[Milsurplus] [Russianradio] Russian US-9 receiver

[Meir WF2U]

Groups,

Thanks to the schematics I got from Helmut, DJ7CF and a full manual for the
US-9 I found on the Internet for download, I'm happy to report that after
consulting with the schematic and tracing the wiring of the dynamotor, I
resolved the problem and the receiver is working fairly well (it only needs
some contact cleaner because some of the controls are a bit noisy as well as
the bandswitch. I'm happy now...
The problem was that the +28 VDC and the +220 VDC leads from the dynamotor
were swapped. I unsoldered the two leads, (they're connected to one side of
their respective chokes) and soldered them back into their correct position.
The dynamotor is working normally and the plug has the correct pins
connected. The whole operation up to the receiver up and running took about
45 minutes, including packing the bearings with new grease. 
I'm just trying to think how this miswiring occurred. The best theory is
that maybe the dynamotor was replaced on the base which contains the
filtering circuitry and the 6 pin plug. The work must have been performed by
incompetent personnel, and then it was put away as a faulty assembly, maybe
with the radio itself. 

Wishing all a great Holiday Season and a Happy New Year

73, Meir WF2U
Landrum, SC, USA