February 2012
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The Raytheon RM-10 Monitor Amp

I found this manual from 1946 in the drawer at the WICC transmitter site, which is a sort of time capsule due to its inaccessibility. I figured I would bring it home and scan it, then return it to the file drawer out on the island.  Step one is done:

Raytheon RM-10 Monitor Amp

Raytheon RM-10 Monitor Amp

This is a cool little monitor amp, capable of driving line level or speaker outputs up to about 10 watts or so.  It could be used as a front or input stage for a larger audio amp.  By the way, 10 watts is a lot more than it seems, if using efficient speakers to convert that power into sound waves.  Specs show total harmonic distortion is between 0.6 to 2 percent depending on power and frequency.  Lower power output levels net less distortion.

Schematic is pretty simple, a pair of 6L6’s in push-pull for the output.   Inverse feedback into the previous stage via the output transformer.  Click on image for higher resolution.

Full manual and parts list is available here.

Now I just need to get the manual back out there.


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