[Milsurplus] Old Radio Coil

[J. Forster]

With all this talk of old radios, I have a mystery coil that I've never
identified. Maybe somebody recognises it.

I can't post a pic because it is not accessible to me at the moment.

I bought the coil as a kid, probably between 1955 and 1960 in an
electronics surplus store, so it is probably Mil. It's certainly built
that way.

The coil is an air core, single layer, solenoid, wound with Litz wire (I
think). The form is brown Bakelite, about 4" OD and 12" long. The winding
extends the full lengthy of the coil continuously, except for gaps at both
ends, about 3/4" wide.

The unusual thing is that it has, mounted to and stood off from the form,
a Bakelite strip about 1/4" thick and 1" wide with plug prongs at regular
intervals of about 1/2". The plug prongs are like the pins on a 5,6, or 7
pin pre-war tube. These pins are connected to the coil and are taps. I'd
GUESS the coil has several hundred turns, tapped perhaps every twenty.

It looks like it is a plug-in coil for some transmitter or receiver.

The entire coil is heavily varnished.

I must confess, in my teens, I used the thing as the secondary for a
spark-excited Tesla Coil.

Since I bought it in Montreal, it may well be something RCAF rather than US.

Any ideas?

Best,

-John

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