[ARC5] ARC-type-12 C-57 (used with R-22)

[Mike Morrow]

Mike Hanz wrote:

> From the ebay example, it controls a .55 to 1.6MHz broadcast
> band radio.  I'm not familiar with the postwar sets.  Is there
> any postwar series that has such a receiver?

There is only one exactly like that, the A.R.C. R-22 aircraft broadcast band receiver.  It covers 0.54 to 1.60 MHz just as its C-57 control panel shows in the ebay photos.  I found one NIB on ebay about ten years ago, complete with its matching serial number D-10A 28vdc dynamotor.  That surprised me because I did not think that A.R.C. shipped receivers with dynamotors installed in the same box.  Every one of several R-22 receivers that I've seen were marked on the name plate with information clearly showing USAF purchase in the 1958 era.  Here's what is on mine:

RECEIVER. RADIO   R-22
STOCK NUMBER 1600-013-424 345
SERIAL NO. AF-58-1056 [my unit's serial]
AIRCRAFT RADIO CORPORATION
BOONTON   NEW JERSEY
PART NO. 17610
CONTRACT AF-33(600) 32467
U.S.                28V

The D-10A dynamotor has the same sort of information.

So...the R-22 is a semi-unusual very late Type 12 receiver.  It has on its front only one 12-pin connector, BNC ANT, BNC LOOP, and TEL connectors, plus ANT trim capacitor and MC-215-type tuning spline connection.  The R-22 is not configured to work with a VHF transmitter system as was the common 1946-vintage R-10A 0.52 to 1.5 MHz receiver, which used three connectors on its front.  The R-22 is a slightly simplified R-10A with a very slightly different tuning range.  One wonders why the USAF was interested in a complete broadcast band tuning set in 1958.

The only technical information I've seen is the schematic that Ken/W7EKB kindly sent me about ten years ago.  Ken must have some very late and scarce Type 12 manuals!

Mike / KK5F