[R-390] R-392 help

[Flowertime01 at wmconnect.com]

Mark, wrote.

R-392/URR is powered by 28VDC without using a dynamotor or vibrator power 
supply. This means that the B+ voltage is 28 VDC!

------------------------------
Yup,

The R-392/URR was a mobile receiver. It mounted in military vehicles and was 
powered off the vehicle generator / alternator and battery. Most military 
vehicles are 24 volts systems. Like today's vehicles have 13.8 volt 12 volt 
systems. Military vehicles have 27.6 volt 24 volt systems. Two 12 volt batteries are 
run in series.

Most were in como vans "communication vans" likely 4 receivers and two 
transmitters. They likely had RTTY machines. You likely were "assigned" a set of 
operating frequencies so you were not "scanning" the bands looking for signals.

Some were used with tank units for AM voice. I do not know if the R392 went 
in the tanks or if they were only used at the "command" end of the links.

The R390 design was best receiver sensitivety of the era. It was "copied" 
over to the follow on receiver models. Moving core inductors even became popular 
in auto radios of the 50's. Collins pioneered single side band voice for 
aviation and that created a whole new line of transceivers and fixed frequency 
"channels" which is where communications is at today. 

The R390 R392 R390A were the last of the "band cruiser" receivers. I cannot 
imagine tuning the ham bands with an R1051 by flipping the 10KC step knob.

I hope you can put up a good stiff 24 -28 volt power supply and get your R392 
back into daily operation.

Roger KC6TRU