JF Antique Radio Repair -- Tube Equipment Repair (Radios, Amplifiers, and Car Radios)
SILVER MICA DISEASE
Silver Mica Disease (in Radios/Tuners Manufactured after 1950)
In general, I do not repair radios/tuners manufactured after 1950 due to the potential of them having Silver Mica Disease.
Radios manufactured after 1950 have inferior IF (Intermediate Frequency) transformers (compared with IF transformers used in earlier radios). These transformers contain capacitors made of silver film on a mica substrate.
The silver is exposed to the elements, causing corrosion, and results in Silver Mica Disease. When Silver Mica Disease is present, a cracking sound like lightning noise is transmitted through the radio.
Here is a link showing what a radio with Silver Mica Disease sounds like: Silver Mica Disease
I do not rebuild these types of IF transformers (replacing silver substrate capacitor with a mica capacitor), therefore I generally do not repair these radios. Repair will be considered on a case by case basis.
If Silver Mica Disease is not present during a repair, the radio/tuner will not come with a guarantee. If Silver Mica Disease is present during service, there will be no repair charge.