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The Official AVS Antenna and Related Hardware Topic! - Page 468

post #14011 of 16033
Quote:
Originally Posted by 300ohm View Post

My experience with Solid Signal has been that they ship even faster than Newegg, which is also very quick. I think youll have it by Friday.

Yeah, I've used the before, but I was doubtful. So far, FedEx thinks you're right.

Quote:
Originally Posted by 300ohm View Post

Thats a High Low Signal Joiner, which joins a Vhf-Low antenna with a Vhf-Hi antenna and not what you need. You need a UVSJ, Uhf Vhf Signal Joiner.
You may be able to get one locally.

I have a UVSJ, but it wipes out WHYY 12 from my 4228 (seeing as the 4228 had to go into the UHF side). That was why I'd just used a standard splitter despite the losses. It seems, however, that I can get WHYY with the VHF YA-6260, so perhaps a little more separation will prevent the multipath that was causing problems. I just added the HLSJ "in case" I can't figure out a clean way to get those VHF stations. My suspicion is that the 91-XG won't have the issue.
post #14012 of 16033
If you use the HLSJ with the 91XG, you will likely loose channel 12 as the HLSJ will attenuate high-VHF by 20-30 dB on the low port.

In a pinch, you can always pick up a gold-plated UVSJ at Radio Shack, catalog number 15-2586.
post #14013 of 16033
Well, the 91XG was a waste. It didn't do any better on WTXF, and frankly doesn't seem at all directional: I can still get Baltimore's WMAR 2 (38 UHF) while getting 6/6 bars on the other Philly stations.

Height, tilt, position on the roof--nothing seemed to matter.

It also can't get the Baltimore Fox station WBFF (not a surprise, since it has an Nm under 10). I guess no NFC opening day for me.

I'm going to call antennasdirect tomorrow and see if they have any brilliant tips, but based on what I've read elsewhere, WTXF is the signal most folks have trouble tuning, and I doubt I'll be an exception. Grrr.
post #14014 of 16033
Have you tried on more than 1 tuner? Did you do a full re-scan?
post #14015 of 16033
Yup, full rescan. Even reinstalled Windows 7 to ensure it was not the problem. Problem exists on each of the tuners (which, btw, are all different generations and act differently re: signal strength, but none sees more than 2 bars for WTXF).

I can get every station I should, and even some I really shouldn't, but I can't get WTXF.

I am going to see if I can get ahold of an engineer there tomorrow, too, and find out if they're running on less-than-normal power right now for some reason.
post #14016 of 16033
Of the 2 different USB tuners I have tried, neither of them perform nearly as well as the many different TV's or converter boxes I have tired do. Both USB's have poor selectivity.

Can you borrow a standard TV or converter box you to see if RF 42 works any better?
post #14017 of 16033
Merconium,
It's possible your computer may be giving off interference to the frequency WTXF is using. Try a standalone digital TV or digital TV tuner connected to your antenna coax, with all other nearby electronics (computers, routers, phones, modems, etc.) unplugged and turned off.
post #14018 of 16033
Quote:
Originally Posted by Digital Rules View Post

Of the 2 different USB tuners I have tried, neither of them perform nearly as well as the many different TV's or converter boxes I have tired do. Both USB's have poor selectivity.

Can you borrow a standard TV or converter box you to see if RF 42 works any better?

These are all PCI/-e cards, and well-regarded ones at that. They're using the same radio systems that any of the TVs and converter boxes do (I think one is a Philips and at least another is the 5th gen LG tuner that appeared in many TVs in the last five years). I've never tried a USB tuner because I've never heard of anyone finding as good of success with them as with PC cards.

The key change here is that I moved 2.5 miles into a much more difficult reception area. I could get everything fine--even WTXF--in July, before the move, using this hardware. And I get everything but WTXF, now, with 90-100% signal strength (amp'd).

I can ask some friends about converter boxes, but virtually everyone I know is running an HDTV without one. Still, worth the try--what can it hurt? A good suggestion I hadn't thought of. Thanks.

Quote:
Originally Posted by arxaw View Post

Merconium,
It's possible your computer may be giving off interference to the frequency WTXF is using. Try a standalone digital TV or digital TV tuner connected to your antenna coax, with all other nearby electronics (computers, routers, phones, modems, etc.) unplugged and turned off.

If I can get a box or TV I'll try, but since I got WTXF for a year just fine using this setup, I just don't think there's a chance this is it.
post #14019 of 16033
Quote:
Originally Posted by Digital Rules View Post

Of the 2 different USB tuners I have tried, neither of them perform nearly as well as the many different TV's or converter boxes I have tired do. Both USB's have poor selectivity.

Add the Hauppauge 2250 to that list. My TV tuners and CECBs are much better at locking in weak signals.
post #14020 of 16033
Quote:
Originally Posted by Ken.F View Post

Add the Hauppauge 2250 to that list. My TV tuners and CECBs are much better at locking in weak signals.

It seems like a lot of folks hate the 2250. Mine are all AverMedia cards, and I've just never had a problem with them.

I'll make an effort tomorrow to get a converter box or see if someone has a small HDTV I can borrow for an hour.
post #14021 of 16033
Quote:
Originally Posted by Merconium View Post

It seems like a lot of folks hate the 2250. Mine are all AverMedia cards, and I've just never had a problem with them.

I said about the same thing in that thread as this one.
post #14022 of 16033
Merconium:

Did you ever wipe your entire channel memory clean and then, without scanning, manually enter in 42.1? Still wondering if your tuner is acting in some way that inextricably ties real 42.1 to virtual 22.1, such that the signal you're getting is still WMPT from Annapolis from the backside of your antenna when pointed toward Philly. If you've already tried that, perhaps you are just located in a shadow/dead spot for WTXF (very frustrating, of course).
post #14023 of 16033
Quote:
Originally Posted by Merconium View Post

Well, the 91XG was a waste. It didn't do any better on WTXF, and frankly doesn't seem at all directional: I can still get Baltimore's WMAR 2 (38 UHF) while getting 6/6 bars on the other Philly stations.

Height, tilt, position on the roof--nothing seemed to matter.

It also can't get the Baltimore Fox station WBFF (not a surprise, since it has an Nm under 10). I guess no NFC opening day for me.

I'm going to call antennasdirect tomorrow and see if they have any brilliant tips, but based on what I've read elsewhere, WTXF is the signal most folks have trouble tuning, and I doubt I'll be an exception. Grrr.

If the station is broadcasting normally (ask tomorrow) and the both the 4228 and the 91XG cannot receive a UHF 42 signal from Roxborough, I can only offer two ideas: 1) RF interference on that channel as previously suggested, perhaps a multiple of a close FM station, or 2) You are getting a frequency-specific multi-path reflection that could be easily identified with a spectrum analyzer. Without an SA, all you can do is move the antenna elsewhere and try again. Perhaps it's due to a tree and the problem will resolve when the leaves fall.

You do have a co-channel 42 (WMPT from Annapolis) but both antennas you've tried should have a F/B of > 20 dB at that frequency which *ought* to keep it from interfering.

FWIW, the 91XG is about the *MOST* directional UHF antenna around.... Bars don't indicate received signal power, they usually indicate the *QUALITY*, that is the decodability of the incoming ATSC signal.

Don't have any further words of wisdom, wish I did...
post #14024 of 16033
Quote:
I am going to see if I can get ahold of an engineer there tomorrow, too, and find out if they're running on less-than-normal power right now for some reason.
FWIW, I watched the Eagles game on WTXF fine Sunday. I only had a little bit of pixelation and drop outs during the 3rd quarter, but there was a thunderstorm between me and the transmitter at that time. I was using my AverMedia Bravo Hybrid PCI-E card, which is definitely less sensitive than my Zenith/Insignia converter boxes, even though they all have 6th gen tuners. On the other hand, if the signal is that weak that the converter box makes a difference, then youll still have tons of dropouts and pixelation episodes, heh.
The Sansonic FT300A and Apex DT502 converter boxes give you both Signal Strength and Signal Quality meters displayed in numbers. These could be helpful in diagnosing your situation.

Quote:
Well, the 91XG was a waste. It didn't do any better on WTXF, and frankly doesn't seem at all directional: I can still get Baltimore's WMAR 2 (38 UHF) while getting 6/6 bars on the other Philly stations.
Get a 2' X 4' piece of 1/2" rat wire mesh, bend it in half so you have about 90 degrees and attach to the 91XG reflector with wire ties. (black UV resistant wire ties preferred, WalMart Auto Dept cheapest source). If you still get WMAR after that, that means youre definitely catching the Baltimore stations from a front reflection, from Iron Hill or something else.

Quote:
You do have a co-channel 42 (WMPT from Annapolis)
Yeah, that was a bad choice of channel assignments on the FCC's part. They really need to review that. A Maryland PBS repeater station potentially messing up FOX for a large portion of Delaware. There are plenty of other real numbers available.
post #14025 of 16033
Quote:
Originally Posted by gcd0865 View Post
Merconium:

Did you ever wipe your entire channel memory clean and then, without scanning, manually enter in 42.1? Still wondering if your tuner is acting in some way that inextricably ties real 42.1 to virtual 22.1, such that the signal you're getting is still WMPT from Annapolis from the backside of your antenna when pointed toward Philly. If you've already tried that, perhaps you are just located in a shadow/dead spot for WTXF (very frustrating, of course).
I have. I've told WMC to delete channels (previously) and then yesterday I even reinstalled Windows.

Now, whether it is trying to lock the wrong signal--that I don't know, and I don't know if there is any way at all to fix that.

Quote:
2) You are getting a frequency-specific multi-path reflection that could be easily identified with a spectrum analyzer. Without an SA, all you can do is move the antenna elsewhere and try again. Perhaps it's due to a tree and the problem will resolve when the leaves fall.
I've tried moving all over the roof--even to unrealistic mounting positions--to no avail. It's nothing if not wooded between my antenna and the broadcast tower.

Quote:
Get a 2' X 4' piece of 1/2" rat wire mesh, bend it in half so you have about 90 degrees and attach to the 91XG reflector with wire ties. (black UV resistant wire ties preferred, WalMart Auto Dept cheapest source). If you still get WMAR after that, that means youre definitely catching the Baltimore stations from a front reflection, from Iron Hill or something else.
Elsewhere I saw suggestions to wrap the reflector in foil (which didn't do anything for me). Another suggestion was to wrap a piece of cardboard in the foil and mount it behind the reflector. Would the mesh work better than these "solutions?" (I know quite little about antenna design.)

Thanks again for all your help!
post #14026 of 16033
Quote:


Would the mesh work better than these "solutions?"

No it wouldnt, just more permanently, heh. Just wrapping the existing reflector with foil may not be enough, I think it needs to be bigger to positively block out the back signals. So try it with aluminum foil wrapped in a couple of 2 ft by 2 ft cardboard pieces to be sure. And maybe experiment with another foil wrapped piece on the side of it that faces towards Iron Hill.

The results of these experiments will tell you if youre catching Baltimore signals from the front on a reflected bounce. If thats true, Im not sure what can be done about it.

Quote:


FWIW, the 91XG is about the *MOST* directional UHF antenna around....

Pretty much so, yeah. Except for the old parabolas no longer sold.
post #14027 of 16033
Quote:
Originally Posted by Merconium View Post

Based on what I've read elsewhere, WTXF is the signal most folks have trouble tuning, and I doubt I'll be an exception. Grrr.

I continue to suspect that 91.3 FM is causing overload. A strong FM station can cause distortion in an amplifier which creates harmonics and intermodulation products. The seventh harmonic of 91.3 falls on 639.1 MHz which is in channel 42 (638-644). Your WPVI antenna will pick up FM very well.

Have you tried connecting the 91 XG directly to the tuner card without the VHF antennas connected?
post #14028 of 16033
Quote:
Originally Posted by Tower Guy View Post

I continue to suspect that 91.3 FM is causing overload. A strong FM station can cause distortion in an amplifier which creates harmonics and intermodulation products. The seventh harmonic of 91.3 falls on 639.1 MHz which is in channel 42 (638-644). Your WPVI antenna will pick up FM very well.

Have you tried connecting the 91 XG directly to the tuner card without the VHF antennas connected?

Yes, I am currently running the UHF (91 XG or CM4228) all by itself. I stopped trying to run both UHF and VHF together in the hope of eliminating one more variable sometime last week.
post #14029 of 16033
Next thing to try is an FM filter. Radio Shack 15-0024 should be available for around $7 locally. Install it before the first active device closest to the antenna, whether it be an amp or the tuner itself.
post #14030 of 16033
Quote:
Originally Posted by Merconium View Post

Yes, I am currently running the UHF (91 XG or CM4228) all by itself. I stopped trying to run both UHF and VHF together in the hope of eliminating one more variable sometime last week.

I also have a 4228 that would overload all preamps, even the HDP-269. I needed to filter out FM in addition to the UHF only antenna. In my case the FM station is off the back of the 4228 antenna. It's 1 mile away and 6 KW ERP.

I assume that the 91XG is better than the 4228.
post #14031 of 16033
Quote:
Originally Posted by ADTech View Post

Next thing to try is an FM filter.

Good point. I believe the OP purchased an HLSJ which will make an excellent FM trap as well, especially at that frequency.
post #14032 of 16033
Quote:
Originally Posted by ADTech View Post

Next thing to try is an FM filter. Radio Shack 15-0024 should be available for around $7 locally. Install it before the first active device closest to the antenna, whether it be an amp or the tuner itself.

Quote:
Originally Posted by Digital Rules View Post

Good point. I believe the OP purchased an HLSJ which will make an excellent FM trap as well, especially at that frequency.

I just tried the HLSJ as a trap, but to no avail. I've also tried playing with the AP-8700's FM trap but with similar success, detailed here.

I did leave a message with WTXF's engineering dept. Thanks to everyone for your continued help. You can imagine the frustration of having 20-30 hours invested in this and feeling more and more fatalistic about the enterprise.
post #14033 of 16033
Quote:
Originally Posted by Merconium View Post

I just tried the HLSJ as a trap, but to no avail. I've also tried playing with the AP-8700's FM trap but with similar success, detailed here.[/url]

In order to be effective, the HLSJ must be installed between the antenna and the preamp.

Your experience with the AP-8700 doesn't make sense. The fixed FM filter is in the circuit all the time. The switch simply adds the variable filter. Yes, the variable filter is designed to eliminate a single frequency, and that's what you really need. When you say that stations get noisy with the FM trap in, do you mean FM stations or TV stations?

Your finding that the 91XG is not that directional makes little sense. It could mean that you have so much multipath that you can't find the right aiming, or it may mean that there is an electrical problem in the balun, F connector, or the coax.
post #14034 of 16033
Quote:
Originally Posted by Tower Guy View Post

In order to be effective, the HLSJ must be installed between the antenna and the preamp.

Yup, that's how it's installed.

Quote:


Your experience with the AP-8700 doesn't make sense. The fixed FM filter is in the circuit all the time. The switch simply adds the variable filter. Yes, the variable filter is designed to eliminate a single frequency, and that's what you really need. When you say that stations get noisy with the FM trap in, do you mean FM stations or TV stations?

I don't think you're correct about the filter being in the circuit all the time. Their instructions are clear that if you want to receive FM you should switch to "FM TRAP OUT" (which is factory set to outside the FM range).

Having the FM trap set to "IN" clearly attenuated FM reception across the FM range--the radio stations got fuzzier. If I had a station tuned with a little fuzz and then switched the trap to "OUT" it cleared up. Winegard's instructions confirm my experience: the preamp is designed to allow FM to pass if you so choose.

Quote:


Your finding that the 91XG is not that directional makes little sense. It could mean that you have so much multipath that you can't find the right aiming,

Here's the TVfool map for WMAR 2: http://db.tt/GOL5fgA
How I'm getting a solid signal is quite beyond me.

Here's WTXF's: http://db.tt/Qj541im

The aiming question is a good one. Iron Hill, a highly ferrous little hill that others have speculated is causing me problems, actually sits about 4.5mi south of me, between me and Baltimore. Perhaps it is responsible for making WMAR come in. If so, it might also have the same effect on the co-channel shared with WTXF. I don't think it is causing problems with WTXF directly, since it is to the back of the antenna when pointed to Philly, but who knows.

Quote:


or it may mean that there is an electrical problem in the balun, F connector, or the coax.

I had the same experience with the 4228. I replaced the balun with no change. Having the same experience with a brand-new 91XG (which I have to suppose has a proper balun, too), seems to eliminate that as a potential source of the problem.

I also swapped all of my coax lines with others, to no effect. Now, I could try that again--I've got tons of the stuff--but since I can get so many other stations, I'm not sure that's it. If I get some spare time this afternoon I can try again.

I've also tried simplifying the connection to the PC: bypassing the splitter there and connecting directly to a card. That didn't change the reception of WTXF.

Sigh.
post #14035 of 16033
Quote:
Originally Posted by Merconium View Post

Sigh.

Wow! You've already done everything that I would have.
post #14036 of 16033
Quote:
Iron Hill, a highly ferrous little hill that others have speculated is causing me problems, actually sits about 4.5mi south of me, between me and Baltimore.

So youre north of Iron Hill. I was under the impression you were a bit south of it, heh. So youre off West Main Street in Newark ?
Theres a lot of complicated territory between you and the WTXF transmitter for a few miles from you in that direction. I think youll definately need to go higher than 16 ft. Play with TVFool heights. At some point you should see a big jump in gain on channel 42.

The good point is that you seem to be on a hill per the TVFool image.
post #14037 of 16033
> I did leave a message with WTXF's engineering dept. Thanks to everyone
> for your continued help. You can imagine the frustration of having
> 20-30 hours invested in this and feeling more and more fatalistic about
> the enterprise.

20-30 hours? You're just getting warmed up!

Ideas:

91 XG with extra directors

bandpass filter the one RF channel you want
CM Jointenna or better yet talk to tinlee.com

ferrite around coax just ahead of tuner
(and just ahead of amp if using one)

> "wrap the reflector in foil"
foil may too thin? Try aluminum flashing (indoors)
or heavy gauge wire mesh (outdoors)
A solid reflector will catch a lot of wind.
If you can secure it sufficiently, go for it.
See also: http://www.prism.gatech.edu/%7Ewn17/

quad shield coax, or Belden 1694A

If you can identify a source of reflections,
there is the two antenna trick. (hdtvprimer.com)

500 foot tower :-)
post #14038 of 16033
I've never had a situation in which an HLSJ was inadequate to attenuate FM overload. I am inclined to shy away from Winegard preamps in metropolitan situations (and near FM transmitters) because their cases are not shielded, so even if you adequately filter FM off the coax, the case might still leak in an excessive amount.

For several years now, I have been using any available garden variety cable TV 15dB amp as a preamp and putting HLSJs on their inputs when needed and have never encountered any overload problems.
post #14039 of 16033
merconium:
Quote:


based on what I've read elsewhere, WTXF is the signal most folks have trouble tuning, and I doubt I'll be an exception. Grrr.

That certainly is possible.

I have been looking for clues in previous posts:
Quote:
Originally Posted by Merconium View Post

Well, the 91XG was a waste. It didn't do any better on WTXF, and frankly doesn't seem at all directional:

Quote:
Originally Posted by ADTech View Post

Perhaps it's due to a tree and the problem will resolve when the leaves fall.
You do have a co-channel 42 (WMPT from Annapolis) but both antennas you've tried should have a F/B of > 20 dB at that frequency which *ought* to keep it from interfering.
FWIW, the 91XG is about the *MOST* directional UHF antenna around.... Bars don't indicate received signal power, they usually indicate the *QUALITY*, that is the decodability of the incoming ATSC signal.

Quote:
Originally Posted by Tower Guy View Post

Your finding that the 91XG is not that directional makes little sense. It could mean that you have so much multipath that you can't find the right aiming, or it may mean that there is an electrical problem in the balun, F connector, or the coax.

I might have missed it, but I have to ask:

Is your coax grounded with a grounding block? Unwanted signals can be picked up by the outside of the coax shield and travel either down to the tuner or up to the antenna if the shield isn't grounded.

Quote:
Originally Posted by Konrad2 View Post

ferrite around coax just ahead of tuner(and just ahead of amp if using one)

If the grounding isn't sufficient, wrap the coax around a ferrite toroid (FT-240-43) just before it enters the tuner, or place ferrite sleeves on the coax (the F connector needs to be off the end of the coax before the sleeves will fit).

An antenna that is supposed to have a very good F/B, which you need for your co-channel interference, can have that good F/B compromised if the unwanted co-channel signal can enter the feed point of the antenna on the coax shield. The fix is to place ferrite sleeves, acting as a choke, on the coax as close to the antenna feedpoint as possible:
http://ham-radio.com/k6sti/balun.htm
post #14040 of 16033
Quote:
Originally Posted by Konrad2 View Post


1 bandpass filter the one RF channel you want
CM Jointenna or better yet talk to tinlee.com

2 If you can identify a source of reflections,
there is the two antenna trick. (hdtvprimer.com)

3 500 foot tower :-)

These are also my choices for troubleshooting the problem.

You can buy a single filter from Blonder Tongue. http://www.solidsignal.com/pview.asp...Hz-%28BPF-U%29

I've also built them using this design software; http://www.wa4dsy.net/cgi-bin/idbpf
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