[ARC5] US Military Aircraft Radios - Opinions

[Mike Morrow]

>Although this may not be the forum on which to ask this, I 
>would like the collective opinions of the various gear 
>mentioned above

I can't think of any place better for such discussions.  I often
regret that the ARC5 and MILSURPLUS lists have such little traffic.
My postings are usually deliberately long-winded and tangential,
made with the hope that something from them might trigger some
interesting traffic.

>The ARC-1 seems to be the best of that type (VHF-AM) of 
>rig, but the ARC-3 and its later variants seem to be amost 
>as good or perhaps even better (they certainly were 
>capable of far more channels), while the ARC-4 was a 
>piece of junk. I don't know anything about the -4A.

The AN/ARC-4A used the same RT-19, a simplified C-54 control box,
J-16 or -22 jack boxes, a different rack, and a simplified external
wiring harness.  In other words, no significant change from the -4.

My opinions are:

A.  VHF and UHF Sets
(1)  SCR-522-A - The most important "command set" of the ETO, and
                 a historically important step into VHF-AM.  But
                 it is large, only four channels, time-consuming
                 to re-channel, and reportedly subject to channel
                 drift due to temperature changes.  Employed a complex
                 British-style pushbutton control box (also bad).
(2)  AN/ARC-1  - Overall the best VHF-AM set of the era.  Provides
                 nine channels plus a guard channel (one crystal per
                 channel!).  Only one unit plus control box/panel.
                 Not too difficult to re-channel.  Not used by USAAF.
(3)  AN/ARC-3  - Used by USAAF/USAF.  Replaced SCR-522-A.  When
                 working properly, it is simple to re-channel because
                 it tunes itself automatically.  Gives the USN AN/ARC-1
                 competition except for being larger (three units),
                 requires two crystals per channel, has no guard channel.
                 Early system used horrible British-style pushbutton
                 control box (C-118), but later an improved panel (C-404A).
                 Saw long service, with 16-channel version (AN/ARC-36)
                 and 48-channel version (AN/ARC-49).
(4)  AN/ARC-4  - USN's stop-gap VHF-AM set.  Only four channels between
                 140 to 148 MHz.  Terrible receiver, but it pioneered
                 the guard channel.  Probably would have been much more
                 servicable in its limited range if an RF stage been
                 provided for the main and guard channel front-ends.
(5)  AN/ARC-5  - Only four-channel VHF, two crystals per channel, rather
                 awkward to re-channel.  But it was servicable in allowing
                 the three-receiver rack/two-transmitter rack AN/ARC-5 and
                 AN/ARR-2 combo to provide six-channel VHF (246 MHz) homing,
                 four-channel VHF-AM comms, and one-channel MF or HF comms.
                 This was an impressive advance in capability over the
                 same-sized original ARA/ATA system.  USN use only.
(6)  AN/ARC-12 - USN's early successful UHF-AM nine-channel plus guard
                 channel replacement of the AN/ARC-1 VHF-AM system.  Only
                 requires installation of the RT-58/ARC-12 in place of the
                 RT-18/ARC-1 in existing AN/ARC-1 systems, plus antenna change.
                 Replaced by AN/ARC-27.
(7)  AN/ARC-27 - One of the most important command sets of all time:  UHF-AM,
                 1750 channels at 0.1 MHz intervals from 225 to 400 MHz.
                 Used by all U.S. military services from early 1950s to 1970s.
                 Pressurized, but AN/ARC-55 was lighter unpressurized version.

B.  MF/HF Sets
(1)  ARA/ATA and SCR-274-N - Innovative and compact MF/HF commands sets introduced
                 in the years just before VHF-AM was demonstrated by our UK partners
                 to be significantly superior.
(2)  AN/ARC-2  - An impressive Collins design for the USN.  Apparently intended to fill a
                 liason function for which its AM-mode and low power were less than
                 satisfactory.  It had long life in some USN backwaters, and could still
                 be found in service on USN training aircraft in the early 1970s.  I prefer
                 the RT-91/ARC-2 rather than the RT-298/ARC-2A.  The RT-91 has an RF ampmeter
                 function that was removed from the RT-298, and build quality is better.  I 
                 suppose the closest thing in the way of a replacement was the AN/ARC-39.
(3)  AN/ARC-5  - These USN MF/HF sets were the ultimate enhancement of the rapidly
                 obsolete HF command set.  The LF/MF receiver had long life into the 1970s.
                 These A.R.C.- and Stromberg-Carlson-made sets are beautiful, but when
                 I see them I think about how fortunate it was that there were outfits
                 like Western Electric that could trim costs and produce gear in the 
                 massive quantities that were needed 65 years ago.
(4)  AN/ARC-8  - This USAAF/USAF set (combo of the AN/ART-13A and the AN/ARR-11 (BC-348-*) is
                 my favorite aircraft radio set.  Some were still in active USAF service in 
                 the early 1970s.  It was replaced in the 1950s by the AN/ARC-21, whose RT
                 was the 130-pound RT-128A/ARC-21, pressurized in an 18-inch diameter drum.
                 It's hard to warm up to something that large, shaped like that.
(5)  AN/ARC-25 - This USN set (combo of the AN/ART-13 and the AN/ARR-15) is the first system
                 in which the USN finally paired up an appropriate receiver to the excellent
                 AN/ART-13.  (I hate those kludges like the ARB, the RAX-1, or the R-26 and
                 R-27/ARC-5 units with those C-131 contraptions that the USN had been using
                 with the ATC or T-47.)  I dislike the fact that the USN ATC or T-47 does not
                 generally have the VFO dial B vernier scale that allows the USAF T-47A
                 frequency to be set more precisely.  This set was replaced in the 1950s 
                 by the AN/ARC-38.

Mike / KK5F