[Milsurplus] instrument inverter

[Jack Antonio]

In the AN/ARC-38, 400 cycle supply does supply receiver and synthesizer
B+, and bias for the transmitter. The servo system motors needs 6 and 18 
volts, and lastly, the blower on the front of the RT unit needs 120 
volts. I found that out of its case, the radio did not get overly warm
with the blower disconnected.(also made the shack a lot quieter).

The point being that if one was so inclined, one could dispense with
most, but not all of the 400 cycle requirement, and just build a small
inverter to run the servo motors.

Not me though, I'm a purist.

Jack

Jack Antonio WA7DIA
scr287 at sbcglobal.net

> Ray,
> 
> How do you get the receiver to function if you supply 400 cps AC power only during

  channel change?  I seem to recall that the receiver HV supply for sets 
like 618S

  and AN/ARC-38 comes from an external 400 Hz AC-input transformer supply

  that operates continuously.  For example, the DY-118/ARC-38

  contains a continuously operating AC-input supply supply

  for the receiver, plus a 28 vdc-input dynamotor supply

  that operates only when tranmitting (or when CW mode is selected).

   If you drop the 400 Hz AC, the receiver HV power supply quits.