[time-nuts] ERC-130, rather FE5650A asjustment

[Taka Kamiya]

Fellow Time Nuts...
I *just* took a shipment of ERC-130 10MHz Rubidium standard.  Inside is FE5650A with no options.  The frequency was little off so I adjusted what I thought was an EFC, except it wasn't.  

I hope you see a row of 4 10 turn trimmers.  I adjusted the second from the left one.  The end result was, kt lost lock.  By carefully walking back, I was able to obtain a lock.  So my guess is either it's a PLL loop gain or PLL amplitude adjustment.  

I read what I can find on Service manuals, but none of the explanations go into the second board.  Does anyone know what this pot is supposed to do, and what adjustment criteria is?  My PLL experience is from 20 years ago with 4044 chips. I know gain and amplitude affects stability and speed.  

By the way, re-reading, I now know the proper way of adjusting frequency.
Thank you.

--------------------------------------- 
(Mr.) Taka Kamiya
KB4EMF / ex JF2DKG
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