OTA Television Frustration

[gwinger]

Lots of interesting ideas. Thank-you all for your responses.

Does anyone remember the days with analog television when someone started broadcasting over their CB radio that was close to your location and your television signal would go bonkers!

My situation kind of remind me of that... changing locations, times of day, and different televisions doesn't matter. It happens, not every show, not every time, but it happens too often. Nothing changes in the camper.

I often wondered if jet planes flying over head caused it? But, always in the last few moments of the most intense show's were watching. That's what doesn't make sense.

Noooooo..... it doesn't do it during commercials .... it doesn't do it at the beginning of the show .... only at the end. Arrrr!

Back then the tv signal was AM. So are CB's. You would lose the picture, but the sound was still good. The sound was FM.
Thanks for taking me back to my days when I serviced TV's for RCA

 

[Tom_M]

If a weak signal is hitting the antenna, a booster will not help. The antenna already is equipped with a booster.

Most RV antennas do have a built in amplifier but a booster will definitely help for a weak signal. The Winegard Sensar Pro can be used with any antenna and mates well with a Winegard antenna. I have both a Sensar IV antenna and a King Jack antenna and the Sensar Pro works well for either one. If you are receiving a strong signal an amplifier can be overloaded and cause problems. The beauty of the Sensar Pro is that it can also be used as an attenuater. The attenuation/gain can be adjusted from -10db to +10db.

 

[Heli_av8tor]

I had problems with one channel and its sub channels at our S&B home. It would work great then I'd be notified that it just went out. Our antenna system starts in the attic, goes to a distribution center in the basement, then to multiple outlets throughout the house and shop. I tried different amps and finally a higher gain antenna without relief. This continued for several months. Then we found a correlation with everytime I was in my (attached) shop the channel would go out.

I had replaced the 18 eight foot fluorescent fixtures with LED ones. Turning on even one bank of 4 fixtures caused the TV to lose Channel 4 and subs. It broadcasts on the low vhf band. The LED drivers didn't have sufficient filtering and were generating RF noise that picked on this frequency.

I replaced all fixtures with ones that have better filtering and are guaranteed to not cause interference.
Problem solved.

Yesterday I discovered the same problem with the LED to fluorescent replacement tubes I put in my motorhome.

 

[Mark_K5LXP]

In the not so distant past, CFL bulbs were major RFI generators. Filtering costs money and not including it made the product cheaper. As mentioned in my earlier post, I have 2 LED spots in my RV I can "hear" on my VHF ham radio, and they're quite strong. A cordless drill battery charger in my garage literally wipes out any use of the six meter ham band, which is 50MHz. There are FCC rules on permissible levels of spectral energy devices are allowed to emit during their normal operation but between "self certifying", offshore production and basic disregard and unaccountability by some manufacturers, we get what we get in terms of interference. Using HF, VHF and UHF spectrum as I do which is fairly atypical of consumers I'm more aware and sensitive to it but even basic consumer devices like TV's, bluetooth, wifi, and endless wireless doodads can be affected. Back in the day hams were the primary villain when it came to messing with neighbor's TV sets but anymore the tables have turned - it's motion lights, battery chargers, solar panel inverters, LED lights and a myriad of other consumer equipment that's wiping *me* out.

Mark B.
Albuquerque, NM

 

[gwinger]

I had problems with one channel and its sub channels at our S&B home. It would work great then I'd be notified that it just went out. Our antenna system starts in the attic, goes to a distribution center in the basement, then to multiple outlets throughout the house and shop. I tried different amps and finally a higher gain antenna without relief. This continued for several months. Then we found a correlation with everytime I was in my (attached) shop the channel would go out.

I had replaced the 18 eight foot fluorescent fixtures with LED ones. Turning on even one bank of 4 fixtures caused the TV to lose Channel 4 and subs. It broadcasts on the low vhf band. The LED drivers didn't have sufficient filtering and were generating RF noise that picked on this frequency.

I replaced all fixtures with ones that have better filtering and are guaranteed to not cause interference.
Problem solved.

Yesterday I discovered the same problem with the LED to fluorescent replacement tubes I put in my motorhome.

The ballasts used in LED fixtures do produce a lot of RFI. The cheaper the fixture, the more the interference. The ballast takes the 120vac and converts is to a low voltage DC using a switch mode ballast. The switch mode takes the
60 HZ, changes it to DC and then to a higher frequency AC and then to DC.

 

[DonTom]

r but a booster will definitely help for a weak signal

Sure, if your TV sensitivity is low to begin with.

-Don- Flagstatt, AZ

 

[Lou Schneider]

Lots of interesting ideas. Thank-you all for your responses.

Does anyone remember the days with analog television when someone started broadcasting over their CB radio that was close to your location and your television signal would go bonkers!

My situation kind of remind me of that... changing locations, times of day, and different televisions doesn't matter. It happens, not every show, not every time, but it happens too often. Nothing changes in the camper.

I often wondered if jet planes flying over head caused it? But, always in the last few moments of the most intense show's were watching. That's what doesn't make sense.

Noooooo..... it doesn't do it during commercials .... it doesn't do it at the beginning of the show .... only at the end. Arrrr!

DTV is a lot less tolerant of interference than the old analog signals. It's a direct tradeoff caused by cramming more information (multiple HD channels) into the same RF bandwidth as a single SD analog channel.

When the DTV changeover happened I was living on WA's Olympic Peninsula. With a roof antenna you could get TV from Seattle, about 25 air miles away across Puget Sound. And if you rotated the antenna you could pick up stations from Bellingham and Vancouver, BC. Analog TV would have some multipath picture ghosting for a few seconds whenever an aircraft flew between us and the TV transmitters. Wind blowing through the nearby evergreen trees would create "micro" multipath ghosts in the picture that weren't noticeable unless you knew what to look for - a slight blurring of vertical lines. But both of these were enough to destroy the new DTV signals - making the picture go to bluescreen so often that we had to give up on OTA TV and install Dish Network with the dish located several hundred feet from our house in a spot with a clear view of the satellite.

 

[John From Detroit]

Most RV antennas do have a built in amplifier but a booster will definitely help for a weak signal. The Winegard Sensar Pro can be used with any antenna and mates well with a Winegard antenna. I have both a Sensar IV antenna and a King Jack antenna and the Sensar Pro works well for either one. If you are receiving a strong signal an amplifier can be overloaded and cause problems. The beauty of the Sensar Pro is that it can also be used as an attenuater. The attenuation/gain can be adjusted from -10db to +10db.

Yup.had to crank it down a time or 3 myself. Plus if you have a directional signal it wills can for the strongest signal..List them in order and show you the strength. You can then peak for best performance.

NOTE Channel numbers it displays are usually DIFFERENT from what the TV sees...
example Detroit
TV 2 Sensro Pro 7
TV 7,. 41

But not always.. Flint 12=12

 

[RedForeman]

It would take a deep dive with a spectrum analyzer to sniff things out but short of that, some testing with turning stuff on and off and noting cause/effect might reveal an interfering source.

I had a situation some years ago where my garage door openers would only work once in a while with a new car that had Homelink built in. I remembered my Yaesu FT-60 HT will listen on a whole lot more bands than it can talk on.

I tuned to 315 MHz and went walking around and found several culprits. The two worst were: the old HP LCD monitor with built in power supply on my desk, and an old DECT 6.0 portable phone base in my wife's office still plugged in even though we never used it. I got a new monitor and moved the phone base to the other end of the house.

I also found two noisy HDMI cables in the vicinity, and replaced those with higher quality cables with better insulation.

Had I been just guessing at it, these things wouldn't have struck me as obvious. But there they were.

 

[Tulecreeper]

Mark's response is about the best "guess" so far. I have some LED bulbs that wipe out the VHF channels when turned on. These bulbs have a built in DC-to-DC converter which is a high frequency oscillator.

OK, but why would it happen at the exact same point in time during a program. The OP didn't say, but I assume it happens at different times of the day but strangely only at the end of random shows. Unless the OP is turning on an LED only at the end of every show, which statistically would be near impossible.