On Sunday, March 29, 2020 at 8:49:05 AM UTC-4, celzey11 wrote: > > Hello all, just ended up winning an IV-26 clock, the kind with 12 tubes > for each digit. The one I got has very worn out tubes, and some segments > barely light, so I want to replace some or all of the tubes. But what type > of IV-26 tubes should I get? It seems like the difference is how the > segments in the tube are wired together. >
"It depends". Type 3 is for vertical-tube clocks (like the mini Elektronika) with the segments connected internally for that usage. Type 2 is used in some horizontal tube clocks, but not all. In particular, I've seen some of those clocks that have 9-pin tubes (with all 9 pins soldered) as if they were Type 1, but were actually wired as type 2 internally. Apparently efficiency was not particularly important under the Soviet system, as this required soldering 432 tube leads in total instead of 240. You need to look at the tubes and boards in your particular clock to see what it has and can accept. Since you have a 12-tube clock, you have one of the older units. The date code should be on the sticker on the outside back of the case, unless it was scraped off (apparently some had at least the serial number scratched out as the clocks "migrated" from their original locations). Changing the tubes on these is a bit of a PITA. First, the PCB material is old-style phenolic, not the FR94, etc. that you're likely used to. That means it is easy to lift the traces off the board when de-soldering the tubes. The boards were usually varnished AFTER the tubes were soldered, so be prepared for some noxious fumes as well. Plus, as I said above, it is 432 pins to solder. The foam holding everything in place will have degrated to a pink goo. All of this is covered in my blog entries on the clock, starting here: https://www.glaver.org/blog/?p=419 I think you already found that, as you emailed me. To answer your email, you could theoretically convert one of these to run on 120V. There are 2 coils on the input side of the power transformer, connected in series for 240V operation (so, 120V each). You'd remove the jumper between the coils and connect them in parallel for 120V. Be careful to maintain the same orientation (one of the 120V leads connected to the A side of each winding, the other 120V lead to the B side of each winding). In all of the clocks I've seen, the transformer was subjected to the same liberal dunking in varnish that the display boards got, and cutting through all of that to convert the clock would have ruined its originality, IMHO. I used an inexpensive 120 to 240 step-up transformer from Amazon as I describe here: https://www.glaver.org/blog/?p=310 If you do decide to go ahead with re-tubing the clock and you're in the US, you could send me an email as I am sitting on a large pile of Type 1 tubes for a project that never got off the ground. This would likely be cheaper / faster than ordering from overseas. -- 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 on the web, visit https://groups.google.com/d/msgid/neonixie-l/11381d81-b0b9-4c04-a3c5-d79aafe63842%40googlegroups.com.
