[Milsurplus] Harvey Wells AR-5A Military Aircraft (History/Info)

[Mike Morrow]

Jim wrote:

>I recently got a Harvey Wells AR-5A military aircraft radio.  It has two
>bands, 200 to 400 Kcps and 550 to 1650 Kcps both AM detection.

I've enjoyed reading the follow-up posts on this thread.  I and a few others
collect these light aircraft radio sets that appeared between the late 1930s
to the late 1950s.  There are many different models.  Most common models
were made from 1946 to 1950 or so.

We are all familiar with the LF/MF beacon band-only receivers, which in
conjunction with directional A-N beacon transmitters could be used to
navigate from one beacon to the next, and could also be used to monitor the
LF/MF tower transmitting frequencies.  Some are:

Radio Frequency Labs B-3
Boonton Radio Type 185/186
Harvey-Wells AR-2
Detrola 438, BC-1206-A, -B
Setchell-Carlson Type 512 (R-76/ARR-13)
Setchell-Carlson Type 524 (BC-1206-C, CM)
Bendix PAR-3
Motorola Airboy and Mitchell Airboy Jr.
RCA AVR-104
Harvey-Wells AR-5 (also had BCB coverage)
Heath MA4A
Lear RM-402C (also had BCB and HF coverage)

The next level of avionics sophistication added a HF AM transmitter
(typically single channel, about 10 watts output).  The most common
configuration consisted of a receiver covering the LF/MF beacon/tower
transmitting frequencies (200 to 400 kc) and a transmitter operating on 3105
kc.  The receivers in some sets also covered the BC band (550 to 1500 kc),
and the transmitters in some cases could operate on 6210 kc also.  In the
early 1950s, IIRC, the standard 3105 kc plane-to-ground frequency changed to
3023.5 kc.  That frequency today is still allocated as a SAR frequency.
Some of the common units of this type were:

Single Unit Receiver-Transmitter
General Electric AS-1B, AS-2A
Harvey-Well ATR-3
Hallicrafters CA-2, CA-4
Motorola Avigator (also received 75 mc marker beacons)
Bassett MC6A

Separate Unit Receiver and Transmitter
General Electric AS-1C (Transmitter located in external
                                           power supply unit)
RCA AVR-15/AVT-15, AVR-15/AVT-112,
         AVR-100 (or AVR-101 without BCB)/AVT-111 (or AVT-110 for dry cells)
Harvey-Wells AR-3/AT-3
Bendix PAR-70/PAT-40 (Bendix made a "spot tuner" converter
             PMR-5 to be used with the PAR-70 to cover either 2870
             or 6440 kc when the PAR-70 was set for 825 kc in the BCB.)
Airadio SU-52B (or SU-41 without BCB)/TRA-1B
Lear AMR-1/AMT-1
Maguire ARR-1/ART-1
Bassett MR3A/MT3A, A6SX/12, AR7/AT-15

The next step in communications improvements consisted of replacing the HF
transmitter with a VHF transmitter, while retaining the LF/MF receiver.

Bendix PAR-70/PAT-50
Bendix PATR-10 (single unit)
Lear RT-10E (single unit, also included tunable VHF
                         receiver and LF/MF/BCB receiver)
General Electric AS-3A (HF transmitter function could
                         be retained as an option in addition to the
                         VHF transmitter.)

Next in technology are the early all-VHF COM/NAV (VOR) units like the Narco
VTR-1.  But these get to be too modern for my collection.

The US Army Air Force Radio Facility Charts (T.O. 08-15-1 and -2) from 60
years ago are interesting if you want to see what frequencies military and
civil air fields were using across the US.  For example, in July 1943,
Chicago NAS Glenview tower transmitted on 278 or 236 kc, and guarded 3105,
3117.5, and 4495 kc.   Its range starion transmitted on 350 kc.  By the end
ot the war, VHF frequencies began to be added.  I have information somewhere
that leadds me to believe that some few towers in the US guarded 3023.5 kc
even after 1960.

My favorite unit in the lists above (but I don't have all that I listed) is
the General Electric AS-1B, which came out in 1945.  It's a very well
designed and built unit.  Harvey-Wells work was just fair, and Hallicrafters
used IMO really cheesy design and construction.  The best designs had RF
stages on the receivers and BCB coverage.  Most all the receivers listed
could be used with a movable or fixed loop antenna, in addidtion to a fixed
wire antenna.  The GE AS-1B was one of the more expensive units.  It cost
about $200 in 1946, so that would be about $2000 in today's dollars.  The
CA-2 was about $130.  The lowest cost radio sets were the little portable
dry cell beacon band receive only units (Airboy, PAR-3), at typically $25 to
$30 in 1946.

As far as your unit goes, the AR-5A came out in 1946 for light civil
aircraft use.  I don't have any information that it was ever used on
military aircraft, though the GE AS-1B or Hallicrafters CA-2 was standard
equipment on some Stinson aircraft that might have been used by the
military.  In general the military needed a HF receiver and an HF
transmitter (like the RCA AVR-20/AVT-15 or -112 combo), and a LF/MF receiver
(like BC-1206) in their light observation aircraft or ferry service.
Obviously plane-to-place communications is impossible otherwise.  I know
there is an old Harvey-Wells advertisement which speaks of units being
provided to the military in WWII, but I don't know which units would be
likely except maybe the AR-2 which came out in 1941.  All the other
Harvey-Wells units mentioned above are post-WWII.

The AR-5A FILTER-RANGE-TOWER-BCST functions are:

FILTER - AF filter is inserted (simple LC network in the first audio stage
V3 cathode) to filter OUT the bothersome 1040 cps tone on a beacon/voice
signal.  Used when voice only reception was desired.
RANGE - AF Filter is bypassed.  Used to hear BOTH range and voice signals.
TOWER - AF Filter is bypassed.  Receiver frequency is set to a fixed
internally preset (with C33A) frequency.  This would normally have been the
default standard LF tower frequency of 278 kc.
BCST - AF Filter is bypassed.  Used to copy BC band.

Hope this hasn't been too boring.  Who but a nut could care about all this?
I really am intrigued by these sets.  I believe the LF/MF receiver / HF
transmitter systems had all died out by the late 1950s in the US.  I regret
that I was too young then to have been interested in radio.  I'd love to
know what 3105 kc sounded like at night in 1946.

Please consider NOT making modifications to your AR-5A.

73,
Mike / KK5F