The Zeeman frequency is calculated by the amount of C-field current you use.
If you change the Zeeman then to get the unit "on frequency" you then have to change the synthesizer frequency and the C-field current to compensate. The amount of C-field change is too big for the front panel knobpot so a resistor change on the A15 board is required. The earlier 5061A current (61miiliGauss) resulted in a synthesizer frequency of 12.6317716 Mhz giving a corresponding Zeeman frequency of 48.82Khz. On later 5061A and B units HP decided that using a different current (76 milliGauss) that was more stable which ended up giving you 12.7317725Mhz and 53.53Khz. There is NO difference in the tubes C-field winding (for 5061A/B and 5071A). The current set resistor on the A15 board and the synthesizer frequency are the only change. Corby Dawson ____________________________________________________________ Learn about VA loan programs and benefits. Click now. http://thirdpartyoffers.juno.com/TGL2141/fc/Ioyw6i3m3mWguucezHInyDvTMZqPNuZVtJ2PrIg6iEz3xSv6sf8Syt/ _______________________________________________ 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.