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Old 9-Apr-2017, 8:05 PM   #1
MikeBear
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Join Date: Jan 2015
Location: Mid-Michigan - Retired on Beta Omicron Delta III
Posts: 76
Intermittent interference/reception issue with RF16 WSMH-66

Last year we moved into a new house, 2 miles South of the old house (if you look up my old posts). I have now installed a new OTA antenna system at this location, which antennas are at 20ft~ at present. New subdivision has evergreen trees and oak trees, that I can't aim around or over, so not much use going higher. HOWEVER, I might be able to do so if needed after working out some logistics. Here is my exact antenna mast coordinates new TVFOOL report:

http://www.tvfool.com/?option=com_wr...e6a457f459d88d

FMfool:

Top antenna is a AC Y10-7-13 VHF only. This is aimed (through neighborhood oak trees) at WJRT Rf12, and goes directly to an MCM fm filter, then into the VHF input of a R.S. UVSJ and is not amplified.

Middle antenna is a HDB91x aimed (through neighborhood oak trees) directly at WSMH-66 (RF16) (161 degrees magnetic) and goes into a 3db attenuator, then into a MCM fm filter then into the "input 1" of a RF46 'Jan Jenca' Jointenna device. Even aimed as it is, this antenna receives all channels EXCEPT WBSF-46 (RF46) as that channel along with WSMH-66 (RF16) is MUCH weaker than all the others. So this antenna being aimed directly at WSMH-66 (RF16) is a compromise, and at the same time helps keep down the signal level of the other stations which run from blowtorch level to just below blowtorch level, while still allowing weaker WSMH to come in acceptably (except for whatever this very intermittent interference is that affects WSMH).

Bottom antenna is another HDB91x aimed directly at WBSF-46 (RF46) (127 degrees magnetic) (but unfortunately aimed through a 60' pine tree that's 110ft away on another persons lot). It goes into an MCM fm filter, then into "input 2" of the 'Jan Jenca' Jointenna tuned only for RF46. At present, there's only 11ft of mast above the roof line. So each antenna is only around 2ft apart. BUT, the WBSF-46 antenna is offset on the side of the mast using a u bolted old Dish Network J mount to make it easier to aim this at the WBSF tower.

The output of the 'Jan Jenca' Jointenna device, goes into an Kitztech KT-200 Coax preamp. So BOTH UHF antennas are amplified after joining in the Jointenna. The output of the KT-200 goes into the UHF port of the R.S. UVSJ (which is power-pass). Then, it all runs through about 80ft of cable to the power inserter, then into a ChannelsPlus 2-port splitter. One side goes to a Tivo Roamio, and the other side goes to my 2013 LG Smart tv.

This is all quad-shield solid copper RG-6 cable by the way. The antenna mast and coaxes are grounded with a ground rod located at the mast pipe, then a #6 solid copper direct burial wire is run 82ft around the house and is clamped/bonded to the main service entrance ground rod.

Here are my signal levels on the base Tivo Roamio (highest measured OTA signals on this no matter what can only go to 72% and 29db, due to their firmware):

WNEM-5 (RF22) = 72% 29dB
WJRT-12 (RF12) = 67% 27dB
WDCQ-19 (RF15) = 67% 29dB
W24DL-24 (RF24) = 67% 27dB
WEYI-25 (RF30) = 67% 27dB
WBSF-46 (RF46) = 60% 24dB (only 31kw actually aimed towards me!)
WAQP-49 (RF48) = 67% 27dB
WSMH-66 (RF16) = 67% 27dB

All channels come in acceptably the majority of the time, (so far, even with the trees) however there's some sort of VERY intermittent 'interference' that happens for around 1-2 minutes at a time on WSMH-66 (RF16). So far I've only seen it on THAT specific channel! It might happen seemingly at random any time of the day, then not happen for an hour or more, then happen again. It consists of the picture pixelating or flashing a bit, then constant audio BEEPS as things pixelate, then it goes away after a minute or so, like flipping a switch. Sometimes the video might just flash, but you lose program audio and there's no beeping. I've never had it last longer than 2-3 minutes, tops.

I have tried a Radio Shack LTE filter, but it made no difference, though I haven't as of yet tried it in FRONT of the KT-200 preamp.

I am wondering if perhaps it could somehow be picking up an individuals cell phone transmission. I haven't seen any ham radio towers here, and haven't noticed if anybody has a 3g-4g boosting amp and antenna on their house, but it's possible. It beats me what's doing this...

I do not have access to a spectrum analyzer, though I sure wish I did.

Any ideas?

P.S. It seems like this might ONLY be happening just to subchannel 66.3, which is Comet tv. I've now flipped to 66.1 (Fox) and 66.2 (Antenna Tv) when it's happened, (after posting this post) and they don't show it happening! What could affect .3, and not affect .1 and .2 at the same time???

Last edited by MikeBear; 24-Apr-2017 at 11:06 PM.
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Old 9-Apr-2017, 10:29 PM   #2
rabbit73
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Join Date: Aug 2012
Location: S.E. VA
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Quote:
What could affect .3, and not affect .1 and .2 at the same time???
Interference to the Comet TV program feed before it is transmitted by WSMH.
http://www.rabbitears.info/market.ph...&callsign=wsmh
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Last edited by rabbit73; 9-Apr-2017 at 10:35 PM.
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Old 9-Apr-2017, 10:46 PM   #3
MikeBear
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Join Date: Jan 2015
Location: Mid-Michigan - Retired on Beta Omicron Delta III
Posts: 76
Quote:
Originally Posted by rabbit73 View Post
Interference to the Comet TV program feed before it is transmitted by WSMH.
http://www.rabbitears.info/market.ph...&callsign=wsmh

Hi Rabbit!

It's starting to look that way, isn't it? I had all the detailed above post prepared to post while watching this station. The issue finally occurred frequently enough in the program I was watching, so that I had time to flip back and forth between .1, .2 and .3, and only noticed it on .3 Comet...

Sinclair owns this station, and they aren't very responsive to emails denoting problems with their broadcasting. When Comet was first turned on, they were broadcasting at the wrong aspect ratio. I emailed WSMH multiple times over weeks, and got no reply at all. I finally emailed COMET itself from their web page contact list, and they got it fixed in 2 hours!
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Old 9-Apr-2017, 11:17 PM   #4
JoeAZ
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Join Date: Mar 2017
Posts: 374
It certainly looks like you've done everything properly and
then some..... The "COMET" affiliate in Phoenix had and sometimes
continues to have issues from what I've read on other sites.
Since everything else is working well, I'd chalk it up to issues with
the originating signal and not any of your equipment.
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Old 10-Apr-2017, 12:08 AM   #5
MikeBear
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Join Date: Jan 2015
Location: Mid-Michigan - Retired on Beta Omicron Delta III
Posts: 76
Thanks!

Well, I finally was able to confirm with another person locally, that they see the exact same issue with this sub channel OTA.

I'm going to email Comet Tv now.

Last edited by MikeBear; 24-Apr-2017 at 11:07 PM.
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