The Official AVS Antenna and Related Hardware Topic! - Page 253 - AVS Forum | Home Theater Discussions And Reviews
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post #7561 of 17632 Old 02-27-2008, 05:50 PM
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Quote:
Originally Posted by PCTools View Post


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.
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post #7562 of 17632 Old 02-28-2008, 09:16 AM
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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.
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post #7563 of 17632 Old 02-28-2008, 09:47 AM
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Quote:
Originally Posted by Junglerock View Post

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

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
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post #7564 of 17632 Old 02-28-2008, 09:55 AM
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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.

***Listing my HT gear in my signature on this board will make me feel like a puny, girlie man. Listen to me now but hear me later***
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post #7565 of 17632 Old 02-28-2008, 11:48 AM
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Quote:
Originally Posted by Rick0725 View Post

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 and a CM7777. In your opinion (or anyone else), how would you compare it to the new Winegard HD 7698P?

Appreciate it,
Rob
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post #7566 of 17632 Old 02-28-2008, 12:00 PM
 
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Quote:
Originally Posted by PCTools View Post

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.
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post #7567 of 17632 Old 02-28-2008, 02:45 PM
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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.
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post #7568 of 17632 Old 02-28-2008, 02:47 PM
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I see the other Rick answered my gain questions for the Phillips wedge. Thanks, guess nothing comes close to the Wade for gain.
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post #7569 of 17632 Old 02-28-2008, 05:20 PM
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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.
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post #7570 of 17632 Old 02-28-2008, 10:36 PM
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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)
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post #7571 of 17632 Old 02-29-2008, 06:16 AM
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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/G...CID=C12585x003
http://www.solidsignal.com/prod_disp...p?prod=ANC3010
The CM-3010 is unamplified (CM-3038 is optional amplifier module):
http://www.pctinternational.com/chan...anual_3010.pdf

However, they have much less gain than CM-4221, even w/o rear screen.
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post #7572 of 17632 Old 02-29-2008, 06:43 AM
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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
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post #7573 of 17632 Old 02-29-2008, 07:02 AM
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Quote:
Originally Posted by fbov View Post

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

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...
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post #7574 of 17632 Old 02-29-2008, 09:54 AM
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Quote:
Originally Posted by Rick0725 View Post

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.

Quote:
Originally Posted by bozey45 View Post

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).

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.
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post #7575 of 17632 Old 02-29-2008, 11:08 AM
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Quote:
Originally Posted by holl_ands View Post

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
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post #7576 of 17632 Old 02-29-2008, 01:43 PM
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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....
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post #7577 of 17632 Old 02-29-2008, 03:46 PM
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Quote:
Originally Posted by holl_ands View Post

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.

Quote:
Originally Posted by holl_ands View Post

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.


Quote:
Originally Posted by holl_ands View Post

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:

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post #7578 of 17632 Old 02-29-2008, 11:30 PM
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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
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post #7579 of 17632 Old 03-01-2008, 04:36 PM
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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???
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post #7580 of 17632 Old 03-01-2008, 11:43 PM
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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
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post #7581 of 17632 Old 03-01-2008, 11:45 PM
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And since the attachments failed to appear ...
LL

 

Antenna Timeline.zip 9.6201171875k . file
Attached Files
File Type: zip Antenna Timeline.zip (9.6 KB, 84 views)
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post #7582 of 17632 Old 03-02-2008, 04:25 PM
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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
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post #7583 of 17632 Old 03-02-2008, 06:00 PM
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"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...
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post #7584 of 17632 Old 03-02-2008, 07:33 PM
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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.
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post #7585 of 17632 Old 03-02-2008, 07:47 PM
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And musn't overlook the coat hanger....it's a classic...
Kerry Cozad measured a "4-leaf-clover" antenna pattern:
https://secure.connect.pbs.org/confe...ns/TC05_43.htm

[Although I might try reworking the feed to improve the VSWR.....]
LL
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post #7586 of 17632 Old 03-02-2008, 11:32 PM
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Quote:
Originally Posted by holl_ands View Post

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.

Quote:
Originally Posted by holl_ands View Post

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?
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post #7587 of 17632 Old 03-03-2008, 06:58 AM
 
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Quote:
Originally Posted by Carnivore View Post

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
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post #7588 of 17632 Old 03-03-2008, 10:58 AM
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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. 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?
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post #7589 of 17632 Old 03-03-2008, 11:07 AM
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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?
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post #7590 of 17632 Old 03-03-2008, 01:27 PM
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Quote:
Originally Posted by Tower Guy View Post

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
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