[R-390] To swap or not to swap those aging "reddish" rectangular mica caps

[Jacques Fortin]

John, I never suggested that all the "red" ones HAVE TO be changed.
The warning was just that due to their age, they CAN fail, but not all...
If you want to completely rebuild a R-390A, go for it, but...!
IMHO, the only capacitors that NEED to be changed are the Sprague
"bumblebees" paper ones  if you find any inside your modules.
Otherwise, wait for the failures to happen, if any !
All depend also of the "running time" you expect for your R-390A.
My own are OFF most of the time, so I do not expect a high number of mica
cap failures... 

73, Jacques, VE2JFE in Montreal

Guided discovery continues as I make progress on the RF sub chassis.I
received C327 replacement for "high Q" 100pf, 1,000 volt mica capacitor to
install on the primary output of T207.I received group input that the green
mica mold caps provides acceptable operational service with very low failure
rates, and the "reddish" color caps are older generation and appear to have
a statistically higher failure rate, and should be replaced with new high q
mica caps.Two examples in the receiver, (1) with all reddish mica
capacitors, and (2) 1 out of 2 reddish capacitors.My course of action is to
keep the green, replace the reddish capacitors.
Or does the group make the case that while the patient out and ready for
surgery to replace both capacitors while opportunity is good?
Thanks in advance to your vast repository of deep informed knowledge as I
work my first end to end refurbishment on this magnificent receiver.Happy
4th of July, celebrate independence day.
John N3JKE