Member Since: October 3, 2012

Country: United States

  • Yes, that is correct, I get a periodic blink (and a serially transmitted 0 or 1) every 750ms (and about 20-30 additional, but non-periodic events a minute). I do get counts from radioactive sources (ye olde school anti static brush) but there is presumably the approximately 80 cpm offset. I’ll scope in as far as I can and get back to you, but I don’t have a 50x or 100x probe.

  • Mine has the same 750 ms tick as well, however mine registers a count with each faint tick. Adding capacitance to (pinching) C4 seems to decrease the frequency. Adding a bypass resistance (light finger touch) across R14 seems to decrease the sensitivity enough to eliminate the 750ms periodic trigger (despite the audible noise remaining). Thoughts? Am I seeing a non radiation induced (ie over voltage) dielectric breakdown in the tube? Is that tick the capacitors' dielectrics talking or a breakdown occurring? I guess I will add an adjustable R14 bypass and adjust the sensitivity just below it picking up the tick (not my favorite fix though).

No public wish lists :(