I would advise being very cautious regarding the tightness of the fit of the tube pins into ANY socket! Certain sockets are so tight that they tend to put a side-loading spreading force on the tube pins enough that in extreme cases the glass tube base will crack. My standard procedure now for any such socket for tubes such as NL6844A and 8422 is to use a tapered aluminum soldering probe to wallow out each socket pin to a much looser fit on each tube pin. If you go too far and open the socket fork too much, you can reach in there using a pointed exacto blade and add back some tension. Sockets adjusted that way give the tube a very easy and buttery feel going in and coming out of the socket, yet they retain good contact. Those russian socket pin forks are some real doozers last time I checked. As I recall they are massive thick things with practically go give at all. My impression of them is they will destroy a tube in a New York minute! My advice is STAY AWAY from those russian sockets by all means. Get the good USA made green ones and carefully open them up for a nice fit. Your tubes will then not break.
On Wednesday, December 17, 2025 at 10:40:22 AM UTC-5 Tom Katt wrote: > I may have answered my own question - of all places, Sphere Research's old > archived website has this to say about IN12 sockets for sale: > > *12+2 Pin Russian mil spec oval sockets, part number PL31a-p, designed for > the Russian IN-12 Nixie, but also fit most oval pattern Burroughs and > National numeric tubes, like the 8422, B-5991, B-59917A, KS-19944L1, etc. > Sockets are marked with pin numbers (same format at the US tubes), solder > tag contacts and have a molded in 2-hole mounting flange. The two center > pins are simply clearance holes (pins 13 and 14), as they are unused on the > IN-12, and rarely used on other tubes of this mechanical format. Slightly > snugger fit than US sockets, but work great on both types of tubes.* > > > *[image: IN12.jpg]* > > Sphere continues to be an asset even after they're gone ;-) > -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion, visit https://groups.google.com/d/msgid/neonixie-l/55353195-bfad-47dd-8f6c-e018c79d4ffan%40googlegroups.com.
