[R-390] Work on Crispy Critter - Update

[John Wendler]

1) Audio chassis rebuilt with 1% metal film resistors replacing the carbon
composition units.  In general, you can get a larger power rating in metal
with the same package size as carbon comp.  These should be more stable and
should have lower noise contribution, too.

I used a pressed series of orange drop caps (series 225P Polyester, 400
WVDC) to replace the paper caps.  A flattened configuration is required by
my audio chassis in order to keep the caps from being crushed between the
terminal board and the main chassis.

2) Found a defective 6AK6 in the local audio chain.  This set off a round
of tube emission testing; the 5654 in the crystal oscillator chassis was
also bad.  The ballast tube was in the IF chassis and an ohmmeter showed
continuity.

3) Not sure if military-civilian tube equivalents are in the Pearls or not
- here is what I found over the web and in the Vade Mecum.   I needed the
civilian equivalents to test on my Electronic Measurements Corp Model 209
emissions tester.  I would expect military tubes to be ruggedized in
comparison to civilian.

5654 => 6AK5
5749 => 6BA6
5814A => 12AU7A
6189 => 12AU7WA

The 6189 was in the crystal calibrator slot.

4) The rear panel of Crispy Critter has the lettering, but no holes or fuse
holders for F102 and F103.  Not sure what this means for rev level; I'm
guessing later rather than earlier - it seems a cost reduction measure.

5) Next up is the IF chassis.  The filter killer has already been replaced;
all filters show continuity.  I note Brown/Black beauties of death that
need replacement.  I also see a bunch of Sangamo capacitors that look like
metal-cased paper.  Do these degrade like the beauties of death?

73 de N5CQU

JP