I have a 5061A that appears to be working correctly except there is no 2nd Harmonic indication. In addition, on the A7 assembly, there is no sine wave out on J2. When looking at the cable from the tube to J1, there is no sine wave there either. However, the Beam I indication is appropriate and I have been through the alignment of the Harmonic generator assembly, the electron multiplier to match the voltage on the tube (which is a high performance tube), the C-Field adjustment, and the modulation frequency adjustment. I have also swapped the A7 assemblies and the A3 assembly with known good units. All to no avail.
The Beam I moves down with Mod On which implies the tube is being modulated. The 2nd Harmonic indication moves when you turn the Loop Gain pot up and down but no steady indication of 2nd Harmonic. I have compared measurements from a working 5061A with the problem child and the findings on the A7 assembly seem to be the only notable differences. I can't think of an explanation for why there would be Beam I but no 2nd Harmonic given the above findings. Anyone with any ideas. Thanks in advance. Joe _______________________________________________ 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.