Make Your Own IF Transformers.

It's easier than you think?

Hardly a week goes by that I don't get an email asking "Where can I get 455 kc IF transformers for tube radios?" Although tubes, sockets, high voltage capacitors, and power transformers, are still being manufactured it seems that IF transformers are not. I usually suggest that they watch their local antique malls for an A M radio with a badly damaged plastic case, which has no antique value, and junk it out for the parts. I have found one site on the web where someone suggests that you wind your own. Even with my coil winding experience, that's a little more than I want to tackle right now. Maybe later.

I have thought about adapting transistor IF cans for use with tubes but I'm not sure they would stand the voltage. One day I was looking at an IF transformer I had removed from it's can and realized that a small RF choke might work. That led to a succession of home made transformers that worked well but vendors kept discontinuing the parts from which they were made.

I have yet to find a satisfactory solution. I was on a good trail with Hammond P-C70-A antenna coils but the procedure involves removing the small coil and unwinding 225 turns from the large one. Hammond has changed their manufacturing process from simply coating the outside of the coil with either coil dope or super glue to vacuum impregnation of the coils with the same substance. This makes the coil impossible to unwind without breaking the wire at some point. When this happens count is lost and a Q meter for accurately measuring inductance is required. I have one but few experimenters do and if you break the wire you are in deep do-do. I experienced at least two breaks in every coil I unwound.

I may end up winding coils after all. Meanwhile I'm going to keep looking to see if I can find another way. I wish it was as easy as I had initially thought.

I am getting close to winding coils. If you want to try it see the page by Harry Lythall - SM0VPO.


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This page last updated June 13, 2014.