[ARC5] U.S. WW II equipment - AN/ARN-6 and -7

[Mike Morrow]

Sandy wrote:

> As I remember (correctly?) the ARN-7 was nothing more than assignment of 
> later AN number to the old SCR-269G radio compass set.

The AN/ARN-7 is very close to what you describe...but there are two
notable enhancements for the R-5*/ARN-7 versus the BC-433-G:
1.  The AN/ARN-7 adds a fourth band for 100 to 200 kHz.  The SCR-269-*
    has only three bands, beginning at 200 kHz.
2.  The AN/ARN-7 provides a CW-VOICE switch on the C-4*/ARN-7 control
    box.  Some BC-434-* control boxes for the SCR-269-G were modified
    to include a CW-VOICE switch, but that was not part of the standard
    configuration for the SCR-269-G.

Mike/W4DSE wrote:

> ...the best of my recollection says there is no inverter used in the
> ARN-6 setup.  The AC for the loop and indicator comes from the receiver.

That is 100 percent true.  One of the best things about the AN/ARN-6
is its need only for 28 vdc...and no rotary inverters to be found anywhere.

The R-101*/ARN-6 uses 16 vacuum tubes (6 x 12SK7, 1 x 12SW7, 4 x 12SX7GT,
1 x 12SY7, 2 x 26A7GT and 2 x 2050).  The best indication from the JAN
nomenclature system that the AN/ARN-6 is a *later* development than the
AN/ARN-7 is individual component number assignment:  R-101 and C-149
for the AN/ARN-6, versus R-5 and C-4 for the AN/ARN-7, for example.

It would not be hyperbole to call the AN/ARN-6 one of the great aircraft
radio sets of all time...used by every US military branch and many foreign
military organizations for almost three decades after introduction.

Mike / KK5F