weird channel bleeding problem

[agnathra]

ok, i've spent about 2 hours reading on the forum and haven't seen anything like this...

just got dtv installed on Friday (moving from Comcast). so he gets everything installed, including a D11 SD receiver and HR20 HD DVR. dishes are a 5LNB and whatever 2nd dish they put up for local channels (aimed at 72.5...i think i said that right).

the HD TV setup is fine. but i'm having a weird problem with the D11. when watching any of the local channels, it will show the tuned in channel for 5 seconds, then another channel bleeds in for 1 second. it's very regular. i count 1..2..3..4..5, and see the glitch, which lasts for one second, and then it goes back to the real channel and the countdown restarts. the channel bleeding in is BET, and this only affects locals. the D11 is connected to the TV via s-video if that matters.

the really weird part: i plug my comcast cable back into the TV's coax jack so i can figure out what station is bleeding in, and the problem goes away. unplug the catv, and the problem's back. called dtv and they think it may be some grounding issue and will send someone out.

i figure you guys are better than the sunday morning tech support...any ideas?

thanks for any help!

[carl6]

With your installation there has to be a WB68 multiswitch installed. It would have four coax cables coming from the Slimline dish and one coax coming from the 72.5 dish. From there, you would have two coax going to the HR20 and one coax going to the D11.

Make sure the 72.5 dish is connected to flex port 1 of the multiswitch. The multiswitch should be grounded, and all coax should go through ground blocks where they enter your house.

Grounding (or lack thereof) could be contributing to your problem, and the fact that connecting your cable line up fixes the problem sure suggests that as a possibility.

Just for grins, try connecting a coax from the D11 to the TV (you don't have to use that input, just make the connection). Also, is the TV plugged into the same outlet as the D11? If not, try different outlets for power and see if it makes a difference.

Carl

[agnathra]

With your installation there has to be a WB68 multiswitch installed. It would have four coax cables coming from the Slimline dish and one coax coming from the 72.5 dish. From there, you would have two coax going to the HR20 and one coax going to the D11.

Make sure the 72.5 dish is connected to flex port 1 of the multiswitch. The multiswitch should be grounded, and all coax should go through ground blocks where they enter your house.

Grounding (or lack thereof) could be contributing to your problem, and the fact that connecting your cable line up fixes the problem sure suggests that as a possibility.

Just for grins, try connecting a coax from the D11 to the TV (you don't have to use that input, just make the connection). Also, is the TV plugged into the same outlet as the D11? If not, try different outlets for power and see if it makes a difference.

Carl

thanks for the input! before i got a chance to try these things, i had bruister back out to try them for me :D

he didn't actually troubleshoot the problem, but he replaced the multiswitch and put a 2-prong adapter on my power cable coming from the troublesome H20.

findings:
1. the bleedover is intermittent. (could it correspond to what channel the other TV is displaying?)
2. replacing the multiswitch didn't fix it
3. adding the adapter to the H20 DID fix it.

so basically, adding the adapter un-grounds my tuner, right? does that mean i have a grounding problem in my house, or with the H20? or with the dish? (he ran a wire from the corner of the multiswitch to an outside water faucet)

more important, might this be a safety issue? i've heard of people on avsforum getting rid of a 60 hz hum in a subwoofer by adding an adapter, and other people saying they were foolish to do it.

thanks again for the help!

[veryoldschool]

Grounding is good. Even better is a "Good ground".
It sounds like you have a noisy/bad ground for your H20.
A good ground will bleed any signal/voltage to ground, where a bad ground [resistive] will allow some of it to go into your receiver.

[K4SMX]

That's the easy way to fix it, but not particularly the right way to fix it. The problem is your receivers were operating with different ground reference potentials because of the interaction between the way they are designed and the ground potential differences between safety ground and the neutral line on some but not all of them.