KU band help

[jpgator]

This is driving me nuts....
10 ft unimesh dish. Was C band only. Put the corotor II on it for dual band. With a little tuning the cband was fine. Only really concerned with X4 for ku band. The first day got x4 no problem. Next day nothing. That afternoon it came back in. Was getting qualities of 70 ish and higher. Now nothing. I have done everything I can think of.

I figured the focal depth of like 46 by the measurements of the dish but signal is no that great and get nothing with ku band. I see others saying their 10 ft unimesh is around 48 on focal depth. I set it there and c band is jam up. 94 or better all the way around - digital channels quality is 85 and higher on all channels. KU band nothing - signal 10 quality 0............. Yes the receiver is set for dual band lnds - new cable run. Dish has a few dimples in it from hickory nuts but not that bad.

I have the scaler as far out as the arms will let it go - which puts it to the 48 inch mark -
I have tried double checking N/S alignment - reset elevation and declination angle, but could be a off a degree - going to get more critical with it tomorrow to see if it makes a difference. Going to swap coax on lnbs tomorrow to make sure the new cable is good.

Being my cband is tweaked to its max - I am in the arc - no matter what sat I am on - up down left right (pushing) makes signal worse. So I believe I am tweaked in where I need to be. Should I not at least be able to get some signal on one these birds - not one ku band bird - I did have the first day - could the lnb have fried???

How critical is the polar axis alignment with the horn?? it close but not perfect.

hellllllllllllllllllllllllllpppppppppppppp...............

I am beating myself to death here....

feel free to email me anyone with 10 ft unimesh dish - want to verify F and F/D ratio. I may have to go out further ?????????

Any help would be appreciated.....

 

[Hermitman]

If you were getting X4 at 70 quality or better, you should have left it there. That shows your antenna and feedhorn alignment was good. Corotor IIs are not set to the polar axis, they are set at the 11 o'clock position for full servo movement. As far as the on one day - off the next, that could be several things. Check cables and connectors. Swap the c band cable with the ku band cable at both the lnb and receiver and see if the problem's the same. If you have the same problem, check voltage from your receiver and that its not set for LNBF but LNB. That will keep the voltage from changing and possibly causing strange operation. When you're adjusting the polarity for the c band, is the servo moving smoothly and changing the picture accordingly? If the servo works ok for c band, it should work ok for ku band. It could be a bad lnb but I'd check other things first. Good luck.

 

[jpgator]

OK - went back and re re re double triple and quad re doople checked everything.. No good -
F depth set at 47 5/8 right now ( went from 46 to 48 1/4 (max)) no change
ratio of .40
C band channels - quality of 95 to 100 signal - quality 95 to 100 ( a few 75 ishers)
Pointing center of dish
Not warped
I am at lat 28 55 ish ( elevation set 29 1/2 ish - declination 4-5 - total reading back of dish is 33 - 34 degrees.
Tracking arc - push and pull only gives worse signals no matter where I am at.
Using motorola - 4dtv receiver 922 - set for lnb not lnbf
I have double checked n/s again
I have run between g4 and w4 looking for x4 - switching focal lengths by 1/4 inch each time from 46 to 48 - nothing.
Oh I have swapped cables on receiver and dish so I know the cable is good -

c BAND is tuned perfectly - KU band nothing (all birds)........ still signal 10 quality .......

I have the lnbs at 12 and 6 actually right now but that shouldn't matter - correct because servo will correct that?? or am I wrong?

What about a ground ???

 

[tvropro]

OK - went back and re re re double triple and quad re doople checked everything.. No good -
F depth set at 47 5/8 right now ( went from 46 to 48 1/4 (max)) no change
ratio of .40
C band channels - quality of 95 to 100 signal - quality 95 to 100 ( a few 75 ishers)
Pointing center of dish
Not warped
I am at lat 28 55 ish ( elevation set 29 1/2 ish - declination 4-5 - total reading back of dish is 33 - 34 degrees.
Tracking arc - push and pull only gives worse signals no matter where I am at.
Using motorola - 4dtv receiver 922 - set for lnb not lnbf
I have double checked n/s again
I have run between g4 and w4 looking for x4 - switching focal lengths by 1/4 inch each time from 46 to 48 - nothing.
Oh I have swapped cables on receiver and dish so I know the cable is good -

c BAND is tuned perfectly - KU band nothing (all birds)........ still signal 10 quality .......

I have the lnbs at 12 and 6 actually right now but that shouldn't matter - correct because servo will correct that?? or am I wrong?

What about a ground ???

I looked at my original documentation I have from Unimesh. Your focal length on the 10 foot is 48.0 inches. This is measured at 1/4 inch inside the feedhorn on a corotor.

Ku is 3 times more critical than c band to align although X4 is hot so it shouldn't be that hard to get.

You may have a bad lnb for ku or possibly a problem with the c/ku switching in the 922.

BTW... all the HITS channels on X4 will be turned off June 1st. They are migrating to AMC-18 C band. Motorola will map them in before then.

 

[Hermitman]

Here's a couple more thoughts for you. Remember, the signal number and the quality number are totally different and some people get them confused. The signal number just indicates you have a signal coming from the lnb to the receiver. With a signal number of 10, you have no signal from the lnb. It should be sitting 80 or above when on a channel or may be jumping around while searching for a signal. You should check that you have 18 volts or so feeding the lnb. A ground doesn't matter because the shielding on the cable acts as the ground. Below is a link to Chaparral's Feedhorn Troubleshooting Guide. It has lots of good info about feedhorn setup.

Welcome To Chaparral Communications

If you're getting 18 volts at the lnb and the receiver is set for a ku lnb but still no signal number above 10, you might try a soft reset first. Turn off the 922 and unplug it for 30 seconds then plug it back in and go through warm up. If that doesn't work then you might consider trying a different lnb. Once you get a good signal number, then just aim the dish to G4 and tune in channels 15 and 16 the best you can. Then just switch over to X4 and put on an active channel. The dish shouldn't move since its the same satellite. Then tweak polarity and bump the dish for the best quality number. Good luck.

 

[jpgator]

ok here we go again.....

did a soft reset - by the way had 19 volts out of the receiver to lnb. Did a soft reset. At this point I got a signal of 10 and quality of 99.... go figure but no picture or sound.
Unit locked up did another reset. back to signal 10 quality 1. Adjusted from 48 1/4 inches at .40 all the way to 46 1/4 in 1/4 inch increments making sure I adjusted the lnbs at 10 ish and 4 ish each time. each time I tried to lift and puch dish for signal. Still at 10 and quality 1.
Backed it back out to 47 7/8 ish and did another soft reset - Signal 10 and quality 99 . went back up and bumped the dish east and west no change - pushed and pulled no change. Cband is still running 98 on g4 16 and 94/96 on 17. W4 channel 500 signal 100 and quality 75.

I don't see a bad lnd coming from factory but could be ( I mean a i had x4 for half a day and lost it got it back and then lost it for good the next day (all ku)).

With my cband signals coming in so good could it be that declination or elevation is off a hair. On Cband every bird I am on wether digital or anolog - push or pull signal goes down and digital the quality goes down. I should be dead on correct?? No matter where I am at in the arc Push or pulling makes signal worse and have good signal.

Any thoughts guys - after all you are the masters......
appreciated.

 

[determined]

When I wanted to go to K band, I bought a corotor and a Ku LNB. It wouldn't work for Ku, not even once, but C band was perfect. I fiddled with alignment for months because everything I was hearing said that Ku was tough to align. After a lot of frustration I decided to replace the new LNB. As soon as I powered up after installing the new Norsat, I got everything on X4 with a 99 quality. My problem was a new but defective LNB. After you are really, really, sure that your wiring and alignment are all up to snuff you might need to try the LNB.

 

[jpgator]

Thats what I am figuring

I called the company I got the corotor from and they tole me some neat things to do to peak the dish - well for focal length (versus the instructions). Tune G1 channel 5 peak the dish for best signal with skew at 30 and -60 (no matter what the alignment is on the lnbs). Then turn to channel 3 and adjust the focal length in and out for best quality ensuring the skew stays at 30 and -60. Got this to quality of 99 - this should be the best focal length you can get. From there its all about your alignment. To my surprise when I tracked my arc with my elevation and declination settings I had - all sats had 94 signal or better some 96-98 on analog and digital signal 100 and quality 99 - on all sats and skew stayed 30 and -60. Thought I was good to go - and again to my surprise ---- no KU bands. Well I called them back and he advised the declination settings tend to be 1 to 2 degrees lower than what they have listed which would mean for me it would be between 2 and 4.6 degrees. Sooooooooooo up on the roof again with the tv. Went and dropped my declination to 2 degrees and they raised my elevation up until it peaked on w3 as he said. then tried the KU band - nothing. From there I would readjust to center and adjust declination 1/2 degree more and then go back to w3 and adjust the elevation for best signal and then try ku band again. I did this every 1/2 degree on declination until I hit almost 5 degrees. No such luck.......... Now my c band is off a bit qaulities of 94ish but I didn't go back and fine tune it back to where I was all 99's. Still tracking good though. Well - he is now on a service call and can't get back to him until later - so I will be getting a new LNB - I will have to mail it back to him and then wait for another - such a pain. I figured it was the lnb from the begining because I had a signal for a day - lost it - skewed it the next day got it - lost it after a few hours and then nothing after that at all - all this without touching any elevation or declination - and I did have qualities in the 70's.
Well such is life for me these days.........

Damned murphy..........

 

[JDOGG51]

If Corotor IIs are not set at polar axis but at 11 o'clock, at what satellite should the Corotor II be set at 11 ? My polar axis is at 79W.

Thanks in advance
JDOGG51

 

[truckracer]

Your true south sat is where the corotor should be set at. Lnbs at 11 and 4 o'clock.
Check your longitude where you live and the dish should be at it's zenith or highest point centered on the polar mount. Set you corotor to 11 and 4 and forget it.

You can fine tune it later. F/d and skew. Mine fell right in place at 11 and 4.

 

[truckracer]

You probably have a bad ku lnb