Dying C-Band LNB?

[colbec]

Just can't figure this one out. I'm having a problem getting 3740 MHz on 103W, no signal at all.
Neighbour signal 3920 MHz comes in clear as a bell, in fact it is the only signal I can get under Free from 103 at all.
Until a week ago I was getting 3740 no problemo.
Tried two receivers, same thing.
Both 3740 and 3920 are H polarity. I have cleaned ends and get good volts at the LNB end. Label on LNB is washed off but it is a Ku/C combo. Dual outputs, one side is dead I believe after a lightning event several years ago.
Don't have a spare LNB, I guess I should have one. In the meantime anything I have forgotten to check?

 

[KE4EST]

I assume this is the only bird you are having issues with? Have you double checked the alignment of the dish. Sometimes if it has been years you can re-seat the feedhorn in the holder, double check that it is aligned properly.
Have you bumped the dish east or west a couple of clicks to see if it comes in?

 

[colbec]

Yep, checked this multiple times. Tried tweaking the dish, no hint of a signal.
Like I say, 3920 is good, signal at 92% screaming at me. 0 on 3740.
According to Lyngsat, SES-3 is the only FTA bird that AAN lives on, so must be the right spot in the sky.

 

[colbec]

Thanks KE4EST, I think I am a bit closer. My receiver is reporting that both 3740 as exists in the my stored list and 3920 are both H polarity but in truth 3740 is V, not H. I have no problem with other satellites V and H so the box is producing the right volts, but I think maybe the LNB is not responding correctly to the voltage switch. Currently I think it only sees H for AAN and probably zero for V, otherwise if it just stuck on the H when I blind scan it would pull in two copies of AAN...?

 

[armadillo_115]

The main question I'd ask is why can you ONLY receive 3920 on 103W? There's several strong transponders on 103W, at least at my location.

 

[colbec]

Well Armadillo I think you are right, I have a feeling at one time I got a lot more from 103 (ION, Qubo and others) but not any more.
I figure I can't do much more until I have a new C-Band LNB to swap out.
I checked a few Ontario suppliers but not all that happy with their offerings. Who are the go to people these days for C-Band stuff?

 

[armadillo_115]

There's an ongoing contest to win a Titanium LNB of your choice @ http://www.satelliteguys.us/xen/thr...ium-satellite-pll-lnbf-conical-scalar.357138/
Enter that and you may not have to buy one. Warning... I plan to be the winner though. lol.

Also,in no particular order:
KE4EST
HyperMegaSat
GotCBand
That's just the ones I bought something from...I'm new to FTA.All have been great to deal with.Other members can give you more sources.(I left somebody out...can't think with this sinus headache)

 

[Titanium]

What happens if you manually edit the 3740 transponder to vertical polarity? What is the receiver's LNB voltages measured on a horizontal and vertical transponders?

RPS carries stock of our Titanium Satellite PLL LNBFs in Ontario.

 

[colbec]

Hi Brian, thanks for the ref.
I have tried two receivers, both output 13 v for V, 18 v for H.
I use blind scanning to register my tps; I can force the power scan to select V only and get no channels.
Currently I get none for H as well, so I'm concluding that the LNB is at fault.

 

[Titanium]

Checking voltages at the both the LNBF and the back of the STB? Could also be a bad switch, coax or connector.

 

[colbec]

Yes, checked voltage at the far end of the coax, all good, perishing cold work in the winter wind. I don't know how professionals manage to check installs, fumbling with voltage testers through gloves when the temp goes down to minus 30.

Just checked it again and now the LNB is picking up V 4091 no problem - and nothing else.
This tells me that the V/H thing is working, but only for one frequency?
This morning it was H 3920, and nothing else.
A couple of days ago it was H 3913 plus one other, but I can't remember which one - might have been AAN which is right next door.

Don't you just love troubleshooting a moving target?

 

[Titanium]

No thank you! Love snowmobiling and boarding, but not a fan of winter otherwise.

Agree with your diagnosis of likely the LNBF.