Lnbs died or dying

[turbosat]

Spent several hours this weekend trying to debug one of my fixed dishes, a 7.5 perfect 10 c-band. It has an old feedhorn, forget which one but the scalar is adjustable, and since I don't have it connected to a c-band receiver to control polarity, I have been just twisting the feedhorn body in the scalar to change the polarity. Has been on 95W for awhile, picking up the My FamilyTV channel and some horse races. Since another channel became ITC Friday on 91W I decided to move the dish over there. Polarity was ok, but for some reason my Traxis 3500 dish-tuning reciever wouldn't pick up Anything below 4000mhz on that satellite.
I tried everything, even made up a new test cable with new compression fittings.
Could get the GemTV channel great, but mostly nothing else-it wouldn't even log any tps lower than 4000. Haven't had that one come up before so I was becoming stumped! Plus the pollen and the gnats, whew.
Today I decided to try another dish, so I moved my NASA dish off AMC3, its a 7.5 or 8' dish , forget which make it is, but a good dish. Pointed it at 91 and pow-everything started scanning in on 91W. I had my answer, dying lnb.
Changed out the entire feedhorn on the first dish, different lnb and all, works fine now. I haven't had more than 2 lnbs go bad in more than twenty years of c-band dishing! Something to keep in mind when you're butting heads with a stubborn problem.

 

[phlatwound]

Glad you got that figured out, turbo, that stuff can drive ya nuts.

I bought a box of 6 assorted used C-band LNBs pretty cheap at a garage sale last summer, finally got a chance to test them last month.....only one was good. I opened up one of the bad ones, looks like it took a lightning hit.

 

[turbosat]

After I looked at that bad one awhile, I remembered it was the one I bought at a scrap-metal place about 3-4yrs ago, hehe. I went there to buy another c-band pole, and saw this old mesh dish in pieces lying right out in the open, with the lnb still attached to bent-over lnb arms so I took it off just for grins. The guy gave it to me for nothing since it had been turned up to the sky for who knows how long. I placed it on top of my stand-alone VC2 box for a couple of days to dry out what moisture was in it, and it worked just fine until last week. An older looking Eagle Aspen 30-35degree.