Explainette record player / projector

[radiotvnut]

Here's an Explainette "30-50" filmstrip projector / record player that looks to be from the late '40's. I think these were used by schools and salesmen in order to view filmstrip's and for listening to the audio soundtrack that came with said film. During my school years, we still used filmstrip's; but, the soundtrack was usually on cassette.

The amp uses 3-tubes (12AT7, 12AU7, and 50B5, along with a selenium rectifier). The cartridge is a near-dead flat metal crystal ten pound tracking model with a "nail" needle. The turntable is direct driven and is currently running at 33 1/3 rpm. I don't know if this unit will run at 78 rpm; but, if it will, I can't find how to change the speed.

One interesting thing I discovered is that the unit will hold a 16" transcription record.

As far as the projector portion, the bulb is burned out; but, I'm not too worried about that at this time. I don't even know if a bulb is still available for this unit; and, even if it is, it's probably expensive.

This unit was made by Operadio and I think they later made the Dukane brand of projectors.

Here's a video I made of the unit:
http://www.youtube.com/watch?v=nw5TTyr3Yjg

[Jon A.]

That must be quite rare, I have never seen anything like it. Oldest projectors used during my school years were those old (16mm?) Bell & Howell units.

Any idea what kind of cartridge would be a suitable replacement? Also, what kind of bulb does it take? Perhaps there's a more modern replacement. I did an internship at a film co-op where there is a whole bunch of old projectors and cameras, and there was a bulb cataloging project going on at one point. One thing's for sure, that selenium has got to go.

[dieseljeep]

Originally Posted by KV-1926R

That must be quite rare, I have never seen anything like it. Oldest projectors used during my school years were those old (16mm?) Bell & Howell units.

Any idea what kind of cartridge would be a suitable replacement? Also, what kind of bulb does it take? Perhaps there's a more modern replacement. I did an internship at a film co-op where there is a whole bunch of old projectors and cameras, and there was a bulb cataloging project going on at one point. One thing's for sure, that selenium has got to go.

I'm surprised they didn't use a 35W4 rectifier! They wouldn't have needed as large of a heater dropping resistor. Also, why the extra dual triode, unless it's used as a solenoid driver, to advance the film strip.

[KentTeffeteller]

I bet the dual triode is definitely used as the solenoid driver. I estimate this as a late 1940's era unit. Operadio later if I recall became Dukane who was best known for Intercom and PA equipment.