[ARC5] Questions that need answers

[Mike Morrow]

Gordon wrote:

>There are two adapters, the MX-20 and -21 in the AN/ARC-5 series that 
>have multi-contact receptacles (old style and new) to bring out B+ and 
>audio for navigation units like the loop, the ZA, etc.

The MX-19/ARC-5 delivers audio output of a navigation receiver for the localizer portion of the old Air Track type of ILS, like the ZA, ZAX, or AN/ARN-9.  This adapter, and components of that type of ILS, are rarely encountered today.

The MX-20/ARC-5 brought power out power to be supplied to a ZB or AN/ARR-1 homing adapter, or perhaps to a DU loop, or even to supply an LM frequency meter.  These are often found on R-23 or R-24/ARC-5 sets.

The MX-21/ARC-5 is the common blank remote control adapter.

The C-24/ARC-5 is the local control adapter, like the FT-260-A in the SCR-274-N system.  The AN/ARC-5 didn't have an exact analog to the SCR-274-N PL-192 plug that would be inserted in the rack connector in the rear of the receiver for local control, though a MX-2/ARR-2 plug could be made to serve the same function.  

AFAIK, that the complete run-down of the plug-in panels for the AN/ARC-5.