Keep in mind that potentiometer R6 is one of the key components of the C-field circuit. Together with R8 and R12, it defines the reference voltage to Q6A/B. The tempco of that wire-wound potentiometer can certainly not be neglected.
I would suggest to check the C-field temperature dependency with an external precision current source feeding the C-coil directly. Adrian Poul-Henning Kamp schrieb: > Using the Fluke 732A as voltage reference improved HP5065A stability, > but not very much, so I looked closer at the constant-current > generator and the C-field pots "calibration": > > http://phk.freebsd.dk/hacks/HP5065A/20150828_c_pot/index.html > > ... and found out that the current-sensing resistors R10||R11 have > a very high temp-co. > > Getting closer... > _______________________________________________ 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.
