[Milsurplus] R-388/51J use

[Mike Morrow]

> I recall the introduction of the original 51J in a small trailer ...
> viewed by invitation only.  No other receiver like it anywhere.
> Sure blew the 348 away. 

That's like saying the Collins KWM-2A (AN/FRC-93) sure blew the RCA ARB/ATB
away.  But these sets were from two different eras serving two very different
functions.

The BC-348 design dated from 1936 and was solely intended for aircraft use.
The 51J (R-388/URR) came about 15 years later for stationary or
transportable/stationary installations.

Comparing the USAAF BC-348-* (AN/ARR-11) to the 51H-3, the commercial model
number for the USN AN/ARR-15, would be more reasonable.

I've never seen a unit marked 51H-3, and I've also never seen its matching
transmitter marked 17H-2.  That was the commercial designation for the
AN/ART-13.  I have a manual for the 17H-2, but not the 51H-3.

73,
Mike / KK5F