[R-390] R-390 alignment attempt #1, need advice - Crystal Deck

[Doug Massey]

Hey frank
You may need to pull the whole Crystal deck out. Which is probably not what you wanted to do.  Take all the trimmers apart clean them and put them back together.  Could be those trimmers are just stuck. It is a common problem with those things.  While you're in there you want to clean all those wafers as you pointed out with deoxit.  Sometimes the same thing happens adjusting any of the ceramic trimmers in the radio.  If you have that assembly apart make sure you check all of them before you put it back together.  Overlooking those trimmers while module is out of the radio can sometimes come back to bite you when you do the alignment especially Crystal deck and RF deck
Good luck with it.  I am sure you will get it going.  This is a great group of guys with a lot of experience and great information 
Doug

Doug Massey N4ZZT
Massey Radio Labs
Johnston SC
www.masseyradiolabs.com

Sent from my iPhone

> On Aug 3, 2014, at 4:39 PM, Frank Hughes <fsh396ss at gmail.com> wrote:
> 
> Hi,
> I went through the first pass of alignment on the R-390, found some things
> that need attention, not sure how to proceed.
> 
> Section 77 , Chapter 3 "Repairs and Adjustments" in TM 11-5820-357-35.
> "Alignment of Second Crystal Oscillator"
> 
> Some of the crystals won't adjust w/ the trimmer.
> 
> Initially did not think this was important, as they are bands I don't use.
> 
> But by the time I got to the RF deck alignment, it became clear that I will
> have to fix them.
> 
> All the manual says is "If no indication is obtained, check the
> "Crystal-oscillator bandswitch".
> 
> If the "Crystal-oscillator bandswitch" is the big wafer switch inside the
> crystal deck, I might be able to get some Deoxit on the wipers/traces, but
> WOW, that thing is buried.
> 
> But could the problem also be a dirty trimmer and/or bad crystal?
> 
> I have a spare crystal deck to swap parts out of, if needed.
> 
> Thanks & 73
> Frank
> KJ4OLL
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