[R-390] R390A RF deck advice

[ngietz at mymts.net]

Guys, I’ve been reading your comments with great interest.
Roger makes a fair point about considering my skill level, since I’m new in this group.
FWIW, I’ve been soldering in old radios for more decades than I want to count.  On this
R390A, I’ve been through the resistors and caps on the AF and IF decks so far, and have 
dismantled, cleaned lubed, reassembled and synced the gear train.

I’m no EE or mathematician, but some online research about the parasitic suppressor 
resistors suggests that (at least in audio circuits, and I don’t see why that wouldn’t apply 
to HF circuits) if the resistor values are too high they can roll off the gain on the higher 
frequencies where good gain might be most needed.  In view of that and after all the 
other work done, it would be a waste not to finish the job, and replace the over-value 
suppressor resistors.  I have no idea whether carbon comp resistors get quieter with age.

Re the brass-screw RF slugs; I’ll do what I probably should have done in the first place and 
check with Fair Radio on whether these are indeed correct.  No big deal to reorder if it gets
this radio up to or near spec.

As far as disconnecting the heater of HR202, my reading of the “RF Deck Electric” section of 
W. Lei’s “Pearls” leads me to think it’s not a good idea after all, considering the crystals are 
cut to run on frequency with the heater operational.  When I was running the receiver before
the RF deck overhaul began, the thermostat seemed to be “tinking” off and on just fine. I
guess I was just surprised at how warm to the touch HR202 was.

So, those are my conclusions so far.
Thanks for your observations.
Nelson