What currently available dual outlet LNB can be modded for GPS locking?

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Basil
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Joined: Tue Sep 10, 2013 7:28 pm

What currently available dual outlet LNB can be modded for GPS locking?

Post by Basil » Mon Jun 07, 2021 9:35 am

I am wondering if you know where I can get a dual output (or more) LNB ready to be locked to 25MHz up the coax? I have a single output LNB from QRO.CZ that works very well with their special Bias-T box and a 10MHz reference that I already have, down the coax? The box must multiply the 10MHz internally.

I want to be able to receive horizontal and vertical signals (SSB and DATV QO-100) at the same time, on the one PF 1.8 metre dish.


If nothing is commercially available, what is currently available that might be modified to enable this please, with some published, clear instructions? I would buy one if anyone here has a spare one to sell.


Thanks and all the best. Chris, 2E0ILY

G8GKQ
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Re: What currently available dual outlet LNB can be modded for GPS locking?

Post by G8GKQ » Mon Jun 07, 2021 10:38 am

Chris

I am not sure if the Octagon LNBs are still available, but I described a modification similar to what you require on the Wiki here: https://wiki.batc.org.uk/Es%27hail-2_LN ... _Reference.

This is the LNB that is in use at Goonhilly for the Spectrum Monitor and WebSDR.

Dave, G8GKQ

radiogareth
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Re: What currently available dual outlet LNB can be modded for GPS locking?

Post by radiogareth » Mon Jun 07, 2021 10:54 am

There is info 'out there' for converting Octagon 2 and 4 way PLL LNBs for external injection. I'd have to dig out the sites I referred to but it can be done. Another alternative is buy a Bullseye LNB ($30 delivered from Aliexpress) which once warmed up are fine on NB, negating the need for lock.
https://www.ebay.co.uk/itm/353490874396 ... SwJ8FgmlJw
is an 'easy mod' and as its dual crystal, you can retain one for DATV and lock the other.
HTH
Gareth

Basil
Posts: 298
Joined: Tue Sep 10, 2013 7:28 pm

Re: What currently available dual outlet LNB can be modded for GPS locking?

Post by Basil » Fri Jun 11, 2021 10:14 am

I have managed to find an Octagon LNB that appears, as far as I can tell, to be the same as the one Dave shows how to modify. It's in Greece though and shipping is more than the cost of the LNB itself, but hey, you can't take it with you I guess :) I will open it with some trepidation when it eventually arrives, hoping in reality it IS the same. Thanks for the replies to Dave and Gareth, much appreciated. Regards, Chris 2E0ILY

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