Further, the strangest case I had to deal with was a correct voltage sweep at the monitor output but wrong voltage at the varactor: the issue was a leaking capacitor between the above voltage rail and ground, namely C406.
Antonio I8IOV > >[email protected] wrote: > >>The main questions on the lockup sweep is going to be: >> >>1) does it make it to / past the right frequency? >>2) how soon after it does get there, does it lock up? > >It crosses the right frequency a few times until lockup, in both directions. >According to my experience, typical lockup time for a healthy unit is 3.5min. > >>3) if it doesn't lock up, does it do something odd as it sweeps past the >right frequency? > >It may get stuck at either end of the sweep span. Normally the sweept voltage >(as available at the voltage monitor output) should vary between about 0.5V and >12.5V and vice-versa. If it reaches 0V or about 14V then one of the voltage >comparator circuits failed, and the unit gets stuck. 0.5V and 12.5V are preset >thresholds for the voltage comparators. I happened to come across both cases, >and the failing components were 100K resistors. > >Antonio I8IOV _______________________________________________ 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.
