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Discussion Starter · #1 ·
TVFool results:




I have an EZ-HD antenna (18" antenna) pointed Mag 85deg. Wineguard AP 8700, split to 2 tv's.




I have bad trouble with the closest PBS when the weather is less than perfect - but I figure with a directional antenna this is to be expected as it's in a totally different direction than the other signals.The others (at 84Deg) are near perfect during perfect weather, but choppy during windy weather. I attribute this to trees. I can get 47.1 in good weather, with little chop.



Yes, lots of trees in the way.


If you look at my photobucket account you can see other views from the antenna in all directions. Trees everywhere, 1 story house.


So I think I may need a more substantial antenna than this EZ-HD antenna. It's great, just doesn't work well with so many trees around. A previous post of mine dealt with possible wiring interference, but I don't believe that to be the issue.
 

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Couple quick things:


1) Picking up channels that are widely off the aiming point will be problematic for all antennas, not just the EZ-HD. 125 degree spread is just too much. A rotor is the best bet for reliable PBS reception.


2) You may have a problem with pre-amp overload. Holl_ands, a communications engineer, suggests that the power input from your two highest stations should not exceed -22.3 dBm UHF and -20.8 dBm VHF. Your two highest stations average -29 dB. Convert that to peak by adding 7 dBm and power input equals -22 dBm at peak. I don't have gain figures for the EZ-HD but gain is added to the power input. If we assume, say 10 dBm, we are now up to -12dBm. This suggests pre-amp overload is occuring. A smaller, high input pre-amp such as the winegard hdp 269 appears to be a better choice.


***error correction. I had the wrong tvfool in front of me. You have six very strong stations. According to Holl_ands, the power input from the top six stations should not exceed -29.3 dBm. Your top six average -29.2 dbm which equals -22.2 dBm at peak. Adding antenna gain, input increases to -12.2 dbm. Pre-amp overload is very likely in your situation. Winegard hdp 269 is a better pre-amp choice.
 

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Quote:
Originally Posted by IMatt
TVFool results:




I have an EZ-HD antenna (18" antenna) pointed Mag 85deg. Wineguard AP 8700, split to 2 tv's.


I have bad trouble with the closest PBS when the weather is less than perfect - but I figure with a directional antenna this is to be expected as it's in a totally different direction than the other signals.The others (at 84Deg) are near perfect during perfect weather, but choppy during windy weather. I attribute this to trees. I can get 47.1 in good weather, with little chop.


So I think I may need a more substantial antenna than this EZ-HD antenna. It's great, just doesn't work well with so many trees around. A previous post of mine dealt with possible wiring interference, but I don't believe that to be the issue.[/TD][/TR][/TABLE]
You mount won't hold much antenna. The smallest Winegard in their new 769X series is the Winegard HD 7694P. Same price you paid for the EZ-HD and probably has 3 to 5 db (maybe 6) more than the EZ.


It would help the drop outs in the wind (if it not your antenna moving but trees) on the stations at 85 Mag.


It won't help the PBS station in the other direction. It might make the PBS weaker as it's off a rear quadrant of the back of the antenna. The 7694 most likely has a much better pattern than the EZ-HD. (Winegard publishes their specs and are on their real, not "trick" antennas very accurate).


If your mount could hold the 7694, you may not even need an amp. I suspect though I can't find it published the EZ-HD is maybe 3db on VHF and 5 on UHF, maybe. Still puts you close to overload that I totally missed looking at your specs. And yes, double agree, there is not antenna that can do that kind of spread between PBS and the others.


If you did upgrade the main antenna, you could put the EZ-HD on a separate mast and coax run with an AB antenna switch inside.

 

[URL='/attachments/15914']HD7694P.pdf 407.224609375k . file[/URL]
 

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He probably would be better off with no preamp as all his stations are very strong and close. The rotator for PBS's direction is a good idea. A second antenna/jointenna might work also.

John
 

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Discussion Starter · #5 ·
Thanks for the quick response and advice, everyone! I'm not opposed to replacing the mount - it came in a kit.


I do understand that getting PBS is pretty impossible with the directional antenna pointed away from that signal. A rotor's not really an option as we utilize the dual-tuners of the HDTivo to record two things at once. I have considered adding a second antenna pointing in that direction, just because PBS has such incredible programming at times.


To the issue at hand: will the DB level getting to the tuner tell how bad the overload may be, or is this number inaccurate because of how the amplifier handles the overload?

As well, if I were to add another identical antenna (plus the antenna combiner), would the 269 continue to work for that setup?



Thanks to this hugely helpful community! I've learned a LOT in the past few months.
 

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The signal quality indicator on the tuner does not help much in identifying overload.

The best thing to do is to go up on the roof, remove the preamp then check the indicator and see if any of the signals improved.

John
 

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For test purposes, you need to remove the pre-amp and the it's power supply from your cabling. This means you use a cable splicer at the antenna to remove the pre-amp and use a splicer or jumper cable to remove the power inserter from the system. Removing the pre-amp may allow you to pick up more stations (overload was squashing low power stations) or may improve picture quality and stability.
 

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Quote:
Originally Posted by IMatt /forum/post/15552630


Thanks for the quick response and advice, everyone! I'm not opposed to replacing the mount - it came in a kit.


I do understand that getting PBS is pretty impossible with the directional antenna pointed away from that signal. A rotor's not really an option as we utilize the dual-tuners of the HDTivo to record two things at once. I have considered adding a second antenna pointing in that direction, just because PBS has such incredible programming at times.


To the issue at hand: will the DB level getting to the tuner tell how bad the overload may be, or is this number inaccurate because of how the amplifier handles the overload?

As well, if I were to add another identical antenna (plus the antenna combiner), would the 269 continue to work for that setup?



Thanks to this hugely helpful community! I've learned a LOT in the past few months.

ctdish has the answer. If you remove the preamp and the signal goes up, you are in overload. So no, the built in meter will not show overload unless you remove the amp and go look.


If you want a one coax solution and no rotor, try combining the EZ-HD pointed at PBS. Even that loss and a slitter at the bottom is only 6db and you have plenty of signal probably.


Remember, at best 50% of putting up an antenna is science, the other is trial and error. Not every super idea I had worked on roof! :mad:)
 

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Another quick test for overload is to aim the antenna away from the towers. If the signal strength goes up (after pointing away from towers), you have overload.
 

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Discussion Starter · #10 ·
Thank you very much for everyone's help - I have my work cut out for me tonight. I'll post back when I try the amp disconnect and antenna re-aim.
 

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Quote:
Originally Posted by IDRick /forum/post/15553118


Another quick test for overload is to aim the antenna away from the towers. If the signal strength goes up (after pointing away from towers), you have overload.

Rick I have a 4221A and one of the stations borderline overloads my amp. But if I turn away from it, the signal goes down in all directions. It never gets over 80. More details if you need them or is a wtf situation? Also no one in any direction ever sees that station above 80. Sorta odd. Unless they are not running the power they claim on their license.
 

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Interesting experience. Hmmm, don't have an answer. We need the pros to answer that one. Try Holl_ands. He's very good.
 

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I would keep his current antenna point it at 75 degress and use a channel 24 jointenna for the PBS station at 309 as well as W24CP at 351 at a higher gain antenna for the PBS station.......
 

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Quote:
Originally Posted by gjvrieze /forum/post/15555774


I would keep his current antenna point it at 75 degress and use a channel 24 jointenna for the PBS station at 309 as well as W24CP at 351 at a higher gain antenna for the PBS station.......

He wasn't totally happy with his current antenna at 85 Magnetic was a lot of the reason for his post. He wanted more gain. And the PBS would be nice, where the jointenna comes into play.


This is why I suggest he upgrade his main antenna and use the old one with a coupler of some kind pointed at the PBS.
 

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Discussion Starter · #16 ·
Well I finally was able to get up on the roof and jumper around the preamp - with all the rain/ice/snow and working late, it's taken me a while to get to it. I didn't adjust the direction.


Get this: it was extremely windy, and after removing the preamp from the equation the channel strengths didn't noticeably change. It doesn't appear that ANY channel was affected at all. PBS was just as blocky as before, I believe due to the wind. I did notice that the audio didn't chop out, although the video became pixelated at times. Previously the audio would chop out.


I still get 100% on a couple of the channels.

Haven't checked the SNR on the channels yet.

I was still running the 2-tv splitter.


Looks like y'all were 100% correct when you suggested the preamp was being overloaded.
 

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First, is it possible that the wind moving the antenna is the problem and not so much the wind moving the trees? Second, I see your TV Fool report is for post trasition. Did the stations in your area transition on the orginal date? If not, then is it not possible that that those stations are not broadcasting on those real stations with the listed power. Lastly, I see you have alot of stations that are close and are LOS (Line of Sight, I am guessing). Why not try an decent indoor antenna? I am using an indoor antenna and I get stations from farther out and one is listed 1 edge. It would remove the chance of the wind moving the antenna. Removing the trees might be a bit harder.
 

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Discussion Starter · #18 ·
First off, the antenna is pretty small, and is bolted up pretty good. It didn't seem to be moving the slightest bit when up there. I'll check again, but everything seemed in order.


Second, there is little change pre- and post-transition, except for some moving to high vhf.


Third, a set-top antenna doesn't do nearly as good as this outside antenna, partially because the house is a 1 story brick house.


I still have to try aiming it a little more N to see if it eliminates the chop on PBS while maintaining signal on those at E.
 

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Quote:
Originally Posted by IMatt /forum/post/15899307


First off, the antenna is pretty small, and is bolted up pretty good. It didn't seem to be moving the slightest bit when up there. I'll check again, but everything seemed in order.


Second, there is little change pre- and post-transition, except for some moving to high vhf.


Third, a set-top antenna doesn't do nearly as good as this outside antenna, partially because the house is a 1 story brick house.


I still have to try aiming it a little more N to see if it eliminates the chop on PBS while maintaining signal on those at E.

That may very well work Matt. PBS is a pretty strong signal on TVFool. It could be your antenna now has a null pointed at PBS, so it might not take much rotation toward PBS away from the stuff to the East to fix that problem.


Let us know and hope that works.
 

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IMatt, thanks for reporting your results. You may also want to evaluate changing height on the antenna. The evergreens to the east may be influencing signal strength. Increasing elevation to look over these evergreens may enable you to rotate the antenna a bit more without too big a hit in signal strength.


Just a thought,


Rick
 
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