Well, I believed to be answering questions from the original poster, not to questions that indeed are troubleshotting advices. Sorry.... Antonio > >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 > >> >>li...@rtty.us 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 3.5 min. >> >>>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 -- time-nuts@febo.com >To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >and follow the instructions there. >
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