[R-390] Need info on R-390A type or variation

[Roger Ruszkowski]

Fellows,
As Nick said this was a fairly common add on by the Navy.
It bolts on it bolts off.

When you were pulling this receiver out of a hot rack every month to do monthly PM
and this receiver was not to be off line for more than two minutes because it was in a 
critical application. IE Navy ship board communication. You wanted some thing you could swap out from the
front side only.  The back of the rack was not accessible. Two audio plugs, a power cord and antenna connection.
Very neat.

Slide the receiver out and uncouple.
Put up the spare receiver and recouple.
Its hot and  ready to run before you can get the front panel screws reinstalled.
No tools needed on the back side that could be dropped into the rack where the tool may not
be recoverable with out extreme maintenance activities.
Right now in front of everyone.
Things can not be left adrift inside cabinets.

The signal corps would of liked to have had this setup inside some radio huts.

The setup was a hot swap for a style of Navy shipboard cabinet. 
Hang on to your bit of history. But get it off the receiver and do some thing
proper with the new power cord you are going to install.

These receivers were real working units doing day to day operations keeping our
military logistics flowing.

Respectfully.

Roger Ruszkowski AI4NI