Vintage Audio Equipment Interstage transformer with 4 windings

Removed from vintage Broadcast industry audio equipment

Absolutely no identity markings anywhere, just hand written numbers indicating the pin numbering.

Octal solder tabs, basic DC test results are below.

Rectangular metal (tin) sealed no connection to any pin

This is not lightweight, 400 grams. I would assume from this weight that this is an iron core based transformer, completely filled with epoxy or a heavy wax type substance (used in a couple - see those descriptions for details)

Without destroying the transformer we will never know, even the tin casing is solder sealed around the edges - this was made to be closed and stay closed.

Measures 45mm wide x 63mm long x 60mm high

Pin 1 & 3 116 Ohms

Pin 2 & 4 116 Ohms

Centre pin - this is the transformer electrostatic shield connection

Pin 5 & 7 514 Ohms

Pin 6 & 8 514 Ohms

Although crude, I then used the meter capacitance measuring function and clearly and repeatedly measured 40pF between ANY 2 windings - this value is allowing for the test lead capacitance.

Removed from some vintage audio equipment, interstage coupling

From the above RESISTANCE measurements (not impedance) all windings are isolated from each other (no taps) and there are 2 windings of a much lower resistance to the other 2 windings.

Without setting up the required equipment I cannot give information about the impedance of these windings at different audio frequencies - that is the joy of electronics, to experiment and discover.