[ARC5] Command Set Loop Connections

[Mike Morrow]

>> The R-23, -23A, -148, and -24/ARC-5 "navigation" sets have a special
>> audio output off the cathode circuit of the 12A6 that is goes to the
>> connector for the front panel adapter.
>
>Mike. I would say, "...can have..." as I have, or had, rather, several of each 
>which did NOT have that connector, and, apparently, no provision for such.

Kenneth,

The connector to which I referred is the 8-pin male connector that joins the
back of *whatever* adapter panel is installed.  All receivers have this connector.
Pin 4 has no connection in the R-25, -26, and -27 communication sets.  But on the
R-23, -23A, -148, and -24, pin 4 goes to a filter network attached to the cathode
circuit of the 12A6.  That's audio for the ILS.  Schematics for the AN/ARC-5 nav
sets point to pin 4 with a note:  "OUTPUT TO INSTRUMENT LANDING EQUIPMENT".

To actually connect the nav receiver to the AN/ARN-9 ILS, the special and
somewhat uncommon MX-19/ARC-5 audio adapter panel must be installed in place
of the blank MX-21/ARC-5 remote control adapter normally found on the R-23,
-23A, and -148.  The only feature on the MX-19 front is the connector that
goes to the ILS.  (The R-24/ARC-5, OTOH, came from the factory with the MX-20/ARC-5
power adapter already in place for use with the R-1/ARR-1 (ZB) homing adapter.)

BTW, if anyone ever comes across some technical documentation on the AN/ARN-9,
I'd be interested.  Almost all remnants of this system, which was just an
improvement on the pre-war USN type ZA Air-Track ILS, seem to have gone into
an alternate universe somewhere.

Mike / KK5F