curiousmarc
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Pulser Perfect
🕑 Added 2020-06-28 04:27:37 +0000 UTCThis is a little epilogue to the HP 8082A pulser repair. I swapped the second circuit in, with the faster transistors, and it indeed produces narrower minimum width pulses, with the required 1 ns rise time. But at the minimum pulse width, the non-delayed pulse was still fatter than the delayed one by about 1 ns. Reading the service manual, I discovered there is a factory selected resistor to balance the two pulses, I suppose to adjust for how each U2 IC came out. Mine was 5.11k, middle of the range. I paralleled 3.3k on it (see pic while I was temporary testing it), and that did it. This is the new "CuriousMarc factory adjustment" for my repaired circuit. Now my two pulses are the same width, and go down to 2ns at the shortest setting, as intended.
Comments
Is that RF black magic approved, being that tall? ;)
