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

[Bob Camp]

Hi

Crystals will not adjust or the oscillator is dead on those bands?

Bob
KB8TQ

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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