Intermittent reception on only 3 HD channels

[MichaelP]

I am having a problem receiving only 3 of the new HD channels that is really a puzzle. I'm hoping y'all can offer some guidance as D* and a technician have been of no help.

I live in San Francisco, specifically in zip code 94112. I have had no reception problems with the HD channels D* turned up on 28 Sept. My problems started on 5 Oct. Ever since these channels were turned up I only get Bravo HD (373) on a regular basis. The other channels in that group I only receive intermittently: USA HD 242, Sci Fi HD 244, MHD 332. The pattern appears to be that from the hours of approximately 9 AM to 7 PM PDT the channels are on for me. The rest of the time I get a 771 Searching for Signal on input X message on the screen when I tune to the channel. Additionally, when I am not getting the channels my signals strengths are very low on several transponders on the sat; typically below 60%. When I do get the channels the signal strengths are fine. My uncle, who lives across the bay in Oakland has no trouble getting the channels.

I have tried all the trouble shooting I can do. The dish alignment is fine; my LNB is brand new; all my cables are in one piece and are firmly connected to any connectors. The BBC test channels indicated that my BBCs are fine; all the Sat test channels tell me there is no problem on my end; I have restarted and RBRd my HR20 multiple times. The technician that came to my house yesterday told me there is nothing wrong with my setup yet I still do not consistently receive these 3 channels and only these 3 channels. I have no problems with any other HD channels. I have yet another service call scheduled for this Tuesday, but I am not all that confident that anything will be accomplished.

What could possibly be wrong?

I have attached an .xls spread sheet with sample signal strengths from my HR20 and my uncle's from last night so the differences can be seen.

Regards,
Michael

[harsh]

I have attached an .xls spread sheet with sample signal strengths from my HR20 and my uncle's from last night so the differences can be seen.Most notable from your spreadsheet is the absence of signal on transponder 14. There also seems to be a trend towards weaker signals from the even transponders.

I'd be looking at a loose or wet cabling situation since it happens around sundown. If you hadn't commented about the "new" LNB, I would suspect a wet (humidity fogged) LNB. The even transponder thing may be a cable quality issue.

[MichaelP]

I've been over the entire cable run from end to end. Nothing is loose and there does not appear to be any moisture anywhere. When I do get the channels I have noticed that Txp 14 has a signal strength in the 90s.

From my perspective this appears to be a problem with the signal being beamed down to me. But then why are not more people in the Bay Area having the same problem?

[MichaelP]

Harsh, I think you are correct about the LNB being "humidity fogged." About 10 minutes ago the sun hit the dish and I now have all the channels; all my signals are in the mid to high 80's and I have a signal strength of 91 on Txp 14 on both tuners. I'll be damned. I guess I'll be getting a new LNB, again.

[MichaelP]

So the tech was here again yesterday to try to fix this problem.

I asked him to replace the LNB and explained why I thought that was the problem (see posts above). He disagreed and convinced me that the problem was my connectors. So we went with replacing all the connectors from dish to HR20. Not very many, and not a very long run since my apartment is kind of small.

And I was able to watch Sci Fi HD and USA HD all evening last night; up until I went to bed at about 10:30 PDT.

But... (and you knew it was coming) when I got up this morning I don't have 242, 244, and 332 again. I get all 4 new HD channels that were turned up this morning. But these 3 channels which have been causing me so much grief are gone again and showing the 771 error on the screen.

This time I am going to insist the LNB be replaced. Any other suggestions?