Any Audio/Videos Experts out there?

[dcarver]

OK, this should be fun..

I have an older Mitsubishi projection TV in the house.

The DirecTV HID Rx lives in the camper, approximately 50 feet from the TV .

The symptoms exist whether or not I use the house mounted dish or the dish on the camper.

The problem -

After about 10 minutes or so, the TV picture gets 'snowy' and 'wavy'. If I open the signal connection e.g. disconnect the cable to the TV, the picture immediately goes back to crystal clear. After 10 minutes, picture deterioration begins.

It didn't do this when the rx was located in the house, so I think it has something to do with the Rx being located remotely and the associated cable runs. Watching the the HUD TV in the camper is crystal clear, it picture doesn't deteriorate.

So far I've tried different cables, connected all cable grounds together, swapped dishes, the problem remains. It does seem that if the weather is wet the signal remains and pix remains strong for a longer period of time. I've tied the AC grounds together (the house and camper 110VAC).

The symptoms exist whether or not I run the camper of AC or off 12 vdc batteries and 110vac inverter.

Any ideas?

 

[Bounce]

You could have a signal loss on your output side. try moving the box in the house and connecting using a shorter cable. if that clears it up, then you're pretty confident its the longer cable that's the culprit. try checking for kinks or shorts in the cable. you may have exceeded the distance supported by the box's ouput "amp". it might be that the box overheats under load (longer cables have more resistance) and then goes into a failure.

 

[RonBB]

A wild guess on my part. Something heating up & then going out of spec. in the receiver. You might call DirectV. I had their service for several years & then the receiver (I had bought elsewhere) died. I called DirectV & they sent me a new one. I didn't even have to sign up for an extended contract. I had been a customer for many years at that point though. Nothing to lose in a call. Best of luck. Ron

 

[jestal]

I have an older Hitachi rear projection TV that did similar sorts of things and it was the TV itself. Tracked it down to the convergence chips that align the three color beams. Those chips run very hot in all rear projection TV's from what I understand and are often the first thing to fail. They will often work fine until they heat up. I replaced them and all is well. If you look inside the TV you can locate them on the main circuit board as three large chips mounted on a large heat sink. In my case, I just got the new chips and replaced them. As I was unsoldering the chip legs I discovered that the actual failure was cracked solder joints where the convergence chips mount to the circuit board, but ,by then, the old chips were toast (due to wire snippers....LOL) so the new chips got installed and I never found out if simply resoldering them would have fixed the problem.

 

[dcarver]

Thanks Guys,

I should have mentioned that if the rx is in the house, close to the tv, all works flawlessly. Off air signals work fine all the time too, indicating the tv is ok and rx is ok. It's only when the rx is remote, e.g. in the camper,does this problem arise.

I have on old tv signal amp laying around somewhere. I may try that in line, I think that would test Bounce's theory.

 

[twowheelnut]

Jebus, Carver, just stop pouring the whiskey to the top of the glass. Try tossing in some water or soda and your vision should stay clear(er).

 

[RayW]

I remember years ago when I was in the Air Force, one of the barracks rats had an expensive stereo set up that would sound fine for awhile but every so often would start to build up a hum, then snap, and all would be clear again for awhile. Turns out the cabling was building up a charge like a capacitor. I sounds like the trouble it pretty much isolated to the extra long cable. I think the only solution may be to bring the tuner in when you're not using it in the camper.

Ray