Before I reply, I want to add that I used to have a five decade HP decimal counter with *incandescent* light bulbs instead of neon lamps. I assume it was a last generation model before they switched to those new-fangled Nixie things. I got it at the end of the day at the Manassas hamfest circa 1995. One numeral was out and the culprit was a bad transistor. IIRC, it was in a TO-5 can and a 2N3904 fixed the problem.
Unfortunately, it mysteriously disappeared after a small flood in the basement. I wasn't home at the time and there was a major clean-up during my absence. The funny thing is that nothing else was missing. It was stacked in the middle a small pile of gear all of which was still there but rearranged. The upshot to all of this is that I would REALLY like to have another one but the few that have turned up on eBay recently were/are too rich for my blood or got snagged by some other bargain hunter before I had a chance. > On Jun 2, 2020, at 2:43 PM, Dekatron42 <[email protected] > <mailto:[email protected]>> wrote: > > There is at least a manual for the 705A and 705AZ modules here: > http://www.bunkerofdoom.com/ <http://www.bunkerofdoom.com/> serach for > Beckman and you'll find the 5500 EPUT meter where there is a schematic and > explanation of the whole unit. Thank you for that. I have a 705B (with tubes) sitting next to my computer. > These units are similar to the Hewlett Packard HP-4A series of modules, I'm > not sure if they are pin compatible and would work if you swapped them for > each other, but the design is very similar. Searching for those right now... Terry Bowman, KA4HJH "The Mac Doctor" https://www.astarcloseup.com/ “The book said something astonishing, a very big thought. It said that the stars were suns, only very far away. The Sun was a star, but close up.”—Carl Sagan, Cosmos, 1980 -- 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/CDE6FC37-2B57-460C-B223-3A10BF613DB6%40gmail.com.
