RCA Test Oscillator, ca. 1929

[polyphase]

Here is a piece I picked up on the auction site a while back, thinking it might be a fun restoration project. That was not to be. All it needed was batteries.

It is an RCA Test Oscillator, model TMV-97-C, circa 1929. Range is 90 to 25,000 kHz with built in modulator. It is spot on accurate, but the numbers on the vernier are near microscopic, so a magnifier is needed (at least I need one).