[R-390] Removing RF Deck -R390

[Robert Nickels]

On 11/29/2025 3:48 PM, Jacques Fortin wrote:
> Once you will be in the RF deck, change the C231 (bathtub 50µF/50V RF gain line decoupling cap) which will give you problems sooner or later.
> Read the removal and re-installations carefully !

Thanks Jacques - I've been reading and re-reading and following the 
procedure in the TM 11-856 manual. I also have the Field and Depot 
manual dated 1962, but haven't found those corrections (so far haven't 
found a 1958 manual).

Just finished removing the RF deck and am puzzling over why sweeping the 
primary of the output transformer to the IF module T207 with NanoVNA in 
S21 mode,   I can't see a hint of a resonant peak at 455 kHz.  The 
manual says it should have a broad peak but there's just nothing.  So 
that'll probably be coming out.

Thanks for that tip on C231,  I'd rather not have to do this more than 
once!

73, Bob W9RAN