west hoping to pick up the Sutro Towers 45 miles away in San Francisco. No Pre-Amp and about 50 feet of RG6 cable.

I was very pleased at the results. I got 29 Digital channels (about half were Spanish or other languages)

I can get all the networks 2 different PBS stations and most channels are giving me somewhere between 5-7 bars of signal strength. Very happy with the picture and my next call will be to Direct TV to cancel my service and go OTA only

I live in Livermore 94550

donnyjaguar

01-31-08, 04:15 PM

I was very pleased at the results. I got 64 Digital channels
That calls for a resounding RIGHT ON!!
I have 19 DTV channels right now and I'm already crying tears of joy. :)
According to most electrical codes, any extra ground rods must be bonded with the main electrical ground.
Not 'round these parts. Although I concede that this is generally fine. Provided the path of least resistance is to ground, you should be fine.
Having a separate ground can cause a ground loop which can cause electrical interference with your electronics. You see this happen when running CableTV into your FM receiver. If you put a pair of baluns back to back you get rid of the ground loop. Most AV equipment nowadays doesn't have the third prong on the cord, largely to avoid these type of problems.

It should be evident that grounding the antenna is not for providing a path from the antenna to the ground when lightning hits it.
Sorry, this is just not correct.
The ground wire is there to remove any buildup of electrical charge (due to wind, etc.) which can actually draw a lightning strike.
This is quite true. If the collective system is more positively charged than the surrounding area, and this can definitely happen if there's no ground, it will be more appealing to lightning.
Lightning most likely will destroy the wire from your antenna to the ground should your antenna take a direct strike. That's why you need to use a nice thick one like 0 AWG. :)
I've heard that some insurance companies will look for non-bonded grounds when claims are made for lightning problems such as house burning, electronic failures, etc. and deny claims if any are found.I've never heard of this insurance company mentality. If it were the case then they would've completely denied the claim of my neighbour whose undrounded satellite dish on the peak of the roof took the hit. The fire gutted the house, BTW. If it was grounded properly this wouldn't have happened.

hdtvluvr

01-31-08, 07:46 PM

Thanks for your opinion. However, if you search the net you will find numerous articles that explain the reason for grounding. Here is an excerpt of one:

"One very important thing to know about grounding. Having it present will NOT protect you if you take a direct or even a secondary hit. What it does, is reduce the probability of getting hit in the first place and it provides much better protection against the damaged caused by the silent hits which is the most common of all static electricity damage. Many misunderstand this important point and I cannot repeat this point too often"

Here is the full link:

http://www.keohi.com/keohihdtv/hdreception/antenna_grounding.html

Hopefully, the OP grounded the coax and antenna.

ccaihc

01-31-08, 09:06 PM

Falcon_77

02-01-08, 01:38 AM

So, I have a Terk HDTVi antenna, it's uhf/vhf. I live in Worcester, Ma. I'm trying to pick up an HD channel from Boston which is 29.3 miles away. Now, antennaweb says it's light purple(which I'm not really sure I know what it means, is that bad?) Now, if I use tvfool it says it's the 3rd best signal and that I should be recieving it. I'm really confused about what I should do. I've tried pointing it everywhere, is there just no way I'm going to recieve ABC or PBS(same tower)?

Can you consider an outdoor antenna or at least an attic antenna? I don't think an indoor antenna is going to get it done in Worcester.

Are you getting any channels right now or are these the only problem stations?

WUNI is close at about 7 miles, which makes amplification problematic as well.

piratefan2

02-01-08, 08:55 AM

Hi,

I have a CM 4228 antenna and a CM 7775 preamp that I hooked up last Sunday. I am new to this stuff, but it was working great. When I came home last night, I couldn't get some channels that are on the fringes of what I can pick up. I checked the connections and they all seemed fine.

I have the 7775 going to a splitter that combines it with a set of rabbit ears (for vhf) before going to the tv.

I tried going straight fromthe 7775 to the TV, and I ended not being able to pick up ANY stations! When I unplugged the 7775 from the power outlet, I was back to getting just my very local channels.

What should I do?

Thanks.

holl_ands

02-01-08, 03:50 PM

Is the VHF/UHF power combiner/splitter between the
Power Insertion Module and the Preamp?

If it is, it may not be passing DC Power to the Preamp.
The fol. Micom device passes DC and has only 0.5 dB insertion loss
(vice 3.5+ dB for typical Cable or SAT RF Splitter/Combiner):
http://www.beachaudio.com/Pico-Macom/Uvsj-p-77211.html?utm_campaign=froogle&utm_content=AD_ID&utm_term=uvsj&utm_medium=cpc&utm_source=froogle&GTKW=uvsj&GCID=C12585x003
Check for inadvertent shorts in the various cables and other components.

Due to high loss, you especially want to avoid DC Passing Satellite
Splitter/Combiners and Radio Shack's RS-1234
"UHF/VHF 2-Way Coaxial Coupler/Combiner":
http://support.radioshack.com/support_video/doc31/31128.htm

piratefan2

02-01-08, 04:07 PM

No. The combiner/splitter is between the indoor component of the preamp (I don't what the technical name for this part is) and the TV.

However, when I went straight from the preamp to the TV (no splitter at all), the TV couldn't get a signal if the preamp was plugged in to the power outlet. When I would unplug the power to the preamp, I would get a signal (just not as strong as it was a couple of days ago).

holl_ands

02-01-08, 04:34 PM

The technical name for the little box that plugs into the wall outlet is
"Power Insertion Module" (PIM)...it inserts DC power onto the coax.
So, YES, your VHF/UHF Combiner is between the PIM and the Preamp.

Where are you located...zipcode and preferably nearby cross streets???

Nicolae

02-01-08, 04:51 PM

I would suggest moving up to the 4221 instead of the 4220. You probably won't want a very strong pre-amp at your range. The Winegard HDP-269 is probably the best bet, but I would suggest trying a 4221 w/o a pre-amp first.

The 4221 may also be enough to receive the VHF channel 12, but you want to consider one of the new Winegards as well:

http://www.solidsignal.com/prod_display.asp?prod=HD7694P

I don't disagree with Falcon_77's suggestions, they're right on target.

However, if you're interested in a lower profile antenna, check out RS 15-2185:
http://www.radioshack.com/product/index.jsp?productId=2348191
http://rsk.imageg.net/graphics/uc/rsk/Support/ProductManuals/1502187_PM_EN.pdf
It has a wide UHF beamwidth (like 4-Bay) to cover both arrival directions,
has a built-in low-gain (10dB), high overload preamp and moderate VHF performance.
Cost is about same as 4-Bay plus Preamp....

So you have a range of options from 2-Bay (probably needs a Preamp), 4-Bay, R-S Disc
and long-range HD7694P that may pick up stations towards SE (with a rotator).

I don't intend to mount anything on the roof, so anything that can't be mounted to a wall like a dish or something is out. Is the 4221 too bulky/awkward for such a mount?

I also don't know if I would even need that much antenna; even with a simple UHF loop I get all the locals with only intermittent dropouts. Again, though, I do want to split it to 2, maybe 4 at some point so I may just be better off with a larger antenna than trying to mess with an (pre)amp at this range?

Also, based on my (probably wrong) interpretation of some graphs over at HDTV Primer (http://www.hdtvprimer.com/ANTENNAS/comparing.html), the 4221 has slightly better gain on channel 12 than a set of rabbit ears. Given that I can currently receive analog channel 12 almost perfectly with (indoor) rabbit ears, is that a good indication that the 4221 will do well for me with channel 12 come 2009? The current analog and digital transmitters are on the same tower, but I believe the analog has the height advantage. Honestly, if the 4221 will suffice for channel 12 and can be wall-mounted I'll probably go with that.

Thanks for the help so far!

piratefan2

02-01-08, 09:48 PM

My zipcode is 28513.

I had the combiner bewtween the PIM and the TV, but I have taken that out of the equation.

I replaced the 7775 with a 7777 and I'm getting the same problem. I get only my closests channels (7, 9, 14) without plugging the 7777 into the power outlet. When I plug it into the power outlet, I get nothing.

I was getting 7, 9, 11, 12, 14, 25, 28, & 50 before I started having these problems.

Is it possible that some water got into my coax cable and that that is causing a problem?

I really appreciate you taking the time to answer my questions.

cpcat

02-01-08, 09:58 PM

Welcome to the random and changing nature of TV reception. Judging from your location, you are too close to your locals for that preamp. You probably don't need a preamp at all. What's most likely happening is you are overloading the TV's tuner and/or the preamp. That's why it improves with the ps unplugged and the splitter in-line. How were you getting the signals initially? See the first line above.:)

piratefan2

02-02-08, 11:22 AM

I was getting a great signal initially. I was able to pick up 5, 7, 9, 11, 12, 14, 25, 28, & 50. Now, all of a sudden, I'm only getting 7, 9, 12, & 14 when the amp is unplugged.

Falcon_77

02-02-08, 11:41 AM

I was getting a great signal initially. I was able to pick up 5, 7, 9, 11, 12, 14, 25, 28, & 50. Now, all of a sudden, I'm only getting 7, 9, 12, & 14 when the amp is unplugged.

Unplugging the power module and keeping the pre-amp in the path will greatly attenuate the signal. Looking at the TV Fool plot for your area (attached), you are too close to local TV stations for the 7777 and/or the 7775 from overload.

With local stations under 5 miles, even the relatively overload resistant Winegard HDP-269 may have problems.

What problems were you trying to solve when you installed the pre-amp?

cpcat

02-02-08, 02:09 PM

I was getting a great signal initially. I was able to pick up 5, 7, 9, 11, 12, 14, 25, 28, & 50. Now, all of a sudden, I'm only getting 7, 9, 12, & 14 when the amp is unplugged.

That's why I said "Welcome to the random/changing nature of TV reception".:)

Initially, the local signals were likely attenuated for some other reason allowing reception of the more distant ones and preventing overload. Under more typical conditions (now) you are experiencing overload at either the amp or tuner or both.

You're better off either with no preamp at all or using a much lower gain amp with higher signal handling characteristics. The bottom line may be that it's difficult/impractical for you to receive the more distant stations due to the locals. One idea would be to run RG-11from your antenna to a low noise distribution amp like the ChannelVision CVT-15PIA at the first indoor opportunity.

Another possibility would be a GaSFet amp with high signal handling characteristics and low noise (also expensive). http://www.tonercable.com/Product.aspx?ID=1615

holl_ands

02-02-08, 06:19 PM

My zipcode is 28513.

I had the combiner between the PIM and the TV, but I have taken that out of the equation.

I replaced the 7775 with a 7777 and I'm getting the same problem. I get only my closest channels (7, 9, 14) without plugging the 7777 into the power outlet. When I plug it into the power outlet, I get nothing.

I was getting 7, 9, 11, 12, 14, 25, 28, & 50 before I started having these problems.

Is it possible that some water got into my coax cable and that that is causing a problem?

I really appreciate you taking the time

Were you simply unplugging power to Power Insertion Module or did you
physically bypass the Preamp???
A Preamp without power is going to block most signals---unless they leak across.

Hopefully you're using the CM-4228 with a rotator in order to optimize reception....
Which may mean pointing one of the two sidelobe nulls (at +/- 30 degrees)...
or rear of the antenna...towards nearby strong stations:
http://www.hdtvprimer.com/ANTENNAS/cm4228.html

========================
Zipcode 28513 is location of the U.S. Post Office, East of Ayden N.C.

There is a tower with two Megawatt transmitters only 1 mile NNE away.
Another tower with a Megawatt transmitter is only 3.2 miles SW away.
And a tower with four more strong stations only 4.7 miles SSW away.

You didn't provide nearby cross streets, but it's clear you are in the midst of
extremely high signal levels.

There is essentially NO WAY to get a Preamp working in your situation.

And even without a Preamp, the strong signals can generate unwanted
intermod products in the RF front-end of your HDTV, making it much less
sensitive on certain affected channels.

========================
These strong signals COULD be leaking into cables, connectors....and even
directly into your HDTV.

First thing is to make sure connectors are secure and carefully crimped.
You may need to cut off and use a crimping tool to install a new connector.
Quad shielded RG-6 is recommended to minimize leakage into the cable.

Second thing to try is to insert an RF Attenuator on your HDTV's input.
Two of 2-Way RF Splitters in series....or a 4-Way RF Splitter will insert 8 dB
of attenuation....which reduces intermod products by a factor of three...or 24 dB.
[And a single 2-Way RF Splitter reduces intermods by 12 dB.]

Radio Shack may have a variable RF Attenuator (RS 15-678) for more
careful tweaking....or order from Antennas Direct:
http://www.antennasdirect.com/attenuator.html

If you are still not quite satisfied, a Dual-Notch Filter tuned to CH14
can also be inserted to attenuate the strongest nearby signal.
And maybe a second tuned to CH38....or simply wait for Feb2009...
http://www.solidsignal.com/prod_display.asp?prod=UT-2700
http://www.summitsource.com/product_info.php?ref=1&products_id=5344
BTW: In these Dual Notch filters, one notch targets the video carrier
and the other targets the audio carrier.

AntAltMike

02-02-08, 07:03 PM

If you are still not quite satisfied, a Dual-Notch Filter tuned to CH14
can also be inserted to attenuate the strongest nearby signal.
And maybe a second tuned to CH38....or simply wait for Feb2009...
http://www.solidsignal.com/prod_display.asp?prod=UT-2700
http://www.summitsource.com/product_info.php?ref=1&products_id=5344
BTW: In these Dual Notch filters, one notch targets the video carrier
and the other targets the audio carrier.

The Winegard notch filters are overpriced junk. They doubled the price recently, so I can't even buy them wholesale for any less than about $45 or so. Holl_and's retail links price them at $58 and $80.

Their notches are not even narrow enough to meaningfully center on one carrier, even with a spectrum analyzer, and you need to find a non-inductive tuner with a really thin blade to tune them. The components that you will be tuning are non-inductive but they are in close proximity to circuitry that is inductive. When I have to use one for maximum attenuation of one UHF signal, I don't even try to land them on the individual notches. I just tweak one to weaken both carriers, and then tweak the other to weaken both carriers.

Unfortunately, the only quality UHF notchtrap readily available to the general public is Blonder Tongue's MWT-u, which you can get from various suppliers for $250, and the best price I can get as a dealer is $200. If you search the internet and stumble across a page that has them for about $115, that is a very obsolete listing. I telephoned them to see what they could get them for and they said they don't even carry that product line anymore.

Eagle Comtronics recently sold me a nice, shielded single notch of about 25dB of depth, and there is one adjustment to widen the notch while sacrificing depth, making it more suitable for attenuating digital signals if necessary.

cpcat

02-02-08, 07:21 PM

Works well. I use it to attenuate a local analog 44. Allows me to insert a post-amplifier inline without intermodulation. Pricey though, as mentioned. Probably not a practical solution to buy two or three of these in this situation.

I agree about the Winegard filters. Not very good. I think they're too shallow and not narrow enough. Read: not a very good notch filter.:)

Falcon_77

02-02-08, 10:13 PM

holl_ands

02-03-08, 12:52 AM

I'm assuming that these traps are worthless for attenuating DTV signals if they only affect NTSC audio and video carriers.

I had a dual channel filter made by Tin Lee, which shows the attenuation throughout the selected channels. I haven't had a chance to test it at the site yet however and it wasn't cheap.

A question have: Is a 5MW peak power analog NTSC signal more harmful than a 1MW average power ATSC signal? i.e. is overload more likely from NTSC signals than ATSC signals?
DTV 8-VSB Peak-to-Average Power Ratio is 7 dB +/- 1 dB, depending on
where you look on the probability distribution curve.

NTSC Peak-to-Average Power Ratio is 5.14 dB for Mid-Gray luminance level,
7.55 dB for Pure White and 2.23 dB for Pure Black. [That's 4.9 dB +/- 2.7 dB]

Peak-To-Average Ratios for ATSC vs NTSC overload was discussed in
Antenna/Rotator/Preamp thread on 26Sep2005, reading down through 29Sep:
http://www.avsforum.com/avs-vb/showthread.php?p=6256839&highlight=peak+ratio#post6256839
http://www.avsforum.com/avs-vb/showthread.php?p=6268128&highlight=peak+ratio#post6268128

Peaks in NTSC and DTV signals cause worst bit errors...just like overload
clipping in audio amplifiers.

NTSC horizontal sync pulses result in a very repetitive (30 Hz), peaky signal....
which doesn't vary all that much.....
Hence NTSC signals are always measured with a PEAK reading meter.

ATSC signals are more like gaussian noise and are always measured with
an AVERAGE reading meter....so need to be careful comparing apples & oranges.

Add 7 dB to ATSC AVERAGE signal level (e.g. 1 MW) to find PEAK signal level (i.e. 5 MW).

Hence a 5 MW NTSC station generates roughly the same PEAK levels as a
1 MW ATSC station---give or take some statistical arguments re how many
bit errors are caused by horiz sync pulse overload vice random ATSC spikes....

[Bit Error Rate derivation is left as a student exercise.....]

holl_ands

02-03-08, 01:34 AM

Specs for Blonder Tongue BT-MWT-U, Single Notch Filter:
http://www.blondertongue.com/headend/mwt.pdf
Note notch can target either video carrier or audio carrier--
but bandwidth is too narrow to be effective against BOTH.

A simple, inexpensive notch (trap) filter can only target a narrow bandwidth...
primarily the video carrier frequency...and will provide much less
attenuation for the rest of the 6 MHz wide channel:
http://www.soontai.com/curve/TRFch5_fg1.gif
http://www.soontai.com/da_filterprofile.html
http://www.dewtronics.com/tutorials/descramblers/notchfilter/neghtw.pdf

A Dual Notch can also target the Audio carrier..and the combination
somewhat suppresses the lower level Chroma carrier....but it's far from perfect.

Dual Notch provides significant, but not "perfect", attenuation of DTV signals....
We don't need 40-80 dB of attenuation. A mere 10 dB attenuation will
suppress intermod products by 30 dB.

The "best" filter is a complex, multipole design, rather than just
one or two "poles". But very few people want to spend that much:
http://www.tinlee.com/Graph_CR7E.php?active=1
http://www.tinlee.com/Graph_CE7_Spec_Order.php?active=1

Really expensive but very effective Multipole Notch Filters:
http://www.cefilter.com/products/display_product.asp?ProdID=57&CatID=3

Yet another Multipole Notch Filter...a DIY Kit:
http://www.dewtronics.com/tutorials/descramblers/notchfilter/df222.html
http://www.dewtronics.com/tutorials/descramblers/notchfilter/notch.html

AntAltMike

02-03-08, 03:53 AM

Soontai filters may be inexpensive, but when I was negotiating with them a few years ago, their minimum quantity for the products I was looking at was 500 units. I think they quoted me $1.35 per unit for cylindrical lowpass filters with about 40dB of rejection and $2.00 per unit for highpass filters. I have stations from one city using channels 33-36, and from another city using 38, 40, 41 and 42, so I can primitively and inexpensively channel them from two separate antennas using "tier trap" grade filters.

I agree with holl_ands that even a cheap tunable notch filter like the Winegard will more than adequately suppress a strong digital channel. For analog reinsertion, we need over 40dB of channel-wide suppression, but to reduce overloads, we need very little attenuation.

Oops department. The filter I bought that I said in Post #6621 came from Eagle was actually a single cavity filter from Communications and Energy. I had ordered from so many companies the day I ordered it that I didn't even remember who I bought that one from. It wasn't real expensive but it did cost over $100.

AntAltMike

02-03-08, 04:03 AM

Yet another Multipole Notch Filter...a DIY Kit:
http://www.dewtronics.com/tutorials/descramblers/notchfilter/df222.html
http://www.dewtronics.com/tutorials/descramblers/notchfilter/notch.html
That kit only goes up to 216 MHz. I've bought similar products that go to cable channel 36 (300 MHz) but never found any that could be tuned into the UHF range. They were designed to notch out the 2.2 MHz offset, "interfering carrier" that cable companies used to use to scramble premium channels back in the 1980s. I used brag that I was the only regular customer for that product who bought it to use it legally, as I used it to reduce aural carriers in adjacent channel master antenna systems.

cpcat

02-03-08, 08:49 AM

AntAltMike

02-03-08, 09:54 AM

The notch dimension specs on the MWT-u

Notch width dB v frequency:

-3 (10 MHz)
-12 (3 MHz)
-20 (1.8MHz)

So if you tune it to +1.5 MHz and +4.5 MHz within a 6 MHz ATSC channel band, the signal will be weakened variously by anywhere from 12 to about 40 dB across the plateau. That would be unacceptable filtering for clearing out a digital a channel for analog insertion/replacement, but more than adequate for addressing overload situations that one can remedy with UHF notch filtering.

One caveat about using the MWT-u, however. I believe that the severe unevenness of the dual notches impressed upon an ATSC waveform will qualitatively degrade it to the point at which it cannot be reliable tunes, whereas gentle attenuation with cheap, Channel Master Jointennas or even Winegard UT-2700s will leave the weakened channel in a processible form. One way around this problem is to use two downleads and insert a directional coupler tap, with a low insertion loss, like a DC-20, with an insertion loss of maybe about half a dB, and put the notch filter and preamp on the through line, and use the weaker, tap port as the signal source for your stronger stations. The awkwardness of doing that is that you'd have to manually switch back and forth between the coaxes, which is inconvenient for scheduled program recording.

holl_ands

02-03-08, 10:13 AM

Specs for Blonder Tongue BT-MWT-U, Single Notch Filter:
http://www.blondertongue.com/headend/mwt.pdf
Note notch can target either video carrier or audio carrier--
but bandwidth is too narrow to be effective against BOTH.

The MWT-U actually has two separately tunable filters so this is incorrect.
Maybe I was thinking of the old Channel Master notch filters????

I haven't used the MWT-U ($250 at starkelectronic.com).

So why does spec sheet say there are "coarse" and "fine" tuning controls...
and I only see two tweakers on the unit??? Wouldn't it need four for dual notch?

Does anyone have any actual MEASURED attenuation curves???
And perhaps instructions for tuning....

cpcat

02-03-08, 10:26 AM

, whereas gentle attenuation with cheap, Channel Master Jointennas

That would seem to be the easiest/cheapest way for an amateur to pre-filter strong locals as these are pre-tuned. I can't imagine the headache of trying to tune 4 or 5 notch filters. I'd probably have to call you.:)

The potential problem with the jointennas though would be that the broader notch might attenuate weak adjacent channels. Also, you'd have to deal with the additive loss of several in series.

cpcat

02-03-08, 10:54 AM

Maybe I was thinking of the old Channel Master notch filters????

I haven't used the MWT-U ($250 at starkelectronic.com).

So why does spec sheet say there are "coarse" and "fine" tuning controls...
and I only see two tweakers on the unit??? Wouldn't it need four for dual notch?

....

There's a coarse and a fine tuning adjustment for each of the two filters. The more prominent/visible adjustment screws are the fine while the coarse are flat and more flush with the housing.

Here's a better pic:

AntAltMike

02-03-08, 11:14 AM

The coarse and fine controls on a Blonder Tongue MWT-u just allow you to more rapidly yet precisely hit the bullseye. Each of the two traps is independently tunable over the entire UHF band. When we use attenuators to reduce aural carriers, we need to attenuate the carrier just the right amount, but if we are not careful, the deepest part of the notch falls below the aural carrier and screws up the NTSC color burst, but that is of no concern here.

The Blonder Tongue MWT-2, 3 and 4 have another knob for trap depth that the MWT-u doesn't have, but I never had to experiment with it. I have dozens of MWT-2s in service to weaken FM radio carriers before they enter an FM strip amp.

The old Channel Master tunable, UHF traps weren't very deep or very sharp, but they had nice vernier dials that made it more practical for a hobbiest without test equipment to experiment with them while eyeballing a picture on a TV screen. They also were well shielded. I still have one in use in an MDU headend. They are each independently tunable over the entire UHF spectrum as well.

You can buy AVCOM spectrum analyzers on eBay for about $700 to $800 that typically have 300 KHz resolution and are excellent for evaluating and managing broadcast HDTV signals. Comparable units sell new for about $3,500. I carry an Applied Instruments, battery operated, 5-2000 MHz white noise generator that I paid about $370 for. It is the size of a pack of cigarettes. I sometimes use it as a signal source when I try to tweak the Winegard UT-2700s, which are murder to do because I don't have a non-inductive tool that fits into their tuning slots, so I have to offtune it, watch the notch jump as I remove the tool, and then re-offtune it until the notch jumps to where I want it to be.

Someone working at Winegard was supposed to find out where they were buying the tweaker tool that they use to pretune these UT-2700s, but she never got back to me. You can tune MWT traps with an ordinary screwdriver, just as you can tune their aural carrier reducers on their strip amps with a small (1/8" or smaller blade) without the inductance of the blade affecting the attenuator notch frequency.

My favorite source of VHF tunable notch traps used to be a company called Star Circuits. They made traps that were the functional equivalent of the kits that holl-ands referenced above, but they were in shiny plastichrome cases. They used to advertise extensively in Popular Science, Popular Electronics and Electronics Now, but they are no longer in business, as their only customers other than me were people who wanted to clear beeping channels.

AntAltMike

02-03-08, 02:56 PM

Does anyone have any actual MEASURED attenuation curves???
And perhaps instructions for tuning....

You can take Blonder Tongue's published specs to the bank.

I just connected a Winegard UT-2700 to a white noise generator and then measured its single trap notch using a Sencore SL753D, which resolves to 100 KHz, but measures it through a 260 KHz wide filter.

My primitive Blonder Tongue BTSA-5 field-grade spectrum analyzer showed me that one notch is presently tuned to around 673 MHz. I then connected it to my Sencore meter, and took readings at 645 and 655, then in 1 MHz increments from 660 to 690, and then 700 and 710 MHz.

The maximum attenuation was 17dB at 673 MHz (around UHF channel 47). The -10dB trap depth points were at 669 MHz and 777 MHz, which is just slightly wider than one entire broadcast channel. The 3 dB attenuation points were are 663 and 685 MHz.

If you tune such a filter to the lower end of the UHF band, the notch widths will narrow slightly, proportionate to frequency, so they will be about 30% narrower at channel 14 than at channel 47.

By the way, the Sencore SL735D is nearly impossible to configure for digital signal measurement. The instruction manual doesn't tell you how to do it, and Sencore can only furnish a magazine article describing the arduous process of developing a digital, "custom" channel plan for the SL754D, which doesn't have exactly the same menu, so I've given up on it. I instead measure frequency samples within the 8VSB channel band, and then add 8dB to whatever the display reads.

ccaihc

02-03-08, 06:48 PM

Can you consider an outdoor antenna or at least an attic antenna? I don't think an indoor antenna is going to get it done in Worcester.

Are you getting any channels right now or are these the only problem stations?

WUNI is close at about 7 miles, which makes amplification problematic as well.

I don't know if it's possible, I am in a dorm. I can get telemundo and one more channel, which is another useless channel.

Dan Kolton

02-03-08, 07:14 PM

Is there an inexpensive method for measuring signal strenght at the antenna (other than the meter on your TV)? What instrument might one use, and how does it distinguish which channel is being measured?

AntAltMike

02-03-08, 08:05 PM

You can buy an analog fieldstrength meter on eBay for $20 to $40, or you can buy a digital meter that is designed to measure NTSC signals for $150 to $200, which is fine for measuring digital signals except that it will only show signal strength, but not quality (no bit error rate or flatness), and you will have to add about 8dB to whatever it says the signal strength is.

Konrad2

02-04-08, 01:20 AM

> Soontai filters may be inexpensive, but when I was negotiating with them a few years ago, their
> minimum quantity for the products I was looking at was 500 units. I think they quoted me $1.35
> per unit for cylindrical lowpass filters with about 40dB of rejection and $2.00 per unit for
> highpass filters.

We have a business opportunity for someone to import Soontai (or similar) filters
and sell them in small quantities. There is enough demand. My local electronics
store gets lots of inquiries, but can't quite figure out that it would be profitable
to carry things that customers are asking for.

AntAltMike

02-04-08, 06:54 AM

I wouldn't touch it with a ten foot pole. There are hundreds of traps, and the customer dissatisfaction rate would be high since, quite often, the filter would not do for them what they believed they needed done. Notice that Radio Shack doesn't even carry directional taps even though there is demand for them. I am certain that the problem is that such products would also take too much sales time and result in too many returns.

Pico used to stock hundreds of thousands of tier-trap cylindrical filters. Low pass, high pass, deep notch. Then, they got out of the business. Back about seven or eight years ago, I found that they had their inventory in "dead stock" that only a few employees knew about, and they read me the inventory quantities of some filters that they had hundreds of units each of. I bought maybe 20 lowpass filters that rolled off at about UHF channel 16, half a dozen that rolled off at 27, and half a dozen highpass filters that rolled off below UHF 23 (they were all actually CATV values, which are off-shifted by 2 MHz). I paid around $6 each for them.

But a couple of years later, they had just gotten rid of that stock. I called the company that supposedly had acquired it, but they claimed they didn't have it. I was persistent, calling different people in different departments at different times at both PICO and the company that had supposedly acquired the stock, but came up empty. They, a few years later, an industry veteran went to work for PICO and I asked him to poke around and see what he could find out about them and even he came up empty. Pico can buy the parts for a fraction of what I ever could, it already had them in inventory, and it has a large distribution network, but it decided to exit that business anyway. If they could no longer make any money in the bullet filter business (because addressable cable boxes minimized the need for channel-trap type filters) then no one else can either.

I now have someone supplying me with cylindrical filters for $12.50 each in quantities of ten of each value, but they won't sell to or take calls from individuals because they could wind up expending hundred dollars of sales time for each consumer sale that they might wind up making

Konrad2

02-04-08, 01:25 PM

> I wouldn't touch it with a ten foot pole.

No one said *you* had to.

> customer dissatisfaction rate would be high

speculation

The stereotypical mom isn't going to be ordering these.

> Radio Shack doesn't even carry

Radio Shack has been basically useless for decades. I'm not
sure it ever was useful.

> I am certain that the problem is that such products would
> also take too much sales time and result in too many returns.

Plenty of places are web-order only. No sales time.
The return shipping would cost more than the filter.
Add a restocking fee and you will not get returns.

> Pico used to stock hundreds of thousands of tier-trap cylindrical filters.

They still sell a few filters. As do a few other companies.

> I was persistent, calling different people ...

You have trouble getting the parts you need, and then you post that
you think that selling these parts would not be profitable, based
on one business model with high sales costs, ignoring other
business models which are successful selling similar items.
That doesn't make it easier to get the parts you need. (Someone
might believe you.)

> Pico ... decided to exit that business anyway.

Companies are run by people. Sometimes people make bad decisions.

Falcon_77

02-06-08, 03:17 PM

I will repost the image from yesterday that was lost when the board crashed.

I later found that Channel Master has these specs on a document on their website. It would be nice if they included these specs on all their antennas.

NJ Bulldog

02-06-08, 05:55 PM

Is there anything wrong installing this antenna against the side of a wall? We have regular wind gusts in the 25 to 35 knots and at least twice a year we can expect 50 knot gusts. The prevailing southerly winds would be hitting my future installation virtually right from behind and I wanted the option of mounting it on the north facing side of my chiminey. I realize that I have to get the best signal and this may not be an option. I'm questioning possible signal degradation and I don't think a wall behind an antenna makes a bit of difference, but I wanted to ask someone in the know. Thanks!

Falcon_77

02-06-08, 08:13 PM

I think this would probably work if the wall faces the towers that you want to receive. However, if the wall is stucco or has some other type of metal siding, this may not be a good idea, but I don't know for sure.

It sounds like a fun experiment, so I will try mounting a smaller CM4220 against a wall tonight to see what it does to the signal.

Falcon_77

02-07-08, 12:14 AM

I will try mounting a smaller CM4220 against a wall tonight to see what it does to the signal.

My tests only showed 1 channel (KABC) with a lower signal quality with the back of the 4220 to the exterior wall. The other channels did not have a noticeable change.

If your stations are straight out from the wall, I think the CM4228 would work in this fashion as well.

NJ Bulldog

02-07-08, 12:36 AM

My tests only showed 1 channel (KABC) with a lower signal quality with the back of the 4220 to the exterior wall. The other channels did not have a noticeable change.

If your stations are straight out from the wall, I think the CM4228 would work in this fashion as well.
Thanks a heckuva lot for the extra effort, Falcon. I have a lot to do before I can test this location, but I'll make sure to post my results.

holl_ands

02-07-08, 02:57 AM

fletchmath

02-07-08, 10:20 AM

Konrad2

02-07-08, 03:41 PM

VHF-LO is not necessarily bad. If WHP is staying with channel 4 after
the switchover a year from now, get a good VHF-LO antenna, or better yet
a channel-4-only antenna.

And a VHF-HI or channel-10-only antennas for ABC.

You could try pointing a UHF antenna west and trying to get 23 from the rear.

And a 2nd UHF pointing south.

> omni-directional antenna

2 problems with omni-directional antennas, 1- they have less gain, so you
get weaker signals, and 2- they pick up more multipath.

You might be able to find a high gain UHF that has lobes spaced such
that you can get both the west and south stations with a single antenna.
Hunt through the graphs on http://www.hdtvprimer.com/

e.g.
http://www.hdtvprimer.com/ANTENNAS/w8800.html
http://www.hdtvprimer.com/ANTENNAS/cm4228.html
http://www.hdtvprimer.com/ANTENNAS/DB8.html
http://www.hdtvprimer.com/ANTENNAS/XG91.html
and so on

> with vhf/uhf coverage

Separate VHF and UHF antennas will perform better than a combo.

You could get 1 antenna and a rotor, but then you can't record one
show and watch another.

Falcon_77

02-07-08, 03:58 PM

If WHP is staying with channel 4 after
the switchover a year from now, get a good VHF-LO antenna, or better yet
a channel-4-only antenna.

WHP will be returning to its analog UHF channel (21), so a VHF Low antenna should not be needed unless reception is needed for that station in the interim.

WHTM and WGAL will both be on upper VHF in 2009, but they are well off angle from each other, but at ~22 miles perhaps a lower gain/wider angle VHF High antenna will get the job done for those two.

You may want to consider combining a CM4221 for UHF with an Antennacraft Y5-7-13 for upper VHF or try the CM4221 to see if it is enough for WHTM now.

fletchmath

02-08-08, 06:44 PM

I posted a couple of days ago; I'm using a RS "mushroom" and getting PBS, NBC, Fox, and CW. In a lark, I picked up the outdoor 15-2187 to give a try (I read some good things, and didn't really think my location all that challenging).

Well, the 15-2187 is an abysmal failure; Even up on the roof, I can only get a lock on PBS; nothing else comes in. The little mushroom does MUCH better.

Does this make any sense at all? I would have expected it to at least compete with the indoor antenna, but it doesn't even match the rabbit ears and loop that I tried first.

holl_ands

02-09-08, 02:39 AM

It's possible the R-S antenna is defective.....maybe.....
Or it's Preamp is overloaded by nearby (SE 7.2 miles) stations.
Or you aren't pointing it accurately enough for each station of interest.
You would need to control a rotator while watching Signal Quality display.
And isn't very good for CBS on CH4 (specs say -20 dB gain for Low-Band VHF).

With a rotator, I would have used an inexpensive 4-Bay (or 8-Bay or 91XG)
antenna and a separate, non-rotating, Low-Band VHF antenna for CH4:
http://www.solidsignal.com/prod_display.asp?PROD=TD-V4
Yes, it's rather big....as it should be for CH4....

If you don't want to use a rotator, you could try a low-gain NON-AMPLIFIED antenna,
although that kind of antenna may not be directional enough to suppress multipath
from the surrounding mountains:
http://www.solidsignal.com/prod_display.asp?prod=ANWGS1000
http://www.solidsignal.com/prod_display.asp?prod=ANWGS1100
http://www.solidsignal.com/prod_display.asp?prod=SMS1000
http://www.solidsignal.com/prod_display.asp?prod=ANC3010

Wireman134

02-09-08, 09:37 AM

That's probably the title of 60% of the posts in this thread... sorry.

I posted in my locals thread earlier, and have concluded that I need a rooftop installation to have a good shot at picking up what I want. I've attached the TV fools output for my location. With an indoor antenna (RS mushroom), I can get a solid signal for PBS, a decent signal for NBC, a passable signal for FOX, a good signal for CW (don't watch it though, so I may be wrong), and no signal whatsoever for the VHF broadcasts, ABC and CBS. The CBS one is a low-vhf signal, which is particularly annoying, or so I gather.

From the tower distribution I gather that I need an omni-directional antenna with vhf/uhf coverage --- am I correct about that? Or, will a directional antenna be able to receive everything? Does anyone have specific antenna recommendations?

Thanks so much,
Ken

I'd try the CM4221 for outside or a DIY 4 bay in the attic combined with a Y5-2-6 Yagi http://www.solidsignal.com/prod_display.asp?PROD=Y5-2-6. Pulls in VHF high band just fine for me 35 miles out.:D Why not just get one antenna and a rotor if your really set on a outside install.
http://www.solidsignal.com/prod_display.asp?PROD=4BG26
http://www.solidsignal.com/prod_display.asp?PROD=CCS1233
http://www.solidsignal.com/prod_display.asp?PROD=CCS822
This is my setup http://www.avsforum.com/avs-vb/showthread.php?p=12852274#post12852274
Do you have open attic space?

holl_ands

02-09-08, 06:08 PM

Channel Master VHF/UHF Combos also may be found at home improvement stores:
http://www.solidsignal.com/prod_display.asp?prod=ANC3016

However, big outdoor antennas seem an overkill for "only" 19 miles, esp. since
it is unlikely to be of use for distant stations because they are so weak.

I'ld start with 4-Bay (roof or attic without rotator) and see if it happens
to ALSO pick up CH10 (fairly easy) and CH4 (more of a challenge)....
After all it's "only" 19 miles LOS...any ol' coat hanger outta work for VHF....

The 4-Bay also is likely to pick up the nearby (7.2 mile) station on the
"back" of the antenna, so no need to readjust rotator direction....
Then you can ascertain whether you need a rotator.....or not...

Wireman134

02-09-08, 11:34 PM

Auzivision

02-10-08, 02:04 PM

Whidbey

02-10-08, 08:06 PM

Neil L

02-10-08, 10:24 PM

Looks to be a Channel Master 4221, or something very similar.
http://www.solidsignal.com/prod_display.asp?PROD=SCM4221A&xzoom=Large#xview

holl_ands

02-10-08, 10:49 PM

Agree, with the 4 bay to start. It should pull in that channel 10. But I don't think that low power channel 4, that one needs a Y5-2-6, YA-6260 or V4 low band VHF antenna.:p
Maybe, but 4-Bay may surprise us at only 19 miles....
Any ol' coat hanger.....

Or a DIY folded dipole (in the attic?) for VHF:
http://www.wfu.edu/~matthews/misc/dipole.html

holl_ands

02-11-08, 01:03 AM

I just bought my first HDTV and am trying to decide what is the best avenue for receiving HD content. I’ve always used cable, was with Insight which just switched to Comcast. I’m leaning toward retaining standard cable and see what the QAM pick ups or possibly upgrading to digital cable. As a secondary (or possible primary) source I’d like to add an antenna.

I have two lines of questions ones related to digital cable and the other related to OTA antennas. I hope I’m not too off topic for this thread, but if I go to digital cable, can I still pickup regular cable on my other TVs or will they each require some type of digital cable box?

As for on topic questions… I am trying to decide which antenna to get. My choices are some sort of small inconspicuous type to mount on top or side of the chimney. By this I mean something like the Winegard Sensor GS-2200/1100, the Radio Shack 15-2187, or Channel Master 3000A. My other choice could be to put multi bow tie or Yagi style antenna in the attic above the garage. By this I mean a CM4228, CM4221A, Winegard HD7080P, or CM3016.

The access to the attic above the upstairs bed room is only 20” square so I don’t think I can get an antenna of any reasonable size up there plus it wouldn’t be easy to adjust or ad an amp if needed. The garage attic isn’t ideal either since the 2nd story of the house is blocking the strongest channels to the west, but is unobstructed for the weaker channels to the north and south. My TV is going to be mounted above my fireplace so the inconspicuous outdoor antenna wouldn’t have far to go where as the garage attic will probably require at 60 or 80 feet of coax and possibly an amp. If I could manage to get an antenna in the attic above the bedrooms, it will be a one-time deal… set it and forget it.

So my million-dollar question is… do you think I would be better off with a lesser antenna mounted somewhere on my chimney or would a more sophisticated antenna hidden in the attic further away yield better results?
Re Cable: Since we don't know what COMCAST offers in your area
(maybe they are ALL DIGITAL???), you need to ask this question in your local
(Indianapolis?) thread....and/or call COMCAST.
If it isn't ALL DIGITAL, the Standard (analog) channels should show up at
any coax wall outlet.
If it's ALL DIGITAL (cable systems are in transistion....), COMCAST will need to
provide a cable box for each TV (extra cost or "free"???).

===============================
Below are www.tvfool.com results for Fisher, IN, 46038 (U.S. Post Office location).
There are several high power stations close to you, meaning you should NOT
be using a Preamp....and you may be closer than the below printout.....

Rules out GS-2200, R-S 15-2187 & C-M 3000A...no need for Preamp anyway...

Should be easy to pick up ANY station where Path = LOS (Line-Of-Sight).
But you'll need a rotator if you want WNDY-DT (MyN, My Network),
WIPB-DT (second PBS), WCLJ-DT and/or WIPX-DT.

Note that WISH-DT (CBS) is on VHF CH9...and WIIH-DT (?) on CH8.

I doubt you'll pick up WLFI-DT (2nd CBS) on CH11 due to capture of tuner's
AGC (Automatic Gain Control) by next adjacent CH13 and CH9.
AGC capture, intermod noise floor and lack of signal strength will also thwart
reception of the remaining weak stations.

In your location, I would put the antenna(s) in the attic so they are
protected from severe weather. You are certainly close enough.

As we said above, start with a 4-Bay (or 8-Bay) on a rotator and try it.
You might get lucky and receive some of the nearby stations on the
"back" of the antenna, so you may not need to rotate for every station.

Either of these should be adequate for VHF CH9. [It's ONLY 12 miles!!!!]
PS: The CM-4228 has much better VHF CH9 gain than CM-4221....about the
same as CH9 gain with CM-3016....but I'm rooting for the 4-Bay.
http://www.avsforum.com/avs-vb/attachment.php?attachmentid=45041&d=1130363811

Most 4-Bay and 8-Bay antennas either come collapsed or have removable
rear screens, so they'll fit into attic. Earlier I posted CM-4228 measurements:
http://www.avsforum.com/avs-vb/showthread.php?p=6422668&highlight=attic+cm4228+dissemble#post6422668
http://www.avsforum.com/avs-vb/attachment.php?attachmentid=82035&d=1179549221

I esp. liked the below attic installation photo showing CM-4228 with rotator.
You can also mount the rotator on the floor....

Auzivision

02-11-08, 09:37 AM

Thank you for your feedback. I’m beginning to lean towards the 4221 or similar four bay bow tie. My wife would like it in the attic, but I might be able to get away with putting it on the back side of the chimney since it most likely won’t fit through the access hole.

Now I’m trying to get an idea of how directional these bow ties really are… I presume the whiskers need to be closest to the source and the shield needs to be furthest. Perhaps some signal will come in on the sides and presume the least will come in from the opposite side of the grid.

So if I mount this to the back or side of my chimney and point it west… do I need to retain some sort of ability to rotate this? I could put it on a corner which would allow 90 degrees of rotation. If I need more, I’m back to the attic. Please let me know what your best guess would be … outside with limited mobility or in the attic with full rotation.

Thanks again for all your help.

Falcon_77

02-11-08, 10:55 AM

Now I’m trying to get an idea of how directional these bow ties really are…

Here is a gain plot (relative to the main lobe) for the CM4221:

http://www.hdtvprimer.com/ANTENNAS/cm4221.html

Yes, the elements (bow-ties) should face the towers, though it is still possible to receive some strong signals through the shield.

Unless you need 11 and 52, a rotor may not be needed. 32 is probably strong enough to be received from the back.

holl_ands

02-11-08, 02:19 PM

Roof: Antenna and coax are exposed to the elements...may have to replace more often...
and whenever it's blown over. Mast requires ground wire per NEC code requirements.
Must figure out a weather proof entry technique, including a spark gap
protection device grounded per NEC requirements....plus perhaps additional
surge protection devices (i.e. gas tube and/or MOV).

Attic: Lasts essentially forever....simple installation. At 19 miles, should be easy.

Tobias Ziegler

02-12-08, 02:26 PM

I acquired this antenna a while back for free. I had never really tried it out until the other day. I hooked it up to the TV in my garage, held it up, and to my surprise it brought in some analog high VHF (>8) channels and UHF channels very clear. All analog, I'm waiting for my coupon converter box to test digital.
[img=http://img90.imageshack.us/img90/3097/sd536573bh6.th.jpg] (http://img90.imageshack.us/my.php?image=sd536573bh6.jpg)

That's a Radio Shack antenna, I don't know the model. It's a good little unit as long as you don't expect the world from it. I use mine as my "sniffer".....when I'm looking for possible locations to try a bigger/heavier antenna, I hold that one by hand as a first test. It's smaller and much lighter than a 4221, but works quite well. By the way...you've got it upside down !!!! ;-)

dizzytaz00

02-13-08, 11:57 AM

Hi about 2 weeks ago I bought a Radioshack HDTV ampifed antenna Model: 15-2187 for $79.99 . Since I can't mount it outside, I use it indoors & it works great atleast ,girlfriend not yelling I want cable:D Has anyone reveiwed or used this antenna?

Ok now i have pictures of this antenna but I've no where to post them. So from this antenna is working soothly. Using indoors & getting signals between 50 to 71 strength on the second floor next to a window.
I do gets some audio glitching on 2 channels. 22.1(cbs) & 28.1 (nbc) which come in hdtv of 720p & 1080I
using the Digitalstream DTX9900 the antenna comes with a 10db gain & is working fine. Any question just ask & I'll see if i can answer them.

iw84no1

02-13-08, 08:57 PM

Hi, I have a question about an antenna that I saw on ebay (I don't see any rules about posting links or talking about ebay, so I hope I'm not breaking any).
It's advertised as a new style for 08 and is really small with both uhf/vhf. Does anyone know about this antenna and how good it is, especially compared to an 8-bay uhf antenna? I'm less than 60 mi from Buffalo, which I need to point to and since this antenna is so cheap, I wonder if it can do the job? But I can't find any info on it on the net.
Thanks

holl_ands

02-13-08, 09:15 PM

Rather than referring to some "small" antenna buried somewhere
within eBay, why don't you ask what antenna you NEED....
which at 60 miles is probably going to be "big" and preferably roofmount.

You can post www.tvfool.com results as attachments
(please provide both Analog & Digital *.png's)
or at least give zipcode and nearby cross streets.

========================
Small? How small?
3-meters, 3-feet, 3-inches????

iw84no1

02-14-08, 07:36 PM

Well, if you search for "uhf antenna", you'll see it. It's not just 1 for sale, it's a few people selling alot of them.
When I asked for advice on an antenna, I was told to get an 8 bay uhf. But right now, with an old vhf antenna, I'm picking up 7 HD stations, including 2 of 7 that are around 60 mi's away, in Buffalo.

Falcon_77

02-14-08, 09:41 PM

iw84no1

02-15-08, 07:41 PM

Falcon, that's the one.
Well, this is why I'm asking. What info do you have on it? Either I didn't search hard enough on the net, but I came up empty.
I emailed and got a response back from a guy that bought this on ebay. He lives about 50mi from the tower he needs to point to. He said that he'll let me know how it works and his results.

holl_ands

02-16-08, 11:24 PM

DTV experts are seriously questioning the methodology and conclusions in a
recent DTV Coverage Study by Centris:
http://www.tvtechnology.com/pages/s.0015/t.11299.html
The study attempts to quantify the impact on viewers of the upcoming
Feb2009 shift to all DTV reception.....

According to a Centris's Press Release, they used www.antennaweb.org to calculate
DTV Coverage by entering zipcodes at increasing distances from broadcast towers:
http://www.centris.com/pages/viewnews.aspx?newsID=34&SiteID=9

Centris predicts fol. percent of current analog viewers will lose one or more
"top-five" network channels: Las Vegas (2.5%), Philadelphia (5%) & St. Louis (10%):
http://www.multichannel.com/article/CA6531546.html
Although FCC Coverage Maps estimate 65 mile DTV coverage, Centris claims
it will only be about 35 miles.

Centris SVP Barry Goodstadt also indicated they assumed the use of a
"small or medium-size omnidirectional antenna installed on their roof", rather
than an indoor set-top antennas which their survey results indicate is actually
used by 75-83 percent of viewers. [But hopefully not at the extreme ranges!!!!]

Unfortunately, the report itself is "proprietary"....

================================
Further muddying the waters, FCC Chairman Kevin Martin says about
5 percent of viewers may be missing one or more stations:
http://www.tvtechnology.com/pages/s.0015/t.11298.html
Absolutely no explanation.....

But I could think of a few:
a. It'll take awhile for some stations to build to full power/antenna pattern.

b. Many long distance CH2-6 stations are moving to short range Hi-VHF or UHF.
[This will especially impact viewers using simple rabbit ears, without a UHF loop.]

c. Many (most?) current DTV viewers are using UHF-ONLY antennas and may
(or may not) need to upgrade their antenna system to also receive VHF.

===============================
TVTechnology's Dave Lung requested viewers email him if they receive
DTV beyond 35 miles:
http://www.tvtechnology.com/pages/s.0115/t.11319.html

===============================
Many users have commented on how www.antennaweb.org failed to
list many if not all of their successfully received DTV stations.

Suggest you include an accuracy evaluation wrt www.antennaweb.org
(and also www.tvfool.com) prediction results in your email to Dave Lung.

PS: And post a copy to this thread.

holl_ands

02-16-08, 11:53 PM

LOCATION: 92563, few miles NE of French Valley Airport, Winchester, CA.
DISTANCE: 70 miles to Mt Wilson.
CONFIG: Attic, CM-4228, Spartan Preamp, 100-ft RG-6, 2-Way RF Splitter, Dish vip622.
COMMENTS: One VHF and two UHF "low-power" stations only 5 miles away.
RECEIVE: All L.A. DTV stations plus KVMD-DT and KVCR-DT if rotate antenna.
[KCOP-DT not reliably received...but that's THEIR problem....]
ACCURACY: antennaweb FAILED to list ANY DTV stations from Mt Wilson (L.A.).

* yellow - uhf KVMD-DT 23.1 IND TWENTYNINE PALMS CA 16° 34.6 23
* red - uhf KVCR-DT 24.1 PBS SAN BERNARDINO CA 325° 27.1 26
* blue - vhf KABC-DT 7 ABC LOS ANGELES CA Feb 17, 2009 (post-transition) 295° 69.8 7
* blue - vhf KCAL-DT 9 IND LOS ANGELES CA Feb 17, 2009 (post-transition) 295° 69.8 9
* blue - vhf KTTV-DT 11 FOX LOS ANGELES CA Feb 17, 2009 (post-transition) 295° 69.6 11
* blue - vhf KCOP-DT 13 MNT LOS ANGELES CA Feb 17, 2009 (post-transition) 295° 69.6 13

holl_ands

02-17-08, 12:34 AM

LOCATION: 92128, about 1 mile W of Post Office, San Diego, CA
DISTANCE: Mt Soledad (14 miles), Mt San Miguel (22 miles) & Tijuana (34 miles).
CONFIG: Attic, CM-4228, No Preamp, 50-ft RG-6, no RF Splitters, Sylvania 6900DTE.
COMMENTS: 60-ft hill in backyard plus 1200-ft Black Mtn blocks 2 DTV on Mt Soledad.
Hill also affects FOX, XETV-DT from Tijuana and lesser impact to 4 DTV from Mt San Miguel.
Big Pine Tree & several smaller trees towards Mt San Miguel.
MediaFlo 50 kW CH53 on Black Mtn (2 miles). Six low power stations 7 miles away.
RECEIVE: All four DTV stations on Mt San Miguel.
ACCURACY: antennaweb FAILED to list ANY DTV stations from Mt San Miguel.

* blue - vhf KGTV-DT 10 ABC SAN DIEGO CA Feb 17, 2009 (post-transition) 209° 14.3 10
* blue - vhf KFMB-DT 8 CBS SAN DIEGO CA Feb 17, 2009 (post-transition) 209° 14.4 8

===========================
If I increase antenna height from (actual) 16-ft to 60-ft, antennaweb
results finally approximate what I see using an exterior test antenna:

* yellow - uhf KSWB-DT 5.1 CW SAN DIEGO CA 145° 22.1 19
* yellow - uhf KNSD-DT 39.1 NBC SAN DIEGO CA 144° 22.2 40
* yellow - uhf KPBS-DT 15.1 PBS SAN DIEGO CA 144° 22.2 30
* lt green - uhf KUSI-DT 51.1 IND SAN DIEGO CA 144° 22.2 18
* red - vhf KGTV-DT 10 ABC SAN DIEGO CA Feb 17, 2009 (post-transition) 209° 14.3 10
* red - vhf KFMB-DT 8 CBS SAN DIEGO CA Feb 17, 2009 (post-transition) 209° 14.4 8

Falcon_77

02-17-08, 01:57 AM

Antennaweb lists only 3 current DTV stations that I can receive, if I use the actual height of 30':

* red - vhf KABC-DT 7 ABC LOS ANGELES CA Feb 17, 2009 (post-transition) 319° 51.8 7
* red - vhf KCAL-DT 9 IND LOS ANGELES CA Feb 17, 2009 (post-transition) 319° 51.8 9
* red - vhf KTTV-DT 11 FOX LOS ANGELES CA Feb 17, 2009 (post-transition) 320° 51.6 11
* red - vhf KCOP-DT 13 MNT LOS ANGELES CA Feb 17, 2009 (post-transition) 320° 51.6 13
* violet - uhf KCBS-DT 2.1 CBS LOS ANGELES CA 319° 52.3 60
* violet - uhf KOCE-DT 50.1 PBS HUNTINGTON BEACH CA 319° 51.8 48
* violet - uhf KDOC-DT 56.1 IND ANAHEIM CA 319° 51.8 32
* violet - uhf KSCI-DT 18 IND LONG BEACH CA Feb 17, 2009 (post-transition) 319° 50.8 18
* violet - uhf KRCA-DT 45 IND RIVERSIDE CA Feb 17, 2009 (post-transition) 319° 50.8 45
* violet - uhf KCBS-DT 43 CBS LOS ANGELES CA Feb 17, 2009 (post-transition) 319° 52.3 43

The VHF predictions for the post transition seem to be ok, but does antennaweb have a grudge against UHF?

I can receive every full power station from Mt. Wilson at 51 miles with 1-2 edge diffraction, with a CM4228. That is 22 stations, not to mention numerous sub-stations. I can also get all but 1 (KABC) if my 4228 is aimed 64 degrees off line, towards KVCR.

With a rabbit ear/loop combo on the first floor, I can receive about 90% of the stations.

I have a YA1713 waiting in the wings for VHF, but the 4228 will probably work for those as well.

jonnyozero3

02-17-08, 12:11 PM

Anyone noticed this yet? I didn't see it in any searches:

http://www.prweb.com/releases/2008/02/prweb672763.htm

http://www.engadgethd.com/2008/02/17/antennas-direct-unveils-clearstream2-long-range-ota-antenna/

Antennas Direct unveils ClearStream2 long-range OTA antenna

Posted Feb 17th 2008 7:50AM by Darren Murph

Just a few short months after Antennas Direct's president witnessed unprecedented sales of its OTA antennas, the firm is fleshing out its product line with the all new ClearStream series. The first device in said lineup will be the ClearStream2, which enables owners to pull in UHF / VHF signals some 55 miles away in a design that measures just 10- x 20-inches. Additionally, the company promises that "up to 98-percent of the available broadcast signal" will actually reach the incoming antenna cable compared to "just 10-percent" in most alternatives. Interestingly, we aren't told how much this unit will demand -- and we're left to imagine what it'll actually look like -- but availability is promised for next month, with mid-range and ultra long-range designs to follow shortly.

cpcat

02-17-08, 12:32 PM

Anyone noticed this yet?

Interesting. I'll be curious to see what the upcoming "ultra-long range" version is like. A healthy dose of skepticism is in order, though. Hard to re-invent the wheel afterall.

andy.s.lee

02-18-08, 08:33 AM

Sorta, but not really, related to the Centris debate, TV Fool has now released it's own analog shutdown analysis here (http://www.tvfool.com/index.php?option=com_content&task=view&id=50).

Best regards,
Andy

w0en

02-18-08, 06:03 PM

Check out the lumenlab coathanger antenna thread. The thread is huge but 400-500 posts in they are starting to play with some loops with claimed amazing results. Just remember some of these guys put the the feedpoint on a 4 bay at the bottom cause it's easier....not too many rf engineers on the thread, but experimenters and homebrewers all. My kudos to them, they may have unearthed a design long ignored with some possibility.

nybbler

02-18-08, 09:08 PM

By a dual loop do you mean two vertical loops with the feedpoint in the center across the loops? I've seen them (and built one) for UHF but they've got a pretty narrow bandwidth. The VHF element is then another loop which goes around the outside of the reflector.

Burnasty

02-19-08, 12:35 AM

I live in McKinney Texas and according to antennaweb live 43 miles from the closest Tower. I recently built an 8 bay UHF antenna mounted in my attic. I have metal lining most of my roof except one corner. I placed the antenna there and am receiving remarkable reception. I am getting hd channels from Dallas and Fort Worth, in total 12, and some 35 analog channels (unfortunatly mostly spanish and bible channels). The antenna I used as a template was the db-8 from antennas direct which with shipping and tax would have cost around $150. I purchased all new materials and my antenna cost me about $45. I did put a 10 db amplified splitter 5 feet from the antenna at my cable hub because I am running over 100 ft. of cable and running to four rooms. All works flawlessly. I hope you all have the luck I have had.

jclemmojoe

02-19-08, 02:12 AM

If you're near Mechanicsville send me a personal message and I'll give you my phone number. I just replaced my combo VHF/UHF Radio Shack antenna with a 91 XG UHF. All I'm looking for is OTA HD reception. Sounds like the Radio Shack is what you need. I'd probably let it go for a case of beer!. It's like new!

Joe Clemmons

firemantom26

02-21-08, 10:56 PM

I am running stacked 4228"s on a cm 7775 amp now and want to replace it with a cm 7777 to be able to pick some vhf high channels. When I have it switch to combined, will uhf channels be as good as before using a cm 7775

mlmahon

02-22-08, 05:27 PM

I am running stacked 4228 on cm 7775 amp now and want to replace it with a cm 7777 to be able to pick some vhf high channels. When I have it switch to combined, will uhf channels be as good as before using a cm 7775
Yes.

firemantom26

02-23-08, 01:10 AM

mlmahon
I am happy to hear that when I have it switched to combined position on the 7777, that I would not loose any uhf signal. The 7775 performs so good and there is only a few that will be on vhf high when the switch is made in Feb 2009

ctmooregottapee

02-25-08, 02:05 AM

moved from prime metro area to the boonies and was looking for any detailed advice for the following tvfool plot; advanced options are very welcome

indy ch10 and 51 are not desired/required, and only one of the fox or cbs nets are needed

i was thinking a 4228 and 7777 aimed at the most difficult stations, ch18 & 22, then hoping enough of the stronger stations would get picked up.

if that doesn't work, would a channelmaster jointenna aimed at those two stations, combined with a 4228 aimed south work?

was also hoping the 4228 would pick up the high vhf ch9, but i'm willing to live without that vhf ch9 as it is pbs with 2 subchannels and 12mbps of HD which is just not worth much to me.

i can do a tower of some height, but would prefer to avoid it due to rough weather. two-story roof access or similar small tower is no problem.

i'm a little hesitant to go crazy as locals in such a small market are sorta crap quality wise and may stuff themselves with subchannels at some point. if i had a shot at chicago then i would def go all out, but some of these guys are not even 5.1 yet.

i noticed some .4db noise PHEMT preamps - compared to the 2.0db noise channel master 7777; is this something i should consider or are there other downsides to the lower noise spec preamps?

appreciate your time to reply, ct

Tower Guy

02-25-08, 12:56 PM

I was thinking a 4228 and 7777 aimed at the most difficult stations, ch18 & 22, then hoping enough of the stronger stations would get picked up.

I'd start with an XG-91 or the 4228, the 7777 and a rotator. I'd put up a Y10-7-13 for channel 9, but mounted below then rotator, fixed at WILL. Next I'd verify what can actually be received. If you ever want to drop the rotator, the XG-91 has less windload than the 4228 and slightly more gain on channels 18 and 22. If you can get all the stations you want and wish to eliminate the rotator, an optimum setup would have 5 antennas and 3 Jointennas. (Channels 28, 41, and 48)

With three Jointennas, the loss will be a factor. The solution is to use a separate preamp on each antenna before the Jointennas, or try the GASFET preamp. In normal cases a GASFET noise figure is too low to be helpful, but if there are losses before the preamp, that generality is wrong. You won't need a preamp for WYZZ.

You will need to clear all trees to get WAND and WBUI. Pick the end of the house that is clear to those two stations. The other end of the house can be the location for a second stack of antennas. A tower will help until you clear the trees, then not as much as you might think.

PCTools

02-26-08, 05:47 PM

Wanted to inquire if anything would be gained by swapping out my NEW X91 and going to the Winegard 9032?

I have no problem pulling in stations at 70 miles on my 40" XBR TV, and having them in the high 80's and low 90's in signal strength. I can pull Detroit in the evening, which is over 150 miles in Digital.

You guys are probably saying, what else do you need? Well, I want more. Believe it or not, my system is ONLY 15 feet off the ground. This is because I have no tower, and laid off. (Cash flow).

Lucky for me, I am in the one of the highest points in Ohio. That is, 880 feet elevation. I live in farm country, and no big buildings between me and the transmitters.

Or maybe do some vertical stacking?

Your comments...
http://img301.imageshack.us/img301/9112/antenna017dr4.jpg

http://img144.imageshack.us/img144/4614/antenna004nk7.jpg

MAX HD

02-26-08, 06:13 PM

The XG91 is the better antenna.Never seen a tripod used on the ground.If you want more height put it on the peak of the roof with no more than 10 ft of masting.Or,use a gable mount on the end of the house for more total height.

A stacked array won't help with stations 150mi away,but the ones 70mi away might be more stable.

PCTools

02-26-08, 06:38 PM

Darn, I just ordered the Wingard 9032 for $29.99 + 18.99 shipping. I thought for sure this baby would do better than the XG91.

But, you guys are the pro's. Hmm.. No more than 10' above the eve. I was hoping to push her up a little more. Even decided to skip the rotor, as this would add more weight.

The Details:

House peak is 15 Ft.

Thought I would take take 3 pieces of 10' pipe and stack them. I would then be 15' above the eve bracket with NO rotor. Do you think I would be looking for a diaster?

Lastly, why do you feel the XG91 is better than the 9032?

The XG91 is the better antenna.Never seen a tripod used on the ground.If you want more height put it on the peak of the roof with no more than 10 ft of masting.Or,use a gable mount on the end of the house for more total height.

A stacked array won't help with stations 150mi away,but the ones 70mi away might be more stable.

holl_ands

02-26-08, 07:01 PM

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

What Preamp are you using????
Do you have any FM or TV stations within 20 miles????
Suggest you post your digital and analog results from www.tvfool.com

PCTools

02-26-08, 07:14 PM

fbov

02-27-08, 12:18 AM

Doh, I just took a step back. :mad: My local TV Installer swears by that darn 9032. So, what happens I end up buying junk! Too late for me to cancel the order. Atleast, I got a good deal on it. $29.99.

Why do you call it junk?

If you look at the raw data in the link Holl_ands posted before you, the 9032 looks inferior to the XG91. Look a little closer and you'll see that the XG91's peak gain is for a channel in the mid-60's. The 9032 is only down ~2 dB over channels 15-52 (?) that we'll retain after 2/09. The 9032 is a lighter, simplier, cheaper design.

Perhaps your installer swears by it because his customers get good picture quality for a reasonable price and he gets fewer call-backs for wind or weather?

In your case, for $30, I'd be tempted to try them both ... can you see a signal difference? One neat thing about ATSC tuners is they all have signal strength meters!

HAve fun,
Frank

PS Also remember (as I failed to in my initial look) that Holl_ands link is to antenna simulations, not empirical data as I implied. I would not be surprised if there were a couple dB difference between antenna models and actual behavior across the channel band, but the relative curve shapes and heights are likely still valid.

Mister B

02-27-08, 09:29 AM

I choose the Winegard 9032 here in West Texas as I was concerned by several comments read on this forum about the wind tolerance of the XG91. I am very satisfied with the results as I am pulling in a digital channel 23 from 80 miles away through a mountain pass.

donnyjaguar

02-27-08, 10:11 AM

FWIW, I use a Delhi CYD1470 (http://www.wade-antenna.com/Wade/UHF%20Antennas.pdf) and it looks to be damn near identical to the Winegard 9032. If its a hunk o' junk that wouldn't explain why I get reception day and night of stations over 100 miles away. :) I haven't owned it long enough to proclaim it'll last a lifetime, but it looks to be well built and there are certainly lots of them around my location. YMMV.

Junglerock

02-27-08, 10:53 AM

If anyone is interested it appears the Winegard HD 7698P is now available: http://www.solidsignal.com/prod_display.asp?PROD=HD7698P At 14' long and 17lbs.:eek:

bozey45

02-27-08, 05:37 PM

Just ordered a 91-XG from Solid Signal so I'll see how it performs here in west central Florida at about 40 ft. up. Should arrive next week I guess. Next decision is one for VHF; Am into DX so will need one to cover 2-13.

PCTools

02-27-08, 07:23 PM

MAX HD

02-27-08, 08:27 PM

Well, let me start-over. The 9032 is NOT a piece of junk. Actually, it is one of the native antennas that is made in the USA and not imported! You can immediately tell the difference in quality and craftsmanship.

Now, since my two of my digital channels Ch. 11 and 13 (Toledo), will no longer broadcast their signals in the UHF Band, I will need to purchase a 7-13 antenna. (Prior to Feb. 2009)

The best one I have found is the Winegard YA-1713. A good gain antenna that is light weight.

http://winegard.com/offair/pdf/Ya-1713.pdf

Comments?

The 9032 is certainly not junk.I've compared it to XG-type on the same mast and the overall performance level across the band was not as good.As a Dxer,I look for best FB,directivity and good frequency response on EVERY channel.

Re:if you want the largest highbander available,I have a few left.Check this thread.

http://www.avsforum.com/avs-vb/showthread.php?t=1000398

MAX HD

02-27-08, 08:36 PM

If anyone is interested it appears the Winegard HD 7698P is now available: http://www.solidsignal.com/prod_display.asp?PROD=HD7698P At 14' long and 17lbs.:eek:

I might try one in this neighborhood with two markets at 55mi and two at 70mi.Kinda salty though at a dollar an inch!

MAX HD

02-27-08, 08:50 PM

But, you guys are the pro's. Hmm.. No more than 10' above the eve. I was hoping to push her up a little more. Even decided to skip the rotor, as this would add more weight.

The Details:

House peak is 15 Ft.

Thought I would take take 3 pieces of 10' pipe and stack them. I would then be 15' above the eve bracket with NO rotor. Do you think I would be looking for a diaster?

You can go 15ft above the peak with the right mast construction,but your hip pocket engineering better be good.Hint..you'll need to use two braces 5ft up from the peak and run them back at an angle and attach them about 2-3 rafters back from the gable end of the roof,lagged into the rafters well.pm me for more complete details if you want to pursue it.

PCTools

02-28-08, 12:16 PM

I purchased the VIP-307 last year. It is a monster, and a heck of a performer.

But nowadays, I would focus on a 7-13 antenna. I have no use for the 2 -6 channels. I am in process of finding the best place to buy the Winegard YA-1713. So far $50 delivered.

I was going to purchase some 10" masp pipe and was floored at the price. Do you feel it is worth the exrta money to get the 1.66" vs the 1.5" stuff? Don't even think about that cheapo 1.25" Lowes stuff.

I am going to do a eve mount with the 91XG and YA-1713. About 14 feet over the peak.

girdnerg

02-28-08, 12:47 PM

If anyone is interested it appears the Winegard HD 7698P is now available: http://www.solidsignal.com/prod_display.asp?PROD=HD7698P At 14' long and 17lbs.:eek:

I noticed that there were several in this series. Is anyone using one in the series, and if so, can you give some feedback?

I ask because I'll have 2 channels going back to VHF in 2009.

Thanks,
Rob

Dru the Fu

02-28-08, 12:55 PM

Background: Currently a D*tv customer. My commitment will be coming up soon and am looking to get rid of my subscription. I've realized that the majority of TV I watch is on local stations and/or DVD. Having a DVR/Tivo is not an issue as I am OK with buying a stand-alone HD Tivo unit and pay that subscription price. My TV's have built in tuners (my main TV has ATSC and QAM). I live in Vacaville, CA (Zip = 95688), which is at about the halfway point between Sacramento and San Francisco. My home is single story with a slate tile roof, with no large trees, no tall buildings, and a small airport a few miles away.

Looking For: I want to get an antenna that is fully compatable for the digital conversion, can receive HD, and can be fed to multiple TV's (via a switch I assume). Having the antenna located/mounted in the attic would be ideal, but I am not opposed to having it outside as long as it's not a beast (D*tv 5-LNB dish size is about as large as I'd like to go), and if it were to be outside, having it piggyback or mount on top of my existing dish would be ideal.

Please, if it's not too much to ask, point me in the direction of a worthy antenna (and line equipment such as amp, switch, etc if needed). I looked into antennaweb.com for a starting point and am lost and confused with the 'results' of my search. If I were to receive on Sacramento stations I can live with that, and receiving San Francisco Bay Area stations would be a Christmas bonus.

girdnerg

02-28-08, 02:48 PM

the antennas are basically the 2-69 winegard platinum antennas with elements cut for ch 7-69.

the platinum antennas are great antennas that outperform the other mfg antennas in the same size ranges. They also hold up better under weather, ice, wet snow, wind because of design differences.

If you live in the boonies, would tend to go with separates for uhf and vhf instead of the large combos...hd7698p for example. the cm4228 and 91 xg would perform better on uhf although the large platinums do decent stuff on vhf

I'm currently using this Philips model (http://www.consumer.philips.com/consumer/en/us/consumer/cc/_language_us/_productid_SDV7700K_17_US_CONSUMER) and a CM7777. In your opinion (or anyone else), how would you compare it to the new Winegard HD 7698P?

Appreciate it,
Rob

Tower Guy

02-28-08, 03:00 PM

I was going to purchase some 10" mast pipe and was floored at the price. Do you feel it is worth the exrta money to get the 1.66" vs the 1.5" stuff? Don't even think about that cheapo 1.25" Lowes stuff.

It really depends on the yield strength of the pipe. Typical water pipe has a yield strength of about 30,000 psi. Structural tubing can be in the 60,000 psi range. (But not always) 1.66" implies a 1 1/4" pipe size and 1.5" implies the actual OD of real tubing. Neither spec refers to the alloy of the material. Good TV mast has a higher yield strength than pipe.

If you want to try water pipe, look for schedule 80. It has a thicker wall than the typical schedule 40.

bozey45

02-28-08, 05:45 PM

That is the wedge design similar to a Winegard out years ago that I used to have and posted about on one of the forums last week. The info has nothing about the gain on various channels; how does it perform for you? I don't see much about Phillips antennas on these forums. Everyone is into Antennas Direct, Winegard and Wade-Delhi it looks like. Just curious how the actual performance is with that Phillips.

bozey45

02-28-08, 05:47 PM

I see the other Rick answered my gain questions for the Phillips wedge. Thanks, guess nothing comes close to the Wade for gain.

PCTools

02-28-08, 08:20 PM

Well, I did some comparisons with the Field Strength Meter tonight on these two antennas.

Long story short, the 9032 could not lock in a couple digital signals, whereas the 91XG could. That impressed me!

Both antennas were setup in near identical conditions. I will have to say, the $40 spent on the PR-9032 was a learning experience. I proofed it for myself that the 91XG is the choice antenna.

Carnivore

02-29-08, 01:36 AM

Hey guys, I'm trying to pick up stations in every direction. Got a rooftop-mounted CM-4221 that almost does the job but seems just a little too directional, I can't find a sweet spot where it gets everything. Oddly enough with the 4221 pointed southeast it's pulling in my most distant station to the north but missing some closer ones in other directions.

I'm thinking about trying a non-amplified Winegard MS-1000 omnidirectional antenna, but it would probably be non-returnable so I'd be stuck with it if it doesn't work.

Any other suggestions? Is there something cheap I could combine with the 4221 to boost the off-axis performance? Most of these stations aren't too far and I don't want to go with an amp or a rotor. I'm up high on the NJ Palisades cliffs across from NYC.

Here are the towers I need:
WNBC-DT NEW YORK, NY 186° 4.5M, CH 28
WNYE-DT NEW YORK, NY 188° 9.4M, CH 24
WABC-DT NEW YORK, NY 190° 4.7M, CH 45
WPXN-DT NEW YORK, NY 190° 5.3M, CH 30
WPIX-DT NEW YORK, NY 190° 5.3M, CH 33
WCBS-DT NEW YORK, NY 190° 5.3M, CH 33 (post-transition)
WWOR-DT SECAUCUS, NJ 190° 5.3M, CH 38
WNYW-DT NEW YORK, NY 190° 5.3M, CH 44
WCBS-DT NEW YORK, NY 190° 5.3M, CH 56
WNET-DT NEW YORK, NY 190° 5.3M, CH 61
WABC-DT NEW YORK, NY 201° 7.9M, CH 7 (post transition)
WPIX-DT NEW YORK, NY 201° 7.9M, CH 11 (post-transition)
WNET-DT NEW YORK, NY 201° 7.9M, CH 13 (post-transition)
WPXN-DT NEW YORK, NY 201° 7.9M, CH 31 (post-transition)
WNJN-DT MONTCLAIR, NJ 297° 11.3M, CH 51
WLIW-DT GDN CITY, NY 108° 28.3M, CH 22
WRNN-DT KINGSTON, NY 15° 45.9M, CH 48 (good digital signal here despite distance)

holl_ands

02-29-08, 09:16 AM

You can try removing the reflector screen on the CM-4221 so it has response both N and S.

That will probably do the job...but there are also some NON-AMPLIFIED quasi-dipole type
antennas you can try such as:
http://www.beachaudio.com/Winegard/Gs1100-p-89565.html?utm_campaign=froogle&utm_content=AD_ID&utm_term=gs1100&utm_medium=cpc&utm_source=froogle&GTKW=gs1100&GCID=C12585x003
http://www.solidsignal.com/prod_display.asp?prod=ANC3010
The CM-3010 is unamplified (CM-3038 is optional amplifier module):
http://www.pctinternational.com/channelmaster/0612/pdfs/manual_3010.pdf

However, they have much less gain than CM-4221, even w/o rear screen.

fbov

02-29-08, 09:43 AM

Another factor could be altitude/elevation - where's it pointed relative to the horizon. The CM-4221 has a tighter vertical spread than horizontal: you're down 10 dB at 25 degrees off axis vertically but over 45 degrees horzontally.
http://www.hdtvprimer.com/ANTENNAS/cm4221.html

Standing at the antenna, the reception aperture is an elipse nearly twice as wide as it is high. Your stations are close together; left-right shouldn't be your problem unless you're aimed high and so only using the bottom part of the elipse, not the major axis.

Most of us are in valleys and pointing up. You're on a hilltop, maybe you'll see improvement pointing down? This won't blend well with Holl_ands idea to remove the screen, unless your back side transmitters need you to aim up.

Have fun,
Frank

holl_ands

02-29-08, 10:02 AM

girdnerg

02-29-08, 12:54 PM

phillips is a 51 element antenna

the hd 7698p a 71 element antenna

the hd 7698p is a deep fringe antenna

the phillips red/blue zone antenna.

the hd 7698p will give you much more gain on uhf

and vhf hi will be in the 8-10 range for phillips

10+ for the winegard.

the winegard is much better constructed

Thanks Rick. I appreciate the response.

That is the wedge design similar to a Winegard out years ago that I used to have and posted about on one of the forums last week. The info has nothing about the gain on various channels; how does it perform for you? I don't see much about Phillips antennas on these forums. Everyone is into Antennas Direct, Winegard and Wade-Delhi it looks like. Just curious how the actual performance is with that Phillips.

If you were asking about the philips I'm using. It's so-so. It pulls in all my stations with a strength of 90+. However, I live in a pretty tricky spot. I'm about 40 miles away from the antenna farm, no LOS, and shooting thru a row of trees. Multi-path on UHF is pretty good, with only a picture pixilation here and there. It doesn't handle it as well on VHF. At least twice during a 1 hour show, I'll get a 2-3 second drop-out. ABC is one of my digital channel on VHF, and it's ticking off the wife, since it always happens when something important is happening (she missed a big clue on Lost last night:cool:).

Anyway, I went with the philips because it was available locally, and given my situation, that was important at the time. Now I'm just looking for a replacement for when I get around to it. I'd prefer to stay with a combo since it would require a major pole-guy wire rework to get the spacing for a dual setup, but it's not out of the question.

fbov

02-29-08, 02:08 PM

Even in L.A., with 5000-ft Mt Wilson, antenna elevation is not required.
Try some simple geometry calculations.....

PS: Palisades Cliff, NY is about 300-ft and WNBC-DT antenna is about 1000-ft,
which is looking UP...with distant stations more towards (4/3 Earth) horizon...

Agreed, 1000 ft over 5 miles is 2 degrees, but you never know what his local conditions might be. He might be in a shadow, or his tuner may not deal well with multipath issues - it sounds like he's ripe for them

I'm in a shallow valley, 7 miles from Roch NY antennas, using a home-built Yagi (pic attached) in a first-story attic aiming into a forest. From Carnivore's post, it sounds like I get better reception than his bigger, commercial, roof-mounted antenna on a cliff 5 miles from the towers. That seems unexpected, don't you think?

My tuner's a Sony 34XBR970, but I'm grabbing a CECB as soon as the coupons are out to see if 6th gen ATSC tuners do better, but I'll also be needing a different antenna, post transition. This one's centered on 675 MHz for channels 16 to 59. In a year, I'll need to cover channels 10 to 45 ...

I'm considering a 4221, but may need a 4228 for its VHF coverage. Thus discussions like this are helpful.

Have fun,
Frank

holl_ands

02-29-08, 04:43 PM

Biggest problem is he's five miles North of Empire State Bldg, and not
all NYC stations are even on the ESB...and then there are all those
buildings his signal is shooting through/above, each contributing multipath clutter....

Direct path is constructively/destructively interferring with "ground/building" bounce path.
FYI: The Televes DAT-75 was specifically designed to suppress the bounce path....

And he didn't say which stations work and which do not....insuff. data....
Nor whether he has tried different antenna locations and heights....

BTW: www.tvfool.com will no doubt yield a much more complete list....

Carnivore

02-29-08, 06:46 PM

Biggest problem is he's five miles North of Empire State Bldg, and not
all NYC stations are even on the ESB...and then there are all those
buildings his signal is shooting through/above, each contributing multipath clutter....

The immediate area is pretty residential, mostly houses with a few multi-storey apt buildings ranging from several blocks to a couple miles away, but none standing right in the signal paths. As I rotate that 4221 I do see multipath come and go on the analog channels.

And he didn't say which stations work and which do not....insuff. data....
Nor whether he has tried different antenna locations and heights....
The CM-4221 is on my rooftop atop a 5-ft mast in tripod mount. It's a 2-storey home plus an attic just like most of the surrounding homes. I can get easily get all of the specified channels as long as the antenna is aimed at them. In fact I can even get them all with an indoor Silver Sensor as long as I aim it at them. I just can't quite seem to get them all at the same time.

The closest I've gotten so far is with the CM-4221 aimed about halfway between the Empire State Building at 190° and WLIW at 108°. In this position my Samsung TV tuner gets every digital channel including the ones way behind it at 15° and 297°, but I get some occasional breakup on WLIW. When I connect that same antenna lead to my DirecTV HR20-100, I don't receive WLIW at 108° or WNJN at 297° at all, and WWOR has some breakup. This makes me think the HR20 is not handling multipath as well as my TV tuner.

If I rotate that CM-4221 any farther away from 190° I lose WNET which seems to put a much weaker signal into my location than any of the other stations on the ESB.

BTW: www.tvfool.com will no doubt yield a much more complete list....

I ommitted the channels I don't care about in my OP but here's the TVfool result, with the red lines being the stations I need:

http://i31.tinypic.com/2ikz6ly.gif

fbov

03-01-08, 02:30 AM

Carnivore,
You've got similar results with antennas of widely varying gain, as long as you can adjust the position? This is sounding more like a tuner issue, or specifically its ability to deal with a strong-but-complex signal field.

I'm also following the converter box thread, and some people have reported excellent performance with the 6th gen LG ATSC chip. It is reportedly much better at multipath, and may be a more-effective option than antenna changes. Coupon-eligible boxes won't have digital outputs or HD, but it's a cheap way to test the hypothesis.

Have fun,
Frank

holl_ands

03-01-08, 07:36 PM

Nearby apt buildings can contribute to the multipath coming via NYC bounce path.

Since multipath (vice signal strength) appears to be your main problem...and presuming you
aren't going to rush out and get a new HDTV, you need a better antenna strategy.

WLIW-DT is at about 90-degree offset from NYC stations....which is nearly impossible
to cover from any reasonable gain antenna unless you either use a rotator...or dual antennas.

You could use another antenna pointed to WLIW-DT and use either an RF switch
or an RF combiner. My first choice would be a CM-4228, which has some
hi-VHF gain for Post2009. [CM-4228 for NYC and CM-4221 for WLIW-DT.]

A simple RF combiner can be tricky because the antenna pointed towards NYC will also
pick up all of WLIW-DT's multipath energy on CH22, thereby possibly degrading the desired
signal from the antenna pointed towards WLIW-DT.
[The WLIW-DT antenna also picks up multipath for all the NYC stations.]

You might get lucky and it will work without fussing with it....or you might
need to insert some attenuation (perhaps 6 dB?) on the NYC port.

A JoinTenna ordered for CH22 would be the best approach for combining two antennas,
although CH20-24 could be degraded...do you care???

fbov

03-02-08, 02:43 AM

I did a little testing today that might be of interest. I'm in a close-but-weak-signal location, per TVFool.com, and have tried a couple antennas. I'm amazed at the degree of signal variation I get, as well as the quality of the simple clip-on bow tie that got me interested in antennas in the first place.

I'm in the Rochester, NY DMA, 6.9 miles from 5 co-located stations, but I still have a weak signal (-70 to -77.5 dBm), probably due to all 2-edge diffraction and a LOS height of 150-175 ft. TVFool chart attached.

Comparisons were done in the center of 15x20 family room aiming through a 3-pane sliding glass door (~1x1.5m panes), aluminum frame, into Al-screened in porch. Beyond the porch is a few hundred feet of forest, a creek, then an open field for ~1000 ft. No buildings in sight, just trees and hills.

I got a Sony 34XBR970 tuner in fall, 2006, and quickly found simple UHF antennas could give an excellent picture, albeit with dropouts (I was new to digital.). I made a small Yagi antenna based on internet directions and local channel frequencies and measured it's performance using the TV's diagnostic screen. Since I wanted OTA for the NFL, I started tracking signal strengths whiler I watched (see attached timeline, chart 1). Not surprisingly, weak stations varied widely over time, and you can clearly see that two stations increased radiated power between seasons. But WHEC, 10.1 real 58 and lowest predicted signal strength, remained inconsistent. WHEC is also one of two stations converting their analog VHF transmitters to digital next year, so I'll have need of VHF 10 and 13.

Reading here about various DTV issues, I decided to upgrade my antenna. I'd tried combining signals from two UHF loops without success, and Radio Shack no longer carried their little 2-bay bowtie; this time I made a 4-bay bowtie, a clone of the CM-4221.

Chart 2 in the timeline shows the results with this new antenna, compared with my Yagi. All the data's on sheet 1. I'd planned to try the 4-bay with/without reflector, front and back, but when I saw channel 8.1 signal rise when I put the Yagi backwards next to the TV, I did front/back with it, too. I'd done azimuth sensitivity when I made it, but some stations came in better backwards than forwards!

Regardless, the worst results with the 4-bay are better than the best with the Yagi.

I honestly considered returning what I bought to make the reflector. The naked 4-bay was giving me 80/100 signal on all stations; the Yagi couldn't give me a lock on them all only 10 minutes earlier! I was putting the 4-bay in exactly the same spot I'd tested the Yagi, mounted on a stand so heights were similar. When I noticed that normally-strongest 31.1 was "only" 90, I tried optimizing the naked 4-bay.

This was a revelation. I'd been testing angular sensitivity, but not position. Moving as little as 6 inches perpendicular to the transmitters made a big difference! The optimum for the 4-bay was rotated ~30 degrees North, tilted back a little and shifted to the "right" spot. Stations all varied a couple points, but it raised the average from 90.6 to 94.2 on the TV's meter.

I mounted the reflector and saw a marked change in directionality. More forward gain (93.2 avg. on the meter) and less rear gain - no surprise. The added weight made it hard to keep the antenna vertical, so it may have taken on some of the upward tilt that was beneficial pre-reflector; when optimized I only got to 95.6 avg.

The best part is that I'm doing just as well from the attic; the antenna's long-term home, and analog reception on channels 10 and 13 is strong and ghost-free. I may not need a 4228 ...

Conclusions
Location matters in 2-edge (diffracted) reception. hdtvprimer has some great stuff on why. When the CECB coupons come out, I'll see how the tuner affects my reception (with the Yagi, of course).
http://www.hdtvprimer.com/ANTENNAS/siting.html

Bowtie antennas are no slouches. They're awfully simple, and the simple expedient of ganging 4 of them in a series/parallel arrangement means there are no impedence issues with a 4:1 balun.
http://www.hdtvprimer.com/ANTENNAS/ganging.html

Reflector bowtie antennas are flexible. You can have high gain and directional focus with the reflector, or the twin lobes of the classic, bi-directional dipole without. (No, I didn't test for nulls at 90 degrees.)

You can make a functional antenna yourself. You will not save money and could get less performance than a commercial unit, but it may be fun ...

Antennas are cheap; get more than you need.

Have fun,
Frank

fbov

03-02-08, 02:45 AM

And since the attachments failed to appear ...

skjardel

03-02-08, 07:25 PM

Would appreciate some help and guidance. I currently have a Terk TV32 antenna mounted outside approx 10' off the ground and receive all of my DT stations(listed below) out of Philadelphia without any problems. My concern is as outlined below two of the stations will move to VHF next Feb and one of them will move to low band VHF. At the moment I can receive these VHF stations reasonably well on my TV's analog tuner but not sure how they will look when they switch to digital. Will my current antenna be adequate when the change occurs or will I need a VHF antenna - and if I do I prefer not to mount a large antenna so what would be the best option - something like AntennaCraft HDX1000?

My zipcode is 08020

DTV Call Compass Compass
Antenna Sign Channel Heading Miles Freq Heading Miles Freq

* yellow uhf KYW-DT 3.1 9° 16.8 26
* yellow uhf WPVI-DT 6.1 9° 16.8 64
* yellow vhf WPVI-DT 6.1 2-17-2009 (post-transition) 9° 16.8 6
* red uhf WHYY-DT 12.1 10° 16.7 50
* yellow vhf WHYY-DT 12.1 2-17-2009 (post-transition) 10° 16.7 12
* red uhf WUVP-DT 29.1 2-17-2009 (post-transition) 10° 16.7 29
* red uhf WCAU-DT 10.1 10° 16.7 67

holl_ands

03-02-08, 09:00 PM

"don't worry, be happy"...
You're only 16.7 bloddy miles away....

FCC is supposed to allocate DTV power so stations have same coverage area.

So general rule is if you can receive the analog channel, it'll be okay when digital
takes over the old assignment. Although it may take awhile for them to
build up to full power and relocate antenna to top of mast...

AntAltMike

03-02-08, 10:33 PM

From sixteen miles away, skjardel might as well go with a Winegard 7010, which is half the size of a 7082, costs half as much and is less likely to blow over in the wind. Cripes, from 16 miles, he might have a chance with a Stealth or a Sensar or a trashcan lid.

holl_ands

03-02-08, 10:47 PM

And musn't overlook the coat hanger....it's a classic...:D
Kerry Cozad measured a "4-leaf-clover" antenna pattern:
https://secure.connect.pbs.org/conferences/technology/2005/Sessions/TC05_43.htm

[Although I might try reworking the feed to improve the VSWR.....]

Carnivore

03-03-08, 02:32 AM

WLIW-DT is at about 90-degree offset from NYC stations....which is nearly impossible to cover from any reasonable gain antenna unless you either use a rotator...or dual antennas.

I tried removing the screen from the CM-4221 today, as per a previous suggestion. No luck getting the 90-degree offset stations no matter how I positioned it though.

Next I tried Radio Shack's 15-1634 amplified omnidirectional antenna, which appears to be a rebadged Antennacraft 5MS921. It actually worked better than I expected, but not good enough, so it's going back.

You could use another antenna pointed to WLIW-DT and use either an RF switch or an RF combiner. My first choice would be a CM-4228, which has some hi-VHF gain for Post2009. [CM-4228 for NYC and CM-4221 for WLIW-DT.]

I'm not sure I need to go that big. The CM-4221 actually does a good job pulling in the current analog hi-VHF stations when aimed at NYC so I shouldn't need more than that for post-2009 hi-VHF. I'd like to keep the size and weight down and avoid having to add a taller mast, so I'm thinking of trying one of two things now:

1. Keep the CM-4221 aimed south at NYC for UHF/hi-VHF, and add a smaller CM-4220 or DB2 aimed east for WLIW-DT.

Or...

2. Aim the CM-4221 at WLIW-DT for more gain than above, and add something like the Antennacraft HBU22 aimed at NYC for a tighter UHF beamwidth and better hi-VHF performance.

The potential problem with #2 is I'd still like to get WRNN-DT to my north (their cool Funimation anime subchannel isn't carried by DirecTV). I know from experience the CM-4221 picks up that channel from the rear when aimed south at NYC, even with the screen on, but I don't know if the HBU22 would have too much rear rejection to do the same.

I also don't want to forget WNJN-DT to the west...that one is pretty strong here and has been fairly easy to pull in way off-axis but again I'm not sure how much adding the narrower HBU22 might complicate that.

So basically I'm planning to point two antennas south and east and hope together they still provide enough pickup to the north and west to get those other channels, which up til now have not been the biggest problems.

As for an RF combiner and/or JoinTenna I'll just experiment starting with the cheapest.

Any thoughts on the above scenarios?

Tower Guy

03-03-08, 09:58 AM

The CM-4221 actually does a good job pulling in the current analog hi-VHF stations when aimed at NYC so I shouldn't need more than that for post-2009 hi-VHF. I'd like to keep the size and weight down and avoid having to add a taller mast, so I'm thinking of trying one of two things now:

I predict that your VHF reception assumption for the 4221 will be faulty.

WABC is moving back to channel 7. The 4221 has -15 db gain on channel 7. The 4221 works better on the higher VHF channels, so it has a reputation as a VHF performer. That reputation has not been true in cities with a DTV station on channel 7. (Like Albany, NY)

The gain data for channel 7 comes from the last graph on this web page:
http://www.hdtvprimer.com/ANTENNAS/comparing.html

Carnivore

03-03-08, 01:58 PM

garyhalstead

03-03-08, 02:07 PM

fbov

03-03-08, 04:27 PM

I predict that your VHF reception assumption for the 4221 will be faulty.

WABC is moving back to channel 7. The 4221 has -15 db gain on channel 7. The 4221 works better on the higher VHF channels, so it has a reputation as a VHF performer. That reputation has not been true in cities with a DTV station on channel 7. (Like Albany, NY)

The gain data for channel 7 comes from the last graph on this web page:
http://www.hdtvprimer.com/ANTENNAS/comparing.html

In addition, WABC's transmitter power on channel 7, post transition, falls from 123 kW analog to 3.19 kW digital. Signal at the antenna will be much lower. Where I live, TVFool predicts the digital transition will drop VHF signal strength at the antenna by about 18 dB.

My conclusion is that a strong signal from today's analog stations may not be a good predictor of post-transition reception. Some aspects of image quality apply (ghosting), but a higher VHF gain may be required than you have today.

HAve fun,
Frank

tyromark

03-03-08, 04:45 PM

In my attic I have an old combination VHF/UHF style antenna. Its one of those where the VHF part looks like many airplane wings lined up several inches apart, and the UHF is a small part of the tail. Its worked well for me pulling in VHF all these years and the UHF is now pulling in a few HD OTA stations.

I want to mount a larger better UHF antenna next to this one but reading in these forums it sounds like to UHF antennas mounted side by side (pointed in the same direction) may cause a conflict.

What if I removed the UHF portion of the old antenna and then used a splitter to combine the old VHF and new UHF together and fed that into an amp. before the signal reached the end point. I still have several analog TVs and VCRs that need the VHF antenna.

Anyone see a problem with this or something different I should consider?

Use a Channel Master 0549 VHF/UHF combiner to join the UHF antenna you're adding to the current VHF one; a splitter won't do. Someone else could tell you if the preamp is a good idea for your proposal or not. You do want to keep several feet of space between the two antennas. I tried out the CM0549combiner with a combo antenna and analog TV just to see if it filtered out the UHF frequencies from the combo antenna, and it worked great. I was impressed. When you say the "tail" of the "airplane" is its UHF section, are you sure this is pointed in the right direction?

fbov

03-03-08, 05:05 PM

I've seen that chart but I'm just 5 miles from the VHF transmitters and the current analog 7 comes in crystal clear with that CH-4221, so I can't see how it would become a problem when that frequency goes digital.

I'm leaning towards option 1 posted above (http://www.avsforum.com/avs-vb/showthread.php?p=13277487#post13277487). If that's the case then I'll just need to choose whether to add a CM-4220 or a DB2. Any thoughts as to which would work better for my needs, or is there not much difference between them? It looks like the DB2 might have a little more reception from behind, is that correct?

You'll see the issue with the CM-4221's gain at channel 7 by comparing "signal Rx" for today's analog 7 with post-transition digital 7 on TVFool.

It seems to me that your option 1 points a low gain antenna at a distant station. It might be logical to do the opposite; get as much locally as you can with a 2-bay, and use the 4-bay for WLIW. For course, a 2-bay will be even worse than the CM-4221 for VHF ...

The neatest idea is Holl_ands' second antenna connected by a JoinTenna. I'd substitute a channel-specific, high-gain Yagi for the CM-4228; it's smaller and should add less unwanted signals to the line.

HAve fun,
Frank

garyhalstead

03-03-08, 05:18 PM

Should I take the UHF part off of the old antenna?

Wireman134

03-03-08, 05:37 PM

Should I take the UHF part off of the old antenna?

No need to cut that antenna up, just get a UVSJ (GOOGLE it) EBAY has it. This little combiner blocks UHF on the VHF side allowing just the VHF to pass and vice -versa with the UHF side. see here; http://www.picomacom.com/products/display_pico.asp?txtSearch=PMC25

:rolleyes:

mdodge

03-03-08, 05:41 PM

And musn't overlook the coat hanger....it's a classic...:D

[Although I might try reworking the feed to improve the VSWR.....]

Yup, it appears the dielectric constant of the paint (assuming the hanger is the more expensive painted type) at the antenna feed point leaves a bit to be desired. Might want to untwist it a bit to give it some air. :D

holl_ands

03-03-08, 05:44 PM

In addition, WABC's transmitter power on channel 7, post transition, falls from 123 kW analog to 3.19 kW digital. Signal at the antenna will be much lower. Where I live, TVFool predicts the digital transition will drop VHF signal strength at the antenna by about 18 dB.

My conclusion is that a strong signal from today's analog stations may not be a good predictor of post-transition reception. Some aspects of image quality apply (ghosting), but a higher VHF gain may be required than you have today.

HAve fun,
Frank
You can't simply look at the lower power assignments for digital.

Analog is always measured with a PEAK reading meter, whereas digital is measured
with an AVERAGE reading meter.
You have to reduce analog power (e.g. 123 kW) by 7-8 dB (factor of about 6)
to find average power (20 kW).
Digital also operates with a much smaller Signal-To-Noise ratio (about 15 dB)
than analog, which permits an even lower digital power level.
And finally, digital is more tolerant to co-channel and adjacent channel interference.

These factors are taken into account in assigning digital power so that the
coverage areas remain the SAME.

holl_ands

03-03-08, 05:55 PM

Yup, it appears the dielectric constant of the paint (assuming the hanger is the more expensive painted type) at the antenna feed point leaves a bit to be desired. Might want to untwist it a bit to give it some air. :D
I was thinking of untwisting so that it connects to a balun looking like a UHF loop
antenna (albeit somewhat out of round) and put two capacitors in series
with loop so that it looks more like an "inverted-L" whip (vice a short) at VHF freqs.
[One capacitor on one of top "corners", the second at the bottom,
where short leg reconnects to balun....disconnects at VHF freqs.]

Carnivore

03-03-08, 07:42 PM

The neatest idea is Holl_ands' second antenna connected by a JoinTenna. I'd substitute a channel-specific, high-gain Yagi for the CM-4228; it's smaller and should add less unwanted signals to the line.

Interesting angle. Where can I find one of those?

fbov

03-03-08, 08:56 PM

I just posted some antenna construction details on the UHF antenna construction thread.

http://www.avsforum.com/avs-vb/showthread.php?p=13285135#post13285135

fbov

03-03-08, 09:16 PM

Keep in mind that the jointenna blocks all frequencies but the one it is tuned for....1 jointenna per antenna

available here. special tuned with about a 3 week lead time

http://www.warrenelectronics.com/antennas/Jointennas.htm

And this gives some interesting info on the Wade line of single-channel antennas. The issue may be getting one aimed at UHF 22 ...
http://www.hdtvprimer.com/ANTENNAS/WadeSCY.html

What makes this appealing to Carnivore's situation is the desire to get a single station at near right-angle to his main source. Combination of both narrow channel gain in the antenna and a JoinTenna sounds like it would do what he needs, if anyone makes the right antenna.

Have fun,
Frank

fbov

03-05-08, 12:56 AM

I just posted some antenna construction details on the UHF antenna construction thread.

http://www.avsforum.com/avs-vb/showthread.php?p=13285135#post13285135

And I just noticed that I screwed up my base dimensions and built my antenna ~10% larger than the intended CM-4221 clone. If the size difference is just a linear frequency shift, I get a much better fit to the 14-52 post-transition UHF channel range.

Thus a question: how will antenna designs change to accommodate the post-transition spectrum
- UHF 14-52 only (all but the 8-bays have gain peaks beyond 52)
- fairly common use of VHF hi
- rare use of VHF low, but in large markets

We're (hopefully) all aware of the many devices with dubious or uncomfirmed performance; what's out there on the possible side?

Have fun,
Frank

holl_ands

03-05-08, 02:38 AM

You may want to maintain coverage for the so-called 700 MHz band if new features turn
out to be "must haves"....such as 1080p MPEG4 file delivery services....or whatever else appears...

FYI: Wade Antennas also makes CYD (and pro J) series Yagis for UHF band:
http://www.wade-antenna.com/Wade/UHF%20Antennas.pdf
http://www.wade-antenna.com/Wade/jseriesuhf.pdf
in addition to the VHF "single-channel" antennas:
http://www.hdtvprimer.com/ANTENNAS/WadeSCY.html

Note that percent bandwidth is about the same, whether in lo-VHF,
hi-VHF or UHF band....hence "single-channel" antennas cover just
one channel in lo-VHF band, three channels in hi-VHF and about 10 in UHF.

Wade-Antennas (in Canada) makes an extensive range of Home, Pro (CATV)
and military antennas:
http://www.wade-antenna.com/

AntAltMike

03-05-08, 09:36 AM

....Carnivore... desire(s) to get a single station at near right-angle to his main source. Combination of both narrow channel gain in the antenna and a JoinTenna sounds like it would do what he needs, if anyone makes the right antenna.

The Jointenna, if installed on the downlead, wipes out too many nearby channels. It would be best to use the Jointenna as just a bandpass filter, putting an F75T on its "all channels" input port, and combining it into the main coax with a 2-way splitter.

Pico/ TruSpec used to make a nice, inexpensive, field tunable bandpass filter, BPF-UHF, that outperformed the Jointenna and sold it for under $40, but they discontinued it years ago. Here is an old catalog page showing its pass-band.

http://www.multicominc.com/active/manufacturer/pico_macom/catalog/section_3/filters/by_page/hpf54mhz_bpfuhf.pdf

You should NOT call the phone number of the host of that linked page to try to obtain one, as they do not have any and don't sell to individuals, and will probably delete that page if anyone calls them.

I'm trying to get Pico to make up some more, but they say they need to be able to sell a thousand to make it worth their while, but I can only commit to taking a hundred and I haven't had any luck getting anyone else to order large enough quantities.

fbov

03-05-08, 11:04 AM

Falcon_77

03-05-08, 11:06 AM

It would be ironic if the upper UHF channel auction resulted in greater need for consumer OTA reception ...

I was thinking about this. Maybe I won't want to filter out above 52, if I could be getting Internet access, etc. over my 4228 some day.

holl_ands

03-05-08, 11:10 AM

Using JoinTenna as a bandpass notch filter on "wideband" antenna input
suppresses multipath on protected channel prior to combiner.

However, if the JoinTenna's other "single-channel" filter port is bypassed,
multipath picked up by that antenna can degrade ALL other channels.

Which is why the JoinTenna is intended to pass (only) one channel on one input
and will notch out that same channel on the other input in order to suppress
multipath both ways.

Of course, both methods can be configured to see which works better.
And see how many channels near the protected channel are affected,
if at all (after all most are only 5 miles away).

fbov

03-05-08, 11:22 AM

mdodge

03-05-08, 12:07 PM

I was thinking of untwisting so that it connects to a balun looking like a UHF loop
antenna (albeit somewhat out of round) and put two capacitors in series
with loop so that it looks more like an "inverted-L" whip (vice a short) at VHF freqs.
[One capacitor on one of top "corners", the second at the bottom,
where short leg reconnects to balun....disconnects at VHF freqs.]

When I get back to work next week, I'll have to look for a coat hanger. Just for grins, I'll hookup a network analyzer to it and do a sweep. I'll send you a Smith Chart of the sweep so you'll have a place to start.
;)

AntAltMike

03-05-08, 12:25 PM

Mike, if I understand you and Holl_ands correctly, the big issue with the JoinTenna is the bite it takes out of the adjacent channel space. The bandpass filter takes a smaller bite, but both interfere with reception from the primary antenna on either side of the target channel.

The Jointenna combines a bandpass filter, a bandstop or notch filter, and a low loss combiner in one device, but its bandstop filter is inconveniently wide, attenuating more than half a dozen channels around its tuned frequency.

If you use either the Jointenna or any other filter just as a bandpass filter on the single channel antenna line, then nothing gets filtered off the main, wideband antenna line, but your desired signal coming from the single antenna will exceed and overwhelm the undesired signal of that same channel that is coming off the wideband antenna, which is not pointed at the single, off-axis transmitter. With analog signals, you would wind up with a double image, but digital signals can withstand low levels of undesired signals and you usually get away with it.

holl_ands

03-05-08, 02:24 PM

When I get back to work next week, I'll have to look for a coat hanger. Just for grins, I'll hookup a network analyzer to it and do a sweep. I'll send you a Smith Chart of the sweep so you'll have a place to start.
;)

Cool...we can compare to VSWR sweeps Kerry Cozad did for loop/rabbit-ears, et. al.

Just to make sure, here's a marked up drawing showing the mods.
Impedance changes due to capacitors is small, so don't expect miracles....as if.....:p

Of course, if you only need UHF, don't bother adding the capacitors....
they're the frustrating part of the mod anyway.... & might receive close in VHF.

For those wondering what an "Inverted-L" antenna is:
http://www.cebik.com/wire/ltv.html
They are normally used in HF band (esp. vehicle whip antennas bent over & tied-back)
to exploit short-range NVIS (Near Vertical Incidence Skywave) propagation.

PS: Years ago my wife went through the entire house and replaced wire coat hangers
with plastic....leaving me with nothing to work with...

Falcon_77

03-05-08, 03:20 PM

As respects the New York DMA, the channels around WLIW do not appear to be all that crowded:

Within a range of 3 channels, I am showing the following for pre-and post-transition:

WMBC ind. 18 18
WLIW PBS 22 21
WFTY telef 23 23
WNYE ind. 24 24

Would getting a 21 jointenna now be a good idea, with the assumption that the notch may be wide enough to pass 22 in the interim?

holl_ands

03-05-08, 03:47 PM

Cuz the trash can lid has better WAF "aesthetics"....like the SS-1000.

goober55

03-07-08, 05:59 AM

dumbfeet57

03-07-08, 05:41 PM

Attached is output from tvfool.com. Although the location I am working with is close to the towers, it is in a valley with N-S ridges both to the west and east (<1/4 mile to each ridge line which are each ~100 ft higher than the house). The antenna is a ~10 yr old Phillips combo rabbit ears/UHF loop w/built-in amp positioned in the upper SE corner (living space, not attic) of the house (2-story). Fortunately there are no significant trees adjacent to the house in the direction of the towers. All analog signals have severe ghosting, but surprisingly (to me anyway), all except the weakest digital station (see attachment) are received fairly well. No changes are anticipated for these stations post 2/2009. There is some periodic pixelization and sound drop that vary in severity from minor to moderate, depending on conditions (but I don't see any consistent weather trends). Signal is passively split to three TVs in various parts of the house, one new digital, two older analog...waiting for coupons :( . Coax runs are probably 50 to 75 feet.

1. I would like to upgrade at as low a cost as possible to eliminate/reduce the reception problems noted above.
2. I would like to keep the antenna indoors, if possible.

Any insight would be appreciated.

DH

alphanguy

03-07-08, 10:38 PM

Well, after much research and wringing of hands, I've decided to stack 2 XG-91's to try to pull in a station that is 78 miles form me. It brodcasts at 50KW, transmitter height is 1000 ft. Currently, I have a radio shack lp-210 with UHF gain of 9.2, and radio shack pre-amp. Since the XG-91 advertizes a gain on this channel (17) for about 14.5 Db... I would hope the stak would pull it in reliably. TVfool puts the signal at my location for this channel at -123. I do receieve analog on this with my current setup, very snowy most of the time, just mildly snowy in the morning and evening. My question is this: Should I stack vertically or horizontally.... advantages or disadvantages of each?

fbov

03-08-08, 12:49 AM

As an overall resource ... all the other links are here.
http://www.avsforum.com/avs-vb/showthread.php?t=546066

You'll find these at the top for a side-by-side:
http://www.atechfabrication.com/information/what_is_the_best_antenna_system.htm
http://www.atechfabrication.com/products/atfx300_precision_antenna.htm

And another on the general antenna topic
http://www.hdtvprimer.com/ISSUES/erecting_antenna.html
with a link part way down to
http://www.hdtvprimer.com/ANTENNAS/ganging.html
He also discusses his experiences with ganging antennas.

Most people will recommend Channel Master or Wineguard over Radio Shack for antenna amps, combiners, baluns, etc. For weak signals, it's a noise issue; the better stuff will give you weaker stations.

The stacking direction will determine the way the reception pattern changes - narrower in the direction of the stack. The principles discussed under ganging above apply regardless of antenna type. Vertical will give a wide pattern that's focused at the horizon; side-by-side a narrow pattern that is not sensitive to tilt.

The one subtlety I've seen with Yagis is that side-by-side needs a secondary boom on each, to move the cross members below the reflector aperture. Verticals aren't involved in reception, but a horizontal cross member can become part of the antenna.

fbov

03-08-08, 01:10 AM

Attached is output from tvfool.com. ... The antenna is a ~10 yr old Phillips combo rabbit ears/UHF loop w/built-in amp positioned in the upper SE corner (living space, not attic) of the house (2-story). ... Signal is passively split to three TVs in various parts of the house, one new digital, two older analog...waiting for coupons :( . Coax runs are probably 50 to 75 feet.

1. I would like to upgrade at as low a cost as possible to eliminate/reduce the reception problems noted above.
2. I would like to keep the antenna indoors, if possible.

Any insight would be appreciated.

DH

Your radar plot looks like mine; no distance to the transmitters, but no signal, either. If rabbit ears in a closet are working, even a little, may I suggest you upgrade them where they are?

An inexpensive choice with a major increase in gain is a 4-bay array. The Channel Master CM4221 is under $25 and I can attest that a clone I built was a tremendous improvement over a small Yagi that, in turn, improved upon a UHF loop, despite a 1-story attic mounting. There's even a thread for making antennas, if you'd like to experiment.
http://www.avsforum.com/avs-vb/showthread.php?t=798265

Literally put this in the same closet you use now. The increased gain should be quite noticable. To take care of distribution, an antenna pre-amp would not be a bad idea as long as you stick to CM, Wineguard and the like. The down side is that the pre-amp is twice as much as the antenna! Sorry ...

(I'll note that he does have a VHF 11 station, but with 16 dB greater signal than his UHF's. The CM4221 is only down 12 dB at ch 11 (201 MHz) vs. ch 14 (473 hz). I get a real nice 8 and 10.)

richo270

03-08-08, 12:01 PM

On the antenna basics page, I read about the signal loosing strength every time one splits it. In my home I have my antenna signal split into 4 different runs of coax to feed TVs in 4 rooms. My question is, would the signal still lose strength if the TVs were off, or only used one at a time, as is usually the case

ctdish

03-08-08, 12:06 PM

The loss is independent of whether the TV's are on or off. So you are losing 6 to about 10 dB by splitting.
John

richo270

03-08-08, 12:33 PM

OK, well that answers that question. The reason I was asking is that I am thinking of how to arrange my system post-transition to the digital signal conversion. I had thought to only get one converter box, and insert it into the line before I split it. Could I use an in-line amplifier after the converter box to make up for the loss, or do I really need a box for every TV?

Thanks,
Richo

Neil L

03-08-08, 03:28 PM

do I really need a box for every TV?I don't know this for sure, but I'm thinking that what is being called a "converter box" is in fact a ATSC receiver with a output that an analogTV can receive. According to HDTVexpert you will need a separate box for each TV.

http://www.hdtvexpert.com/pages_b/diecast.html

Does anyone know for sure if those LG boxes are really converters, or tuners?

richo270

03-08-08, 06:55 PM

Neil,

Yes, of course you are quite right. As I understand it, these boxes are both converters and tuners. Converters, in that they take the over-the-air signals that now will be in digital form, and convert it into an analog form that most of our old TVs can see. And they also are a tuner, in that we will have to use these boxes, usually through the remote that comes with them, in order to change channels.

This will not be much different than what I do now. I have two inputs into my house TV system. One is a Dish satellite antenna that goes through a Dish box, that I have to use to select any of the many Dish channels. The other is an over-the air antenna input that sees my local UHF TV signals. I have an A-B switch that lets me switch between them to go into my house network, and when I am on the Dish network, I have to go to the room with the Dish box to change channels.

Those of us who live in rural areas will not get any local channels over our Dish network, and so we will not get any local news, weather, or sports from our local area, except over our over-the air signal.

Thus what I think I understand is that once the Digital Transition happens, I will have to go to my central TV signal distribution center to BOTH change the Dish channels for the whole-house TV network, AND use the Digital-to Analog converter/tuner to change/tune the over-the-air signals, because my old analog TVs do not have digital tuners.

This will be the case if and only if, I can use one digital-to-analog tuner/converter for my whole house system. Thus my original question, can I use one digital converter box, and split it up, perhaps with an in-line amplifier to overcome signal loss?

If I can not do this, then of course I would have to distribute my antenna signal to all my TVs , and get a number of converter boxes to translate and tune each TV individually. Not my first choice.

Thanks,
Richo

alphanguy

03-08-08, 08:21 PM

fbov

03-08-08, 11:25 PM

Richo,
I'm no expert, but I've read enough to give a layman's response.

Regarding the coupon eligible converter boxes (CECBs), they are a replacement tuner, not a converter. They only output the single channel they're tuned to output, via either composite, (rarely S-video, but all with stereo audio) and always RF/antenna on ch 3 or 4. They do not, however, convert the entire digital reception range to RF for the TV's receiver to tune. The TV stays on 3/4.

That means you need a separate box for every channel you want to watch, usually one for each TV - a set-top box, STB. If you replicate your current satellite box model, the one CECB works the same. I believe there are satellite combiners, but if you're combining RF, it's just like splitters.

The RF signal distribution is straightforward, regardless if you're distributing digital RF to STBs or distributing STB output RF to TVs. There are two parts, reception and distribution. For the latter, the dish box or CECB should give you plenty of signal; search one of the dish threads for your box to be sure.

The antenna needs to provide enough signal for the CECB to decode reliably - maybe 80+ on the built-in signal level meter. That starts with sufficient size/gain, proper mounting and aiming, and includes a mast-mounted pre-amp if you have a long cable run or want very faint stations. The single CECB simplifies distribution; individual CECBs will likely demand a mast pre-amp to ensure enough gain through the splitters.

How's that sound?
Frank

PA_MainyYak

03-09-08, 11:04 AM

I am on the outskirts of Windber, PA over 80 miles from Pittsburgh. Using a DB8 multidirectional UHF/HD antenna and PA-16 UHF Amp kit both made by Terrestrial Digital, I pull in ALL of the Pittsburgh digital HD stations at 80% !!
as well as the Johnstown, PA locals at 100%. Did not expect this kind of reception. Very pleased.

I live in Brownstown and even with Laurel Mountain in the way, I'm able to (sometimes) pick up the Pittsburgh stations. I'm not surprised at your altitude that the Pittsburgh stations come in. Have you had any luck with the Altoona stations?

richo270

03-09-08, 02:53 PM

[QUOTE=fbov;13331683]Richo,

Regarding the coupon eligible converter boxes (CECBs), they are a replacement tuner, not a converter. They only output the single channel they're tuned to output, via either composite, (rarely S-video, but all with stereo audio) and always RF/antenna on ch 3 or 4. They do not, however, convert the entire digital reception range to RF for the TV's receiver to tune. The TV stays on 3/4.

Thanks Frank,

I do understand that I will have to tune all of my TVs at the CECB, and that is fine with me. If I am willing to tune all my TVs with the one box to the same channel at one time, sometimes in another room, then I think what you are saying is that I can get by with one box.

I am trying with this to simplify my system as much as I can. My situation is that from my TVFool readout post-transition, I will have 2 stations transmitting in the VHF Lo bands, two in the VHF Hi bands, and 3 in the UHF bands. Plus, I will have a number of translators that will remain with analog signals. Most all of these will have very marginal signal strength.

Currently I get only marginal reception with a rooftop antenna system with a rotator and amplifier. The two main local analog signals come in OK, but the rest are quite snowy, which is fine, I do not watch them much, and I am used to it. I am not line-of-sight, living up in the mountains and bouncing the signal off of several mountains to get to me. One of my main concerns is that I may not get signal lockup at the CECB box with the marginal signal strength.

So it looks like I will have a UHF and VHF signal coming in, then splitting it so part goes through the converter to translate the digital signal, and part remaining analog to pick up the low power repeaters Then I will have to recombine them to go over my home distribution network. When you combine that with my Dish signal, it sounds like I will have a number of signal switches to deal with. My wife is not happy with that.

Thanks,
Richo

fbov

03-09-08, 08:49 PM

Richo,
Don't upgrade anything until you get your CECB and give it a try. People on those threads report some boxes have excellent sensitivity; verify the problem before fixing it.

And sadly some switching is in your future.

Frank

scsiguy72

03-10-08, 02:44 PM

I put up a VU-120RX (Radio Shack $29.00) Chimney mount and get most all the channels I want. I don't have a pre-amp or rotor.

The only real problem I have is Channel 11.1 I get very poor pixilation and the signal is the weakest on that channel. The source is less than 10 compass points different but it is VHF.

If I aim directly at it, I lose some of my independent stations and the networks get occasional dropouts. Would a pre-amp help and if so any recommendations?

* yellow - vhf KNTV-DT 11.1 NBC SAN JOSE CA 259° 39.3 12
* yellow - uhf KTFK-DT 64.1 SAH STOCKTON CA 311° 19.4 62
* red - uhf KTNC-DT 42.1 AZA CONCORD CA 315° 19.5 63
* violet - uhf KTVU-DT 2.1 FOX OAKLAND CA 266° 40.8 56
* violet - uhf KCSM-DT 43.1 PBS SAN MATEO CA 266° 40.8 43
* violet - uhf KQED-DT 9.1 PBS SAN FRANCISCO CA 266° 40.8 30
* violet - uhf KRON-DT 4.1 MNT SAN FRANCISCO CA 266° 40.8 57
* violet - uhf KGO-DT 7.1 ABC SAN FRANCISCO CA 266° 40.8 24
* violet - uhf KMTP-DT 33.1 IND SAN FRANCISCO CA 266° 40.8 33
* violet - uhf KPIX-DT 5.1 CBS SAN FRANCISCO CA 266° 40.8 29
* violet - uhf KCNS-DT 38.1 SAH SAN FRANCISCO CA 266° 40.8 39
* violet - uhf KOVR-DT 13.1 CBS STOCKTON CA 1° 42.5 25
* violet - uhf KBWB-DT 20.1 IND SAN FRANCISCO CA 266° 40.8 19

fbov

03-10-08, 03:29 PM

scsiguy,
There's a bunch of info here on various antenna options, along with gain curves for comparison. This analysis includes the VU-120 in VHF, in case you want to see your gain curve.
http://www.hdtvprimer.com/ANTENNAS/comparing.html

Options I see:
- Increase antenna gain by changing to a bigger UHF/VHF (CM3671B) or a UHF with substantial VHF-high sensitivity (CM4228)
- Add a mast pre-amp. You have a threshold station here. A good (NOT Radio Shack) low noise pre-amp will give you a better signal-to-noise (S/N)ratio so your current antenna can use the gain it's got.
- Add a rotator, since with an angular change, you get all stations.
- Use 2 antennas, a VHF aimed at KNTV and a UHF aimed like you have the VU-120XR, with a low noise pre-amp to combine UHF and VHF feeds.

My guess is that a rotator would do the job, but require adjustment, control line installation, etc. A different antenna may be all you need, but you won't know until you try it; return policies vary so you may be stuck withit if it doesn't work. The pre-amp should give the S/N ratio enough of a boost to make 12 look good, power is supplied by the existing coax down lead, and you can always change the antenna if you're not happy.

AVS members generally recommend Channel Master or Wineguard mast pre-amps. The critical spec for you is noise factor; lower is better, and 2 dB in UHF is pretty good.

Have fun,
Frank

nybbler

03-11-08, 08:34 PM

Many of you are familiar with Wade-Delhi's power zoom UHF extender. I've always wondered... since that thing is supposed to increase gain, has anyone ever tried attatching more than one to the front of a UHF antenna? Theoretically... could you attatch 2 or even 3 and get more improvement in gain?

Adding more directors to a yagi improves gain, but I think it's pretty much logarithmic, so you quickly reach a point of diminishing returns.

donnyjaguar

03-12-08, 11:50 AM

I'm guessing you could keep adding range extenders to the Delhi, but the practical limit is probably just one. The boom would sag under the weight and pull the elements out of alignment and this would have a detrimental effect on performance.

Falcon_77

03-12-08, 03:31 PM

The only real problem I have is Channel 11.1 I get very poor pixilation and the signal is the weakest on that channel. The source is less than 10 compass points different but it is VHF.

What does analog 11 look like? Is it badly ghosted or filled with noise? The VU-120 is not very directional for VHF, at 10 degrees off, it appears to be down less than 1dB.

What tuner are you using? Do you need Low-VHF for the interim? If not, a 7-51 antenna may be a better choice.

PanamaMike

03-12-08, 05:45 PM

Falcon_77

03-13-08, 01:17 AM

I wanted to know if it's possible to feed multiple TV's via one antenna. Is it possible to have it tap into the main cable line that feeds the entire house?

A faq or something of the sort that would help me better understand how I could use an antenna would be much appreciated.

It is certainly possible to feed multiple TV's with one antenna, though a distribution and/or pre-amp may be needed to get this done.

It is not possible, however, to use a cable TV line and add an antenna to it, w/o filtering out the cable spectrum that lies in the OTA spectrum at least. A separate cable run would be needed if you want to have both.

As for a FAQ, this page might be useful, though it is rather lengthy and has one of the worst color schemes:

http://www.tvtower.com/hdtv_antenna_and_reception.html

The distances noted on the antennas, however, seem to be way too short for most areas. 20-45 miles for a 3671, for instance. I would go with 50+ for that one, though most areas won't need Low-VHF capabilities.

wildwillie6

03-14-08, 07:18 AM

There's also a pretty good FAQ on antennas at http://www.plainmoney.com, though it may be a bit basic for your needs.

The distances noted on the antennas, however, seem to be way too short for most areas. 20-45 miles for a 3671, for instance. I would go with 50+ for that one, though most areas won't need Low-VHF capabilities.

I wonder about quoted distances like those . . . I assume they're just being conservative, to avoid disappointment. But I'm regularly getting signals from 95 miles away over two mountain ridges, using a ChannelMaster 4248 with 7777 preamp.

richo270

03-14-08, 01:04 PM

I wanted to know if it's possible to feed multiple TV's via one antenna. Is it possible to have it tap into the main cable line that feeds the entire house?

A faq or something of the sort that would help me better understand how I could use an antenna would be much appreciated.

Regards,

Mike

Hi Mike,

Another way you might go is to do what I do and have a simple A/B switch you can get from Radio Shack, and switch either your cable TV (I have satellite) or the antenna feed into you whole house system. That way you can use a single coax system throughout your house. I seldom watch my local antenna stations in other rooms, so the switching is not a big hassle.

For my main TV in the room with the satellite box, it is even easier if your TV has both coax and AV inputs (the red and white jacks). I run my satellite input into the AV TV inputs, and the antenna into the coax F-connector input. Then on the TV remote I can chose any of the antenna channels, or hit 00 and it will switch to the satellite AV input.

Regards,
Richo

Falcon_77

03-14-08, 03:20 PM

There's also a pretty good FAQ on antennas at http://www.plainmoney.com, though it may be a bit basic for your needs.

The antenna page on that site is here:

http://www.plainmoney.com/antenna/

I will have to disagree with this statement, at least in part:

What are the harder channels to get good reception on?

Generally, the higher-numbered channels. That's especially true of the UHF (Ultra High Frequency) channels above 13, which are usually more difficult than all the VHF (Very High Frequency) channels 2-13.

Higher UHF channels (~50+) are generally more difficult to receive than lower ones (20's-30's), but Low-VHF (2-6) DTV channels are usually the most difficult. Upper VHF 7-13 stations may be the "easiest" to receive, but it depends on the circumstances.

99gecko

03-14-08, 07:03 PM

It is a re-engineered 1950's Hoverman being dubbed the Double Bay Gray-Hoverman. It has been rethought by retired antenna engineers and OTA hobbyists using modern antenna modeling software.
Early indications are that it outperforms the CM4228 in the UHF bandwidth up to ~ channel 53.
http://hardware.slashdot.org/hardware/08/03/14/2021223.shtml

Oh yeah, it is open source.

fbov

03-14-08, 08:43 PM

... Early indications are that it outperforms the CM4228 in the UHF bandwidth up to ~ channel 53.

Because it's designed to peak at ch 53, not 63 like most commercial UHF antennas. The single G-H curve looks a lot like my 125% 4221 - it's shifted to lower frequencies - and not surprisingly, 127mm pops up a lot in the G-H design since 10" (254 mm) is the basis dimension of a 125% 4221.

For more information:
http://www.avsforum.com/avs-vb/showthread.php?p=13331468#post13331468

holl_ands

03-14-08, 11:57 PM

FYI: The Hoverman was discussed in this thread:
http://archive2.avsforum.com/avs-vb/showthread.php?t=567148
Links are all broken, so you'll have to search..

Fol. is a picture of my old Hoverman (vertical zig-zag) in action.
[Note moon in top left...and broken element at bottom.]
I use it for mobile testing, because it collapses to a small size.

I've tested the 4-Bay Hoverman vs CM-4221 vs DTA-5000 Smart
Antenna vs CM-4228. Missing an element, it's close to CM-4221....
[At least on CH 18, 19, 30 & 40.]

PanamaMike

03-15-08, 12:11 AM

Hi Mike,

Another way you might go is to do what I do and have a simple A/B switch you can get from Radio Shack, and switch either your cable TV (I have satellite) or the antenna feed into you whole house system. That way you can use a single coax system throughout your house. I seldom watch my local antenna stations in other rooms, so the switching is not a big hassle.

For my main TV in the room with the satellite box, it is even easier if your TV has both coax and AV inputs (the red and white jacks). I run my satellite input into the AV TV inputs, and the antenna into the coax F-connector input. Then on the TV remote I can chose any of the antenna channels, or hit 00 and it will switch to the satellite AV input.

Regards,
Richo

Thanks for the input guys, it's much appreciated. My situation is as follows. I have a Dish Sat. system and use 722 DVR. I can tune local channels using the 722, but there are days the signal is week, or based on the direction of the antenna, I lose at least one channel.

I'm using a silver sensor type antenna. I've used the antenna mapping sites before, I've learned I'm approx. 9 miles away from the main towers. This is supposed to be close and provide for a good signal, but since I live in a somewhat hilly area, I guess I may be getting blocked signals or getting some sort of RF interference. I was hoping to be able to determine which of these may be my issue.

As far as asking about multiple tuners to one antenna. I've been playing with the idea of getting multiple HD PVR cards for an HTPC so that I can record multiple OTA channels simultaneously since all the best shows usually run at the same time. It would be nice to just get once nice antenna rig to do this.

Also a secondary use would be to get OTA for other TVs that would be on different levels in the house. Running cable would be an expensive and difficult proposition, that's why I asked about tapping into the regular wires.

Mike

Mike

fbov

03-15-08, 01:20 PM

... I've tested the 4-Bay Hoverman vs CM-4221 vs DTA-5000 Smart Antenna vs CM-4228. Missing an element, it's close to CM-4221.... [At least on CH 18, 19, 30 & 40.]

Missing an element? I'm seeing extras! This is an interesting design, especially the folding-element reflector - fairly compact compared with a 4221's. Assuming it's a 10" basis, Ch 18-40 should be it's sweet spot.

holl_ands

03-15-08, 07:16 PM

My Hoverman has two vertical "whiskers" sort of resembling the feed on a CM-4221,
and short "kinks" on some elements.
http://www.wtfda.org/images/stories/pdf/hoverman.pdf
Note above pdf has vertical "whiskers", but is missing "kinks"....

BTW: I'm not sure whether we ought to call it a 4-Bay (cuz it's nearly
same size at CM-4221)....or a 3-Bay....recount the "bow-ties"....

My Hoverman appears to be same as in the lo-rez R-S Hoverman picture
found in the Super Gray-Hoverman report:
http://www.digitalhome.ca/ota/superantenna/
However, the Super Gray-Hoverman greatly extends the "kinks" and
eliminates the vertical "whiskers".....and used a more efficient screen reflector.

fbov

03-15-08, 09:57 PM

I've seen these links. If I'd known it was for real, I might have given it a try, especially if I had an old VHF Yagi sitting around. Instead I'm staring at my second 4221 clone - new CM baluns and diplexer on order.

And of course, it's performance improvement is real; it trades upper UHF for better 14-52 channel gain, just more severely than mine. Does anyone gang these together?

Frank

gcd0865

03-16-08, 09:15 PM

Hi All:

Thanks to everyone on this board for all the very helpful information, as I'm currently upgrading my antenna setup in preparation for my upcoming HDTV purchase. I'm testing out a YA-1713 on analog channels 11 and 13 at a distance of 65 miles over pretty flat terrain. The digital versions of both channels are currently on UHF, but will revert back to 11 and 13 next February. The analog 11 and 13 currently come in at around a 6-7 out of 10 in the daytime, and 7-8 out of 10 in the evening (no multipath/ghosting at all for either channel).

Wondering whether these signal strengths will be sufficient for when the digital channels revert back to 11 and 13 next February. I've read on this board that the Funke PSP-1922 VHF-high antenna has a little more gain than the YA-1713, but I'm not sure how much more (a little confused about the dBi and dBd ratings I saw). How much might the analog signal strengths on my 11 and 13 improve if I switched to the 1922?

Also had a few questions about the 1922. I see that the 1922 is about 13 feet long, whereas the YA-1713 is 8 feet, 4 inches long. Is the maximum width (at the rear) also about 35 inches (same as the YA-1713)? The rear reflectors look to be considerably larger than those on my 91XG - true? And would RG-11 coax fit within the 1922's connector assembly?

Thanks in advance for your kind assistance...

MAX HD

03-17-08, 12:21 AM

cpcat

03-17-08, 08:01 AM

Hi All:

I've read on this board that the Funke PSP-1922 VHF-high antenna has a little more gain than the YA-1713, but I'm not sure how much more (a little confused about the dBi and dBd ratings I saw). How much might the analog signal strengths on my 11 and 13 improve if I switched to the 1922?

Also had a few questions about the 1922. I see that the 1922 is about 13 feet long, whereas the YA-1713 is 8 feet, 4 inches long. Is the maximum width (at the rear) also about 35 inches (same as the YA-1713)? The rear reflectors look to be considerably larger than those on my 91XG - true? And would RG-11 coax fit within the 1922's connector assembly?

Thanks in advance for your kind assistance...

I don't think it's much wider but it's certainly longer and heavier. I noticed a significant improvement with the 1922 over the antennacraft Y10 7-13 which should be equivalent to the Winegard. I wouldn't go to the trouble of RG11 if I were you for vhf and it won't fit inside the balun on the 1922 anyway. You will pick up .1db or so from the raw connection on the balun which would be more than you'd get from RG11 over RG6 at vhf frequencies.

holl_ands

03-17-08, 11:28 AM

FYI: If you look at the gain for some of the simpler Funke antennas and compare to
equivalent W-G/C-M products, you'll quickly see that Funke uses dBi = dBd + 2.15 dB.

Carnivore

03-17-08, 02:31 PM

Following up on my earlier (http://www.avsforum.com/avs-vb/showthread.php?p=13260604#post13260604) post re NYC stations, I was able to get most of what I wanted by combining two antennas without having to use a Jointenna. I aimed a 4-bay CM-4221 at the Empire State Building for NY UHF & VHF channels, and an 2-bay DB2 at Long Island for WLIW-DT 22. I ran separate RG6 lines from each antenna into the house and joined them inside with an ordinary Channel Plus splitter/combiner. This arrangement also picks up nearby NJN even though I'm not aimed at it.

My only disappointment is that I'm not picking up WRNN-DT 48.3 to my north from the backside of the 4221. Maybe I'll be able to remove the screen after the transition but for now I need it to get WNET's weak signal from the Empire until they upgrade it.

What do I need to do now to minimize lightning risk? HERE (http://i31.tinypic.com/mhexbr.jpg) is a picture of the installation.