Ulf I suspect we are the same "Get it done". Not a science project. Though science comes into it. I just find the various new devices may be more easily obtained. L&Cs are getting hard to come by. So far I don't have failed FETs or anything else. But that day will come. Regards Paul
On Wed, Aug 26, 2020 at 3:14 AM Ulf Kylenfall via time-nuts < [email protected]> wrote: > Paul, > > A 60 MHz xtal oscillator divided by 12 and comparedwith the incoming 5 > MHz. Then there is this thing > how to acheive a good symmetrical FM injecting > the 137 Hz signal without affecting the loop filterparameters. > > Keeping the original design with modern typesof semiconductors is less > work/effort, provided that the > unit keeps working... > The A7 original design used a non selective2nd harmonic detector. And uA > 709's.That one was easy to motivate an upgrade. > > I am a bit lazy otherwise. > > As mentioned, the semiconductors that have failed > in A3 were all dated 1968. > At the time without knowing the exact types of the JFET'sI replaced them > with 2N4416 only to discoverthat that was the type HP specified in a > laterrevision of the A3. > Best Regards > Ulf Kylenfall > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
