My 2nd G7 giving me grief (hum)

I have built 2 PSUs and two G7s. I am having some trouble getting my second G7 up and running. I have fully assembled the mic and all I get is hum. If I tap the mic body with my finger I can hear the tapping sound on the output of a working mic pre(tube microphonics). I have verified that the first PSU is good with the first mic, clean and clear.

The boards are home etched. I have cleaned and scrubbed the PCBs with flux remover. I used water soluble flux on both mics. The PCB substrate may be different on this 2nd mic. I'll check that later.

The first mic worked without too much trouble. The second one has stumped me. I have tried both PSUs with the 2nd mic with the same outcome.

Here are my readings:

5.93 v heater, .21 mA draw
181.2 V plate, undetectable current

I have tried several (4) EF86s and two different capsules, all with the same hum. I have searched the forum for threads on the G7 here and don't know what else to do.

any ideas?


Vetsen

assuming you get no signal at all, trace the signal, check connections of the transformer (lundahl?) measure continuity of the lundahl output to pins 2&3 of the xlr, and housing of the mic to pin1.