[Boatanchors] MacKayMarine Master Oscillator MR-513-73

[Fuqua, William L.]

  I have had this for many years but have not taken a close look at it.
It has 3 frequency dials, 2 switch crystals and one variable (0-10kHz) and with frequency multiplier
covers 2 to 4 MHz which was normal for early Master Oscillators such as the VOX-1 and Northern Radio.
Very small and light weight for a master oscillator of its day.
Can't find anything useful about it.
  I figured out conversion scheme which involves 4 oscillators and 3 Mixers.
Appears to be very straight forward and I could trace out the schematic but would rather not.
  Anyone have some info on this?
TNX es 73
Bill wa4lav