[ARC5] AN/ARC-12, A.R.C. Type 12, Other Things.

[Mike Morrow]

Dave wrote:

> Please note that this link is mis-named.
> The [A. R. C. Type 12] set is *not* an AN/ARC-12.  That is
> a very different radio.

Indeed.  The RT-58/ARC-12 is a post-WWII USN 10-channel crystal-controlled UHF-AM command RT unit.  It is the same size as the RT-18/ARC-1 VHF-AM command RT unit.  The RT-18 may be removed from its rack and the RT-58 substituted with no other changes except  (perhaps) the antenna.  Instant UHF-AM.

It's odd how hard it is to kill the persistent nonsense about the A.R.C. Type 12 being the AN/ARC-12.  Fair Radio was selling the RT-58/ARC-12 more than 50 years ago.

> I don't believe ARC-type-12 was ever incorporated in
> an AN/ARC-** set.

The AN/ARC-60 UHF-AM command set uses the R-508/ARC (A.R.C. Type 12 R-19) VHF receiver and two CV-431*/AR (A.R.C. Type 12 TV-10*) UHF Transverters.  The receiver converter in the CV-431* is just a mixer diode and 110 MHz crystal heterodyne oscillator.  In spite of such a simple circuit, the rated sensitivity of the 228 to 258 MHz R-508 with CV-431* is 7 uV for 10 dB s+n/n.  That's identical to the rated sensitivity of the 225 to 400 MHz RT-178/ARC-27 of 5uV for 6 dB s/n.  That surprises me.

The A.R.C. Type 15 VOR/LOC navigation radios carried AN/ARN-30* designation.

Mike / W6MAB wrote:

> I spent some 1400 hours in the rear seat of T-34B aircraft as a
> primary flight instructor in the Navy.  With some of my more
> advanced students, I could relax a little bit and fiddle with
> the ARC Type-12 nav receiver.

Almost 50 years ago I took my NROTC aviation indoctrination training in the T-34B at NAS Corpus Christi.  IIRC the T-34B's A.R.C. Type 12 installation was VHF-AM, using the T-11A instead the UHF-AM TV-10A.  I don't remember if the VOR was A.R.C. Type 15 (AN/ARN-30) stuff.

The TS-2A aircraft we flew in still had the AN/ARC-2A and R-23A/ARC-5 installed.  An AET2 told me that it was almost impossible to get repair parts for them.  These old aircraft didn't get much respect.  Trainee graffiti was everywhere.  I remember one that said "Built by Baltimore Railroad Scrap Iron Company" and another that warned "Do not exceed Mach 2 with hatches open".

In the classroom that Summer I scored 9 on FAR and 6 on AQT and did not screw up the training flights too badly, because 18 months later I got orders for pilot training at Pensacola after commissioning.  Unfortunately my EE degree got me "drafted" by ADM Rickover's gang into nuclear propulsion and submarines instead...just a few weeks before commissioning.  I showed up at Mare Island Nuclear Power School still carrying an officer designator (1390, IIRC) as a pilot trainee instead of the 1170 designator of a submarine officer trainee.

Mike / KK5F