Was perfect / Now Audio Dropouts and Pixelation

tally · 12-Jan-2015, 12:16 AM

This is my Signal Analysis:

http://www.tvfool.com/?option=com_wr...46aeb18652e11a

I am using this antenna: RCA ANT751

My signal was fine for two years. This past month I started getting occasional pixelation and audio dropouts. This occurs on every channel and it happens about once every three minutes for about 1 second or less. The hd image looks great all the time except when the incident occurs. The pixelation is very slight. The signal on my antenna meter on the TV shows full bars.

The is a group of 2 pines in line of sight of the antenna (just the top of the trees) about 75 yards away. The only thing that possibly happened was the trees grew a bit.

Could it be the pines? Not sure where to start here but i would rather not raise the antenna as it is cold here; and I will probably wait until spring. I am splitting the signal (only two locations in the house).

At any rate, should I temporarily try a booster and what kind?

Any suggestions on what the issue could be other than the pines? Thank you.

ADTech · 12-Jan-2015, 1:46 PM

Trees grow.

Water gets into stuff (cables, connections, etc).

New electrical and electronic stuff gets installed in the vicinity.

Several possibilities.

GroundUrMast · 12-Jan-2015, 7:30 PM

If it's the trees, wind and moisture on the trees will generally make the symptoms more pronounced.

Aircraft flying past may account for such symptoms. They reflect signal, causing a form of multi-path interference at your antenna. You mentioned a regular pattern... Are you under the flight path of the approach to a scheduled airport?

As already mentioned by ADTech, moisture in a connection of matching transformer will produce degraded system performance. The simple test is to disassemble, inspect and substitute known good parts in place of the potentially compromised parts. Generally, a cable with moisture inside the jacket should be discarded, it will have been permanently damaged due to corrosion.

ADTech · 12-Jan-2015, 7:45 PM

See if there is a precise or a random interval to the disruptions. That will tell us if it's electrical or electronic interference and might offer addition clues to a source.

Canadianeh · 13-Jan-2015, 2:22 AM

.. or does it coincide with heavy breezes / gusts, that may make those trees/branches sway?

tally · 13-Jan-2015, 4:08 AM

Thanks all for the replies. There is really no pattern other that what I stated in the first post. It always happens every 3 minutes or so. I am not in the path of aircraft approach. Based on the above responses, it is either the pines I mentioned above or it could be the connector at the antenna. If it is the connector, I am not scaling the roof until it warms up here in Minnesota! As far as the pines go, what I know for sure is the antenna is pointed right at them. When I installed a few years ago, the antenna probably just barely cleared the top of the trees. We have had two growing seasons, so I am betting it could be the pines.

GroundUrMast · 13-Jan-2015, 4:13 AM

In the real estate business the three most important factors that determine the value of a property are: Location, Location & Location. The same applies to antenna performance. Any chance that you can find a mounting location that avoids the trees? If the trees belong to you, can you consider eliminating them or replacing them with a lower growing option?

Jake V · 13-Jan-2015, 11:49 AM

If you need to wait until warm weather to get up on the roof (that wait would annoy me to no end) then maybe you can consider getting a a small indoor antenna and some new coax. Connect it to one television, run the coax out a door or a window and aim west. Just to see if the problem clears. Your TV Fool Report shows no height from the ground and the signal strength is strong. I'd be surprised if you can't manage to find a sweet spot to get your channels. [This would not be a permanent arrangement but it would be a pretty cheap experiment.]

If it turns out that the ANT-751 is not big enough because of the trees you might be able to go with a larger antenna (maybe something like an HBU-33 or HBU-44).

But when warm weather comes I'd agree with GroundUrMast. Check every connection. Run a new length of coax directly from the antenna to one television to test. Make sure your antenna is pointed correctly.

ADTech · 13-Jan-2015, 1:27 PM

See if you can find a temporary (perhaps) antenna location that goes around or even under the suspect trees, provided that you aren't further blocked by additional trees or other structures.

Usually, if you can see the sky or horizon in the right direction, that's a spot worthy of trying out.

tally · 30-Aug-2015, 12:45 PM

I am resurrecting this thread. I finally got around to replacing the antenna (now a winegard hd7694p), installed a new mast (higher now), re-pointed the antenna to 267 degrees and away from the pines that I thought could be the issue, tried two separate cable runs. Argghh! I am stilling have an issue. A bit better but a millisecond audio drop every 5 minutes or so. I have also tried separate runs to the TV as I thought that could be the issue.

Oh what to do now? Could I have a bad internal TV tuner? Seems like that would not be it. Should I try to amplify to signal? This run is 50 feet max to the TV. Could this be some type of atmospheric aberration? Could it be the hodgepodge of wires I have behind my receiver / some type of electrical interference from the receiver? It is a big receiver (HK AVR 254) that is very close to the antenna cables? Very frustrating.

tally · 31-Aug-2015, 1:02 PM

Well I finally figured it out. I was browsing the internet last night about electrical interference and OTA. I stumbled into a thread where some were have aberrations in their signal with certain HDMI cables (i.e. maybe if a HTPC is plugged in and near the OTA cable). I then started researching firetv sticks and chromecast and found a similar issue as they have an HDMI port in the end of the stick.

Viola! The issue was my firetv stick. I unplugged it from the back of my TV and no more blips in my signal! As a side note on HDMI cables, those with ferrite cores on the end seemed to correct the issue.

Hopefully this helps someone out. In hind sight, I probably could have retained my old antenna, but I am getting more channels with the winegard. I now am going to try an HDMI adapter to see if moving the firetv away from the TV corrects this issue.

rabbit73 · 31-Aug-2015, 2:46 PM

Subtitle:
Going Wireless is Asking for Interference

Good detective work, tally!

ADTech did suspect interference.

That's a source of interference that I didn't know about.

Is your antenna coax grounded with a grounding block? That can reduce interference.

http://forums.androidcentral.com/goo...reception.html

https://forums.developer.amazon.com/...?threadID=4821

http://forums.plex.tv/discussion/165...ering-kills-me

Did I miss another good link?

Thanks for letting us know the cause and the solution; I'm sure it will help others.

tally · 31-Aug-2015, 3:15 PM

Quote:

Originally Posted by rabbit73

Is your antenna coax grounded with a grounding block. That can reduce interference.

Yes I'm grounded with a block approximately 8 to 10 feet away from the antenna.

I did read some of those threads and others. No one really had a solution or posted back on what happens if you move the firetv stick.

Here is what I am going to do. I ordered and will place ferrite cores on my hdmi cables plus I am going to add a ferrite core to the hdmi extender (which I also just ordered) in addition to moving the firetv away from my TV and see what happens.

rabbit73 · 31-Aug-2015, 3:18 PM

Quote:

Yes I'm grounded with a block approximately 8 to 10 feet away from the antenna.

Good.

That means the interference is more serious than I thought and is also coming in other ways. We will be hearing more reports like yours.

Besides unplugging, the aluminum foil and ferrite core solutions seem to work in some cases. The foil probably makes the stick temperature rise too high because it can't dissipate heat as well.

ADTech · 31-Aug-2015, 3:38 PM

FWIW, I've previously encountered instances of Chromecast and Firestick USB dongles causing interference into VHF channels.

I even had an ebay external hard drive power supply causing interference between 200 and 230 MHz at my own house that I discovered when I set up an antenna test range in my back yard a year or so ago.

rickbb · 31-Aug-2015, 6:15 PM

It's amazing at the sources of and the effects of RF interference.

I visited the large radio telescope in Greenbank WV a couple of years back and they won't allow anyone to have WiFi or a cell phone that lives within 10 miles of the dish. When you visit you not only have to turn off and remove the batteries from your cell phone, but your digital camera too.