Hand machined mechanical pencils

TV CRT tube socket (02/11/11)

I have a pile of bare television CRT tube stems with pumpout tubes, and I needed a connector for them. You'd think a connector/socket for such a common application would be available, but I couldn't find anything, not even the pinout dimensions. I did pull a socket out an old TV but it was very "stiff" and there was a risk of stressing the pins with repeated use. So I made up a little socket using Nixie tube pins from Kosbo.

Here is a "proper" socket, pulled from a TV:


To measure the pin layout, I pressed the pins into a bit of plasticine and then scanned it along with some 5mm squared graph paper. After a bit of scaling and rotating in Photoshop, I was able to measure the pin positions. As far as I can make out, the pins are on a 15.3mm diameter pitch circle. There are 14 positions around the full circle, but positions 2, 3, 12, 13, 14 are missed out. Here are pictures of the completed PCB:

Measuring the pin positions

PCB artwork

It's a bit fiddly to align with the pins, but it provides a nice gentle connection.