Producing a cheap nixie tube socket from D-Sub connector.

[`]

The original Bakelite vacuum tube sockets for a lot of nixie tubes like IV-18 are only really available as pulls from old military gear and are getting increasingly expensive. There's a solution mentioned as a comment Mike's electric stuff that you can use the pressed metal inserts from PCB mount female DB9 connectors as a cheap replacement, I thought I'd give this a try.



The pins are extremely easy to remove from the connector by drilling out the retaining rivet, they appear to be gold plated.



A quick board (circular-layout.ulp) to test how the sockets fit, leaving the drills pretty slack to take into account the amount of variety in the tube bases. I had originally intended to bed the pins down to the middle collar but decided using them at their full length would allow for more flexibility.




The center drill will be reduced when used for real, it's not necessary for this particular tube but the pip length varies enough that it's necessary to prevent fouling. These particular tubes contain mercury giver pellets which would be unfortunate to break.Not having any routing space in the middle makes layouts with a lot of tubes extremely challenging, I've found it best to avoid that if at all possible.



The only way to reasonably solder these in was to have a tube inserted in the socket during assembly, for a final build up I'll have to be extremely careful to have the splits in the pins around the same way, it looks a little messy otherwise and these pins will be a visible part of the product. There's enough slop in this setup that even my most bent tube looks completely normal when seated in this board.


In all a significantly better solution than I was imagining it to be, total cost was tens of cents per socket.

[T3sl4co1l]

If you don't want to (or don't have) D-sub connectors to pillage, you can get Mill-Max PC mount pins.  They're rather expensive, but the result is still cheaper than buying NOS sockets.

Tim

[Paul Moir]

I wonder if you could make a pin holding jig out of spare PCB space?  Even one layer would help, or you could stack up a few layers.

[`]

I wonder if you could make a pin holding jig out of spare PCB space?  Even one layer would help, or you could stack up a few layers.

Definitely scope for that, I found that using the tube was enough for my purposes though. The pin inserts have such a low thermal capacity that there's no chance of it doing any damage to the dumet seals of the tube. If I was making a significant number of these I would probably make a jig that has rising male pins which are populated with the inserts and then the PCB is slid over the top for soldering.