National NC-100 family tree (long)
Larry
technical threads in r.r.a.b.....
OK, here is part of my National research:
enjoy, (if the newsreader doesn't choke...)
National "coil-catacomb" radio family tree:
Filename: NC-100.txt
Copyright 1998, by Lawrence R. Ware
All rights reserved.
Introduction:
The National Radio Company, Inc. Introduced the first of its now
famous "coil-catacomb" radios with a brief announcement in 1935.
For the first radio of the series, the NC-100, deliveries started in
1936. The amateur version, the NC-101X) followed shortly thereafter.
Alphabetical Listing of all known National "Coil-Catacomb" Radios and
variants: (If you have one I don't know about, please drop me a line.
:-)
(Model designations in alphabetical order)
AN/GRR-3 (M3 page 95)
GRR-3 (M4 page 110)
WWII years?
NC-100ASC according to Moore
BC-903-A (M3 page 95)
WWII vintage
.54-30 MHz.
No crystal filter,
Navy version of NC-100A according to Moore.
(BC-903-A is perhaps an Army Signal Corps designation.)
NAO (AWA)
A very odd radio perhaps never went beyond prototype stage?
Appears to be another NC-100A variant with the extra RF preselector
stage on
rear (See RAO series.) Front panel has direct reading "A" type dial
and catacomb bandswitching knob, small rack handles, front mounted
fuse holders. Does not appear to have Crystal filter installed. Shown
in National photographs as a rack mount system, c
omplete with duel Dynamo rack mount
power supply. Appears to have Navy Grey paint instead of the classic
Black Wrinkle finish.
Post war? No other information available.
NBL (AWA)
Another very odd radio. Appears almost identical to NAO, except for an
added 1/4" phone jack, labeled "XTAL," and another extra control
labeled "OSC TEST." Appears to be another NC-100A variant with the
extra RF preselector stage on rear (See RAO series.
) Front panel has direct reading "A" type dial
and catacomb bandswitching knob, small rack handles, front mounted
fuse
holders. Does not appear to have Crystal filter installed. Shown in
National
photographs as a rack mount system, complete with duel Dynamo rack
mount
power supply. Appears to have Navy Grey paint instead of the classic
Black Wrinkle finish. Perhaps another post war prototype? No other
information available.
NC-80X (M3 page 88, M4 page 101)
1937-38
4 bands, .55 to 30 MHz
1560 kHz IF, crystal filter, Balanced and unbalanced antenna inputs,
AC/DC
power. Slide rule dial, low cost catacomb radio.
Tube lineup:
6L7 Mixer
6J7 HFO
6K7 1st IF
6K7 2nd IF
6K7 3rd IF
6C5 Detector
6B8 AVC
6J7 BFO
25L6 AF out
25Z5 Rectifier
NC-80XB (M4 page 101)
Battery version of NC-80X,
6V6 AF output, needs 135V B+ and 6V heater power.
NC-81X (M3 page 88, M4 page 102)
1937-39
Ham band only model of NC-80X
5 bands, 10, 20, 40, 80, 160 meters.
NC-81XB (M4 page 102)
Battery model of NC-81X
The radio that started it all.
NC-100 (M3 page 88, M4 page 102, Man, Riders, NC1937, others)
1936-1938, 5 bands, 540-30,000 kHz
455 kHz IF (M3, M4), 456 kHz IF (Riders 8),
No crystal filter, PW dial system,
Tuning eye tube version.
This and the NC-100X are the so-called "Art Deco" design Nationals.
Horizontal bright red stripe, silver and black vertical stripes set
these apart from all the other coil catacomb models.
Tube line up: (from manual, agrees with M3, M4, & Riders)*
6K7 RF amp
6J7 Mixer
6K7 HF OSC
6K7 1st IF
6K7 2nd IF
6C5 Detector
6J7 AVC
6J7 BFO
6E5 tuning eye tube
6F6(2) Audio out (push pull)
80 Rectifier
*See Noise-Limiter Note
References include:
1935 National catalog (#250) page 17, text block describing new NC-100
radio
in preparation. (Possible first ever reference in print to NC-100?)
Sept. 1936 article in "Short Wave craft" magazine:
The New National NC-100 Receiver, by James Millen and Dana Bacon.
Oct. 1936 issue of "Short Wave Craft" magazine ad.
Dec. 1936 issue of "Radio Craft" magazine ad.
Dec. 1936 issue of "All Wave Radio" magazine ad.
Feb. 1937 issue of "All Wave Radio" magazine ad.
1938 National Company Engineering Bulletin, (from: "Notes on Amateur
Radio
Transmitter Design" by James Millen, 1938) "The National NC-100
Receiver"
by James Millen and Dana Bacon.
Riders volume 8
NC-100 Battery (M3 page 88, M4 page 102, Man)*
1936-38, battery version of the standard NC-100
*See Noise-Limiter Note
NC-100A (M3 page 88, M4 page 102, Man)
1938-45,
"A" variant, new direct readout tuning dial replaces the PW type.
The first of the "A" series.
5 bands, .54-30 MHz, 455 kHz IF, s-meter
Tube lineup:
6K7 RF Amplifier
6J7 1st Detector
6J7 HF OSCILLATOR
6K7 1st IF
6K7 2nd IF
6C8 2nd Detector/Limiter
6F8 AVC / 1st Audio
6J7 BFO
6F6G(2) push-pull Audio out
80 Rectifier
(Note: The NC-100A and XA were also available in two different battery
powered versions: The first and more common required external B+ and
filament power. The second more unusual version contained an internal
vibrator based power supply and required only 6 VDC to be provided.)
NC-100A special (M3 page 88, M4 page 102, PC)
NC-100A with LF band, 200-400 kHz (Sometimes incorrectly called the
NC-100ALF)
NC-100ASC (M3 page 88, M4 page 102)
Moore's 4th says see GRR-3. (AN/GRR-3)
NC-100ASD (M3 page 88-89, M4 page 103, Man)
200-400 kHz and 1.3 MHz to 30 MHz, 5 bands, S-meter, 456 kHz IF
Band 1: 200-400 kHz
Band 2: 1,300-2,800 kHz
Band 3: 2,800-6,400 kHz
Band 4: 6,400-14,000 kHz
Band 5: 14,000-30,000 kHz
115V 60 or 25 Hz power supply
Binding post antenna connectors
Built to Army Signal Corps standards, this has a push-pull s-meter
on-off
switch instead of the more common toggle.
Tube line up: (from manual, agrees with M3 and M4)
V-101 6K7 RF amp
V-102 6J7 First Detector
V-103 6J7 HF Oscillator
V-104 6K7 1st IF
V-105 6K7 2nd IF
V-106 6F8G 1st Audio + AVC
V-107 6C8G 2nd Detector + 2nd Audio
V-108 6J7 CW/BFO Oscillator
V-109 6V6G Audio out
V-110 5Z3 Rectifier
NC-100S (M3 page 89, M4 page 103)*
NC-100 with special 12" speaker
*See Noise-Limiter Note
NC-100X (M3 page 89, M4 page 103)*
NC-100 with crystal filter, this is the other National "Art Deco"
design
coil catacomb radio. This radio was also available with a 200 - 400 KC
low
frequency band. The low frequency version is sometimes incorrectly
called
the NC-100XL or XLF.
*See Noise-Limiter Note
NC-100X battery (M3 page 89, M4 page 103)*
NC-100 battery powered model with crystal filter
*See Noise-Limiter Note
NC-100XA (M3 page 89, M4 page 103)
NC-100A with crystal filter
NC-100XAL special (M3 page 89, M4 page 103)
Has both Crystal Filter and special 200-400 KC LF band.
Binding post antenna terminals.
NC-100XS (M3 page 89, M4 page 103)*
NC-100X with 12" speaker
*See Noise-Limiter Note
NC-100XAM (M3 page 89, M4 page 103)
NC-101X (M3 page 89, M4 page 104)
1936-39
Ham band only version of NC-100, PW dial,
Tuning eye tube, crystal filter, 455 kHz IF
5 ham bands, 160, 80, 40, 20, 10 meters
tube line up:
6K7 1st RF
6J7 Mixer
6K7 HF OSCILLATOR
6K7 1st IF
6K7 2nd IF
6C5 Detector
6J7 AVC
6J7 BFO
6F6(2) push pull Audio out
6E5 tuning eye
80 Rectifier
Earliest reference to this radio I have found is an ad in Feb. 1937
QST magazine. I also have a photocopy of a letter from James Millen to
Bill Orr briefly discussing this unit.
NC-101X variation (M3 page 90, M4 page 104)*
S-meter replaces "eye" tube
Push-pull s-meter switch
*See Noise-Limiter Note
NC101X battery (M3 page 90, M4 page 104)
Battery version of NC-101X, needs 180V B+ @ 35 ma and 6V heater power
6K7 1st RF
6J7 Mixer
6K7 HF OSCILLATOR
6K7 1st IF
6K7 2nd IF
6C5 Detector
6J7 AVC
6J7 BFO
6F6 Audio out
6E5 tuning eye.
NC-101XA (M3 page 90, M4 page 104)
1939-41
Amateur band version of NC-100A,
S-meter, noise Limiter, crystal filter, 455 kHz IF
5 bands, 160, 80, 40, 20, 10 meters
6K7 1st RF
6J7 Mixer
6K7 HF OSCILLATOR
6K7 1st IF
6K7 2nd IF
6C8 Detector/noise Limiter
6J7 BFO
6F8 first Audio/AVC
6F6 (2) PP Audio output
80 Rectifier
NC-120 (M3 page 90, PC, M4 page 105, AWA)
I have conflicting information concerning the NC-120. An original
National
photograph (provided thanks to Alan Douglas) of this radio is also
marked
"RAO-2". I know of at least one NC-120 with contract data plate still
attached that says it is part of radio type CAN-46187. Yet this radio
continues to be a minor mystery, Virtually identical to the RAO-3/4
and
RAO-6, it is clearly a member of the family, yet my copy of the RAO
3&4
manual states that the manual is unsuitable for use with the RAO-2 due
to
significant differences between the radios. Mine, also has a
panadaptor
output, which is shown in only SOME of the National NC-120/RAO-2 rears
view
photographs. Antenna connections are another problem, Mine has
standard
National type binding posts, yet National Company photographic records
show
an unusual coax connector as correct. My antenna binding posts are
clearly
unmodified.
Similar to NC-100A with added RF stage bolted/welded to rear of
cabinet.
Separate coil catacomb and variable tuning capacitor ganged to main
controls.
S-meter, s-meter switch, crystal filter, 455 kHz panadaptor output
(SO-239
type) Some have Binding Post type antenna connectors, some coax based
antenna
input.
5 bands, 540-30,000 kHz
Band A 14-30 MHz
Band B 6.4-14 MHz
Band C 2.8-6.4 MHz
Band D 1.3-2.8 MHz
Band E .54-1.3 MHz
Tube Data from my radio:
V-101 6K7 1st RF Amplifier
V-102 6K7 2nd RF Amplifier
V-103 6J7 1st Detector
V-104 6K7 1st IF Amplifier
V-105 6K7 2nd IF Amplifier
V-106 6C8G 2nd Detector & Limiter
V-107 6F8G 1st Audio & AVC
V-108 6K6GT 2nd Audio (output)
V-109 6J5 HF OSCILLATOR
V-110 6J7 BFO OSCILLATOR
V-111 VT-145/5Z3 Rectifier
NC-127 (M3 page 91 & 123, M4 page 105)
WWII vintage
(Moore's reports 4 bands, I believe it should be 5) .54-30 MC
455 kHz IF, crystal filter
Similar to NC-100XA
Has rack type handles and front panel captive style rack-retaining
screws.
Tube line up from Moore's 3rd:
2 6K7 RF amps.
1 6J7 Mixer
1 6J5 HFO
2 6K7 IF amps.
1 6C8 Detector/NL
1 6J7 BFO
1 6F8 1st Audio/AVC
1 6V6 Audio out
1 5Z3 Rectifier
NC-127D (M3 page 91 & 123, M4 page 105)
Used in experimental triple diversity system.
Only one system (three receivers) believed to have been made.
Added two position "DIVERSITY" control and a DIVERSITY IF GAIN
CONTROL.
NC-1-39 (M4 page 105)
5 bands, .54-30 MHz, crystal filter,
Moore reports this is another modified NC-100XA with two headphone
jacks.
Designed for headphones use only, no Audio power amplifier.
Tube line up from Moore's 4th:
1 6K7 RF Amplifier
1 6J7 1st Detector/mixer
1 6J7 HFO
2 6K7 IF amps.
1 6C5 2nd Detector
1 6J7 AVC
1 6J7 BFO
1 80 Rectifier
NC-1-39S (M4 page 105)
5 bands, 200-400 kHz, .495-1.060 & 1.3-14.4 MHz
Same as NC-1-39 except for band coverage.
Radio is intended for VLF and Direction Finding, (DF) use.
NC-156 (MAN)
Navy NC-100XA variation, with 1560 KC IF system, and unusual tuning
ranges.
Unlike the later NC-156-1 and - 2, the standard NC-156 does not have
the extra RF stage. Also known as Type CNA-46144, and the RBH, the
manual I
have lists General Electric Supply Corp. as the primary contractor.
(See RBH)
Ten (10) tubes, s-meter, 1560 KC crystal filter.
5 bands,
300-600 kHz
600 kHz - 1.2 MHz
1.7-3.9 MHz
3.6-8.2 MHz
8-17 MHz
Tube line up: (from manual)
V-101 6K7 RF amp
V-102 6J7 First Detector
V-103 6J5 HF Oscillator
V-104 6K7 1st IF
V-105 6K7 2nd IF
V-106 6F8G 1st Audio + AVC
V-107 6C8G 2nd Detector + Limiter
V-108 6J7 CW/BFO Oscillator
V-109 6V6G Audio out
V-110 5Z3 Rectifier
NC-156-1 & NC-156-2 (M3 page 91, M4 page 106, PC, MAN, AWA)
Navy NC-100XA with two RF stages and 1560 KC IF chain
Eleven tubes, s-meter, 1560 KC crystal filter. Only known difference
between
the -1 and -2 versions is removal of a "dummy" plug, (replaced with a
blank plate) on the rear of the radio.
5 bands,
300-600 kHz
600 kHz - 1.2 MHz
1.7-3.9 MHz
3.6-8.2 MHz
8-17 MHz
(See RBH series)
Tube Data from my NC-156-1 radio:
V-101 6K7 1st RF Amplifier
V-102 6K7 2nd RF Amplifier
V-103 6J7 1st Detector
V-104 6K7 1st IF Amplifier
V-105 6K7 2nd IF Amplifier
V-106 6C8G 2nd Detector & Limiter
V-107 6F8G 1st Audio & AVC
V-108 6K6GT 2nd Audio (output)
V-109 6J5 HF OSCILLATOR
V-110 6J7 BFO OSCILLATOR
V-111 VT-145/5Z3 Rectifier
NC-200 (M3 page 92, M4 page 107, Man, Riders 14, AWA) 1940-43
Ten bands, 6 general coverage, 4 ham bandspread.
490-30,000 kHz, bandspread - 10, 20, 40, 80 meters
Crystal Filter, 12 tubes, s-meter.
Ten ranges, calibrated frequency dial, this is the first of the coil
catacomb
radios to have both "general coverage" and "bandspread" ham bands in
the same
radio. The main tuning control has a push-pull function that allows
you to
select either the six general coverage or 4 ham bands as well as set
the
desired tuned frequency. This radio has the odd "slatted sides" also
seen
on NC-2-40 series radios. Possibly the first to use them? The cast
"coil-catacomb" on these and later models which have both general
coverage
and amateur bandspread ranges have a far more complex internal
construction.
Tube lineup from manual:
6SK7 RF Amplifier
6K8 1st Detector
6J5 HFO
6K7 1st IF Amplifier
6SK7 2nd IF Amplifier
6C8 2nd Detector/Limiter
6SJ7 AVC
6SJ7 BFO
6F8 1st Audio and Phase inverter
6V6(2) push-pull Audio output
5Y3G Rectifier
NC-200RG (M3 page 93, M4 page 107)
rack model of above
NC-200TG (M3 page 93, M4 page 107)
Table model of above, (may be same radio: nomenclature issue.)
NC-200TGM (M4 page 107)
NC-200TG without ham bandspread
NC-2-40 (M3 page 93, M4 page 108)
1943-44
(Successor to NC-200 according to Moore)
6 bands, .49-30 MHz, 455 kHz IF
Crystal filter, 13 tubes, s-meter
6SK7 RF Amplifier
6K8 Mixer
6J5 HF OSCILLATOR
6K7 1st IF
6SK7 2nd IF
6C8 Detector/NL
6SJ7 AVC
6SJ7 BFO
6J5 1st Audio
6F8 Phase Inverter
6V6(2) push-pull Audio out
80 Rectifier
NC-2-40C (M3 page 93, M4 page 108, SRPP page 234, Riders 15)
1945-46 (M3, M4) 1946-47 (SRPP)
115-230V, 455 IF, crystal filter, s-meter
six bands, 490-30,000 kHz
6SK7 RF Amplifier
6K8 Mixer
6J5 HF OSCILLATOR
6K7 1st IF
6SK7 2nd IF
6SL7 Detector/NL
6SJ7 AVC
6SJ7 BFO
6SN7 1st Audio/Phase Inverter
6V6(2) push-pull Audio out
5Y3GT Rectifier
NC-2-40CR (SRPP page 234)
Rack version of NC-2-40C
NC-2-40CS (M3 page 93, M4 page 108, SRPP page 234, Riders 15)
Same as NC-2-40C except
LF band 200-400 kHz and 1000-30,000 kHz coverage.
NC-2-40CSR (SRPP page 234)
Rack version of NC-2-40CS
NC-2-40D (M3 page 93, M4 page 108, SRPP page 235, Man)
1946-49 (M3, M4), 1947-48 (SRPP)
10 Bands, 6 GC + 4 ham bandspread, 10, 20, 40, 80 meters.
490-30,000 kHz
455 kHz IF, crystal filter, s-meter
tube line-up:
6SK7 RF Amplifier
6K8 Mixer
6J5 HF OSCILLATOR
6K7 1st IF
6SK7 2nd IF
6SL7 Detector/NL
6V6 AVC
6SJ7 BFO
6SN7 1st Audio/Phase Inverter
6V6(2) push-pull Audio out
5Y3GT Rectifier
NC-2-40DR (M3 page 93, M4 page 108)
Rack model NC-2-40D
NC-2-40DT (M3 page 93, M4 page 108)
Table model
NC-2-40S (M3 page 93, M4 page 108, Man)
(Odd coverage .2-18 MHz, otherwise same as NC-2-40 according to
Moore.)
6 bands, 200-400 kHz, 490-1,060 kHz, 1,000-2,400 kHz, 2,200-5,000 kHz,
4,500-10,000 kHz, and
9,000-18,000 kHz
External type 2-42 power unit required. Cable with 7 prong connectors
supplied. 115/230 VAC
Binding post antenna terminals, s-meter, crystal filter
Tube line up: (from my manual copy)
V-1 6SK7 RF Amplifier
V-2 6K8 1st Detector
V-3 6J5 HF OSCILLATOR
V-4 6K7 1st IF Amplifier
V-5 6SK7 2nd IF Amplifier
V-6 6C8 2nd Detector/Limiter
V-7 6SJ7 BFO
V-8 6SJ7 AVC
V-9 6F8 1st Audio/Phase inverter
V-10 6V6 Audio out
V-11 6V6 Audio out
V-12 6J5 headphone Amplifier
V-13 80 Rectifier (in power supply)
Notes: The manual copy I have states:
"Made for Pan American Airways System, Chrysler Building, NYC" on the
cover.
NRCL (M3 page 95. M4 page 110)
1944-45
NC-100 variant for dual diversity system, part of NCRM system.
NCRM (M3 page 95)
1944-45
NC-100 based dual diversity system.
Probably experimental, M3 only reference so far.
R-115 (M3 page 95 & 123, M4 page 111, AWA)
WWII vintage
AC/DC set, no crystal filter
6 bands, 200-400KC and 490KC to 18MHz
Similar to NC-200, but without Amateur Bandspread or Crystal filter.
Made for US Coast Guard.
(R-115 sounds like a JAN (Joint Army-Navy) designation, which would
Probably have a AN/SRC-*** (for surface ship) or AN/GRC-*** "system"
Designation as well.)
Tube line up (from Moore's)
4 117N7
3 12SK7
1 12K8
1 12J5
1 12SC7
1 12C8
1 12SR7
1 12SJ7
(This must be a very odd set...)
Contract: TCG-23454 Order # CG-80110? Date: 10DEC1940
R-116 (AWA)
NC-100A based US Coast Guard Radio Receiver, may never have proceeded
beyond prototype stage. Mostly unknown, Has Crystal Filter, BFO and
AVC
control, 300/600 Ohm speak terminals & Binding post type antenna
terminals.
Contract: TCG-33675 Order #: CG-80265? Date: 15MAY1941
RAO Notes: Moore's 3rd reports RAO-1 through RAO-8 as identical
radios. I
have found that this is not the case. Each model has variations enough
to
justify separate listings. Some radios have s-meters, some have aux.
"panadaptor" outputs. Several different "antenna" connectors were
used,
including binding posts, an odd oversized Motorola type plug and
SO-239's?
(I continue to wonder how original/correct the SO-239's are?) Minor
differences in rear panel layout of power, speaker, antenna, and
battery
connectors exist. I suspect that differences between manufactures
exist even
within the same series number. (At least in tube line up, i.e. 6F6,
vs. 6V6,
vs. 6K6 audio output.) Because the RAO series were built during WWII
primarily for the Navy, small engineering changes may have been made
from
production run to production run just because of parts availability.
Information that exactly matches many RAO series radios has proved
difficult
to locate. Several RAO's I have examined do not exactly agree with the
Navy
documents for that model. It appears that some units were built only
by
National, (RAO-2/6?) some only by Wells-Gardner, (RAO-4?) and some by
both
companies. I continue to research this issue. Where the National
NC-120 fits
into this puzzle remains unclear, I own one NC-120 and have seen
several
others. None exactly match photographic records from National.
Moore's 4th adds another variation: On page 111 an RAO without a
suffix number/code.
(See RAO)
I have located several references in National documentation to an
RAO-9 radio. (See RAO-9)
This remains mostly a mystery set.
Moore's 3rd lists generic data for the RAO-1 through RAO-8 as follows:
Crystal filter, added RF stage, 455 kHz IF, 5 bands, 540-30,000 kHz.
Tube line up:
6K7 1st RF
6K7 2nd RF
6J7 Mixer
6J5 HF OSCILLATOR
6K7 1st IF
6K7 2nd IF
6C8 Detector / noise Limiter
6J7 BFO
6F8 1st Audio / AVC
6V6 Audio output
5Z3 Rectifier
RAO (M4 page 111)
1938, 5 bands, .54-30 MHz coverage.
456 kHz IF, crystal filter.
Moore (4th) lists the Navy designation as: CNA-46072, with GE as the
contractor.
Moore reports that this very early version does not have the added RF
stage attached to the back.
RAO-1 (M3 page 95. M4 page 111)
WWII vintage
Built for US Navy, similar to NC-100A with added
RF stage bolted/welded to rear of cabinet. Separate coil catacomb and
variable tuning
Capacitor ganged to main controls.
May have been built by Wells-Gardner as well as National, using
National parts.
RAO-2 (M3 page 95, M4 page 111, AWA)
WWII vintage
Built for US Navy, similar to NC-100A with added
RF stage bolted/welded to rear of cabinet. Separate coil catacomb and
variable tuning
Capacitor ganged to main controls.
This is the Navy version of the NC-120 radio.
(See NC-120) Part of CNA-46187 radio system.
High S/N known 2112, date code: 11/20/1943
RAO-3 (M3 page 95, M4 page 111, partial Man)
WWII vintage (Navy type CWQ-46187-A)
Built for US Navy, similar to NC-100A with added
RF stage bolted/welded to rear of cabinet. Separate coil catacomb and
variable tuning
Capacitor ganged to main controls.
Built by Wells-Gardner as well as National, using National parts.
115V 60 Hz
.54-30 MHz, five bands., odd antenna connector,
S-meter, s-meter switch, crystal filter, no panadaptor output.
Known contract(s):
NXss-21446 high S/N known: 853, Date: 11/18/1943.
Tube Data from manual in my files:
V-101 6K7 1st RF Amplifier
V-102 6K7 2nd RF Amplifier
V-103 6J7 1st Detector
V-104 6K7 1st IF Amplifier
V-105 6K7 2nd IF Amplifier
V-106 6C8G 2nd Detector & Limiter
V-107 6F8G 1st Audio & AVC
V-108 6K6GT 2nd Audio (output)
V-109 6J5 HF Oscillator
V-110 6J7 C.W./BFO Oscillator
V-111 5Z3 Rectifier
RAO-4 (M3 page 95, M4 page 111, partial man, PC)
WWII vintage (Navy type CWQ-46187-B)
Built for US Navy, similar to NC-100A with added
RF stage bolted/welded to rear of cabinet. Separate coil catacomb and
variable tuning
Capacitor ganged to main controls.
Built by Wells-Gardner as well as National, using National parts.
115 or 230V 60 Hz (except for dual input main power transformer, same
as RAO-3.)
540 kHz - 30 MHz, five bands, odd antenna connector.
S-meter, s-meter switch, crystal filter, no panadaptor output.
Tube Data from manual in my files:
V-101 6K7 1st RF Amplifier
V-102 6K7 2nd RF Amplifier
V-103 6J7 1st Detector
V-104 6K7 1st IF Amplifier
V-105 6K7 2nd IF Amplifier
V-106 6C8G 2nd Detector & Limiter
V-107 6F8G 1st Audio & AVC
V-108 6K6GT 2nd Audio (output)
V-109 6J5 HF OSCILLATOR
V-110 6J7 C.W./BFO OSCILLATOR
V-111 5Z3 Rectifier
(Note that my Wells-Gardner RAO-4 has a 6V6 audio output, not the 6K6
the Navy (National) manual specifies. 6V6 is printed (inked) next to
the tube socket in mine.)
Known contract(s):
NXss-21446 High S/N unknown
(See RAO-3)
RAO-5 (M3 page 95, M4 page 111)
WWII vintage
Built for US Navy, similar to NC-100A with added
RF stage bolted/welded to rear of cabinet. Separate coil catacomb and
variable tuning
Capacitor ganged to main controls.
May have been built by other contractors (Wells-Gardner, etc.) as well
as National, using National parts.
Moore reports (4th) that the USN code for this radio was: CWQ-46229
RAO-6 (M3 page 95, M4 page 111, Man, Pvt.)
WWII vintage, Navy type # CNA-46187-D, Part of Navy CNA-46233 Receiver
System.
Built for US Navy, similar to NC-100A with added
RF stage bolted/welded to rear of cabinet. Separate coil catacomb and
variable tuning
Capacitor ganged to main controls.
May have been built by Wells-Gardner as well as National, using
National parts.
540-30,000 kHz, 11 tubes, five bands, crystal filter, s-meter
455 kHz IF, has aux. panadaptor output, (SO-239.)
Odd oversized antenna connector is correct for the type 6.
Known contract data:
NXsr-38306 high S/N ? Date: 22SEP1943 (from my manual copy)
NXsr-38306 high S/N 648 Date 31JAN1945 (Pvt. Communication)
NXsr-38306 high S/N 653 Date 15JUN1944 (Pvt. Communication)
Tube data from manual in my files:
V-101 6K7 1st RF Amplifier
V-102 6K7 2nd RF Amplifier
V-103 6J7 1st Detector
V-104 6K7 1st IF Amplifier
V-105 6K7 2nd IF Amplifier
V-106 6C8G 2nd Detector & Limiter
V-107 6F8G 1st Audio & AVC
V-108 6K6GT 2nd Audio (output)
V-109 6J5 HF OSCILLATOR
V-110 6J7 C.W./BFO OSCILLATOR
V-111 5Z3 Rectifier
RAO-7 (M3 page 95, M4 page 111, Man, Pvt., AWA)
WWII vintage, Navy type # CNA-46233
Built for US Navy, similar to NC-100A with added
RF stage bolted/welded to rear of cabinet. Separate coil catacomb and
variable tuning
Capacitor ganged to main controls. Has panadaptor output on back,
(SO-239.)
NC-127 look alike, with heavy rack type capture screws around face.
(May have been built by Wells Gardner as well as National. Open
question yet.)
.54 to 30 MHz, five bands W/crystal filter.
455 kHz IF
Known contracts:
NXsr-55614 high S/N 1587 date: 31MAY1945 (Navy Bureau of
Ships)
NXsr-38306 high S/N 444 date: ?
Part of Navy CNA-46233 Receiver System.
In the case of the RAO-7 some interesting information was found in a
copy of
the: "Preliminary Instruction Book, Contract NXsr-55614, 13FEB1945."
The
document states that:
1073 "Receivers" were contracted for, along with 1073 "Spare Parts
Sets,"
107 Stock Spare Parts Sets," 4146 "Preliminary Instruction Books,"
(this data is from one of them) 4646 "Final Instruction Books," and
107
unspecified "Additional Spare Parts." (Pvt. Communication)
Tube Data from manual in my files:
V-101 6K7 1st RF Amplifier
V-102 6K7 2nd RF Amplifier
V-103 6J7 1st Detector
V-104 6K7 1st IF Amplifier
V-105 6K7 2nd IF Amplifier
V-106 6C8G 2nd Detector & Limiter
V-107 6F8G 1st Audio & AVC
V-108 6K6GT 2nd Audio (output)
V-109 6J5 HF Oscillator
V-110 6J7 C.W./BFO Oscillator
V-111 5Z3 Rectifier
RAO-8 (M3 page 95, M4 page 111)
WWII vintage
Built for US Navy, similar to NC-100A with added
RF stage bolted/welded to rear of cabinet. Separate coil catacomb and
variable tuning
Capacitor ganged to main controls.
May have built by Wells-Gardner as well as National, using National
parts.
RAO-9 (Brief mention in my National RAO-7 manual, AWA)
Part of Navy System: CNA-46283
Has both small rack mount "handles" and "Capture" Screws on front
panel
(like NC-127) Crystal filter, Panadaptor output, odd coaxial type
antenna
connector. Another NC-100A variant with the extra RF preselector
built on
the back. No other data available yet...
RBH series (M3 page 96, M4 page 111, MAN, Pvt.)
(Note that Moore's 3rd & 4th do not differentiate between the 3
versions.)
Navy NC-100XA type variations, some with two RF stages, the extra
stage bolted to rear like most RAO series. Unusual 1560 kHz IF
(See NC-156, NC-156-1, NC-156-2)
Known contracts:
RBH Contract # 87668, major part of CNA-46144, contractor was the
General Electric Supply Company.
RBH-1 Contract Number NXs- 738, major part of CNA-46188 system, high
serial number unknown, contract date was April 30, 1942
RBH-2 Contract Number NXss-19881, major part of CNA-46188 system, high
S/N known: 1269, Contract date was January 2, 1943
RBH-3 Contract Number NXsr-33381, major part of CNA-46188 system, high
serial
number unknown, Contract date was June 30, 1943
RBL-1 through 5 (PC, Man, AWA)
Built on NC-100A chassis, this VLF-LF receiver is only a NC-100A look
alike
on the outside. Under the skin, it is a completely separate design
based on
TRF tuning and regenerative detection. 10-600 KC made by National and
Wells Gardner using National parts. WW II years.
(A very interesting, and fun to use radio. Without a coil catacomb, It
doesn't really belong to the NC-100 family. Often mistaken for a
NC-100A.)
RC-120 (AWA)
NC-100A variation built for the US Coast Guard.
This one has a tuning eye instead of the normal for the 100A series
S-meter. In addition, does not appear to have a Crystal Filter
installed.
2 to 18 MHz in three bands
Contract TCG-33991? 24SEP1941
(Apparently a very early 100A variant...)
"Airways Ground Receiver" (AGR) series:
AGR Series note: All AGR series radios were rack mount versions,
designed for the standard 19" rack environment.
They were sometimes supplied with an optional enclosure for desk or
tabletop use.
RCD (PC)
Early NC-100X CAA variant. Has Crystal Filter, and 6E5 tuning eye
tube.
Push-Pull Audio output. With 200 - 400 kHz low band.
I believe this was the first of the CAA AGR series. This radio seems
to be a
standard early NC-100 (W/tuning eye) equipped with the low frequency
first band option, (200 - 400 KC) in a 19" rack mount configuration.
Tube lineup:
6K7 RF amp
6J7 Mixer
6K7 HF OSC
6K7 1st IF
6K7 2nd IF
6C5 Detector
6J7 AVC
6J7 BFO
6E5 tuning eye tube
6F6(2) Audio out (push pull)
80 Rectifier
Known Contract:
Contract (unknown) Order # 37-7383 high S/N 101
Built by National, information from data plate on radio.
RCE (M3 page 96 & 123, M4 page 112, AWA) "Airways Ground Receiver" *
Modified NC-100 for airport control tower use.
>From about 1937-38, 5 bands, 200 - 400 kHz, 1.3-30 MHz
457 kHz IF, no crystal filter, Binding post antenna terminals.
Tube lineup from Moore's 4th:
6K7 1st RF
6J7 1st Detector/mixer
6J7 HF OSCILLATOR
6K7 1st IF
6K7 2nd IF
6C5 2nd Detector
6J7 AVC
6J7 BFO
6J7 INS control
6C5 1st Audio
6V6 Audio output
80 Rectifier
Known Contracts:
Contract (unknown) Order # 38-2833 high S/N 187 01OCT1937
Built by National, modified by Westinghouse Electric and Manufacturing
Co.
Contract (unknown) Order # 38-2832 high S/N 478 unknown
Built by National, modified by Bendix Radio
*At least one prototype unit produced directly by National with
crystal control. Photographs #938 & 968, 969. 970 & 971 in AWA
National records. Labeled as the model RCE-X.
RCF (Man, Pvt.) "Airways Ground Receiver"
"Interchannel Noise Suppression" radio.
457 kHz IF, does not have variable bandwidth IF transformers.
Does not have crystal frequency control option.
(Interestedly, the picture in the RCF manual of the radio shows a
Bendix Radio Corp. data plate.)
Tube lineup from manual:
VT-1 6K7 RF amp
VT-2 6J7 Mixer
VT-3 6J7 HFO
VT-4 6K7 1st IF Amplifier
VT-5 6K7 2nd IF Amplifier
VT-6 6C5 Detector
VT-7 6C5 1st Audio/squelch
VT-8 6J7 BFO
VT-9 6J7 AVC
VT-10 6J7 I.N.S. Amplifier
VT-11 6V6 Audio output
VT-12 80 Rectifier
Known Contracts:
Contract (unknown) Order # 39-2748 high S/N 118 Date:
30JUN1939
Made by National, supplied by Federal Telegraph Co. Newark, NJ
RCH (AWA photo)
Modified NC-100, PW dial, I.N.S. system.
5 bands, 200 - 400 kHz, 1.3-30 MHz
Known Contract(s):
Contract (unknown) Order # 40-1760 high S/N unknown Date:
19OCT1939
Made by National, supplied by Bendix Radio Corp. Baltimore, MD
RCK (M3 page 96, M4 page 112, RCP manual page 5,AWA) "Airways Ground
Receiver"
Moore's 3rd calls this a NC-100A Moore's 4th a NC-100. It is a
modified NC-100 (no A) chassis with PW dial. Mostly an unknown variant
(mentioned briefly in RCP manual) and I have some photographs
(#1030-1036, 1058, 1059) from the AWA National archives o
f a type RCK-1. The photographs show both C.O.N.S. and variable
bandwidth IF, and a dual 120/240 VAC power supply.
No Crystal control option.
Contract Cca-617? Order # unknown high S/N unknown
Built by National for General Electric Supply Corp. Washington, D.C.
Contract, Cca-978 Order # unknown high S/N unknown
Built by National for Bendix Radio Corp.
Contract (unknown) Order # 38-2833 high S/N 187 Date:
01OCT1937
Built by National, modified by Westinghouse Electric and Manufacturing
Co.
Contract (unknown) Order # unknown high S/N 235 Date:
30JUN1939
Part of VF Radio Equipment No's 6736 (Pvt. Communication)
RCL (M3 page 96 & 123, M4 page 112, Man, AWA) "Airways Ground
Receiver"
Modified NC-100, Roughly WWII vintage
5 bands, 200 - 400 kHz, 1.3-30 MHz
455 KC IF with odd modified variable coupling IF transformers.
The IF coupling can be changed from sharp to broad from a front panel
switch
on this radio. This feature was later deleted when government
contractors
refurbished these radios.
(See type RCP & RCQ.)
Squelch circuit (CONS) added. Crystal oscillator tuning option added,
Tube lineup from Moore's 3rd & 4th.
6K7 RF amp
6J7 Mixer
6J5 HFO
6K7 1st IF Amplifier
6K7 2nd IF Amplifier
6C5 Detector
6F8 1st Audio/squelch
6J7 BFO
6J7 AVC
6J7 CONS amp
6V6 Audio output
80 Rectifier
RCP (M3 page 96, M4 page 112, PC {2}, Man, PVT) "Airways Ground
Receiver"
Moore calls this a NC-100A on page 96 of his 3rd edition,
This is incorrect, it is a NC-100 (no A) chassis with PW dial.
Modified NC-100, Roughly WWII vintage
200 - 400 kHz, 1.3-30 MHz
455 KC IF with three odd modified variable coupling IF transformers.
Squelch circuit (CONS) added. Crystal oscillator tuning option,
Known contracts:
CAA Contract # Cca-24653 Order 46-1467, high S/N 825 30OCT1945, built
by National, modified by Schuttig & Company, from an RCK or RCL. (See
manual page 5)
Tube data from manual in my files:
V-1 6K7 RF Amplifier
V-2 6J7 1st Detector
V-3 6J5 HF OSCILLATOR
V-4 6K7 1st IF Amplifier
V-5 6K7 2nd IF Amplifier
V-6 6C5 2nd Detector
V-7 6F8G 1st Audio & CONS
V-8 6V6 2nd Audio (output)
V-9 6J7 BFO
V-10 6J7 AVC Amplifier
V-11 6J7 AVC control
V-12 80 Rectifier
RCQ (Man, Pvt.) "Airways Ground Receiver"
Modified NC-100, Communications Receiver,
200 - 400 kHz, and 1.3-30 MHz
455 kHz IF, with two odd modified variable coupling IF transformers,
Squelch circuit (CONS) added, Crystal oscillator tuning option.
Tube data from manual in my files:
V-1 6K7 RF Amplifier
V-2 6J7 1st Detector
V-3 6J5 HF OSCILLATOR
V-4 6K7 1st IF Amplifier
V-5 6K7 2nd IF Amplifier
V-6 6H6 2nd Detector & noise Limiter
V-7 6F8G 1st Audio & CONS
V-8 6V6 2nd Audio (output)
V-9 6J7 BFO
V-10 6J7 AVC Amplifier
V-11 6J7 AVC control
V-12 80 Rectifier
Known contracts:
CAA, contract # CCA-26227 high S/N 404 05FEB1948, made by National,
modified
by National Electric Machine Shops, Silver Springs, MD. From a type
RCK or
RCL. (See manual page 5) (I believe this was the last of the CAA
contracts.)
An acquaintance has reported owning one of these with S/N B366.
Unfortunately all the contract data plates are long gone on his radio.
Could there of been more than one series?
RHZ (unknown variant, mentioned briefly on page 5 of RCQ manual, Pvt.)
Known contracts:
CAA, contract # Cca-15856, high S/N 35, made by National, modified
by:
Communications Equipment Corp.
Pasadena, California - USA
CAA Contract # Cca-232876, high S/N 1048, made by National, modified
by:
Communications Equipment Corp.
Pasadena, California - USA
A Note on Noise Limiters; still more variations:
During the production years of NC-100's, NC-101X's and NC-100A's
National
introduced a new "noise Limiter" circuit to many of its models. This
change
was documented in a brief (4-page) addendum supplied with owner's
manuals for
affected radios. A 6C8G and a 6F8G has replaced the 6C5 second
detector and
the 6J7 AVC tubes previously employed. The 6C8G elements comprise an
infinite impedance diode second detector and the new series-valve
noise
limiter while the 6F8G is used for AVC and a new first audio stage.
The circuit was described in some detail in the October 1939 issue of
QST.
The really interesting thing about this noise-limiter is that the
design
change was made in mid-production for many of the early Nationals
without a
model number change. The collector will run across later radios with
the
change and earlier radios without it.
Bibliography & Notes:
Major sources of information included:
AWA - Antique Wireless Association photographic records from The
National Radio Company, Inc. provided to the author by William Fizette
and Alan Douglas.
M3 - Moore's 3rd edition: "Communications Receivers, The Vacuum Tube
Era: 1932-1981" 3rd Edition, by Raymond S. Moore, RSM Communications,
Key Largo, Florida, copyright 1993, ISBN 0-9618882-2-9
M4 - Moore's 4th edition: "Communications Receivers, The vacuum Tube
Era: 1932-1981" 4th Edition, by Raymond S. Moore, RSM Communications,
La Belle, Florida, copyright 1997, ISBN 0-9618882-4-5
MAN - Original and photocopy manuals in my files.
MAG - Original and photocopies of magazine article's in my files.
(Cited where of interest) From CQ, QST, etc.
NA - original or photocopy National Radio Company, Inc. advertisement
in my files.
>From magazine's, ARRL handbooks, etc.
NC - Original and photocopy National catalogs in my files.
NF - Original and photocopies of National Flyer's and brochures in my
files.
PC - My personal collection. (I own these radios)
PVT - Private communications, with current owners, former National
employees, Knowledgeable fellow National collectors, etc.
A Brief History of the National Company, Inc.
By John J. Nagle, (K4KJ) Herndon, VA
The National Sliding Coil Tray Receivers. &
Restoring the National Company Sliding-Coil Receivers.
By William Fizette, Editor A.W.A. Journal
RIDERXX - John Riders "Perpetual Radio Trouble-Shooter" (volume XX)
manuals.
(SRPP) - Shortwave Receivers Past and Present, Communications
Receivers, 1945-1996, 2nd edition, by Fred Osterman, Universal Radio
Research, 6830 Americana Parkway, Reynoldsburg, Ohio copyright 1997,
ISBN 1-882123-06-9
Contract data: Contact numbers, Order numbers, dates, S/N's, etc. are
as reported by owners, from manual copies, and my personal radio
collection.
You are invited to help "fill in the blanks."
-Larry
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