James and Brooke, Thanks for the informative replies. I have done pretty much what you suggested. The result is a nice sloped line in the positive direction, indicating that the FRK-L Rb source is running fast at a rate of about 1e-9.
I checked the lamp and crystal osc monitors and both are within spec. The crystal mon was 5V (2-16V is the suggested range), so I adjusted it up to 10V with the range adjust trimmer. I don't know if an FRK-L running for 13 years is expected to be 1E-9 high in frequency or if the unit could use some maintenance. The suggested drift of 1e-11 per month would add up to 1.5 e-9 over 13 years, so it may well be within spec and need some C-field adjustment. Unfortunately, when it was mounted in its box, the C-field adjust hole was covered up. I'll need to power it down and do some disassembly and drilling to make that adjustment accessible. Suggestions? Comments? _______________________________________________ time-nuts mailing list [email protected] https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
