OTA Antenna Maintenance
 

TV Fool report:
http://www.tvfool.com/?option=com_wr...dfafc857406256

I've had a Winegard 7698P OTA UHF/VHF w/ WG AP-8700 pre-amp for over 6 years now with solid signal strength, very few dropouts on all channels from NYC.

For the past few months my signal (during summer and winter) has degraded;
especially on 5-1 and 4-1 and 9-1 (had to re-aim to get 2-1 perfect)
7-1, 11-1, 13-1 is strong.
Seems like VHF is strong and the UHF channels have become weak;
especially at certain times of the day (early and late they are weak).

At first I thought it was the pin oak in the line of sight, but it has since lost all it's leaves and I have the same issue.
I have been re-aiming it with little gain.

Sigh, what type of maintenance do I need to do on this antenna?
Is the pre-amp passed it's life expectancy?
Any tests I can run to narrow down the cause?

Thanks guys.

Where is your antenna located? Roof? Attic?

Did you inspect your connections to make sure they are tight, and not corroded? Sometimes they come loose and, in the cold weather, shrink just enough to be only partially connected. And sometimes water gets in and corrodes them. In this case (if the coax is still good) it's easy to chop off an inch of coax and put on a new connector. And antenna baluns do go bad and are easily (and cheaply) replaced.

It's certainly possible that your pre-amp has issues, especially if mounted outside. Though, in my experience, they tend to just quit and you loose signal rather than just provide a degraded signal.

connections...
 

the antenna is on the roof... checked all the downstream connections, will check the connections to the pre-amp next time I'm up there.

The most critical part of your system is the balun and the jumper from the balun to the preamp. Start there.

balun
 

I don't have a balun in my setup...?
Is it in the cartridge housing where the uhf phase lines enter and go out coax?

Yes, the balun is inside the housing for that antenna. At this point, you must consider that any part of the system is suspect and it will be necessary to substitute each, one-by-one, with a known good part, even if it means that you end up with a completely separate system. That seems like a lot of work, but it is easier than guessing.

The CB-8269 Cartridge Housing has been known to have problems; I consider it the weakest link in an otherwise good design. There is a troubleshooting video by Winegard:

How To Troubleshoot a Winegard Antenna Cartridge Housing

https://www.youtube.com/watch?v=TlQk...ule1MX8jCAfvPQ

http://forum.tvfool.com/attachment.p...1&d=1499537712

http://forum.tvfool.com/attachment.p...1&d=1499537896

http://forum.tvfool.com/attachment.p...1&d=1499538211

http://forum.tvfool.com/attachment.p...1&d=1499538454

http://www.solidsignal.com/pview.asp?p=cb-8269
http://www.winegarddirect.com/viewit...(CB8269)&post=

interesting mod
https://www.youtube.com/watch?v=mpZNtxy4INM

He soldered the external balun wires to the prongs, but that doesn't improve the connection between the prongs and the wires from that part of the antenna.

Do you have any way to measure signal strength so that you will know if you are making any progress?

the only way I have to measure the signal strength is through the signal strength meter on the Tivo...
I connect the ipad via facetime and point it at the TV, then I take the cell phone on the roof and I can see the signal strength as I re-aim :)

replace terminal board
 

for $15 I will just replace the CB-8269 and take it from there, instead of trying to take it apart and troubleshoot it.
thanks!

The TiVo diagnostics screen is good; it should give you signal strength, SNR, and uncorrected (RS) errors.

Lots of good suggestions.

The only thing I might add is the following.

Remove all the outdoor connections and carefully examine the center conductors and dielectric foam for any corrosion or contamination while you are at it.

You should always use a butyl rubber tape to seal all outside connections when you are done.

And you should always use a solid copper center conductor coax when possible.

This is especially important when using a line powered preamp like the 8700 and others.

Many low cost RG6 cables use a copper coated steel center conductor which not only can rust, but because steel is a very poor conductor of electricity, on longer runs, you will have a voltage drop to the preamp that may effect performance.

Solid copper core is certainly necessary with high-current draw amps with very long runs. If one has a low-draw pre-amp, the extra DC resistance of the the CCS core is irrelevant, especially on amps that have power supplies that provide several volts more voltage than the pre-amp actually required. The 8700, for example, draws very little power, as do most of the rest of the legacy 8700/8800 WG amps.



If you use SC coax and don't weatherproof it, it will rot out, just like CCS will, making the distinction again, irrelevant.

If care is taken to weatherproof, the cable runs are of moderate length (<100'), and you're not using a power hog of a preamp (the current 7777 comes to mind), there isn't a bit of performance difference between the two types of cable. At RF (TV signal) frequencies, there is no difference.

CB
 

is the CB-8269 the only balun I can use on the 7698P?

Did you try that?

Did you do the troubleshooting test shown in the first video to see if both sections of the antenna are working OK?
Yes, that is the way it has been designed, which is unique to that series of antennas by Winegard. Most other antennas combine the VHF and UHF sections in another way using shorting stubs.

http://forum.tvfool.com/attachment.p...1&d=1483889050

in RCA ANT751:

http://forum.tvfool.com/attachment.p...1&d=1483891000

The CB-8269 does two things, it combines the VHF and UHF sections so that they don't interfere with each other, and its internal balun converts the antenna to 75 ohms for the coax downlead.

You could do a custom modification as done in the second video above. Connect a balun to the VHF section and another balun to the UHF section and combine them with a UVSJ.

http://forum.tvfool.com/attachment.p...6&d=1483489795

http://forum.tvfool.com/attachment.p...1&d=1483891748

http://forum.tvfool.com/attachment.p...1&d=1483892367

http://www.channelmaster.com/TV_Ante...p/cm-94444.htm

http://www.solidsignal.com/pview.asp?p=uvsj

Guys, I swapped out the balun with a new one and it did not help my reception, sigh.
I am wondering if the connection between the UHF and VHF elements on the antenna is the issue - see pic.
https://goo.gl/photos/vT6N7UQ7MoGwJFNMA

The next step is to test each section of the antenna for reception as shown in the Winegard video.

balun
 

thanks rabbit... the video shows how to troubleshoot the balun to see if it is the cause of poor reception... but I have replaced the balun with a new one, that would eliminate the balun as the culprit.

I did notice the uhf/vhf lines coming into the balun had some oxidation going on, if you will - from moisture? I will try to scrape that off/file it down to see if my reception improves.

I learned a really really long time ago that, just because something is new, does not automatically mean it is actually good. It's only "good" when proven to be so.

The video shows more than that. It also says to test each section of the antenna for proper reception using a conventional balun with clip leads connected to the UHF section and then the VHF section without using the CB-8269.

balun
 

OK. So if I test with the clips and one part of the antenna is bad, then I guess I need a new antenna?
Can you recommend a balun w/ clips like the one in the video?
Than you.