do LNBs age?

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FTAer0024

SatelliteGuys Family
May 17, 2011
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Greetings to all. There was an auction on Ebay where the seller stated that the LNB works OK but the picture was not as sharp as it used to be. Do they really age with time to the point where picture quality starts to degrade?
 

SatelliteAV

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Sep 3, 2004
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Yes, LNBFs can age. It won't make a picture burry, but the frequency can drift on a DRO type LNB. This would cause the receiver to not lock onto a preprogrammed transponder.

Check out the LNB sticky if you want to learn more about a failing LNB.
 

waylew

SatelliteGuys Pro
Aug 23, 2010
2,964
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northern WEST new york
Yes, LNBFs can age. It won't make a picture burry, but the frequency can drift on a DRO type LNB. This would cause the receiver to not lock onto a preprogrammed transponder.

Check out the LNB sticky if you want to learn more about a failing LNB.
Just fer instance,years ago I bought 2 DMSI BSC321S lnbfs,had used one on different dishes and the other one stayed new in the box.Anyway I was trying to set up an old Directway dish for Cozi and it was giving me fits.Had scanned in the channels from another dish/lnb but could not get a lock on anything with the Dway/BSC,even tho I knew it was pointed right.Finally did a blind scan and got some of the channels but the frequency's were way off,ok the LO had drifted.Put the "new" BSC on and had the same problem!So even "new" in the box after so many years the LO can change.Long story short (too late) I bought a new Geosatpro PLL lnbf and everything is working just fine now. :D
 

SatelliteAV

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Sep 3, 2004
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A stored DRO will definitely drift frequency. Maybe not as fast as a LNB going through extreme temperature variations, but once the materials start aging the tuning slugs shift, caps dry out, etc.

Pulled a five year-old and unused QPH-031 out of storage a few months ago and the LO had drifted 4mhz. The unit out in the weather for the past 6 years was 5mhz off. Time takes its toll on man and machine... :D
 

waylew

SatelliteGuys Pro
Aug 23, 2010
2,964
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northern WEST new york
Yeah,I had a WTF moment when I put the "new" one on and it did the same as the used one.But it was definitely off,and I know the one that was in use had worked correctly previously.I just put it down to an "oh well" and upgraded to the GSpro pll.:D
 

madmadworld

Official TV Watcher
Pub Member / Supporter
Apr 7, 2006
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Pulled a five year-old and unused QPH-031 out of storage a few months ago and the LO had drifted 4mhz. The unit out in the weather for the past 6 years was 5mhz off. Time takes its toll on man and machine... :D
have had a QPH-031 quit after about 6 years.
knock on Wood.
have some CalAmps & Norsats 13+ years old working fine.
 

cyberham

SatelliteGuys Master
Jun 16, 2010
6,057
5,085
British Columbia
When using my universal LNB, frequencies on my receiver are consistently reported 3 MHz high. Maybe this is due to aging of the LNB. Can I tune the LO to resolve this without having laboratory frequency measuring equipment?
 

SatelliteAV

SatelliteGuys Master
Lifetime Supporter
Sep 3, 2004
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Roseville, CA
Can I tune the LO to resolve this without having laboratory frequency measuring equipment?

What do you have to lose if the option is to retire the LNBF?

Remove the plastic case and remove the sealant on the tuning slugs. Use a non metallic tool to tune the slug for centering the frequency. Blind scan to identify which slug changes the frequency on the high band section.

I would document which slug is tuned and the number of turns. Which slug to tune? Experiment and find out... Each LNBF is different.
 

cyberham

SatelliteGuys Master
Jun 16, 2010
6,057
5,085
British Columbia
Option 1) Do nothing and continue to enjoy a finely working LNB. Option 2) Learn something about LNBs.
I will argue with myself which option to take. When the weather turns warm and I have idle time, I may find it hard to resist taking Option 2.
 

Anole

SatelliteGuys Master
Sep 22, 2005
11,819
14
L.A., Calif.
more options

What do you have to lose if the option is to retire the LNBF?

Remove the plastic case and remove the sealant on the tuning slugs. Use a non metallic tool to tune the slug for centering the frequency. Blind scan to identify which slug changes the frequency on the high band section.

I would document which slug is tuned and the number of turns. Which slug to tune? Experiment and find out... Each LNBF is different.
Go a fraction of a turn!



Some members have moved DBS LNBFs down to 10750 LO.
I found it a foolish exercise, but to each his own. :up ;)
(and you have to modify 'em to not be circular, of course)

Another idea I read about here in the forum, was to just change the LO frequency in the receiver setup by a few MHz.
Then all your received frequencies are back to normal.

Probably the best option is to use crystal controlled LO (PLL).
Those should outlast you. ;)
 
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