[MRCA] Korean War Radio Sets (and Numbering Systems)

[Mike Morrow]

Robert wrote:

> Well, the fact remains that in early December 1950, at least one Marine 
> squadron at Yonpo was still flying Corsairs carrying VHF equipment.  

I don't doubt it at all...I did not mean to imply that there wasn't a lot
of VHF-AM use, only that there was a lot of UHF-AM use as well.  I've seen
a lot of AN/ARC-27 components with 1952 contract numbers...and that set
became one of the most widely-used UHF-AM units, even into the 1970s on
older aircraft.

With respect to the AN/PRC-6, the several manuals I have and the several
units I have collected since 1969 bear nothing indicating use before 1952.
I'd be very interested in contract and order numbers and dates for any
example with 1949 provenance, just for my own enlightenment.

Documents with 1949 dating for the AN/GRC-3 series abound.  It's curious
that the JAN RT component numbers (66, 67, 68, 70) are before the RT-77
for the very late WWII AN/GRC-9, or RT-82 for the post-WWII AN/APX-6,
or even RT-91 for the very late WWII AN/ARC-2.  That seems to indicate
the design of the advanced-technology AN/GRC-3 series began while WWII
was still in progress.  The JAN RT component numbers for the backpack
units (174, 175, 176) are much in line with equipment appearing in the
Korean War era, including the RT-178/ARC-27 and the RT-159/URC-4.
The RT-196/PRC-6 falls out of expected sequencing if it appeared in 1949.

Granted, the numerical sequencing of JAN component numbers sometimes fails
spectacularly as a method to estimate date of appearance for service.
JAN system numbering is even worse.  The so-called AN/VRC-12 series with
the RT-246/VRC would have been expected on an early 1950s set rather than
one like the AN/VRC-12, appearing in 1961.  However, all the several *other*
JAN system nomenclatures in the AN/VRC-12 series start with AN/VRC-43,
and the second RT component is RT-524.  It looks like some JAN bureaucrat
grabbed earlier skipped VRC- and RT- numbers for the first components,
and then was compelled to assign more appropriately contemporary component
and system numbers for the remainder of the set components.  Those later
JAN numbers are much more appropriate for a set appearing around 1960.

But sometimes it works.  The R-5/ARN-7 ADF is older than its successor,
the R-101/ARN-6.  The R-5 versus R-101 is the clue.  And though not JAN,
I believe that the antenna relay in the SCR-274-N should have been the
BC-452-A rather than BC-442-A, but apparently some large oddball transmitter
had already been assigned BC-452 by the time BC- number for the SCR-274-N
were assigned.

73,
Mike / KK5F