[R-390] RF subchassis separation

[Craig Heaton]

1: No signal below 8MHz, that is most likely the 17MHz that sits alongside
the 200KHz calibration crystal. Fair Radio is one source.

2: No Crystal Calibrator signal, since you are referring to the RF section.
With tube extenders check voltages. In the Y2k manual there are
voltage/resistance checks listed. Try a tube replacement or two. Those
crystals are getting hard to find like hen's teeth. Someone one the list
might have one, make sure it is packaged well for shipping. International
Crystal can make one, but very pricey. If there are harmonics but not where
they should be, (use a freq counter coupled to that section of the RF)
suspect one of the dozen or so silver mica caps. Shotgun time. 

Craig,

-----Original Message-----
From: r-390-bounces at mailman.qth.net [mailto:r-390-bounces at mailman.qth.net]
On Behalf Of Mark Richards
Sent: Thursday, March 13, 2014 10:05 AM
Cc: r-390 at mailman.qth.net
Subject: Re: [R-390] RF subchassis separation

Removal of the entire RF and Crystal Oscillator section was a lot easier
than it first appears.  Simply a few green-headed screws, remove some
cabling, and it comes out as an entire unit.  It looked intimidating, which
caused me to believe that it was... like a schoolyard bully.

Now that the RF deck is removed I was able to clean up the bandswitch,
replace a few capacitors, and poke around in the crystal oscillator
section.. as mine doesn't work properly.  No issues found in that area (with
components that are testable in circuit); no signs of overheating or stress.
So it's either tube/s or crystal.

Question A: As I keep hearing crystal replacement as the answer to this
problem, can someone here lead me to a source?

I should probably replace the pair.  Test revealed that < 8MHz I have no
radio.. so likely the other crystal gave up, too.

Decided not to disassemble any further, as in repairing the loose shaft 
that started this whole mess.   It works mechanically.  Why fix it.. 
unless I want perfect stock appearance perfection, which I am less inclined
towards after all this work.

Went about removing each of the slugs to be certain I had not mixed these up
and managed to snap two of them.  Easy to do as they are old and seem quite
brittle.

Question B: Is the best fix a dab of epoxy?  Looks as if it cannot be
soldered together...

/K1MGY

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