[R-390] Z-503

[ROSS HOCHSTRASSER]

Hi all, Pardon me for not shuffling through endless pages of R-390A info, but I need to know the value of the capacitor in Z-503.  I am having AGC problems and am coming to my wits end. When  this receiver landed on my bench, Z-503 was open. I obtained one from K1ANX which has a good coil and may be A-OK, but I can't get a satisfactory response when tuning it. I am unable to get full action out of the AGC on strong stations. Swapping the IF module with my other receiver, the problem follows the IF module. I have recapped it, changed all of the tubes, checked all of the resistors, even changed (most) of the silver micas to no avail.  I am suspecting that Z-503  is not at resonance due to  an intermittent cap.( I could very well be wrong on this...)  The  manual I have shows the cap, but offers no value, in the parts list it lists the cap as part of Z-503, but gives no value. HELP!! Thanks, and 73 Ross W1EKG