TV Fool  

Go Back   TV Fool > Over The Air Services > Help With Reception

Notices

Reply
 
Thread Tools
Old 3-Jan-2017, 1:35 PM   #1
olimazi
Member
 
Join Date: May 2010
Posts: 55
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.
olimazi is offline   Reply With Quote
Old 3-Jan-2017, 6:08 PM   #2
Jake V
Senior Member
 
Join Date: Jan 2014
Location: Virginia!
Posts: 328
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.
Jake V is offline   Reply With Quote
Old 3-Jan-2017, 6:24 PM   #3
olimazi
Member
 
Join Date: May 2010
Posts: 55
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.

Quote:
Originally Posted by Jake V View Post
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.
olimazi is offline   Reply With Quote
Old 3-Jan-2017, 6:31 PM   #4
Tower Guy
Senior Member
 
Join Date: Dec 2009
Location: Delmar, NY
Posts: 1,164
The most critical part of your system is the balun and the jumper from the balun to the preamp. Start there.
Tower Guy is offline   Reply With Quote
Old 3-Jan-2017, 8:00 PM   #5
olimazi
Member
 
Join Date: May 2010
Posts: 55
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?

Quote:
Originally Posted by Tower Guy View Post
The most critical part of your system is the balun and the jumper from the balun to the preamp. Start there.
olimazi is offline   Reply With Quote
Old 3-Jan-2017, 11:07 PM   #6
rabbit73
Retired A/V Tech
 
Join Date: Aug 2012
Location: S.E. VA
Posts: 2,550
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://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.
Attached Images
File Type: jpg cb-8269prongs.JPG (131.8 KB, 1356 views)
File Type: jpg cb-8269balun.JPG (88.3 KB, 354 views)
File Type: jpg CB-8269snip1b.jpg (136.8 KB, 327 views)
File Type: jpg Winegard cb-8269cuL.jpg (79.5 KB, 2517 views)
File Type: jpg Winegard CB-8269new_1.jpg (117.0 KB, 2532 views)
File Type: jpg Winegard VHF Test2.jpg (84.5 KB, 1911 views)
File Type: jpg Winegard UHF Test2.JPG (76.2 KB, 1926 views)
__________________
If you can not measure it, you can not improve it.
Lord Kelvin, 1883
http://www.megalithia.com/elect/aeri...ttpoorman.html

Last edited by rabbit73; 8-Jul-2017 at 7:31 PM.
rabbit73 is offline   Reply With Quote
Old 4-Jan-2017, 1:23 AM   #7
rabbit73
Retired A/V Tech
 
Join Date: Aug 2012
Location: S.E. VA
Posts: 2,550
Do you have any way to measure signal strength so that you will know if you are making any progress?
__________________
If you can not measure it, you can not improve it.
Lord Kelvin, 1883
http://www.megalithia.com/elect/aeri...ttpoorman.html
rabbit73 is offline   Reply With Quote
Old 4-Jan-2017, 5:38 PM   #8
olimazi
Member
 
Join Date: May 2010
Posts: 55
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

Quote:
Originally Posted by rabbit73 View Post
Do you have any way to measure signal strength so that you will know if you are making any progress?
olimazi is offline   Reply With Quote
Old 4-Jan-2017, 5:43 PM   #9
olimazi
Member
 
Join Date: May 2010
Posts: 55
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!

Quote:
Originally Posted by rabbit73 View Post
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://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.
olimazi is offline   Reply With Quote
Old 4-Jan-2017, 8:55 PM   #10
rabbit73
Retired A/V Tech
 
Join Date: Aug 2012
Location: S.E. VA
Posts: 2,550
The TiVo diagnostics screen is good; it should give you signal strength, SNR, and uncorrected (RS) errors.
__________________
If you can not measure it, you can not improve it.
Lord Kelvin, 1883
http://www.megalithia.com/elect/aeri...ttpoorman.html
rabbit73 is offline   Reply With Quote
Old 4-Jan-2017, 11:29 PM   #11
WIRELESS ENGINEER
Senior Member
 
Join Date: Dec 2013
Location: Eastern Ohio
Posts: 101
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.
WIRELESS ENGINEER is offline   Reply With Quote
Old 4-Jan-2017, 11:59 PM   #12
ADTech
Antennas Direct Tech Supp
 
Join Date: Jan 2010
Posts: 2,932
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.
__________________
Antennas Direct Tech Support

For support and recommendations regarding our products, please contact us directly at https://www.antennasdirect.com/customer-service.html

Sorry, I'm not a mod and cannot assist with your site registration.
ADTech is offline   Reply With Quote
Old 8-Jan-2017, 1:28 PM   #13
olimazi
Member
 
Join Date: May 2010
Posts: 55
CB

is the CB-8269 the only balun I can use on the 7698P?
olimazi is offline   Reply With Quote
Old 8-Jan-2017, 3:33 PM   #14
rabbit73
Retired A/V Tech
 
Join Date: Aug 2012
Location: S.E. VA
Posts: 2,550
Quote:
for $15 I will just replace the CB-8269 and take it from there, instead of trying to take it apart and troubleshoot it.
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?
Quote:
is the CB-8269 the only balun I can use on the 7698P?
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.



in RCA ANT751:



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

http://www.solidsignal.com/pview.asp?p=uvsj
Attached Images
File Type: jpg Stub Illustration2.jpg (110.8 KB, 1429 views)
File Type: jpg RCA ANT751stubsRev2.jpg (133.7 KB, 7633 views)
File Type: jpg balun.JPG (15.1 KB, 1276 views)
File Type: jpg UVSJ.jpg (44.9 KB, 1298 views)
__________________
If you can not measure it, you can not improve it.
Lord Kelvin, 1883
http://www.megalithia.com/elect/aeri...ttpoorman.html

Last edited by rabbit73; 8-Jan-2017 at 4:27 PM.
rabbit73 is offline   Reply With Quote
Old 9-Jun-2017, 8:33 PM   #15
olimazi
Member
 
Join Date: May 2010
Posts: 55
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

Last edited by olimazi; 9-Jun-2017 at 8:35 PM.
olimazi is offline   Reply With Quote
Old 10-Jun-2017, 2:36 AM   #16
rabbit73
Retired A/V Tech
 
Join Date: Aug 2012
Location: S.E. VA
Posts: 2,550
The next step is to test each section of the antenna for reception as shown in the Winegard video.
__________________
If you can not measure it, you can not improve it.
Lord Kelvin, 1883
http://www.megalithia.com/elect/aeri...ttpoorman.html
rabbit73 is offline   Reply With Quote
Old 12-Jun-2017, 6:48 PM   #17
olimazi
Member
 
Join Date: May 2010
Posts: 55
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.

Quote:
Originally Posted by rabbit73 View Post
The next step is to test each section of the antenna for reception as shown in the Winegard video.
olimazi is offline   Reply With Quote
Old 12-Jun-2017, 6:57 PM   #18
ADTech
Antennas Direct Tech Supp
 
Join Date: Jan 2010
Posts: 2,932
Quote:
but I have replaced the balun with a new one, that would eliminate the balun as the culprit.
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.
__________________
Antennas Direct Tech Support

For support and recommendations regarding our products, please contact us directly at https://www.antennasdirect.com/customer-service.html

Sorry, I'm not a mod and cannot assist with your site registration.
ADTech is offline   Reply With Quote
Old 12-Jun-2017, 11:54 PM   #19
rabbit73
Retired A/V Tech
 
Join Date: Aug 2012
Location: S.E. VA
Posts: 2,550
Quote:
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.
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.
__________________
If you can not measure it, you can not improve it.
Lord Kelvin, 1883
http://www.megalithia.com/elect/aeri...ttpoorman.html
rabbit73 is offline   Reply With Quote
Old 14-Jun-2017, 12:46 PM   #20
olimazi
Member
 
Join Date: May 2010
Posts: 55
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.

Quote:
Originally Posted by rabbit73 View Post
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.
olimazi is offline   Reply With Quote
Reply

Bookmarks

Go Back   TV Fool > Over The Air Services > Help With Reception


Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off




All times are GMT. The time now is 4:52 PM.


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Copyright © TV Fool, LLC