I am placing this post in the satellite forum as well.

I have a client with two Samsung SIR TS-160 HD DSS receivers. One's output goes to a Toshiba TV, one's to a Fujitsu pro plasma. The DSS signal is diplexed with cable, and both units receive signals from the same multiswitch.

The Toshiba-connected DSS works perfectly, no matter which receiver I use. I use the component output for HD, and a normal video output is connected to give them aspect ratio freedom when they are not watching HD. It looks great.

The plasma-connected DSS has the same problems with either receiver. I use the VGA connection as the client's plasma has two VGA connectors but no component input. When viewing the VGA connection, there is a variation in brightness as you go from top to bottom of the screen. You are probably thinking that this is 60 Hz hum, and it looks like it, but there are more than TWENTY such areas top to bottom. In other words, it looks like power line hum but it is more than 20 times the frequency of the power line!

Oh, yeah, another little item: this interference ONLY shows up on the video coming from the satellite. When I switch channels and the DSS receiver creates its own graphics to show the channel and program, that portion of the image is totally perfect, while the portion coming from the satellite has this problem.


Well, I saw this problem and thought, great, the plasma, not made for consumer use, somehow has some glitch in the VGA that screws it up. But then I looked at the regular video output, and it looks fine, except... the vertical portions of lettering are much narrower than on the Toshiba-connected receiver (remember, same receiver), and these vertical lines have what looks like very rapid dot crawl running up them constantly.

In the room with the plasma, I have made sure the light dimmers are switched off, not just totally dimmed. I have disconnected all other components from power. I have tried the other satellite signal in the system, the one that looks fine on the TiVo, and I get the same result.

Couple questions.

You indicated cable diplexed with the satellite. What happens when you disconnect incoming cable signal from the system at the multiplexer end?

If the noise goes away, you have a ground potential difference, easily solved with a ground lifter on the incoming cable line. Xantech 634 is the model I'm familiar with.

By the way, it's a useful product to keep in the van.

I second Fred... this has helped many times... Tributaries and many others have these jewels.

Another quick try... put a "cheater plug" (ground lifter) on the endand see if it goes away. This will again probably be fixed with the cable piece. We have had to have power re-routed before when the plasma circuit was on a different side of the electrical panel... supposedly being out of phase can cause this. The electrician rewired so the plasma was on the same circuit as the source and our bars vanished.

Ernie...

One more thing...and since I'm not familiar with the plamsa OR the receiver you reference, this is just a guess...

is the a selectable 720P/1080I setting on the sat receiver? If so, have you tried changing this and does it make a difference?

I worked with a Hitachi AND an NEC not too long ago that had VERY specific likes as far as which HD format you fed them...

avdude

Yep. That was EXACTLY the problem.

Our company is growing, and it was not me doing the whole install. Somebody else had opened and connected the DSS, and was not as paranoid as I was. He had just flipped a switch, got some kind of picture, and went home. I was only there basically to bless it when the customer brought it to my attention, and since I had not opened it and connected it, my memory was not jogged into thinking about the 720 vs. 108i issue. Somehow I even thought it only showed an image with the VGA connection when switched to 720. But noooooooooooooooooooooooooooo.........

So, several hours later, after even trying a component to VGA transcoder (where it worked because only 720 worked through the transcoder) I flipped the switch and fixed the problem.

Thanks for your other input, guys.

I do always carry a Xantech cable ground lifter with me. I did not think of that because it is orders of magnitude higher than 60 Hz. We (DirecTV, who fought me off for about an hour today) never could figure out what sort of artifact could make a signal of about 1000 Hz appear on the image like that.

And, of course, when I went there today, before solving the problem, it did not even appear on the screen when I got there.

I did not get around to disconnecting the cable signal, because both receivers worked on the other TV. In order to put a ground lifter on the plasma, I was about to call another guy and two mules to lift it down. This client wanted one of those "half inch on each side" mounts that can clip your fingers right down to size if you are not careful.

But all is well tonight.

SWEET!