Hallicrafters SX-43 User manual

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installation
and
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operating
• •
Instructions
for model SX-43
radio rece'iver
MARCH 1949
94XI80
the hallicrafters CD.
MANUfACTURERS Of RADIO AND UHTRONIC EQUIPMENT, CHICAGO 24, U. S. A.

INSTALLATION AND OPERATING INSTRUCTIONS FOR
RADIO RECEIVER MODEL SX-~3
GENERAL INFORMATION
I. INSTALLATION
It is recommended that, upon receipt, the
carton and then the unpacked receiver be care-
fully examined for any damage which may have
occurred during shipment. Should any damage be
apparent, immediately file claim with the car-
rier, stating the extent of damage.
IMPOR!AN!. Unless otherwise marked, this re-
ceiver is operated from 105 to 125 volts 50-60
cycle a-c power. If in doubt call your local
utility company for information.
Connect the R-42 Reproducer, or the R-44,
as the case may be, to the 500 and "e" termin-
als on the SX-43.
Turn the VOLUME control to the left as far
as possible. (See Fig. 2) This turns off the
radio. Plug the power cord into the a-c out-
let.
Attach an antenna (aerial) to the post
marked A-1. This antenna wire should be, pref-
erably, outdoors above surrounding structures
and from 25 to 100 feet long. Attach a wire
from a good g):"ound to the post marked GND. In
general the better the antenna system, the bet-
ter the signal will be heard.
Having followed instructions to this point
you are now ready to operate your receiver.
Let's first tune in a-m (standard broadcast)
stations.
2. GENERAL OPERATION
1. To turn the receiver on, the VOLUME control
is turned to the right to about 4 on the knob
scale. When the ~eceiver is on, the dial scales
and the meter will light up.
2. Turn the BAND SELECTOR knob left to the red
dot. (See Fig. 3)
3. Set the three toggle switches to the "right"
hand position. (See Fig. 4)
4. Set four of the six right-hand control knobs
to the following positions: "SELECTIVITY" to
red dot, "RECEPl'ION" to red dot, "SENSITIVITY"
to 10, and "VOLUME" to 4 or the desired amount
of volume. (See Fig. 5)
it
~
~
Figure 2. View showing Volume Control
Figure 3. View showing Band Selector Switch
RECEIVE
Figure 4. View showing three toggle switches
1 -

Pigure 5. View showing six right hand controls
Figure 6.
View showing Bandspread and Main Tuning Dials
Figure 7. View showing Carrier Meter
-2-
5. Set the bandspread (fine tuning) dial to
the high end of the dial, (counte~clockwise).
6. The knobs for CRYSTAL PHASING, RECEPTION,
CW PITCH, and SENSITIVITY should in all cases
be left set at the red dot or "0".
7. Now tune in stations by tuning with the
main control knob. (See Fig. 6) As thesta-
tion is tuned in, the carrier meter needle (See
Fig. 7) will move from the left side of the
scale to the right. Carefully tune the recei-
ver by causing the meter needle to move as far
to the right as possible. At this point the
receiver is properly tuned to the station.
8. To control the volume, adjust the VOLUME
control (See Fig. 2) by turning it to the right
for a louder signal or to the left for a softer
signal.
9. The frequency calibration on the main tun-
ing dial for the broadcast band is shown on the
scale at the bottom of the dial. (See Fig. 6).
This scale as all other s'cales is calibrated in
kilocycles and tunes over the broadcast band
from 540 to 1650 kc.
10. When the TONE switch is in the LOW posi-
tion, the higher audio frequencies a.re attenu-
ated. If a broa.d audio response is preferred,
the TONE switch may be set at HIGH.
11. For normal reception the SELECTIVITY
control is set at NORMAL BROAD. However, when
tuning a weak station near to the frequency of
a strong station, it will be easier to separate.
the two signals if the SELECTIVITY control is
switched to the NORMAL SHARP position.
Figure 8. View showing Selectivity Control

3.· FM RECEPTION
Thus far we have tuned therece·iv.er ·for. a-lil
reception. If it is desir'ed to use it on f-m
reception, all controls should be set as previ-
Qusly described with the exception of the fol-
lowing:
1. The RECEPl'IOll knob should be switched to FM
(green dot) and SELECTIVITY knob set at NORMAL
BROAD. (green dot).
2. The BAUD SELECTOR switch should be set on
the green dot. This covers the band 86 to j09
me.
3. Tune in f-m stations by turning t.he BAND
SPREAD tuning knob. The band spread dial indi-
cates the frequency of reception. Note that as
the f-m station is tuned-in the carrier level'
meter pointer deflects to the righ~.
When meter pointe~ is at maximum deflection the
station is tuned .in.
The carrier level meter is calibrated to read
relative ~ignal strength. It also functions as
a tuning indicator, the receiver being tuned to
the desired signal with maximum deflection of
the meter needle. When using the carrier level
meter, the RECEPTION switch should be set to
the red ddt for AM reception or to the green
dot for FM reception. The SENSITIVITY control
must be set at 10 and the volume controlled with
the VOLUME control.
~.SHORT WAVE RECEPTION
So far we have covered two bands of the
receiver {Broadcast 540-1650kc}, and the f-m
band 86-109 me.} For the other five bands of
t.he set,. operation is the same, the only dif-
ference being in the setting of the BAND SE-
LECTOR switch knob, which may be t~ned to the
desired band. On bands 5 a.nd 6 tuning is done
with the BAND SPREAD control as the general
coverage dial is switched out of the circuit.
-3-

DETAILED AND TECHNICAL OPERATING INSTRUCTIONS
I. GENERAL
The Model SX-43 is a 11 tube superhetero-
dyne radio receiver designed to provide ampli-
tude modulated (AM) reception over the frequen-
cy range of 540 kc to 55 mc and frequency modu-
lated (FM) reception over the frequency range
of 44 to 55 mc end 86 to 109 mc bands. Cali-
brated bandspread is provided for the 80, 40,
20, and the 10 meter Amateur bands.
FREQUENCY COVERAGE
BUf)
COYERAGE rTPE 0' RECEPrIOI
1
.540 to 1.65 mc AM/CW
2
1.65 to 5.0
mc
AWcw
S
5.0
to 15.1 mc AM/CW
SA 13.9 to 14.4 mc
AM/CW
4
15.1 to 44.0 me AMlcw
5
44.0 to 55.0 mc
AM/FM
6
86.0 to 110
mc
FM
Adequate overlap is provided at ends of all
bands.
The receiver as normally supplied is de-
signed to operate from a 105 to 125 volts 50/60
cycle, single phase source of a-c power. These
operating instructions also cover Universal
Models which operate from a 105 to 250 volts,
25/60 cycle single phase a-c source.
2. A-C OPERATION
Be sure line voltage is 105 to 125 volts
and frequency is 50 to 60 cycles before insert-
ing power cord plug into power outlet. Be sure
all tubes are securely inserted in their proper
sockets before receiver power is turned on. The
chart below lists the current and voltage data.
Power Consumption • • ••• 90 Watts
Frequency • • • • • • • 50/60 Cycles
Line Voltage 117 Volts
Line Current 0.77 Amperes
During a-c operation, the shorting plug
supplied with the receiver must be in the octal
socket on the rear apron of the chassis.
3. D-C OPERATION
The receiver may be operated from a 6 volt
d-c source, generally a storage battery, and a
270 volt d-c supply in the form of "B" batter-
ies or vibrator type power pack. Consult the
-4-
chart on power requirements at the end of this
paragraph and provide battery or power pack fa-
cilities capable of supplying these demands.
The receiver is connected to the d-c supply as
follows:
1. Remove the octal shortiIl$J plug for a-c oper-
ation from the socket S0-1 located on the rear
apron of the receiver chassis.
2. Wire an octal plug, as shown in Fig. 9, and
plug it into socket S0-1. Use *19 (AWG) wire
leads for the 270 volt "B" supply connections
to pins *3 and *5, and *12 (AWG) wire leads for
the 6 volt battery connectio~s to pins *1, *7,
and *8. CAUTION: Check the wiring carefully
before connecting to the battery supply. The
chart below lists the current voltage data.
"B" Voltage • • • • •••
"B" Current • • • • • • •
Filament Voltage • • • •
Filament Current ••••
270 Volts
105 mao
6 Volts
3.8 Amperes
Total battery drain when operating from a 6-
volt vibrator power supply is approximately 11
amperes.
VIBRAPACK
BATTERIES
+
Figure 9. 'Octal plug wiring diagram
q. OUTPUT CONNECTIONS
Output connections for the speaker are pro-
vided for on the rear apron of the chassis. Two
output impedances are available. Either the

500 or the 5,000 ohm speaker connection may be
used according "to the output impedance desired.
"This arrangement of dual output impedances will
accommodate most requirements. The Halli-
crafters Model PM-23 speaker requ1res 5000 ohms
impedancej the Hallicrafters Model R-42 and R-
44, requires 500/600 ohms. However, any stand-
ard type, permanent magnet dynamic speaker with
proper output transformer may be connected to
the output terminals. If the permanent magnet
dynamic speaker impedance is unknown, try the
5000 ohm and then the 500/600 ohm impedance,
and use the one which gives the better tone
quality and volume.
5. PHONO INPUT CONNECTION
A receptacle is provided on the rear apron
of the chassis for connecting a phonograph
record player to the receiver. This receptacle
is designed to accommodate a Cinch, type M-93,
pin connector plug. (See Fig. 10 for diagram)
CRYSTAL
PICK-UP'"
TO PHONO
...--+1 .;.: -~u. _-J-- INPUT ON REC.
;)
SHIELD
LEAD
JI
PLUG, CINCH
TYPE M-lI'
Figure 10. Phono input diagram
6. ANTENNA AND GROUND CONNECTIONS
The Model SX-43 is designed for a 300 ohm
antenna impedance. The antenna impedance is
not critical and excellent reception can be ob-
tained from an antenna of from 50 to 600 ohm
impedance. For maximum performance, the best
possible antenna should be employed.
The antenna terminals on the Model SX-43
are arranged for any type of antenna from those
requiring a ground to those using a trans-
mission line. The transmission type of antenna
connects to the A-1 and A-2 terminals whereas a
single wire antenna utilizes terminal A-I for
the antenna lead. A-2 and GND terminals must
be connected together and connected to a good
ground.
7. DETAILED OPERATIONS
a. bontro~s and Their functions. In order to
obtain the·desired results from the receiver,
it is recOmmended that you become familiar with
the function of each control. Red indicators
on the controls for broadcast reception and
green for f-m reception are there to simplify
operation. Controls and their functions are as
follows:
-5-
(1) BAND SELECTOR. The BAND SELECTOR knob
operates the bandswitch to select the de-
sired band frequ.encies.
(a) General Coverage DiaL. The genex-
a1 coverage dial has four ca.librated
scales and a logging scale. Thre~
scales are calibrated in megacycles and
the broadcast scale is calibrated in.
kilocycles. The outer logging scale is
divided into 100 divisions for logging
use. The dial settings for the various
amateur bands are indicated on the main
tuning dial by red lines and the abbre-
viations 80 M, 40 M, etc. directly above
the lines. When tuning the amateur
bands with the calibrated bandspread
dial, the general coverage dial must be
set at the setting corresponding to the
amateur band desired. Since the gener-
al coverage and bandspread tuning sys-
tems are electrically related on the
first four bands, it is necessary to
set ·the bandspread diaL to the high
frequency end or minimum capacity when
tuning the receiver with the generaL
coverage diaL controL to obtain correct
receiver frequency readings on the gen-
eraL coverage diaL.
(bl BandsPread DiaL. The bandspread
dial has five scales calibrated for the
amateur bands and one scale cali-
brated for the high frequency FM band.
The first three scales are calibrated to
read receiver frequencies in kilocycles
when the general coverage dial has been
set to the corresponding indexing line.
The FH and the 6 meter amateur band
tuning is ~one with the bandspread dial
as the general coverage dial and conden-
ser is switched out of the circuit on
bands 5 and 6. On band 5 the receiver
employs dual conversion, substantially
reducing image interference and per-
mitting normal bandwidth for 6 meter
AM amateur reception.
(21 NOISE-LINITER-ON Switch. This switch
opens or closes the noise limiter circuit
and is to be set at ON when the operator
wishes to limit excessive noise resulting
from automobile ignition and other forms of
noise interference.
The noise limiter circuit "clips" the
intermittent noise peaks down to the level
of the desired signal where they tend to
become unnoticeable.
(3) RECEIVER-STAN])BY Switch. When set at
STANDBY, this switch renders the receiver

inoperative, while transmitting or for any
other purpose, although the tube heaters
remain hot and read~ for instant use.
(4) CRYStAL PBA8IKG Contro~.. This control
permits the discrimination of code signals
whose frequencies are very nearly the same.
The
SELECTIVITY control must be set at one
of its two crystal selectivity positions
When using the phas ing control.
It is extremely simple to attain single
signal c-w reception with the SX-43. First,
set the RECEPTION switch at CW and the
SELECTIVITY control at CRYSTAL SHARP. Pick
a good solid c-w signal, preferably a com-
mercial station because a commercial is
likely to stay on long-enough for you to
complete the phasing adjustment for single
signal reception.
You will find on tuning across this
signal that it has two amplitudes. Tune
first to the 'Weaker of these two amplitudes.
How, turn the CRYSTAL PHASING control until
the 'Weaker of tl;Le two amplitudes is reduced
to a minimum. Then, tune to the stronger
of the two amplitudes and adjust the PITCH
control to a tone most pleasing to you.
This adjustment for single signal selecti~
itywill hold with no further adjustment
unless you change the phasing control. (See
Fig. 11 for an illustration of single sig-
nal operation.)
Ad Jus, phaaioB control cucn.lIy
....Iil Irw .. cakcr ampli.udc is
roiuccd to a minimum.
Figure 11.
Itroo.r amplit:udc and then
odius, pitCh control un.il
you jICf Il0l. moo. pI ... iDB
co copy.
Illustration showing Single Signal Operation
-6-
8.
(5) SELECtIYlfY Control.. This control de-
termines the sharpness of the response.
Four degrees of selectivity are provided,
raDging from CRYSTAL SHARP for c-w code re-
ception under difficult receiving condi-
tions to NORMAL BROAD response for Be re-
ception.
.. NORMAL BROAD (for high fidelity
reception) •
2. NORMAL SHARP (for reduced adjacent
channel interferences).
3. CRYSTAL BROAD (similar to sharp i-f
response but with sharper cutting
on sidebands).
4.- CRYsTAL SHARP (position of extreme
selectivity - practically no side-
band. content).
(6) tOlE Control. This control selects
the tone qualities desired by the operator.
The types of response available are LOW,
and HIGH.
(a) LOV. The high audio frequencies
are attenuated to provide a minimum re-
sponse for voice reception when the
background noise level is objectionably
high.
(b) HIGH. The bass and high frequen-
cies ;;;- passed at the same level there-
by providing as near a true reproduc-
tion of the original transmitted signal
as possible. The response is essen-
tially flat between 70 and 8,000 cycles
per second for good fidelity reception.
(7) CW PlfCH Control. This control varies
the frequency of the beat frequency oscilla-
tor thus varying the pitch of the c-w code
signal as desired.
(8) S8KSlfIYIfY Control. This control ad-
justs the sensitivity by varying the re-
sistance in the cathodes of the r-f and i-f
amplifiers. Turning the control to the
right increases the sensitivity. This cen-
trol must be set at maximum sensitivity
when using the carrier level met~r. At any
other setting of this control, r~adings of
the carrier meter are meaningless.
·S" METER ADJUSTMENT
Adjustment of the "S" meter control is per-
formed by varying the knurled knob located on
the rear apron of the receiver chassis. This
control enables yoU to properly set the "S"

meter to zero. In order to make the adjustment
correctly, advanCfe the SENSITIVITY control to
10. Set the "reception" switch to Ave ,position.
Short the two antenna terminals to the ground
terminal and tune receiver off station. Then
adjust the "5" meter control until pointer
rests at "0". Remove the short from the an-
tenna terminals and the meter will indicate the
relative carrier strength of each incoming sig-
nal as it is tuned in.
SERVICE
I.· REPLACING TUBES
All tubes are accessible at the top of the
chassis through the hinged cover of the cabinet.
When replacing tubes, check tube type carefully
and replace with the correct type. Refer to
top view of the chassis to determine ~he loca-
tion of the tubes (See Fig. 12).
2. REPLACING DIAL LAMPS
The receiver employs three dial lamps with
the b~onet type sockets to illuminate the main
and bandspread tuning dials as well as the
meter scale. The lamps are to be replaced with
AI
o o
A2
o
~
6BA6
R.F.
GND.
e ~===l:=l=?
OSC.
MIXER
with 6-8 volt, 250 ma, (blue bead) *44 G.E.
type, or equivalent. Replace the tuning meter
lamps with a 6-8 volt, 150 mao (brown bead) il!47
G.E. type or equivalent.
3. SEQ'ICE OR OPERATING QUESTIONS
Factory type service is available at Halli-
crafters authorized field service centers. For
Warranty Service or further details regarding
operation or servicing of the receiver in gen-
eral, contact the dealer directly. Make no ser-
vice shipments directly to the factory before
first writing for authorization and instructions.
rhe factory cannot accept responsibiZity for
unauthorized shi~ents.
5000 500. COM.
~LINE
~ CORD
PHONO
@---- .......... @
F. M.
DETECTOR
3!!,p. I.F.
A.M.
DETECTOR
BFO. a
11.1 Me. OSC.
920318
Pigure 12. Top view of Chassis
-7-

REMOTE CONTROL OPERATION
Connect a single pole single throw relay to
pins lI!5 and 8 on PLl located on the rear apron
-
-
of the recei'Ver. Receiver "SEND- RECEIVE"
switch is then placed in "SEND" position. When
the Transmitter is turned on the Receiver is
automatically disabled.
RELAY
Figure 13.
Schematic Remote Control Operation
-8-