What kind of tube is this

[lawbadman]

Hi,
I found two of these tubes some time ago. I cant find any information on it so I have no idea what it is good for.
Does anyone know how to use this tube and what it does?



Thanks
Lawrence

[lawbadman]

Here is another angle, if it helps.

[Giaime]

If I read correct, the name is CEA95. My tube database doesn't known it...

Btw the plate structure looks strange... It might be a triode, but I think for special purposes.

[Shoog]

Is it some kind of magic eye tube, with the big plate been the display screen.

Shoog

[Colt45]

by the looks of the structure, I'd say it is a <i forget the name>

it is sensitive to light, sort of like a photo-diode, but in tube format..
there is no heater, and the plate has some sort of mildy radioactive substance on it (like cesium? i forget)




for use of transmitting a signal via visible light, like the audio track on a old film.

I think I've got a similar tube from tim..

[PeteM]

I'ts a photodiode

I worked at a factory that made silicon photodiodes vacuum multipliers and CRT's amongst other things like neutron detectors and Boron isotopes.

I cant' help with specs but remember seeing one of these in the lab for calbration purpose.

Pete

[Alastair E]

Used to use these in old cinema projectors!--Machines like Kalee with B.A.F Soundheads and Westar machines.

Biassed at around 90v, the film audio track was projected through a slit and optics to the selenium coated cathode which then emitted electrons depending on light intensity

Used to go noisy, microphonic and all sorts, Just an ornament these days!

[Brian Beck]

The specs are on page 3 of:

http://www.ccscomm.ca/PDF%20Files/rel_anal_lab.pdf

[Sch3mat1c]

Yup what Colt said, the word is phototube. The cathode is coated with cesium which has a lot "work potential", basically electrons are more prone to being bumped out by light rays. Add 300V and you get a few micro to miliamperes plate current depending on intensity. I think response drops off around 10-20kHz typically.

Tim

[lawbadman]

Thanks a bunch Guys.

Now that I know what it is I really dont have any use for it. Anyone have any ideas?
I may just end up selling them anyway, if they are worth anything.




thanks
Lawrence