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---------------------------- Original Message
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Subject: [ARC5] A.R.C. Type K "Command Set"
Receiver History (KK5F) - Long
From:
"Mike Morrow" <kk5f@earthlink.net>
Date: Sun,
February 10, 2013 8:23 am
To: arc5@mailman.qth.net
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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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