But wasn't it powered with Greek fire?
What transformer are you using?
That's terrific! Well done!
Seems to me it's an electromagnetic speaker, the listening device in many old style telephones. They work by superposing the AC field to a permanent magnet's field., which produces the variable force to a magnetic membrane.
They are not designed to be used as microphones, but still manage to produce some sound.
That would indicate a non-working carbon mic to me. All those I have used indicated something, quite variable, depending on position.
Yup indeed, the membrane is magnetic, it seems to be a "rattling in a sort of controlled way" device.
Yup, I know, but people hook these up to phantom power, and that makes no sense...
Two working units gave me an OL readout on my Fluke when trying to measure resistance, could be that the corroded contacts are hard to probe and get a good reading of.
Known as a 'receiver' in the US. This one looks like a 1950s-1960s era Ericsson maybe? The interesting thing is that diaphragm has to be spaced away from the magnet correctly or it will stick and won't vibrate. Very much like a LDC.
It's from an old "Dutch phone company " phone, late 50's could be right, bakelite horn, cottonwrapped wire.
