[ARC5] A.R.C. Type K "Command Set" Receiver History (KK5F) - Long
Mike Morrow
kk5f at earthlink.net
Sat Feb 9 16:23:51 EST 2013
There have been recent requests for various details of the RAT/RAT-1,
RAV, ARA/ATA, and other components descended from the A.R.C. Type K.
The following is a tabulation of the various forms that the A.R.C. Type K
command set receivers have taken between 1936 and 1950. The descriptions
are mine, based on the best information I have accumulated in the past 30
years or so. There will likely be some disagreements with information
presented, especially in the RAT/RAT-1 and RAV sections. There may also
be some need for correction of details. I gladly solicit comments and
criticisms of content and conclusions. Such have helped my understandings
on many occasions in years past. The comments below do not come from a
burning bush in the desert. :-)
Mike / KK5F
Revision 20130209
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RAT/RAT-1, RAV, ARA/ATA, SCR-274-N, AN/ARC-5, Type 12/15 Receiver Chronology
A. USN A.R.C. Type K Command Set (1938)
Other researchers have shown that development under US Navy contract of
the ancestor to receivers now known as "command sets" began as early as
1936 by Aircraft Radio Corporation (A.R.C.) as the Type K command set.
This was not a production set, and apparently the design, as far as it
went, was concluded by late 1938. See Mike Hanz's web page
http://aafradio.org/NASM/Hmmmm.html
for a look at four Type K receivers, covering:
Type K Model 2 200 to 580 kHz
Type K Model 2 520 to 1500 kHz
Type K Model 2 3.0 to 6.0 MHz
Type K Model 2 6.0 to 9.0 MHz
B. SIDE NOTE - Contemporary Liaison Transmitter Requirements
B.1 USN GO-3 (1937) Liaison Transmitter
Westinghouse produced the GO-3 liaison transmitter, which is the last GO-*
transmitter whose upper limit was 13.575 MHz.
1937 GO-3 .300 to .600, 3.000 to 13.575 MHz
B.2 USN GO-4 (1938), -5, -6 (1939) Liaison Transmitters
General Electric produced the GO-4, GO-5, and GO-6 liaison transmitters.
1938 GO-4 .300 to .600, 3.000 to 26.500 MHz
1939 GO-5 .300 to .600, 3.000 to 26.500 MHz
1939 GO-6 .300 to .600, 3.000 to 26.500 MHz
All earlier GO-* liaison transmitters had an upper frequency limit of
13.575 MHz. Coverage of all RU-* liaison receivers (RU-4/5/6/10/11/12/18/19)
ends at 13.575 MHZ. The new GE transmitters created a need for additional
liaison receiver coverage from 13.575 to 26.5 MHz. To satisfy that need,
A.R.C. in 1939 developed the Type K based RAT (12-vdc) and RAT-1 (24-vdc)
receivers with almost precisely that coverage, from 13.5 to 27.0 MHz. The
RAT could be paired with A.R.C.'s 1939 RU-11 (12-vdc) or RU-12 (24-vdc) to
provide a liaison receiver system that fully complemented that of the GO-4/5/6.
Doubtless, A.R.C. could foresee that other (future) liaison transmitters
systems would require receiver coverage above 13.575 MHz. That happened
with the Westinghouse GO-7, GO-8, and GO-9 (all 1940) and the Collins ATC
(1942), all of which operated up to 18.1 MHz.
C. USN RAT and RAT-1 (1939) Liaison Receivers
Two-receiver RAT and RAT-1 liaison receiver systems were made by A.R.C. in 1939.
The RAT (12-vdc) receivers are:
CBY-46083 13.5 to 20.0 MHz
CBY-46084 20.0 to 27.0 MHz
The RAT-1 (24-vdc) receivers are:
CBY-46108 13.5 to 20.0 MHz Same receiver as used in RAV below
CBY-46109 20.0 to 27.0 MHz Same receiver as used in RAV below
These are the first production versions of Type K designs which ultimately led to
the "command set" receivers that were made in the millions by 1945. But this
first production set was a liaison service set, not command service.
Only 50 each of RAT and RAT-1 were built, but it's likely that only small numbers of
the GO-4, -5, and -6 transmitters were built as well.
D. USN RAV (1940) Liaison Receivers
In 1940, the 24-vdc RAV system was introduced. The RAV was A.R.C.'s liaison receiver
system which totally abandoned A.R.C.'s 1930's RU system's TRF/plug-in coil design.
The RAV covers the complete range of contemporary liaison transmitters by using eight
of the latest Type K based receivers.
The RAV receivers are:
CBY-46102 190 to 550 kHz
CBY-46103 520 to 1500 kHz
CBY-46104 1.5 to 3.0 MHz Same receiver as used in ARA below
CBY-46105 3.0 to 6.0 MHz Same receiver as used in ARA below
CBY-46106 6.0 to 9.1 MHz Same receiver as used in ARA below
CBY-46107 9.0 to 13.5 MHz
CBY-46108 13.5 to 20.0 MHz Same receiver as used in RAT-1 above
CBY-46109 20.0 to 27.0 MHz Same receiver as used in RAT-1 above
The CBY-46108 and -46109 are also part of the RAT-1, while the CBY-46104,
CBY-46105, and CBY-46106 are also part of the ARA. There is no 12-vdc version
of the RAV. The RAV is designed for local control only and is *not* provided
with any components for remote control. Only 46 RAV sets were made.
E. SIDE NOTE - A Competing Liaison Receiver
E.1 USN RAX-1 (1940) Liaison Receivers
General Electric produced the three-receiver liaison receiver RAX-1 whose
coverage complements the complete coverage of their GO-4/5/6 liaison
transmitters. Its coverage and intended use is identical to that of the RAV.
The RAX-1 liaison receivers are:
CG-46115 0.2 to 1.5 MHz
CG-46116 1.5 to 9.0 MHz
CG-46117 7.0 to 27.0 MHz
GE's RAX-1 and A.R.C.'s RAV may be seen as direct competitors to each other.
The last two RAX-1 receivers utilize two RF and three IF stages, in contrast
to the one RF and two IF stages of any RAV receiver. The tuning band spread
of the RAX-1 is better than the RAV. The RAX-1 requires three small dynamotors,
the RAV eight. The RAX-1 utilizes 22 vacuum tubes, the RAV 48. The overall
power consumption, weight, and volume of the RAX-1 is superior to the RAV.
t is little wonder that the RAX-1 easily won in competition with the RAV,
and saw widespread utilization by the tens of thousands...but the RAV only
by 46.
F. USN ARA (1940) Command Receivers
In 1940, the 24-vdc ARA system was introduced with the ATA transmitter system.
The ARA/ATA is the first production “command set" version of Type K based design,
consisting of five receivers:
CBY/CCT-46129 190 to 550 kHz
CBY/CCT-46145 .52 to 1.5 MHz
CBY/CCT-46104 1.5 to 3.0 MHz Same receiver as used in RAV above
CBY/CCT-46105 3.0 to 6.0 MHz Same receiver as used in RAV above
CBY/CCT-46106 6.0 to 9.1 MHz Same receiver as used in RAV above
(CCT indicates receiver made by Stromberg-Carlson)
The CBY/CCT-46145 broadcast band receiver was always supplied with the CBY/CCT-62036
power adapter panel for service with the ZB-* VHF homing adapter.
The two ARA receivers CBY-46129 and CBY-46145 are identical to the RAV receivers
CBY-46102 and CBY-46103 *EXCEPT* that the loop antenna connection posts and switch
are removed for the ARA version. The ARA command receiver system, unlike the RAV
liaison receiver system, was provided with components required for remote control.
Local control adapters are not part of the ARA.
G. USAAF SCR-274-N (1941) Command Receivers
In 1941, A.R.C. developed a USAAF version of the USN's ARA/ATA command set as the
SCR-274-N. It ultimately consisted of four receivers:
BC-453-A, -B 190 to 550 kHz
BC-946-B .52 to 1.5 MHz
BC-454-A, -B 3.0 to 6.0 MHz
BC-455-A, -B 6.0 to 9.1 MHz
SCR-274-N receivers and transmitters are identical to their ARA/ATA equivalents
except that the ARA/ATA utilize low impedance (300 ohm) AF while SCR-274-N -A
model receivers utilize high impedance (4000 ohm) AF. Later -B model components
could be wired for either high or low impedance AF. Paint finish and minor
mechanical details, plus the eventual elimination of the local/remote switch on
the antenna relay, and the elimination of the antenna relay vacuum capacitor
(on -AM model), illustrate some other minor differences between ARA and various
versions of the SCR-274-N.
The BC-946-B broadcast band receiver was always supplied with the FT-310-A
power adapter panel for service with the AN/ARR-1 VHF homing adapter.
Some SCR-274-N receivers were made by A.R.C., some by Colonial Radio, Lewyt
Corporation, and other contractors. By far, most were made by Western Electric.
H. USN AN/ARC-5 (1943) Command Receivers
In late 1943 the US Navy received the first units of the "improved" ARA/ATA, the
final MF/HF command set system used by the USN. This is the AN/ARC-5. Ignoring
VHF components, these are:
R-23/ARC-5 .19 to .55 MHz [or improved R-23A/ARC-5]
R-24/ARC-5 .52 to 1.5 MHz
R-25/ARC-5 1.5 to 3.0 MHz
R-26/ARC-5 3.0 to 6.0 MHz
R-27/ARC-5 6.0 to 9.1 MHz
R-148/ARC-5X .19 to .55 MHz [12-vdc version of R-23A/ARC-5]
Most LF/MF/HF AN/ARC-5 components were made by A.R.C. or Stromberg-Carlson.
The loop posts/switch of the RAV re-appeared on the R-23, R-23A, R-24, and R-148.
These four receivers were also wired to serve as a MF localizer receiver for the
short-lived AN/ARN-9 Air-Track ILS, by using the audio adapter panel MX-19/ARC-5.
All receivers had AVC, which required a minor change in tube line-up. Most R-25,
R-26, and R-27 receivers have "stabilization" modifications to allow preset
locked-tuned operation of these communications receivers. Those mods are indicated
by a yellow circle-S stamp on front.
The R-24/ARC-5 broadcast band receiver was always supplied with the MX-20/ARC-5
power adapter panel for service with the AN/ARR-1 VHF homing adapter. It is
unlikely that many R-24 units were used in that application, since the much more
versatile AN/ARR-2 all-in-one VHF homing receiver was available for installation
in AN/ARC-5 receiver racks about the time that the AN/ARC-5 was placed in service.
I. A.R.C. Type 11/12 (1946)
I.1 A.R.C. LF/MF Navigation Receivers
The only post-war legacy of the LF/MF/HF Type K design (outside the components used
in the mid-1950s RT-427/ARC-39) is the commercial and military A.R.C. Type 11/12
LF/MF navigation receivers, available in 14-vdc or 28-vdc models: These receivers
have neither BFO circuitry nor (after early versions) local indicating dials. All
connections are made at the front panel, including a BNC loop connection.
R-10A .52 to 1.5 MHz
R-11A .19 to .55 MHz {JAN nomenclature R-510/ARC (14-vdc) or R-511/ARC (28-vdc)]
R-22 .52 to 1.5 MHz
I.2 A.R.C. VHF Receivers
Although the intent of this write-up is not to discuss VHF receivers, since those
are the most common A.R.C. Type 12 or 15 components encountered here are some
details:
A.R.C. VHF receivers in Type 15 VOR/LOC sets:
R-13 108 to 135 MHz JAN nomenclature R-445/ARN-30 (28-vdc)
A.R.C. VHF receivers in Type 12 COMM sets:
R-15 108 to 135 MHz JAN nomenclature R-509/ARC (28-vdc)
R-19 118 to 148 MHz JAN nomenclature R-507/ARC (14-vdc), R-508/ARC (28-vdc)
J. USAAF Oddities Made From The SCR-274-N Set
J.1 USAAF - UK “Standard Beam Approach” (SBA) Receiver (1942)
Some BC-455-B receivers were modified in the UK to cover 28 to 41 MHz for the
“Lorenz” type of directional VHF (dot-dash) beams used in the UK for airfield
instrument approaches using the “Standard Beam Approach” (SBA) system.
Externally, the modified receiver had a dial calibrated from 28.0 to 41.0 MHz
plus a UK-style antenna connector on the left side. It was stamped “MOD CBA”.
It is unknown who performed these conversions or how many were made.
BC-455-B MOD CBA 28.0 to 41.0 MHz
Gordon White addressed details of these in "CQ Magazine", June 1968.
J.2 USAAF - AN/ARA-1(XA-1) Radio Compass Adapter (1943)
The AN/ARA-1(XA-1) utilizes a loop-fed BC-453-B and/or BC-946-B with a compass
adapter (modulator) to control an aural output and visual LEFT-RIGHT beam
indicator meter. Details of the modifications required for the receivers
is unknown to me.
J.3 USAAF - AN/CRW-3 Guided Glide Bomb Control (1944)
Some SCR-274-N BC-454-B and BC-455-B receivers were incorporated into the glide
bomb radio control system AN/CRW-3. This control system was part of the
late-WWII GB-4 glide bomb. The standard receivers were modified slightly to
provide a connection to the RF and IF stages for an external electronic gain
control signal from AM-41/CRW-3. The dial was removed except during frequency
adjustment. The original nomenclature was altered with a paper tag to end with
a “-BM”. The receivers were mounted in special mountings for the AN/CRW-3.
BC-454-BM 3.0 to 6.0 MHz
BC-455-BM 6.0 to 9.1 MHz
Dave Stinson at one time posted on his web pages a copy of the operating
instruction manual for the AN/CRW-3.
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