Yes, they do show up... but usually for big-ish bucks. I want to build a small affordable replacement that anybody with a 531xx can have.
My design is currently leaning towards a board with the clock generator and a 5V reference for the gain calibration (they spec 5V +/- 1mV). I was going to use a couple of 2P4T slide switches to route open circuit, 5V, normal clock, and inverted clock to the two output connectors. I think the cost to build would be in the $20 range and fit on a 2x2" or so circuit board... certainly more attractive than a $500 big ancient box with unobtainium parts in it. The board should be able to perform all the calibration steps for the counter. I don't think the signal requirements are super critical. They are using 1:2 splitters and splitter/180 degree phase shifters and relays to generate the output signals passively from the inputs. I think a digital clock generator would be a LOT more accurate than those phase shifters. ---------------- > Actually, you can get J06 HP-59992A calibrators on eBay. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
