[R-390] Re: [Milsurplus] Transplanting R-390 IF modules to R-390A

[Flowertime01 at wmconnect.com]

Mike,

It was not that the R390/A rang in the Radio Direction Finding System.
The system used a motor driven relay that switched the ring of antennas into 
the receiver. the motor driven relay also provided a circular sweep signal for 
the CRT display. The R390/A filters let a lot of hash noise from this 
switching unit into the signal. The R390 IF deck swapped into the R390/A receiver 
produced a cleaner display than using a R390/A in the setup.

The R390's were all tied down and were not available to use. Folks with 
R390's were not even acknowledging that the even existed. Radios or people. The 
R390/A were cooler than the R390/A. This was a consideration in the air 
conditioned trailers most of the DF site people worked in.

Roger. AI4NI