Watching through the video, I can see where I misspoke. I said that the most significant digit is either a 1 or a zero, with a plus or minus. Not true; the leftmost Nixie is only plus or minus. A zero is implied, and a “1” in the most significant digit is actually indicated by the “over range” annunciator on the right side of the display window. Sorry about this mistake.
I love older HP test equipment, their engineers did amazing things with the available technology. Looking forward to part 2! Try plastic razor blades, combined with holders they make the perfect tool for removing the sticky stuff even on front panels. Little risk of damaging any surface. Regards, David
The Nixie driver modules are interesting in themselves, they use four pairs of neon lamps driven by discrete transistor flip flops. Each pair corresponds to A, B, C and D lines in BCD code; one lamp is straight signal and the other one is inverted. They illuminate photoresistors on a ceramic plate, connected in a branched circuit decoding BCD into one-of-10 driving the cathodes. The whole board is a discrete transistor counter with carry-out, so they're daisy chained.
@@t1d100 not repaired yet, but getting close. Those defective caps are due to arrive today, then I’ll know if there are other issues. Video coming soon!
Watching through the video, I can see where I misspoke. I said that the most significant digit is either a 1 or a zero, with a plus or minus. Not true; the leftmost Nixie is only plus or minus. A zero is implied, and a “1” in the most significant digit is actually indicated by the “over range” annunciator on the right side of the display window. Sorry about this mistake.
I love older HP test equipment, their engineers did amazing things with the available technology. Looking forward to part 2! Try plastic razor blades, combined with holders they make the perfect tool for removing the sticky stuff even on front panels. Little risk of damaging any surface. Regards, David
Built at a time when America was at it's Best! Just Beautiful .....
Ładny miernik i magia lamp. Pozdrawiam
👍👍👍👍👍
The Nixie driver modules are interesting in themselves, they use four pairs of neon lamps driven by discrete transistor flip flops. Each pair corresponds to A, B, C and D lines in BCD code; one lamp is straight signal and the other one is inverted. They illuminate photoresistors on a ceramic plate, connected in a branched circuit decoding BCD into one-of-10 driving the cathodes.
The whole board is a discrete transistor counter with carry-out, so they're daisy chained.
I am sure that you have it repaired, by now. But, for fun, my guess is a cap associated with the chopper.
@@t1d100 not repaired yet, but getting close. Those defective caps are due to arrive today, then I’ll know if there are other issues. Video coming soon!