[Boatanchors] Collins 70H-13A oscillator information please?

[David Ross]

Ian Wilson wrote:
> Picked up one of these. It appears to be permeability tuned, with a subminiature
> tube. Any information on the connector, frequency range, etc, would be
> appreciated.
>
> 73, ian K3IMW


The 70H-13A covers 2.0 - 4.0 Mcs, it was used in the KWT-6 (URC-32) and 
the 18Z-3 (ARC-58) radios.  It is a Stabilized Master Oscillator and 
contains a varactor diode that is used to pull the oscillator frequency 
and lock the 70H-13A frequency to an external reference.  (The design of 
the earlier 70H-13 predated usable & consistent varactor diodes -  the 
70H-13 used a saturable reactor to pull the oscillator frequency.)

There should be two subminiature tubes in it, plus two thermal switches 
and a heater element.  The cover & baseplate are made of mu metal.

73
Dave Ross    N7EPI