Dave will guess you are sub sampling the 10 Mhz ref. Yes it should be 4.7K. Not sure why but old military gear resistors were like that. Circa 1942 at least in schematics I have seen. Regards Paul WB8TSL
On Sun, Jun 25, 2017 at 2:25 PM, David C. Partridge < [email protected]> wrote: > Yes, does indeed look like it should be 4K7! > > -----Original Message----- > From: time-nuts [mailto:[email protected]] On Behalf Of David C. > Partridge > Sent: 25 June 2017 18:50 > To: 'Discussion of precise time and frequency measurement' > Subject: [time-nuts] Tracor 527A and 10MHz reference input > > A friend says his Tracor 527A works fine with a 10MHz Ref input even > though it doesn't have the divide by 2 circuit from the addendum to the > 527E manual applied. > > I'm puzzled by this - I can't quite see how the reference input circuit > can produce a 5MHz output when fed with 10MHz (unless his reference source > has a large 5MHz sub-harmonic). > > Am I missing something here? > > On a related note, the schematic for the divide by 2 circuit in the front > of the 527E manual shows a 4R7 resistor from the base of the 2N3904 to > ground - this just feels all wrong!! Has anyone built this and did they > change the resistor to (e.g. 47R or 4K7)? > > Thanks > Dave > > > > > _______________________________________________ > 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. > > _______________________________________________ > 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. > _______________________________________________ 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.
