Driving an old electrostatic CRT with modern electronics? - Videokarma.org TV - Video

dr.ido · #1 06-17-2006, 01:01 AM

Yesterday I was given an orphan 7" round CRT. It came out of an old automotive scope.

I was thinking about building something around it. I assume this CRT has a long persistance green phosphor so a computer monitor would be a better idea than a TV. Maybe an old Mac SE in a case styled after a 1940s style TV.

Is it possible to adapt a modern chassis to drive this CRT or would an old scope be a better starting point?

Pictures of the CRT to follow, I'm not at my usual PC at the moment.

vintagecollect · #2 06-17-2006, 02:10 AM

Let us know your results, I'm surprised no AKer's mentioned experimening with pic tubes.

larschr · #3 06-17-2006, 01:50 PM

I have an old true dual beam Philips scope tube, but i have given ut trying to get some kind of picture on it. I do not have suitable power supplies to do it, and the main problem is of course the 3kV 2nd anode voltage. I have also tried to test some old indicator/"magic eye" tubes, but again the only power supplies i have that may give suitable voltages are so powerful that a short circuit would be like a small explosion, and i would need rectifyers and probably some smoothing caps. If i understand right, there is one pin to "light" the beam and another one to control it? Does someone have a simple circuit to test a 6U5 indicator tube?

Chad Hauris · #4 06-17-2006, 02:00 PM

A 6U5, etc. tube does not need real high voltage...they are usually used at around 200-300 volt plate voltage in radios.

Here is a web page with more about the eye tube:

http://antiqueradio.org/magiceye.htm

wiseguy · #5 06-17-2006, 05:05 PM

CRT's are fun to play with and experiment with..!!
I am not sure if i am allowed to post this,but it is from a previous post on pioneer speakers repairs..look at my thread below.
http://audiokarma.org/forums/showthr...t=72637&page=2

dtuomi · #6 06-17-2006, 07:05 PM

Wow, I'm really envious of the clock. I'd love to have one of those.

David

Keefla · #7 06-17-2006, 07:40 PM

Quote:

Originally Posted by dtuomi

Wow, I'm really envious of the clock. I'd love to have one of those.

David

Did you buy it as a kit or a 1 off? if a kit id like to get my grubby mits on one!

wiseguy · #8 06-18-2006, 07:16 AM

I purchased just the bare board and his eeprom,everything else i added..(capacitors/resistors,my own CRT,and my own cabinet)..
you cant buy them any more,but someone in germany has bare boards
for sale using their own design and eeprom.
.. another one i built shown in the pictures below..(the admiral bakelite cabinet was hard to photograph)
this set is using the same type of driver board,but without the HV multiplier,it is driving a 7JP1 crt..since 7JP4's are kinda hard to find.. it is a perfect functioning set.the set is complete w/it's working original chassis.all you do is unplug the CRT socket and re-attach the admiral chassis socket..ERIC H should like this one since it is a 7" admiral set..LOL
the board is epoxied to the inside top of the cabinet..it has been running on the same CRT for over 4 yrs now non-stop..

dr.ido · #9 06-19-2006, 05:02 AM

I've seen some of those scope clocks on other web sites before. They're cool, especially the one built into the Admiral TV.

I'd like to do something different though. Another thought I had today... A vector based video game, perhaps based on a Vectrex (thougth they aren't exactly easy to find).

Still I'm not in a hurry with this so I'm sure I'll come up with something eventually.

I have noticed that there is no part number on the CRT so that might slow things down a bit. Do these CRTs have a standard pinout?