Weird problem.

[wejones]

I wasn't sure what category to put this in. I think we need a new category, like general trouble-shooting or something. Ie this isn't installation or any specific brand specific...yet.

Anyway, I've been surfing around several C-band sats today, with no problems. Then suddenly, I tuned in a strong transponder, but the signal strength would be up at like 80%, then 0% then 80%, 0% etc, etc, etc. It would stay on for 5 or 10 seconds, then off for 5 or 10 seconds. Weird I thought, but since I've been watching other transponders all morning, I figured it was just that transponder. But I switched to another transponder... same thing. After about 5 satellites and dozens of transponders, I found that ALL transponders were doing this. I switched to the Ku side of the sat I was on. Rock solid.... no problem.

So I figured that my DiseqC switch was flakey, so I bypassed the switch. Still doing the on--off--on--off thing. I checked an analog channel on the sat I was on. Rock solid.


I tried cycling the power on/off on my Ultra. Same problem.

I thought there might be some conflict down the line, so I disconnected the passthru on my Ultra. Same thing... on/off/on/off.

Finally, I decided to run the C-band LNB directly off my Ultra, bypassing the "T" and the analog receiver........ Rock solid signal. ???

At this point, I thought I had it narrowed down to either the "T" , but while thinking I decided to hook it back up the original way, to the "T"......Rock solid.!?!?!?!

At this point, I don't have a clue about what the problem was. I have it hooked up exactly the way when I had the problem, but it's working perfectly now. Has anyone ever had problems with one of those power passing (on one port) "T"s??? Has anyone ever experienced digital reception going on and off but analog rock solid??

This is very weird. I almost hope that it malfunctions again, so I can figure out what caused it.

[rainman]

might have been a dirty connection at the T and when you took it loose and reinstalled it cleaned it self.

[pmb1010]

bird standing on your LNB?

[wejones]

Originally Posted by rainman

might have been a dirty connection at the T and when you took it loose and reinstalled it cleaned it self.

The connection I took off though feeds both analog and digital, and the analog wasn't affected, so you'd think a dirty connection there would have messed up the analog too. Perhaps the lnb was oscillating at a freq that didn't affect the analog, but somehow did affect digital, and removing the power stopped the oscillation. I used to have a lnb that would go into oscillation, and wipe out one transponder at a time, but if I unplugged, the oscillation would go away.
Next time it does this, I'll try unplugging the analog receiver.
I'm also not sure about how the power passing "T" I'm using. I've heard that some use diodes that could be voltage dependent. I may switch back to a regular "T" with a separate DC block.

I don't think the bird thing is likely this time , although once I had a flock of turkeys around my dishes, and lost reception on one of the small dishes, which I blamed on the turkeys. I think they may have just jumped up on the lnbf arm. I don't think they would go after my big dish.

I thought the weird C-band thing was starting again today. I went to C-band briefly, and a signal popped up, then went away, however it was one of those newsfeed channels, so I guess it really went away. The other transponders were OK.

Oh well, I'm sure it will eventually happen again, and allow me to do more experimentation.

[rainman]

Originally Posted by wejones

The connection I took off though feeds both analog and digital, and the analog wasn't affected, so you'd think a dirty connection there would have messed up the analog too. Perhaps the lnb was oscillating at a freq that didn't affect the analog, but somehow did affect digital, and removing the power stopped the oscillation. I used to have a lnb that would go into oscillation, and wipe out one transponder at a time, but if I unplugged, the oscillation would go away.
Next time it does this, I'll try unplugging the analog receiver.
I'm also not sure about how the power passing "T" I'm using. I've heard that some use diodes that could be voltage dependent. I may switch back to a regular "T" with a separate DC block.

I don't think the bird thing is likely this time , although once I had a flock of turkeys around my dishes, and lost reception on one of the small dishes, which I blamed on the turkeys. I think they may have just jumped up on the lnbf arm. I don't think they would go after my big dish.

I thought the weird C-band thing was starting again today. I went to C-band briefly, and a signal popped up, then went away, however it was one of those newsfeed channels, so I guess it really went away. The other transponders were OK.

Oh well, I'm sure it will eventually happen again, and allow me to do more experimentation.

I have found analog feeds to be a little more forgiving of dirty connections than digital.