[R-390] PTO Question

[DW Holtman]

Hello,

I'm in the process of restoring a PTO for a friend. I have done about at 
a dozen or more with good success, but they have all been Collins or 
Cosmos. This one is either a Progresstron or a Dubrow. I would like to 
know which one?

 It has a corrector stack similar to the Collins.The the internal 
compensator coil (the end stop adjustment) has about 6 turns of wire 
vise two turns on the Cosmos. The heating coil is a glued on red rubber 
mat instead of the coil being sort of inside of a metal Pocket on the 
middle  cover.

It does not present any problems that I can see servicing it, I'm just 
very interested.

Any help identifying this PTO would be greatly appreciated. Thank you in 
advance.

Best,
DW Holtman
WB7SSN
http://www.heavymetalradios.com/