New 508 PQ issues

[Don Cohn]

Today I connected my new 508 to a Pioneer 50" RPTV using an S-Video cable and noticed that I had a faint horizontal line scrolling from the bottom to the top of the screen. When I pointed out the lines to my girlfriend she said that she would not have noticed them if I hadn't pointed them out to her and thought it was no big deal. She suggested that I just chill out as the PQ was better than cable.

Later on the evening we decided to watch a DVD and all through the movie I kept seeing these horizontal lines rolling up the screen. I thought I was imagining things when my girlfriend says "See you even get those lines on the DVD it's just your TV".

Now, I know I have never seen this problem before so, after the movie, I disconnected the 508. When I did, the lines went away. Next, I hooked up the 508 using the RCA composite cable. The lines came back. Yikes! I then disconnected the RCA's and went with the coax connection. No lines!

Hhmmm. So, it seems that if I use S-Video or RCA composite I have to put up with a faint horizontal line scrolling up the screen. This scrolling line thing is there on the TV no matter what the video source is, as long the 508 is connected to the TV. The 508 doesn't even have to be on, just connected via anything other than the coax. I can't seem to figure this one out. I've never connected anything up to this TV that has caused this problem before.

Is there anyone else that has seen this problem or that can suggest a fix?

Thanks,

Don

[scooper]

Don - that is not really a PQ problem, but more likely one of grounding.

[TomCat]

Probably a ground loop. What you're seeing is local 60 cycle power impressed upon the NTSC field rate of 59.94 Hz. Since the two frequencies are almost the same, they beat together resulting in one (or two for 120 Hz generated in some power supplies) line(s) slowly rolling up the screen.

It may not be the 50x that's at fault, it could be connected equipment, your TV, or just a combination, or a problem with your home's AC service. Neither my 501 or 721 do this.

The fix is to get a humbucker coil, which lifts the ground by using 2 transformer coils back-to-back in a single housing. I'm not sure where you can get one, but they are used extensively in professional video. You will probably need RCA-to-BNC adapters once you find one.

[Eyedox]

I am curious what the difference between the DISH PVR 501 and the PVR 508 is? Also, is the 508 the newer model?

[Steve Mehs]

Eyedox, only difference between a 501 and 508 is that the 501 has a 40GB hard drive and the 508 has a 80GB hard drive. Also the first 508's shipped with two remotes, but I think now they only come with one. Other then that they're the exact same unit, same face, same software, same remote.

[Don Cohn]

Thanks to everyone that responded. I too thought that I might have ground loop type of problem. The problem seems to have gone away for now.

I disconnected and reconnected all the wiring and the problem went away. Magic!

Cheers,

Don

[gcutler]

Originally posted by Steve Mehs
Also the first 508's shipped with two remotes, but I think now they only come with one.

I was expecting 2 remotes, but I watched the "Installer" open the box and there was only 1 remote. The packing list only said Remote (as in singular). I'm using my universal remote anyway :D