[Milsurplus] questions re early Stabilized Master Oscillators

[Ray Fantini]

My ARC-38A uses varacaps hung external of the PTO for tuning correction so they were around for a while also the regular ARC-38 used a small variable capacitor and a servo system driving a syncro motor for frequency correction of the SMO. I never ran across the satutrable reactor, can you point to a diagram online?
Ray Fantini KA3EKH

-----Original Message-----
From: milsurplus-bounces at mailman.qth.net [mailto:milsurplus-bounces at mailman.qth.net] On Behalf Of David Ross
Sent: Friday, July 09, 2010 1:53 PM
To: milsurplus
Subject: [Milsurplus] questions re early Stabilized Master Oscillators

   Before varicaps came into common usage, Collins used saturable 
reactors to electrically adjust the frequency of PTOs in their 
Stabilized Master Oscillators, specifically in early ARC-58s & TRC-75s & 
URC-32s.  (Similar function to a varicap in modern VCOs.)

   I have never seen a Collins SMO that used a saturable reactor -  my 
guess is that as soon as varicaps became available, all SMOs with 
saturable reactors were removed from service and replaced by SMOs with 
varicaps.

Question 1    -    Did Collins use saturable reactors in any other 
SMOs?  (that is, other than early ARC-58s & TRC-75s & URC-32s)

Question 2    -    Did any other manufacturers use saturable reactors in 
SMOs or other PLLs?

Dave Ross    N7EPI