View Full Version : Brought home a Projector today.


Eric H
01-08-2009, 09:49 PM
A Norelco Duo-View, I think this is a PA-2A model?

It's in good shape other than the finish which is almost totally gone, the chassis looks clean even though there was a lot of Mouse dung in the bottom of the cabinet.

I have no idea if the CRT is any good but the mirrors look nice and shiny.

I know this has about 25,000 volts of HV and can produce X-Rays, does anyone know if the rays are just at the face of the CRT or also at the HV rectifier tubes. I'm guessing it uses a tripler system like the Philco 48-2500?
The HV cage looks a lot like the Philco in fact.

ChuckA
01-09-2009, 07:39 AM
Eric,

That uses the Protelgram projection unit, I have the manuals on my web site:

http://www.myvintagetv.com/manuals_and_documents.htm

Don't lose any sleep over any x-rays, they are "soft" and the cabinet and projector case will block them.

I have one restored, but never modified a set to use it.
http://www.myvintagetv.com/norelco_pa2.htm


Chuck

jeyurkon
01-09-2009, 09:26 AM
1/r**2 helps a lot. Unless you're right next to the projector you should be o.k. The HV rectifier does produce x-rays as does the CRT.

As ChuckA said, they are soft x-rays ranging from a very low energy up to the 25KV max. However, most of them are of lower energy and will be stopped by the case. It won't stop the higher energy x-rays though.

The glass has enough high Z elements in it to reduce the higher energy x-rays. The HV rectifier, because it's construction will only let the x-rays exit in a directional pattern. I don't know how it's oriented, but likely in a direction where they'll be stopped by the chassis.

If you are working on the HV section with the cover off, then you should probably minimize your time there out of an abundance of caution.

John

Dan Starnes
01-09-2009, 06:37 PM
Pretty neat.
Dan

ChuckA
01-09-2009, 09:56 PM
Actually you can't work on a Protelgram HV box, it's sealed and oil filled. More than likely PCB laden too.

Chuck

jeyurkon
01-10-2009, 07:30 PM
Guess I should have looked at your documents first! :o

John