Weird lnbf frequency problem

[iammike]

The cheap lnb's I got with in my Corotor package have been having major problems, like they did last summer too, with all the heat we've been having lately. Just for grins I decided to try playing with my old ASC421 lnbf.

I had a lot of trouble with it at first, and couldn't figure out what I was screwing up. I can't get any 4dtv channels, but I could get analog perfectly if I changed the lnb offset by -10 mhz. I thought that was pretty weird, so the next thing I did was hook up my Coolsat and do some blind scans. I'm getting some pretty high quality numbers, a lot of channels are in the 90's, so the lnbf looks like it's installed properly, but every transponder it finds is off by 10mhz. This isn't a big deal with the Coolsat, as it doesn't really care what frequency it uses, but my 922 isn't happy.

Does anybody know a way to adjust the frequency a 922 uses for digital channels, or any way to adjust the lnbf's frequency? I'm guessing I probably need to purchase a new lnbf but thought I'd ask for advice first.

Thanks,
Mike

 

[caddata]

...major problems, like they did last summer...

When integrated circuits are manufactured, the manufacturer doesn't know what he's going to be able to sell until they've been tested. The IC's can't be marketed until they've been graded.

The most important test in the grading process is when they are subjected to elevated operating temperatures. Those circuits that pass with the highest temperature rating are sold for critical applications (aircraft, military, medical) are worth more money and are all they hope to produce. Circuits that meet lower ratings are sold at progressively cheaper prices.

Sounds like the circuits in your LNBF's probably met the lowest temperature rating, and those hot summer days are taking their toll.

As a test, put some ice cubes in a ziplok bag and drap it over the amps to see what happens. My guess is that performance will improve.

Otherwise, your dish may be warping from the heat.

Harold

 

[iammike]

Harold,

Thanks for the reply. My lnb's are known for having issues in hot weather. They're stability rating sucks. But you get what you pay for, I got a Corotor II+ with these 2 lnb's thrown in as a package for around $140 bucks a couple years ago. They work great in cold weather but during the summer they're no good. I can pick up some good Norsat lnb's that would almost certainly fix the problem, but I'm not sure I want to pay the money. I've also been thinking about dropping 4dtv, at least for a few months, and just using the BUD for FTA with my Coolsat and PC cards. Hence the lnbf.

What I find really curious is the frequency being so far off. There doesn't seem to be any stability issues with it, its just consistently off by 10mhz. I've seen minor 1 or 2mhz variations before, but 10 seems kind of huge. Since I'm seeing the same variation on two different receivers I'm kind of at a loss, as it doesn't appear to be a receiver configuration issue.

I'm kind of hoping someone will reply back with a hey dufus do this and it works message. Telling me what stupid thing I've done. Otherwise I might try one of the new bsc621's.

 

[Mr Tony]

is the LNB skewed right? I know my ASC421 skew is taken from 3:00 or 9:00 (if standing in front of the dish). Its weird

As long as I start with the 0 at 9:00 or 3:00 and skew from there it works fine

 

[iammike]

is the LNB skewed right? I know my ASC421 skew is taken from 3:00 or 9:00 (if standing in front of the dish). Its weird

As long as I start with the 0 at 9:00 or 3:00 and skew from there it works fine

I did have the skew wrong to start with when I had it attached to the 4dtv. The analog channels were coming in 1 channel off from where they should. For example on G1, EWTN was on channel 12 instead of 11 and I couldn't get the shopping channel. When I rotated it EWTN was on 11 again and shopping was on 12, but I had to enter in almost a full 10mhz reduction in frequency to clean up the picture. When I hooked up the Coolsat, all the DVB stuff comes in when I blind scan with the correct polarity but with the frequency shifted 10mhz.

This is probably a dumb question, but wouldn't the skew just affect polarity and not the frequency?

Thanks,
Mike

 

[Mr Tony]

ah crap you're right....I didnt read about the frequency being off by 10...that almost sounds like the LNB is bad

 

[iammike]

ah crap you're right....I didnt read about the frequency being off by 10...that almost sounds like the LNB is bad

Ice your our guru on things satellite. You're supposed to tell me some secret trick that will instantly fix it. I'm so disappointed.

Thanks for trying! I was thinking bad lnb too.

Mike

 

[Mr Tony]

Reason I say that is I had the same issue with the ASC421

When its cold out (like around 0) the H side doesn't work and when its hot out the frequencies fluxuate....mine are within 4 or so and not 10 but I know that LNB is going

 

[iammike]

Yeah, we don't get the cold weather you do but it's been danged hot here lately. Overnight lows haven't been much below 80 and we've been pushing 100 during the day. I think it's supposed to cool down some this weekend. I'll do some more blind scanning with the Coolsat and see if the frequencies get any closer.