Old Radio from Crystal Research?

Question

I just came across an old radio.
It’s called Metronoma from Crystal Research Laboratories, Inc
The Model # is MP-100-PA.
It has 1 tube inside (like the old TV’s had) 2 wire’s going to something that look like a speaker. I don’t know old the radio is, but looking at the inside I would say it goes back some years. If anyone has some information about this radio please let me know.

Answer 1

I have one of these. It's not a radio. It's an early electronic metronome used by musicians. The single tube is a 2D21 thyratron that sends timed pulses to the electromechanical "knocker" on the back panel.(that's what looks like a speaker). There's a knurled knob on the back that varies the spacing between the sheet of balsa wood in the knocker and the electromagnet, giving a sort of volume control. The dial on the front is calibrated in beats per minute. There's also a small neon lamp on the front panel that flashes with every beat. These are collectible and quite rare. They were introduced in the late forties and still made as late as 1970. It sold for 20 bucks when new. I've seen 'em go for as high as $175.00 now.

Answer 2

google this

metronoma crystal research

6 pages of hits