TV reception problems

[Volvodriver]

Changed the bat wing antenna to the King Jack and like it alot more than the wing. But here is a couple of things that make me crazy. First off, I had it installed by an rv tech that knows his business and has his own shop for over 30 years. The problems are these:

Bedroom and main tv's are same make and model of Samsungs. When I adjust the King and tune the tv's never get all the same channels on both sets. Maybe 85 to 90 % of same but never all on both. Some times odd channels on both that can be selected but will not come on and screen shows weak signal alert and re-scan alert. Next problem is if shows are on on the main and bedroom light switch is turned on it freezes or screen pixelates until switch is off. If different channels are on in bedroom and channel is changed it affect main and sometimes vice versa on the freeze from one to the other.

Any comments or hints on what the causes would be would be appreciated.

Dave

[Flybob]

As for different channels; weak channels are not consistent in signal level, If you do the setup channel scans at different times, the signal levels will be different and they will lock on different channels.
As for the light issue, do you have LED lights. Some of the have very poor RF components in them and when on they generate RF interference. Only solution is to replace the noisy ones with higher quality LEDS.

[Netcomdude]

Dave,

If your signal level is good, you should be able to split it at least 2 ways -3.5 Db loss with no problem.
Most TV antennas like yours have a +20 DB amp in them.

Not sure why both TV ‘s don’t lock onto identical channels during a scan other than the signal level on some channels are border line in strength to what the TV is calling a good signal or not and the internal difference in the tolerance levels of the scanning circuit in each TV.


What I do know........


Here is an answer to the TV freezing when you turn on the lights. Assuming they are LED.

I had this problem, and still do but less now that I changed and fixed a few things. That’s a different story.

LED lights are Diodes, a one way bridge that only passes electricity one way. Like a bridge, they are only able to carry a certain load. In the case of an LED (current) not weight.

The brighter ones have a small circuit in the fixture called a LED driver circuit. It is a constant current driver circuit that compensates and limits the current through the LED would just burn out.

This is called “thermal runaway”
In the electronics world.

These circuits are like mini switching regulator power supply’s and have an internal oscillator or clocking speed. I don’t know what frequency it operates on but it radiates RF (radio frequencies) like crazy.

Someone told me the cheep Chinese lights are worse than the better, more costly fixtures.

In the case of TV signals, which are extremely low (in the micro volts) external signals (noise) can get into the desired signal.

The driver circuits may be even radiating harmonics (upper or lower) that land in the TV channel frequencies.

Loose coax connections which are inherent to the RV industry allow this to be more pronounced

My local channel 10 would go out (pixilate and freeze) whenever “ANY” LED fixture was on.

After I replaced the TV with a Samsung upgrade and reworked all the connections “everywhere”, the problem is at bay and I can get a couple of LED lights on now.

Just not all of them in the camper.

Mine only affects off air channel 10
(192 - 198 MHz)

Pretty frustrating Turing on a light switch and having the TV stop.

Took me a while to even realize the TV reception and lights were related.

I never took the troubleshooting further but the problem was reported a lot when RV’s started switching to LED lighting.

I’m sure at the factory they never realized this when certain lights, Tv’s and wiring configurations are utilized. Let alone what off air channels would be affected. There is no channel 10 in Indiana where my RV was manufactured, so I can’t blame them too much.