Horizontal line in TV screen

[popsuscdds]

Greetings:
We installed a new 22 inch flat screen drop down TV in our Safari Trek. With the TV on we noticed a wavy horizontal line that takes about two to three seconds to go from the top of the screen to the bottom. Watching the TV became a pain. So I experimented lots of ways. The TV is 12 volt and the Satellite Receiver, DVD player, and VCR are on 120 VAC. I plugged everything into an extension cord that went direct to shore power thru a window and without going thru the inverter/charger. I had the generator on. The TV is on 12 Volt. The lines disappeared. Basically I bypassed the Inverter/charger. I tried to figure how I could get 120 VAC before it gets to the inverter/charger. Perhaps I could take a line from the Main breaker in the rear of the coach all the way under the coach up to front.(A Ton of Work). Instead I turned off the Inverter/Charger while watching TV and the lines are gone. It took me awhile to figure that the Charger is the culprit.
Have Fun!
Milt

[popsuscdds]

Greetings:
What I didn't say: Leave everything hooked up normally either on shore power or on generator. No cord thru the window. Just turn off the charger. Don't forget to turn it back on after using the TV. That is all I had to do to get rid of the lines. Not all motor home electrical systems are the alike. Not all TV's are alike. This worked for me.
Dumb me !!
Have Fun!
Milt

[Bob (WA0MQE)]

Milt, if your Trek is still wired the way it came from the factory, the inverter should be plugged into a GFCI safety outlet. Some of these outlets have a bad habit of being very RFI (noisy). You might check and see if this is the case. Although it could still be the inverter also. Your's should be a modified sine wave (MSW) and they too can be noisy, especially with some of the modern tv's. If your's does have the GFCI outlet you might consider replacing it with a newer one. Some of them have a capacity attached across the leads to help cut down on electrical noise.

[popsuscdds]

BOB (WAOMQE);
Thank you very much for the info. I have read on IRV2 about the advantages of the Pure Sine Wave inverter over the Modified Sine Wave but because I wanted the postpone the purchase I took the approach of bypassing the Inverter/charger as a start. Thanks for info re: the GFCI outlet. I'll look into it.
The previous and first owner of our 2000 coach changed the inverter charger in 2002 to the present Xantrex 258 for unknown reasons. He passed away shortly after. His family stored the coach for years and on occasion used it. We bought it in 2009. At home I found that when plugged into shore power at home the batteries would be taken to less than 8 volts over night. The house batteries are not strictly deep cycle batteries but of a Napa variety that really is more of an automotive battery. I took the coach to ASE Supply in Portland, Oregon. Their expert found that the isolator was not wired correctly.The battery shut off switch was inop. The Temperature Sensitive Charging line was miss wired (this was the main culprit). A Xantrex Freedom Basic Remote was purchased and I installed it at home. The batteries are still alive and performing well but I expect them to die any time.
I have always enjoyed research and problem solving so owning this coach has worked out well for me.
Thank you again
Milt
Have fun!

[wa8yxm]

Let me guess: You see that running on INVERTER and your INVERTER is a MSW right?

This is a very common MSW inverter issue, Very common.

Recommendations: If you can bypass the inverter and use shore power. but by all means REPALCE WITH TRUE SINE INVERTER.

Oh, the problem is "Hum" from the retangular waves getting through the power supply filters on the TV. As I said, very common with MSW inverters.