Zenith IF transformer capacitor repair


Repairing Zenith 455 KHz IF transformer capacitors with silver mica disease

zenith r615 radio Zenith R615 radio, chassis 6J05.
This radio had the classic symptoms of silver mica disease.
Intermittent static crashes, Changing sensitivity, beginning 10-15 minutes after turn on.

IF can AM 455 KHz.
1st IF can part # 95-1101
2nd IF can part # 95-1102

IF transformer

IF can without shield IF can with shield removed.

Typical parts layout of IF can.

This is 1st IF can, contains two capacitors.
IF can parts

capacitor capacitor plate with contacts.

This is the 2nd IF can, It contains three capacitors.

Capacitor prior to cleaning. Note the silver oxide migration bridging the clear areas in the center and outside.
Capacitor silver oxidation removed with a pencil eraser, then cleaned with Q-tips dipped in Isopropyl alcohol.
The capacitor contacts were cleaned with alcohol also.
capacitor plate

clean capacitor Capacitor after cleaning, partially reassembled.

Schematic of Second IF can 95-1102. 1102 IF can

1101 IF can Schematic of First IF can 95-1101.
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