What's wrong with this Newvicon tube camera?

[Ben321]

I bought this small handheld Newvicon tube video camera from eBay, and it worked perfectly for the first few minutes it was on, and then it started to lose the red color channel, and now it has no red color output. Everything is a shade of blue, green, or cyan. I displayed this picture as a test picture (attachment called Test Image.png) on my computer monitor in Photoshop, and then captured it with the camera in question along with a USB video capture dongle. This is the resulting picture (attachment called Captured Image.png). As you can see, there's missing red in the picture. I was hoping here I might find someone familiar enough with imaging-tube based cameras, that they could maybe tell me what would cause the loss of a color channel. Other than that one problem, it works as expected.

[Ben321]

Does nobody know what is wrong with this camera, based on the description I gave and pictures I posted?

[jonpaul]

bad tube, or lose connection eg tube socket

j

[Beauregard42]

It may be a potentiometer inside the camera. This kind of tube used a color filter over the tube, with a WHITE-CYAN-GREEN pattern. They subtracted the cyan from the white to get the red channel, and the green from the cyan to get the blue channel. Open it up and check all the caps and pots.