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SILVER MICA MIGRATION IN US 1948 - 1964 RADIOS

Many of the radios that are sent to us that were manufactured between 1948 to 1964 have a problem with their Intermediate Frequency transformers (IF Transformers) that make them VERY expensive to repair.

The symptoms of these bad IF cans is a radio that has continuous snaps, crackle, pops and volume that varies without touching the radio. Industry wide, these cans were used by almost all the radio manufacturers in the 1948 - 1964 period because they were compact and cheap. Typically, the standard AM radio has two of these IF cans and an AM/FM radio may have up to four.

These IF transformers can be seen in the following photograph -

 

These IF "cans" shown in the photo consist of a coil (inductor) and cheaply made mica sheet capacitors. Here is a photo of one taken apart -

And, here is a photo of the defective Mica sheet capacitor that is found in that IF transformer-

In order to fix this, the IF transformer must be removed from all its connections within the chassis, and the Mica capacitors removed from the IF transformer and substitute capacitors mounted underneath the IF transformer once the IF Transformer is placed back into the chassis. Just the removal of the Can and disassembly of the IF transformer is a time consuming and tricky process.

Here is a photo of an IF transformer placed back into a chassis with the now outboard capacitors installed and circled.

A more detailed discussion of the steps involved in the repair of these transformers can be found here - Silver Mica Migration.

WHAT THIS MEANS FOR YOUR RADIO REPAIR BILL

If we receive a radio for repair and we discover that the radio has the above Mica (IF Transformer) problems, we will notify you that we have found one or more of these defective IF transformer/capacitors in your radio.

This notification typically occurs after we have started to work on your radio, because the radio must power up and produce sound for us to detect that the problems exists. That means we have already expended some labor and parts (generally) on your radio. We try to diagnose this problem at the earliest possible moment, so as to not incur too many charges prior to notifying you of the existence of this problem.

WE MAY OR MAY NOT ELECT TO REPAIR YOUR RADIO

At this point we may elect to continue with repair of your radio, or not. Whether we proceed is dependent on our ability to find back-up IF transformers which we may need in repair of this problem. This is obviously model dependent. We will either notify you that we have elected to not proceed or give you a cost as explained below.

COST TO REPAIR

The cost to repair these IF transformers, besides any other problems with your radio, are in the neighborhood of $55.00-$85.00 per IF transformer. If you have two (AM radio) then this will be an additional $110.00-$170.00  on top of any other repairs required to render the radio operable. If it is an AM/FM radio then up to four IF transformers must be repaired for an additional cost of  $220.00-$340.00. This may make repair of your radio unreasonable ( in your mind).

OPTIONS

At this point, you have two choices:

1. Authorize us to go ahead and finish the repair of the radio which will include the cost of pulling the IF transformers and replacing the MICA capacitors, or,

2. Tell us to halt with any further work and send a final bill.

If you select (2.), we will prepare a final bill reflecting the deposit given when you sent us the radio. If additional money is owed because of repairs done to the radio, we will discount that 40% for the final amount. If you want the radio returned, the shipping charges will be added to the bill (but not discounted).

We are seeing more and more radios of this vintage with this problem. They are typically the less expensive table models, but those "cheapie" IF transformers also show up in much more expensive radios.

Radio Repair Guy