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Old video camera CRT eyepiece

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Paul Saulnier

New Member
I was curious about the eyepiece of an old video camera I have from 1991, and when I took it apart, I was surprised to find a mini black & white cathode-ray tube in the eyepiece complete with a warning indicating not to open the case.

Inside the eyepiece component case, there is the CRT, as well as a circuit board. The board is connected by four wires (3 brown, 1 yellow) to the rest of the video camera. Various numbers appear, but no idenifying markings appear otherwise. The camera is a Hitachi E22A.

Do you think it might be possible to use this eyepiece CRT as a screen for something? Could I simply somehow connect power and a video signal to the four wires and get an output?

Thanks
 

Paul Saulnier

New Member
I actually figured out some new information.

The middle two wires can accept video information from an RCA jack wire. The two end wires must be the actual power?
 

Nigel Goodwin

Super Moderator
Most Helpful Member
As you have already discovered, it's just a simple CRT monitor, it would be best to leave it connected up while you measure which leads are power, and which are signal.
 

Sebi

Active Member
I always started to find the relative big electrolytic capacitor on power input rail. It show also the polarity.
 

Paul Saulnier

New Member
Using a voltmeter, I have found some more information

I have attached a picture detailing the information I found. I hope it makes sense to you.

Perhaps you can give me an indication of which pins should be connected to what. I determine the video input pinholes by simplying connecting the video input wires to the holes while the camcorder is on, and powering the display on its own.
 

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963Exp

New Member
Hi,
I actually have a couple of these (not same brand) that I've put together for looking at security cameras as I set them up. They come in real handy for seeing what the camera is looking at at the same time your adjusting it. I also rigged one to an old helmet that goes to the reciever from video off an R/C car. Sort of a poor mans heads up display.

My experiance on these is just this -
I look for the shielded set of wires which usually equate to "video in". Then I try to establish ground by looking at the PC board, or merely "Ohming" it out. Then to find V+, I merely go through each of the remaining wires while I've got ground (V-) hooked up, when I see it light up, then I know I've got the correct one.

Here's a couple of things that you might find -
Occasionaly you'll find one that has an LED in there that was designed to light up in the record mode. Occasionally you'll find other LEDs as well, and once I found one that had an additional input that provided some "burned in" on screen graphics. Odds are, that depending upon how old this unit is, you probably have some LEDs in there that would account for the additional wires.

Hope this helps!

Kel
 

Paul Saulnier

New Member
What do you mean by ohming it up?

The CRT piece is very small. It only has four wires as shown in my diagram above, and there's no LEDs or anything, just the cathode ray tube itself, and a small circuit board which likely controls the CRT.
 
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