[Milsurplus] ARN-7 I-81-A question

[jmfranke]

I am trying to use a I-81-A indication from an ARN-7 receiver.  I know the indicator snychro operates from 400 Hz, but I do not know the rotor excitation voltage.  According to the schematic I have, the rotor voltage comes from the main power transformer pins 9 and 11 through resistor R74B.  So, I would like to have the transformer voltages and the value of R74B and/or the terminal voltages on pins 2 and 4 of the indicator which I believe correspond to pins C and Q of plug PL-122.  Any help would be appreciated.

Thanks,

John  WA4WDL
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mailman.qth.net/pipermail/milsurplus/attachments/20061202/01c32ea0/attachment.htm