Kenwood TS-120S User manual

HF SSB TRANSCEIVER
ee
RS.

INTRODUCTION
You
are
the
owner
of
our
latest
product,
the
new
TS-120S(V)
transceiver.
Please
read
this
in-
struction
manual
carefully
before
placing
your
transceiver
in
service.
The
unit
has
been
carefully
engineered
and
manufactured
to
rigid
quality
standards,
and
should
give
you
satisfactory
and
dependable
operation
for
many years.
AFTER UNPACKING:
@ Shipping container:
Save
the
boxes
and
packing
in
the
event
your
unit
needs
to
be
transported
for
remote
Operation, maintenance, or service. :
@ The following explicit definitions apply in this manual:
Note:
If
disregarded
inconvenience
only,
no
risk
of
equipment
damage
or
personal
injury.
Caution:
Equipment
damage
may
occur, but
not
personal
injury.
CONTENTS
3
4
SECTION
2. PREPERATION
FOR USE.
4
2.1
ACCESSORIES
4
aie
INSTALLATION
4
2.3
5
2.4
ANTENNA
AND
POWER
SUPPLY
6
SECTION
3.
CONTROLS
yf
3.1
FRONT PANEL....
Z
3.2 REAR
TOP PANEL.
9
SECTION 4. OPERATION
41 RECEPTION
4.2 TRANSMISSION. eres 11
4.3. VOX OPERATION...
4.4 SEMI-BREAK-IN OPERATION....
4.5 FIXED CHANNEL OPERATION ..
4.6 CW OPERATION
4.7
4.8 FIXED STATION OPERATION.
4.9 DIGITAL DISPLAY CALIBRATION ..
4.10 ANALOG DIAL CALIBRATION
SECTION 5. ADDITIONAL INFORMATION
SECTION 6. OPTIONAL ACCESSORIES
SECTION 7. CIRCUIT DESCRIPTION
BLOCK DIAGRAM
SECTION 8. TROUBLESHOOTING .

TS-120S, TS-120V SPECIFICATIONS
Fie arian to oertbreserEnb sc scanntysetntneoettED sa
bd
04 cEEDED-cUUdosetntbnseennbeananys att ence
Frequency Range..........M0)248.27Al 2:08. 4 80 meter band: 3.50 ~ 4.00 MHz
40 meter band: 7.00 ~ 7.30 MHz
20 meter band: 14.00 ~ 14.35 MHz
15 meter band: 21.00 ~ 21.45 MHz
10 meter band: 28.00 ~ 29.70 MHz
WWV: 15.0 MHz
. SSB/CW
. Negative ground only
Grounding
Power Requirements
TS-120S TS-120V
Receive 0.7A 13.8 VDC 0.7A 13.8 VDC
Transmit 18A 13.8 VDC 4A 13.8 VDC
Final Power Input ...
TS-120S
200W PEP for SSB operation
160W DC for CW operation
160W PEP for SSB operation
140W DC for CW operation
TS-120V
80~
15m
band
25W
PEP
for
SSB
operation
20W DC for CW operation
25W PEP for SSB operation
20W DC for CW operation
10m band
Audio Input Impedance
Audio Output Impedance
Audio Output....
RF Output Impedance
Frequency Stability
- 5002 ~ 50 kQ
42 ~ 162
More than 1.5 watts (with less than 10% distortion) into an 8-ohm load.
502
. Within 100 Hz during any 30 minute period after warmup.
Within +1 kHz during the first hour after 1 minute of warmup
Carrier Suppression j.icssiissviscciscsssssscessaceessescsstseans Carrier better than 40 dB down from the output signal
Sideband Suppression.. . Unwanted sideband is better than 50 dB down from the output signal.
Spurious Radiation . Better than 40 dB down from output signal.
Harmonic Radiation . Better than 40 dB down from output signal
Image Ratio... Image frequency better than 50 dB down from the output signal
IF Rejection IF frequency is 70 dB or more down from output signal
Receiver Sensitivity ... 0.25 uV at 10 dB S+N/N or better
Receiver Selectivity ... . SSB 2.4 kHz (—6 dB)
4.2 kHz (— 60 dB)
*CW 0.5 kHz (—6 dB)
1.5 kHz (—60 dB)
* Optional CW filter installed.
Semiconductors...
TS-120S TS-120V
Ic
26
26
FET
16 16
Transistor
90
85
Diode
142
137
Dimensions:
T S31 20S isc sasnceisaeeneiah wisest eter 241W x 94H x 293D mm
(9-1/2W x 3-3/4H x 11-9/16D inch)
TS ENZO ase ve successcasansescsevaigathacnea stan vasaiandedeat 241W x 94H x 235D mm
(9-1/2W x 3-3/4H x 9-1/4D inch)
WIG E sicics rassamemecwaasamagiinusrriaereirnt oem TS-120S: 5.6 kg (12.3 Ibs.)
TS-120V: 4.9 kg (10.8 Ibs.)

SECTION 1.
eet enkn eno cUUUby onda setb tbe eRELy ULL att tn oottb beet
1. SINGLE-CONVERSION SYSTEM USING ALL
CIRCUITRY
The single-conversion system, with a unique Phase Locked
Loop circuit, FET balanced mixers and MOS FET's, assures
excellent spurious and intermod characteristic.
2. BUILT-IN DIGITAL DISPLAY
The digital display affords easy reading of operating frequen-
cy to an accuracy of 100 Hz on any band and any mode.
3. BUILT-IN IF SHIFT CIRCUIT (Passband Tuning)
An IF SHIFT system is built into the transceiver to allow shif-
ting of the IF passband, thereby eliminating adjacent-
channel interference.
4.3.5 ~ 29.7 MHZ AND WWV BANDS
The transceiver is designed to operate on LSB/USB/CW in
the 3.5 ~ 29.7 MHz bands. WWV (14.5 ~ 15 MHz) is also
built into the transceiver to permit accurate frequency
calibration.
5. COMPACT, LIGHTWEIGHT DESIGN
The TS-120S(V) has many advanced features, yet it is com-
pact and lightweight, suitable for mobile and field operations
as well as fixed-station operation.
6. EASY OPERATION
All controls and switches are carefully arranged for easy of
Operation, ensuring convenience and versitility.
POR
2.1 ACCESSORIES
The following accessories are furnished with the TS-
120S(V):
Instruction manual
External speaker plug
7P DIN remote plug
DC power cord..
Fuse, 20A (TS-120S)
4A (TS-120V) ...
ok Soe oe be
cannnesctnins
eugene sc utysennntoceene cross tt tne sennntaecEENE Dat
SECTION
2.
PREPERATION
FOR
USE
FEATURE
7. ALL SOLID-STATE DESIGN
The all solid-state, compact unit features a wide-band final
stage, eliminating the need for peaking controls.
8. FOUR FIXED CHANNELS
Four FIXED channels can be installed, one for each of 7, 14,
21 and 28 MHz bands. The 3.5 MHz and 28 MHz FIXED
XTAL position can be exchanged by simply moving a con-
nector on the AF-GEN unit.
9. FULL RANGE OF AUXILIARY FUNCTIONS
The TS-120S(V) is equipped with VOX, balanced gate
system noise blanker and a 25-kHz marker.
10. OPTIONAL CW FILTER YK-88C
The TS-120S(V) permits. use of the optional YK-88C CW
filter. CW semi-break-in operation is provided using the
built-in VOX and CW side-tone circuits.
11. WIDE VARIETY OF OPTIONAL ACCESSORIES
The following optional accessories are available: Regulated
Power Supply (PS-30, PS-20), Mobile Mount (MB-100),
CW Filter (YK-88C), External VFO (VFO-120) External
Speaker (SP-120).
uy sotneaunensscunnacentysettnsstnebUnnbctyoet YARD oe At AHE EAH UMEDA
2.2 INSTALLATION
It is preferable to choose an operating location that is dry
and cool, and to avoid operating the transceiver in direct
sunlight.
Allow adequate ventilation, particularly during mobile opera-
tion.

2.3 INTERCONNECTION
Connect the transceiver as illustrated in Fig. 2-1.
Microphone
Either a low or high im-
Headphones
TS-120S Use headphones of 4 to 160
pedance microphone (5002
to 50 k®) can be used. The
P.T.T. switch should be in-
solated from the mic circuit
(shown in ‘‘a’’). Use a
impedance. The optional HS-
4 headphone is best suited for
use with the TS-120S(V).
Stereo-type headphones can
also be used.
o 53a
microphone with a separate
switch and MIC line so both
P.T.T. and VOX are available. 7, a
{Ay
Transformer
Microphone ve 3|g -
(a) this
View from cord side
—o
—F
¥ Switch
—
Transformer
Microphone omc) y Switch Gea a,
(b} notthis Microphone connection
Microphone) © 3) g
—¢—-0
Transformer © Switch
ornate
{c} not this
GND terminal
It is recommended that an ground
lead be connected to the GND
TS-120S
Key
For CW operation, connect
your key to the KEY jack at
Use shielded cable.
the
rear.
External
speaker
Besides the built-in
speaker, as external
speaker can also be
used. Connect to the
rear EXT SP jack using
the supplied plug.
External VFO
For connection of ext-
ernal VFO-120.
Note: VFO-520 and
VFO-820 cannot be
oS used,
REMOTE connector
Extemal accessories can be con-
Either a low or high imped-
ance microphone (5002 to
502) can be used. The P.T.T.
switch should be insolated
from the mic circuit (shown in
a’). Use a microphone with
terminal at the rear of the set to nected to the TS-120S(V)
prevent the possibility of electric through the REMOTE connector.
shock. TVI and BCI. Use as The PTT terminal and be used for
short, and neary a lead as possi- m vs remote control of send/receive
ble.
Fig.
2-1
Interconnection
of
TS-120S
operation.
Microphone Headphones
Use headphones of 4 to 162
impedance. The optional HS-
4 headphone is best suited for
use with the TS-120S(V).
Stereo-type headphones can
also be used.
TS-120V
a separate switch and MIC
line so both P.T.T. and VOX-
TS-120V
Key
For CW operation, connect
your key to the KEY jack at
the rear. Use shielded cable
a a External speaker
pie Besides the built-in
speaker, as external
speaker can also be
used. Connect to the
rear EXT SP jack using
the supplied plug.
SP-120 (Gesze
REMOTE connector
External accessories can be conn-
ected to the TS-120S(v) through
are available. ‘. a
{A B}
ee View from cord side —
Transformer
+
Microphone de—3|8
2
(a) this swith
Transformer
Microphone dea] Switch
(b) not this
Microphone connection
Microphone [) © _ 3|
Transformer © switch
(c) not this
the REMOTE connector. The PTT
GND terminal
It is recommended that an ground
lead be connected to the GND
terminal at the rear of the set to
terminal and be used for remote
control of send/receive operation.
External VFO
For connection of ext-
ernal VFO-120
prevent the possibility of electric
shock. TVI and BCI. Use as
short, and neary a lead as poss-
ible.
Fig. 2-1 Interconnection of TS-120V
Note: VFO-520 and
VFO-820 cannot be
used.
VFO-120

2.4 ANTENNA AND POWER SUPPLY
Connect the antenna and power supply as shown in Fig. 2-2 for fixed-station or mobile operation:
Fixed station operation
Power supply
For fixed station antenna in-
stallation, see Page 17
TS-120S
UHF type connector
=aG-
Antenna socket | <
G
— DC power terminal
Connect battery to DC power
terminal. For detailed instruc-
tions, see Page 15.
For mobile antenna installa-
tion, see Page 15.
rey-Black Red-White
Note: Use either
battery or regulated,
Bsupply,but not
both.
Fixed station operation Power supply
For fixed station antenna inst-
allation, see Page 17
DC power terminal
For mobile antenna inst-
allation, see Page 15.
Connect battery to DC power
terminal. For detailed inst-
tuctions, see Page 15.
Mobile station operation
Red- ws
Fig. 2-2. Antenna and Power Supply Connection of TS- 120V
= |
Note: Use either
battery or regulat-
ZA ed supply, but not
both.

SECTION 3.
CONTROL
6) ANTI VOX CONTROL
@) DELAY CONTROL.
@) VOX GAIN CONTROL
() SUBDIAL
(@ METER
@ DIGITAL DISPLAY
(@ STANDBY
SWITCH
(@ MODE SWITCH
) MIC CONNECTOR
@© PHONES JACK-——
@ Vox SWITCH
(@® METER SWITCH _~ }
@ FIX SWITCH
() MAIN TUNING KNOB
(2 RIT INDICATOR
( CARRIER LEVEL CONTROL
(@® mic CONTROL
—(DAF GAIN CONTROL
'
AF GAIN-@-RF GAIN
re |e)
(1) RF GAIN CONTROL
(9) BAND SWITCH
(3 IF SHIFT CONTROL
20) POWER SWITCH
@) NOISE BLANKER SWITCH
—— @) RF. ATT SWITCH
= @3) RIT SWITCH
(® RIT CONTROL
22) CALIBRATOR SWITCH
Fig. 3-1 Front Panel
3.1 FRONT PANEL
@ METER
The meter has three functions, two being selected by the
METER switch. In receive the meter is automatically an S-
meter showing receive signal strength on a scale of 1 ~ 9,9
+ 20, + 40 and + 60 dB. In transmit, the meter shows
IC (TS-120S), RF output (TS-120V) or ALC level depending
on METER switch position.
@ DIGITAL DISPLAY
The digital display indicates true operating frequency to an
accuracy of 100 Hz.
@ MODE SWITCH
The mode switch selects type of operation.
ES Bisataviesccors Used for lower-sideband operation. (LSB is
most common in the 3.5 and 7 MHz bands.)
USBy, 4.082 Used for upper-sideband operation. (USB is
most common in 14,21 and 28 MHz bands.)
CW rassanceer aces Used for CW operation.
@ STANDBY SWITCH
This switch selects receive or transmit function.
In the REC position, the transceiver is normally in the receive
mode unless the microphone PTT switch is depressed, in the
SEND position, the TS-120S(V) is switched to the transmit
mode.
CAUTION: Do not transmit without an antenna or dummy
load. Equipment damage will occur. Such damage is not
covered by warranty.
© MIC CONNECTOR
Connect your microphone (MC-30S, MC-35S, MC-50, etc.),
referring to Fig. 2-1. The TS-120S(V) accepts both low and
high impedance microphones.
© PHONES JACK
The headphone jack allows use of 4-to-16-ohm
headphones. HS-4 optional headphones provide optimum
results. Stereo-type headphones can also be used. This will
disable the internal and. external speaker.

@ VOX (VOICE OPERATED TRANSMIT) SWITCH
This function is used for SSB VOX or CW semi-break-in -
peration. In the MAN (manual) position, the transceiver is
keyed by either the standby switch or the microphone PTT
switch for VOX operation, the standy switch remains in
RED. (See page 12.)
METER SWITCH
During transmission, the meter switch determines meter
function. The switch selects between:
REC Kae vdedsansearee The meter monitors the output of the final
stage power amplifier during transmis-
sion. During SSB operation, adjust the
MIC control so that the meter pointer is
within the ALC zone. Similarly, adjust the
CAR control for CW operation.
IC (TS-120S).... The meter monitors final stage collector
current.
RF (TS-120V)... In this position the meter monitors the
relative RF output of the transceiver.
@ FIX (fixed channel) SWITCH
The TS-120S(V) has a built-in fixed channel oscillator
(crystals are user-provided, optional) which is activated by
the FIX switch for fixed channel or VFO operation.
(® SUBDIAL
The subdial is calibrated from O to 500. It is driven from the
main tuning knob to indicate the transceiver’s operating
frequency.
@ MAIN TUNING KNOB
This control is used to select the desired operating frequen-
cy. The scale on the control knob is calibrated at 1 kHz in-
tervals, allowing accurate tuning. For exact frequency, read
the Digital Display.
(@). RIT INDICATOR
This light emitting diode indicates the RIT circuit is ON.
@ IF SHIFT CONTROL
By using this control, the IF crystal filter center frequency
can be shifted +1 kHz, allowing adjustment of tone quality,
or eliminating interference from adjacent frequencies.
For normal operation, this control should be set to the center
“0” position (detent).
@ RIT CONTROL
When the RIT circuit is ON, this will vary receive frequency
by about +1.5 kHz. When the control is set to the “0”
center position, there is no frequency shift.
(@ CAR (CARRIER LEVEL) CONTROL
This control is used to adjust the carrier output level only
during CW operation. Adjust the control so the ALC meter
indication is within the ALC zone.
8
(@® MIC (MICROPHONE GAIN) CONTROL
This adjusts mic amplifier gain during SSB operation. Again,
adjust the control so the ALC meter indication is within the
ALC zone.
@
AF
GAIN
(AUDIO
GAIN)
CONTROL
This
control
adjusts
the
receiving
audio
amplifier
gain.
Volume
of
the
received
signal
increases
as
the
control
is
turned
clockwise.
(@® RF GAIN CONTROL
This
adjusts
the
receiver
section’s
RF
amplifier
gain.
Turn
the
knob
fully
clockwise
for
maximum
gain.
Turn
counterclockwise
to
reduce
the
gain.
BAND SWITCH
The
9-position
switch
selects
all
the
amateur
bands
from
3.5
to
29.7
MHz
and
WWV.
Set
the
switch
to
the
desired
band.
@
POWER
SWITCH
This
switch
the
TS-120S(V)
ON
and
OFF.
@) NB (NOISE BLANKER) SWITCH
This
switch
is
used
to
reduce
pulsating
ignition
noises
of
the
type
usually
emitted
from
motor
vehicles.
@ CAL (CALIBRATOR) SWITCH
Fully
turning
the
MIC
control
enables
the
CAL
SWITCH
to
operate.
This
switch
energizes
the
built-in
25
kHz
marker
circuit.
@ RIT SWITCH
This
push
switch
turns
the
RIT
(Receiver
Incremental
Tun-
ing)
circuit
ON
and
OFF.
With
the
switch
depressed,
the
cir-
cuit
is
activated
and
the
RIT
indicator
is
illuminated,
allowing
the
receive
frequency
to
be
shifted
by
about
+1.5
kHz
in-
dependent
of
the
transmit
frequency
by
using
the
RIT
con-
trol.
The
RIT
circuit
is
turned
OFF
when
the
switch
is
out.
@ VOX GAIN CONTROL
This
control
adjusts
VOX
circuit
sensitivity
for
both
SSB
and
CW
operation.
@ DELAY CONTROL
This control is used to adjust the “Hold” time of the VOX cir-
cuit. Clockwise adjustment gives longer hold-time.
@ ANTI-VOX CONTROL
This
control
is
used
to
adjust
the
VOX
system
so
that
it
is
not
tripped by sound from the speaker.
@ RF ATT SWITCH
Turning this switch ON attenuates antenna input by approx.
20dB to protect the RF amplifier and mixer circuit from too
strong signals.

(ANT CONNECTOR
@ COOLING FAN (6) EXT VFO CONNECTOR
(@GND TERMINAL
(cw KEY JACK
(4) SPEAKER JACK
(8)
REFERENCE FREQUENCY
ADJUSTMENT ACCESS
(5) REMOTE CONNECTOR
—(7) DC POWER CONNECTOR
Fig 3-2 Rear, Top Panel
3.2 REAR PANEL
@ ANT (ANTENNA) CONNECTOR
This UHF connector should be attached to a suitable anten-
na for transmitting and receiving. The antenna cable should
be of a 50-ohm unbalanced type, terminated in a PL-259
plug.
@ GND (GROUND) TERMINAL
The TS-120S(V) should be grounded through this terminal
to avoid the possibility of TVI and BCI. Use as short, and
heavy a lead as possible.
@ CW KEY JACK
For CW operation, connect your key to this terminal using a
two conductor phone plug and shielded cable.
@ SPEAKER (EXTERNAL SPEAKER) JACK
An external speaker of 4 ~ 16 ohms impedance (such as
the SP-120) can be connected here. This will disable the in-
ternal speaker.
To ALC circuit
Unswitched AF OUT 5
(8)
From
standby
switch
(PTT Circuit)
© REMOTE CONNECTOR
This is used for interconnecting a linear amplifier or other
equipment. For connection, refer to the illustration below,
fig. 3-3.
© EXT VFO (EXTERNAL VFO) CONNECTOR
This is for connection of an external VFO-120. (Note: the
VFO-520 and VFO-820 cannot be used, since their
operating frequency is incorrect.)
@ DC POWER CONNECTOR
This is used to connect the DC power supply.
REFERENCE FREQUENCY ADJUSTMENT
For PLL reference oscillator adjustment. Use WWYV signal
for calibration.
@ COOLING FAN
The cooling fan operates when the heat-sink temperature
rises.

vette enunb -cnnne cannes etntba
sun -at
easeants
Turn fully
clockwise.
Turn fully
counterclockwise.
Set to desired
mode CW, USB
or LSB.
Set to
Transmit-
receive
selector
switch
desired band
SECTION 4. OPERATION
!
!
1
!
'
1
!
|
!
1
1
!
|
!
!
!
I
'
|
I
l
|
!
!
sO unt ent Et ARLE UHH -enn nt ABREU AUN
oo AEEDU OULU aunts cette scannas canta
Settings for transmission
Turn CAR and
MIC fully counter
clockwise.
p Set to
@z 4 desired band
Set to desired mode.
en
=
oe
Microphone
Fig. 4-1 Control and Switch Settings
4.1 RECEPTION
First connect the antenna, microphone and key. Then, set
the controls and switches referring to Fig. 4-1. For SSB
operation the MODE switch should be set to comply with
common operating practice; that is, it should be set to LSB
for the 3.5 and 7 MHz bands and to USB for the bands
above 14 MHz.
Ascertain that the TS-120S(V) is ready for operation, then
turn, the POWER switch ON. The meter, dial scale and
digital display will illuminate, indicating the transceiver is in
operation. The transceiver is fully solid-state, allowing
reception as soon as the POWER switch is turned ON.
Advance the AF GAIN control clockwise until some receiver
noise is heard from the speaker. Turn the main tuning knob
so the desired signal can be heard clearly.
While turning the main tuning knob, the frequency (MHz
digits) reading on the digital display will change at the edge
of each band (for example, from [28.999.9] to [29.000.0]
MHz). When tuning above or below a band edge, the 1 MHz
and 10 MHz digits are blanked, as shown below.
3.999.9 7.000.0_][14.000.0 21.000.0 }| 28.000.0 || 29.999.9
| 4 | 4 | 4
000.0 999.9 999.9 999.9 999.9 000.0
4.1.1. WWV RECEPTION
To receive WWV at 15 MHz, set the BAND switch to
JJY/WWYV and turn the main tuning knob until the subdial
reads “500”. The digital display indicates ‘’.000.0” instead
of 15.000.0.
10
4.1.2. NB SWITCH
The TS-120S(V) has a sophisticated noise blanker designed
to reduce ignition-type pulse noise. The noise blanker is par-
ticularly important for mobile operation. When necessary,
activate the noise-blanker by depressing the NB switch ON.
4.1.3. RF GAIN CONTROL (Fig. 4-2)
For normal operation, this control should be turned fully
clockwise for maximum sensitivity. Receive sensitivity is
reduced by turning the control counterclockwise.
Adjust the RF GAIN so the S-meter does not show ex-
cessive deflection. This minimizes noise during reception
and allows the S-meter to indicates signal peak (or a little
below that point), noise is markedly reduced when the signal
is absent.
S-meter peak point
AF GAIN —@)— RF GAIN
6
8
0
Full
Clockwise
position
S-meter reading
at full counter-
clockwise position
of RF GAIN control
Signals below
this level are
attenuated
AF GAIN —@)— RF GAIN
6
84 Turn
counter
to
clockwise.
Fig. 4-2 RF GAIN Control Operation

4.1.4. RIT CONTROL
By using the RIT (Receiver Incremental Tuning) control, the
receive frequency can be shifted by about + 1.5 kHz without
changing the transmit frequency.
If the frequency of the station you are working changes, your
receive frequency can be reset by turning the RIT switch ON
and adjusting the RIT control. Adjusting the control
clockwise increases the frequency. The RIT shift can be
checked by the digital display. When first calling another
station, the RIT should be OFF, otherwise your transmit and
receive frequency will coincide.
4.1.5. IF SHIFT CONTROL
The IF SHIFT control is used to shift the passband of the IF
filter without changing receive frequency. By turning this
control in either direction, the IF passband is shifted as
shown in Fig. 4-3.
The IF SHIFT is effective in eliminating interference when
the receive signal is superinposed on nearby signals during
operation in USB, LSB or CW mode.
Turned in @ direction
=
Turned in © direction
=
IF filter passband
characteristic
|
\
X 0
X
Interfering signal Interfering signal
RIT—@)>- IF SHIFT RIT—@>-IF SHIFT RIT —@> IF SHIFT
0
<\N -AN
e€ oO ® Oo
Turn in @ direction
to eliminate inter-
ference from signal @)
Turn in © direction
to eliminate inter-
ference from signal ©
Fig. 4-3 IF SHIFT CONTROL
(1) USB Mode
Adjust the IF SHIFT control in the @ direction and lower
frequencies are cut. Adjust the control in the © direction
and high frequencies are cut.
(2) LSB Mode
Adjust the control in the @ direction and higher frequencies
are cut. Adjust the control in the © direction and low fre-
quencies are cut.
(3) CW Mode
By using the IF SHIFT in conjunction with the RIT, tone
quality can be adjusted.
4.2 TRANSMISSION (Fig. 4-4)
CAUTION:
Before transmitting, be sure to connect an antenna or dum-
my load with a VSWR of less than 1.5:1. Never attempt to
transmit with the antenna terminal left open.
When testing the transmitter, connect a 50-ohm dummy
load, rated at more than 100W (TS-120S), 10W (TS-120V).
Refer to Fig. 4-1 for initial control settings.
When the TS-120S(V) is ready for transmission, use the
following procedure:
SSB Operation
Set the MODE switch to LSB or USB.
Meter switch to ALC.
Standby switch to SEND.
Speak into the microphone and adjust the MIC GAIN for
meter deflection within the ALC zone at signal peaks.
PBWN-@e@
@ CW Operation
1 Set the MODE switch to CW and the meter switch to
ALC.
2 Set the standby switch to SEND and adjust the CAR
control so the meter deflects within the ALC zone. If a
key is connected, it should be depressed during the ad-
justment.
TS-120S
Power meter
Dummy load
Fig. 4-4 Testing with Dummy Load or
Power Meter
11

4.2.1. FINAL STAGE PROTECTION
The TS-120S(V) features a VSWR protection circuit to
protect the final-amplifier transistors. The circuit in the TS-
120V is different than the circuit in the TS-120S.
(1) TS-120V
If the VSWR increases because of improper antenna im-
pedance, the protection circuit activates to prevent the final-
stage transistors from being overloaded. In this case,
transmitter output power is reduced.
(2) TS-120S
Three different protection circuits are designed into the TS-
120S
!) The same VSWR protection method as used in the TS-
120V is used in the TS-120S. That is, the final-stage
transistors are protected by detecting VSWR of the
antenna system and automatically lowering transmitter
output power if the VSWR is too high.
ii) When the heat-sink temperature rises, a detection cir-
cuit activates a cooling fan. Under normal conditions,
this cooling fan sufficiently cools off the heat sink
radiator.
iii) The heat-sink temperature could rise abnormally during
long transmissions, if the area adjacent to the heat-sink
is blocked. In this case, the TS-120S automatically
returns to the receiving mode, and transmitting is not
possible until the heat-sink cools to the proper
temperature.
NOTES:
1. If transmitter output decreases due to activation of the
protection circuit caused by high VSWR, recheck and
retune the antenna system carefully.
2. When the cooling fan starts to turn, determine that ade-
quate air flow is possible in the heat-sink area.
(3) Operation of the Cooling Fan
The cooling fan operates when the heat-sink temperature
rises, and it ceases to operate when the temperature
decreases to normal. The heat-sink is made of die-casting
aluminum and is actually the rear panel. It must be kept
clear of surrounding objects, in order that heat will dissipate
easily.
The cooling fan is designed to operate when the heat-sink
temperature is at a specific level, regardless of whether the
unit is in transmit or receive mode.
4.2.2. MIC GAIN CONTROL (Fig. 4-5)
This control adjusts the microphone input level. When using
the TS-120S(V) in USB or LSB mode, connect a microphone
and set the standby switch to SEND (antenna or dummy
load MUST be connected).
Set the meter switch to ALC and speak into the
microphone. Adjust the MIC GAIN control so the meter
does not deflect out of the ALC zone at signal peaks.
12
The TS-120S(V) accepts either a low or high impedance
microphone (500 2 to 50 k&2). When using a low impedance
microphone (500 {2) the MIC GAIN control should be ad-
vanced higher than when a high impedance microphone is
used, while observing the ALC meter.
e@ ALC (Automatic Level Control)
The ALC monitors the transmitter final stage output to
minimize distortion in your transmitted signal. It
automatically adjusts output to an optimum level.
Pointer should not deflect beyond
ALC zone at signal peaks.
Fig. 4-5 ALC Adjustment
4.3 VOX OPERATION
4.3.1. VOX SWITCH
VOX (voice operated transmit) is used to switch the TS-
120S(V) into transmit mode by your voice. Depress the
switch ON and speak into the microphone. The transceiver
automatically switches to transmit mode (the MIC control
should be adjusted in advance as explained in Item 4.2.2).
Both the send switch and the MIC P.T.T. switch are left in
the REC position.
4.3.2. VOX GAIN CONTROL
This adjusts the VOX circuit sensitivity. Speak into the
microphone at normal voice levels and adjust the control.
Clockwise increases sensitivity, allowing transmission with a
low voice level. Transceiver operating condition can be
checked by the sound from the speaker. When the speaker
is silent, the transceiver is in transmit mode.
Note that if the control is advanced too far, the VOX circuit is
“tripped” by ambient noise.
4.3.3. ANTI-VOX CONTROL
This prevents the VOX circuit from being “tripped” by sound
from the speaker.
Adjust
the
control
so
the
VOX
will
not
operate
at
the
desired
speaker
volume
level.

4.3.4. VOX DELAY CONTROL
This
control
adjusts
the
transmit
hold
time
of
the
VOX
cir-
cuit.
If
the
hold
time
is
too
short,
the
transceiver
will
return
to
receive
mode
as
soon
as
you
stop
talking
into
the
microphone.
This
can
be
eliminated
by
turning
the
control
clockwise.
Adjust
the
control
comfortable
operation
at
a
normal
rate
of
speech.
4.4 SEMI-BREAK-IN OPERATION
The
TS-120S(V)
has
a
built-in
side-tone
oscillator
to
permit
semi-break-in
operation,
besides
the
normal
CW
operation.
During
semi-break-in
operation,
the
transceiver
is
placed
in
transmit
mode
when
the
key
is
depressed,
returns
to
and
receive
mode
when
the
key
is
released.
The
VOX
circuit
is
activated
by
the
side-tone.
For semi-break-in operation, set the VOX switch ON and the
MODE switch to CW.
For semi-break-in operation, adjust the VOX GAIN to insure
that the transceiver is set in transmit mode whenever the
key is depressed. Also, adjust the VOX DELAY for desired
hold-in. VOX and ANTI VOX adjustments are not required.
4.5 FIXED CHANNEL OPERATION (Fig. 4-6)
The TS-120S(V) has a built-in crystal-controlled oscillator
for fixed-channel operation. This feature is most useful for
commonly used frequencies, nets, or any situation where
crystal-controlled operation is required. To use the fixed-
frequency oscillator, turn the FIX switch to the FIX position.
The TS-120S(V) accepts a maximum of four crystals one
each for the 7, 14, 21 and 28 MHz bands (the 28 MHz band
includes 28.0, 28.5, 29.0 and 29.5 MHz, so it is possible to
Operate in 28.1, 28.6, 29.1 or 29.6 MHz with a 28.6 MHz
crystal). For operation in the 3.5 MHz band, change the
position of the connector from the 28 MHz to the 3.5 MHz
position as shown in Fig. 4-6.
AF-GEN UNIT X49-1110-01
ves (8)
SIDE TONE
28
7.14 213.5 Insert
° Tc3
0000) Oise.)
11
TO For
TC6 TCS TC4 3.5 MHz
(7) (14) (21) uw operation
T\ 28 Miz
Green White operation
eee
Fig.
4-6
3.5
MHz
or
28
MHz
crystal
selection
The crystal frequency is determined by the following for-
mula:
Crystal frequency (MHz) = 5.5 — X + Operating frequency
(MHz)
= 3.5 (80m band)
= 7.0 (40m band)
= 14.0 (20m band)
= 21.0 (15m band)
= 28.0 (10m band)
= 28.5 (10m band)
= 29.0 (10m band)
X = 29.5 (10m band)
x KKK KK OK
Crystal Specifications:
Type of crystal holder: HC-25/U
Oscillation frequency: 5.5 ~ 6.0 MHz
Multiplication: Fundamental
Frequency tolerance: +0.002% at normal temperature
Oscillation circuit: See Fig. 4-7
-——
Q1 : 28C460(B)
Q2 : 28C1959(Y )
pl
47k
a
Fig.
4-7
Crystal
Oscillator
Circuit
“4
13

4.6 CW OPERATION (Fig. 4-8)
For CW operation, your transmit frequency should be
“zeroed” to the transmit frequency of your contact station.
Receive frequency is 800 Hz lower than the transmit fre-
quency of your contact station, so that his signal is received
as a 800-Hz beat note. This also allows your contact to
receive your signal without having to retune receiver.
Tuning methods are detailed in the following paragraphs.
Contact station frequency
Receive frequency
t
Transmit frequency Sy
!
!
oe
Beat signal
Your frequency
Transmit frequency Receiver frequency
Beat note
Fig. 4-8 Tuning for CW Operation
4.6.1. OPERATION WITHOUT OPTIONAL CW FILTER
Set the IF SHIFT control to its center position and the RIT
switch OFF. Adjust the main tuning knob for an 800-Hz
beat note and your transmit frequency will then coinside
with that of your contact station (“zeroed”). During recep-
tion, the side-tone monitor is activated by pressing down the
key (VOX OFF). In this case, listen to the side-tone superim-
posed on the receive signal and adjust the main tuning for
similar side-tone and incoming CW avoid tone. By so doing,
transmit frequencies will be zeroed.
You may now adjust the RIT for a pitch which suits your
preference. If intereference is encountered, adjust the IF
SHIFT. For more convenient and effective CW operation,
use of the optional YK-88C CW crystal filter is recommend-
ed.
4.6.2. OPERATION WITH CW FILTER (YK-88C)
Set the IF SHIFT to its center position and the RIT to OFF.
Adjust the main tuning knob for maximum deflection of the
S-meter. Receive signal pitch will be about 800 Hz, in-
dicating correct tuning.
4.6.3 KEY CONNECTION (Fig. 4-9)
Your key should be connected as illustrated in Fig. 4-9 when
using an electronic keyer, make sure that polarity is correct.
Always use shielded line from the key to transceiver.
TS-120V
Before connecting, check that the
polarity is connect. The KEY jack
provides +9V. Use shielded
cable
Fig. 4-9 Key Connection
4.7 MOBILE OPERATION (Fig. 4-10)
The TS-120S(V), being compact in design, is ideal for mobile
operation. Satisfactory mobile operation is achieved
through proper power and antenna connection, and thought-
ful transceiver installation and adjustment.
4.7.1. TS-120S(V) INSTALLATION
Secure the TS-120S(V) under the dashboard using an op-
tional MB-100 mounting bracket as shown in Fig. 4-10. As
an
alternative,
use
strapping,
making
sure
that
the
TS-
120S(V)
will
not
slip
out
of
place
while
driving
the
vehicle.
NOTES:
1.
Do
not
install
the
TS-120S(V)
near
the
heater
outlet.
2.
Allow
sufficient
space
behind
the
TS-120S(V)
to
ensure
proper
ventilation.
4.7.2. HOW TO HANDLE THE POWER CABLE
When connecting or disconnecting the power cable to or
from the power connector, be sure that the power switch is
always in the “OFF” position. Observe polarity of the cable.
The TS-120S(V) operates on 13.8 VDC, negative ground.
Battery polarity must be correct. The power cord is color
coded:
CAUTION: Observe battery polarity.

Loading coil
Antenna Antenna bracket must have
[\
Antenna bracket
must have good
metal to metal
contact. Bence
CTI
oe
eS
good metal to metal contact. 5)
To ant term TS-120S(V)
ia
TS-120S
Bumper mounting
bracket
f
Pass coaxial cable
through the drain hole.
Rubber
grommet
terminal as possible.
Use short heavy leads
Fuse should be as close to the battery
Fig. 4-10 Mobile Operation
Since an HF antenna is large and heavy, it must be installed to withstand
strong wind stress.
Use fuse block, battery acc-
essory position, 20A minim-
um rating
As short as possible.
/
Turn POWER switch OFF
before connecting/-
disconnecting the power cord.
POWER CABLE
TS-120V TS-120S
red ®
red or black ©
red or white ©
black or gray ©
Connect the TS-120S(V) power cable to the battery ter-
minals, with consideration to current requirements and noise
prevention. The maximum current drawn by the TS-120S
reaches to between 18 and 20A when transmitting.
Therefore, the cable should be made as short as possible, us-
ing the specified fuse. Also, determine that the power
system of the car (including the battery and generator or
alternator) will handle the increased load of the TS-120S(V).
Route battery and ANTENNA leads away from all high
voltage secondary circuits to prevent ignition noise in-
terference.
4.7.3. MOBILE ANTENNA
(1) Antenna Installation
Use a rugged mount for the mobile antenna because HF
antennas are larger (and have more wind load) and heavier
than VHF antennas. A bumper mount is recommended for
general use. The ground side of the mount must be ground-
ed perfectly to the body of the car since the body itself func-
tions as the ground plane for the mobile antenna. (Refer to
Fig. 4-10.)
NOTES:
1. Some cars have a urethane bumper. For such cars,
ground the antenna mount to the body.
15

2.
When
tuning
the
newly
installed
antenna,
use
the
TS-
120S(V)
in
the
following
procedure:
*
Turn
the
CAR
control
fully
counter-clockwise
for
minimum
transmit
power.
+
With
the
TS-120S(V)
in
transmit
mode,
raise
transmit
power
output
slowly
by
rotating
the
CAR
control
clockwise.
The
antenna
can
be
adjusted
with
minimum
power.
*
Transmitting
with
full
power
is
recommended
after
the
antenna
is
adjusted
for
a
VSWR
below
1.5:1.
3.
Antenna
installation
is
critical
for
successful
mobile
operation.
For
further
information
refer
to
THE
RADIO
AMATEUR’S
HANDBOOK,
RADIO
HANDBOOK,
or
other texts.
(2) Coaxial Cable Connection (Fig. 4-10)
When
the
antenna
is
mounted
on
the
vehicles
bumper,
the
coaxial
cable
from
the
antenna
can
be
routed
to
through
a
drain
hole
in
the
trunk.
When
the
antenna
is
roof
mounted
connect
the
cable
through
the
hole
in
the
door.
In
this
case,
care
should
be
used
not
to
allow
rain
water
to
come
into
the
vehicle.
(3) Antenna Adjustment (Fig. 4-11)
Some
mobile
antennas
are
not
designed
for
50-ohm
im-
pedance.
In
this
case,
impedance
matching
between
the
antenna
and
the
coaxial
cable
(509)
is
required.
This
can
be
achieved
by
using
an
antenna
matching
device
or
coupler.
t Adjust length
One turn coil
Bumper Antenna
ground
Grid Dip meter
Disconnect
Coaxial cable
Fig. 4-11 Adjusting Antenna Resonance
16
The
antenna
to
be
used
should
first
be
checked
with
a
dip
meter
to
insure
that
it
is
designed
for
your
operating
band,
then
the
impedance
matching
should
be
checked
with
an
SWR
meter.
(See
Fig.
4-11)
The
VSWR
should
preferably
be
less
than
1.5:1
for
satisfac-
tory
operation.
For
antenna
adjustment
refer
to
the
antenna
instruction
manual.
4.7.4. NOISE REDUCTION
In
motor
vehicles,
ignition
noise
is
generated
by
the
ignition
coil
or
distributor.
Other
sources
of
noise
include
the
wiper
or
heater
motor.
Although
the
TS-120S(V)
is
equipped
with
a
noise
blanker
to
minimize
ignition
noise,
it
is
imperative
that
some
preven-
tive
measures
be
taken
to
reduce
the
noise
to
the
lowest
possible
level.
(1) Antenna Location Selection
Since
ignition
noise
is
generated
by
the
vehicles
engine,
the
antenna
must
be
installed
as
far
from
the
engine
as
possible.
(2) Antenna Matching
In
general,
mobile
antennas
have
a
lower
impedance
than
50-ohm
coaxial
cable,
resulting
in
a
mismatch
between
the
antenna
and
the
coax.
Such
trouble
can
be
eliminated
by
using
an
antenna
tuner
between
the
TS-120S(V)
and
the
coaxial
cable.
© Matching Circuit Examples
AT-120
H OUT PUT
IN PUT OUT PUT IN PUT:
L
Fig. 4-12 Matching Circuits
(3) Bonding
The component parts of motor vehicles, such as the engine,
transmission, muffler system, accelerator, etc., are coupled
to one another at DC and low frequencies, but are isolated at
high frequencies. By connecting these parts using heavy,
braided ground, straps, ignition noise can be reduced. This
connection is called “bonding”.
(4) Use Ignition Suppressor Cable or Suppressor Spark
Plugs
Noise can be reduced by using spark plug with internal
resistors, or resistive suppressor ignition cable.
(5) Battery Power Connection
It is recommended that battery power be supplied directly to
the TS-120S(V) from the battery terminals.

(6) Battery Capacity
The power system of a motor vehicle is comprised of a
battery and an alternator (when generates power while the
engine is running) to supply current to loads or to charge the
battery.
Since the transceiver draws hi current, during transmit care
should be excersised so the power system is not overloaded.
When using the transceiver, the following points should be
observed from the viewpoint of battery maintenance:
@ Turn the transceiver OFF when the lights, heater, wipers
and other high-draw accessories are used.
@ Avoid transceiver operation when the engine is not run-
ning.
@ If necessary, use an ammeter and/or a voltmeter to
check battery condition.
4.8 FIXED STATION OPERATION
4.8.1. Power
The TS-120V power requirement is 4A at 13.8 VDC when
transmitting with full power. The Kenwood model PS-20
power supply for fixed stations matches the TS-120V in
design and performance.
The TS-120S requires more than 18A at 13.8 VDC when
transmitting with full power. Use the Kenwood model PS-
30 power supply for fixed stations.
4.8.2. ANTENNA
Fig. 4-13 Rotary Beam Antenna
For HF fixed-station operation, an antenna specifically
designed for amateur operation is recommended. Antenna
types include the wire antennas, verticals, rotary beam, and
other antennas. HF antennas are quite large and must be in-
stalled to withstand strong wind, heavy rain, etc.
Any antenna used with the TS-120S(V) should be of 50-
ohm impedance and should be connected using an ap-
propriate coaxial cable such as RG-8/U.
Impedance matching is important. Impedance mismatching
will result in a high VSWR and power loss, or can cause un-
wanted harmonic radiation and interference (TVI, BCI).
The impedance match can be checked with an SWR meter.
Generally satisfactory operation is assured when the VSWR
(Voltage Standing Wave Ratio) is less than 1.5:1.
For impedance matching between the antenna system and
transceiver, use of the AT-120 Antenna Tuner (option) is
recommended. A rotary beam antenna is very effective for
DX operation in 14, 21 and 28 MHz bands. (Fig. 4-13)
4.9 DIGITAL DISPLAY CALIBRATION
4-14)
Connect the antenna and set the BAND switch to WWV.
Turn the main tuning dial to about 500” to receive the 15-
MHz WWY signal. Adjust the dial until a low-frequency
beat is heard. Next, depress the CAL switch and a marker
signal is superimposed on the WWV beat signal. A double
beat (two beat signals of high and low frequencies) will now
be heard.
While receiving this double beat, adjust the Counter unit
trimmer through the reference frequency adjustment access
opening (at the side of the TS-120S(V)) so the two beats are
heard as a single beat. This completes calibration of the
Digital Display. After calibration depress and release the
CAL switch.
os
Fig. 4-14 Digital Display Calibration
Trimmer
_ Access
Insulated tuning tool
First, remove cover
4.10 ANALOG DIAL CALIBRATION (Fig. 4-
15)
The main dial scale is graduated at 1-kHz intervals. One
revolution of the main dial covers 25 kHz. To calibrate the
scale, turn the CAL switch ON and in SSB mode zero-beat,
or in CW mode tune for an 800 Hz beat. Hold the main tun-
ing knob from rotating and slip the calibration ring to the
nearest major (5 kHz) graduation. The dial is now calibrated.
Note: For exact frequency, read the Digital Display.
Hold main dial
Turn Calibration ring
Fig. 4-15 Analog Dial Calibration

Hy -canbEy- conn canto -cnttts-entn =a yoenntn atta
ent
eunnns-caui sauna -enntts-ct to sentets at ee
SECTION 5. ADDITIONAL INFORMATION
5.1 GENERAL INFORMATION
Your TS-120S(V) has been factory aligned and tested to
specification before shipment. Under normal circumstances,
the transceiver will operate in accordance with these
Operating instructions.
If your transceiver fails to work, contact the authorized
dealer from which you purchased it for quick, reliable repair.
All adjustable trimmers and coils in your transceiver were
preset at the factory and should only be readjusted by a
qualified technician with proper test equipment.
Attempting service or alignment without factory authoriza-
tion can void the transceiver’s warranty.
5.2 HOW THE TX FINAL TRANSISTORS ARE
PROTECTED
Final transistor protection is provided by sampling the
reflected power. As the reflected power is increased (higher
SWR) transmitter drive is reduced, thus decreasing input to
the final transistors. This in turn reduces collector loss,
protecting the final transistors.
5.3 ORDERING SPARE PARTS
When ordering replacement or spare parts for your equip-
ment, be sure to specify the following:
@ Model and serial number of your transceiver, Schematic
number of the part, Printed circuit board number on
which the part is located, Part number and name, if
known, and Quantity desired.
5.4 SERVICE
Should it ever become necessary to return the equipment for
repair, pack in its original box and packing, and include a full,
detailed description of the problems involved. Also include
your telephone number. You need not return accessory
items unless they are directly related to the service problem.
NOTES:
When claiming warranty service, please include a photocopy
of the bill of sale, or other proof of purchase showing the
date of sale.
poennnne etna
The following optional accessories are available for use with
the TS-120S(V).
= * Model PS-20 Regulated DC Power Supply
Perfectly matches the design and characteristics of the TS-
120V. Equipped with a protection circuit which guards
transceiver against damage due to shorts or overload.
= Model PS-30 Regulated DC Power Supply
The PS-30 is a regulated DC power supply with a large
capacity. The output is 13.8 VDC/20A (Intermittent). Since
terminals for 13.8 VDC/5A are also provided, in addition to
output power cables for use with the TS-120S, the PS-30
can be used as a power source for other mobile transceivers
(such as 2-meter rigs).
= Model AT-120 Antenna Tuner
The AT-120 is a compact antenna tuner designed for use
with the TS-120S(V) in either a mobile or fixed station. The
SWR meter is illuminated so that it can be used in the car
even at night. Also, it is equipped with a highly accurate
SWR detecting circuit for matching within the impedance
range between 20 and 300 ohms on five bands between 3.5
and 29.7 MHz.
18
SECTION 6. OPTIONAL ACC
ESSORIES
= Model VFO-120
The VFO-120 is an all solid-state VFO with high stability,
designed to match the TS-120S(V) in design and perfor-
mance. “Split frequency” operation is possible by using the
TS-120S(V) with the VFO-120. Also, the T-F switch makes
it possible to check the transmit frequency while in the
receiving mode.
= Model SP-120 External Speaker
The SP-120 is an external speaker designed exclusively for
use with the TS-120S(V). It matches the TS-120S(V) in
design and tone quality.
= MICROPHONE MC-30S, MC-35S
Dynamic microphone with PTT switch specifically designed
for mobile operation.
Impedance: 50 k® (MC-30S)
500 & (MC-35S)
= MICROPHONE MC-50
Unidirectional dynamic microphone with locking PTT switch
provides excellent performance for VOX operation.
Impedance: 50 k® and 6002 (switchable)

= HEADPHONE HS-4
High-performance dynamic headphones with specially
designed ear pads for listening.
Impedance: 82
= YK-88C CW CRYSTAL FILTER
High selectivity (5600 Hz at —6 dB, 1.5 kHz at —60 dB)
crystal filter for CW operation. Easily installed in the TS-
120S(V).
* PS-20 PS-30
VFO-120
SP-120
MC-50 HS-4
= * HAM-CLOCK HC-2
24-hour type clock with pre-fix dial for easy reading of time
in most of countries in the world. It operates more than one
year on a single battery.
= * DE-LUXE HEADPHONE HS-5
Open-back type headphone designed for excellent tonal
quality and comfortable fit. The air type ear pads can be
readily replaced with the pressure type ones.
AT-120
MC-30S, MC-35S
* HC-2 * HS-5
* is not available in U.S.A.
19

finn cenny-caneno senna uuu eneans ennui cuuunosentnns-ettnne ete
‘Savvnsavescanuysenanesunnnscanuyseninesuunnes ttn -etnaacausnecatttstntnca
RECEIVING CIRCUIT
The signal from the antenna is fed to the 8.83 MHz IF trap
circuit. This signal is stepped up about 10 dB and
impedance-converted by a wide-band transformer before it
is applied to the bandpass filter (BPF). The BPF is common
to transmission and reception, eliminates the need for a
preselector, and makes the RF section compact in design.
The signal from the BPF is fed to the dual-gate MOS FET
wideband RF amplifiers consisting of a 3SK74 (Q1) and a
2SC1815 (Q2), where the 2 MHz to 35 MHz signal is
amplified about 20 dB.
The RF amplifier output is through a wide-band transformer
to the input balanced transformer of the balanced mixer (two
3SK74s, Q3 and 04), where it is mixed with the VCO output
from the PLL and converted to the 8.83 MHz IF. This signal
is applied to the IF unit through the ceramic filters, NB gate
circuit and the crystal filter. The NB circuit is controlled by
the NB switch on the front panel.
The signal, passing through the crystal filter, is amplified
about 90 dB by the three-stage 3SK74 MOS FET IF
amplifier (Q1, Q2, and Q3) and is demodulated into audio by
the four-diode ring detector.
From the final IF stage, the signal also passes through a
buffer amplifier and is fed to the AGC circuit where it is
detected and amplified. Receiver gain is controlled by this
AGC voltage applied to the second gates of the RF and IF
amplifiers, with the time constant determined by R38 (2.2
MQ) and C40 (1 uF). Input levels of 2 dB and 34 GB are in-
dicated as S1 and SQ on the S-meter. The AF signal is
amplified by Q1, a 2SC2240 (GR), gain controlled, and
further amplified by an HA1366W (Q7, the power-amplifier
IC, to drive the speaker. This signal, which is transistor-
coupled
with
Q14,
a
2SC1815(Y),
and
Q15,
a
2SA1015(Y),
is sampled for ANTI-VOX control, so the VOX circuit is not
tripped by the speaker output. This new system is a depar-
ture from the conventional transformer-coupled sampling
systems.
20
i
SECTION
7.
CIRCUIT
DESCRIPTION
09 AENR ONE andebs-e.bE HAHN eUnd ds abe atte cetn
URE.
sttato
sents.
canna
contnts
et
antag
ebEgn-eLLUyUNNN
sd
EELS
ante
cetbEE
SO
anbttS
HAS
atE
TRANSMITTING CIRCUIT
The
microphone
signal
is
amplified
by
transsitors
Q18,
a
2SC2240(GR),
Q10,
and
Q11,
each
a
2SC1815(Y),
and
is
fed
to
the
four-diode
balanced
modulator
(BM)
circuit.
Microphone
impedance
is
500
2
to
50
kQ.
The
8.83
MHz
DSB
signal
from
the
BM
is
amplified
about
10
dB
by
Q12,
a
2SK19
FET,
and
is
fed
to
the
IF
unit
where
the
unwanted
sideband
is
removed
by
the
crystal
filter
to
produce
an
SSB
signal.
The
gate
of
Q12
is
also
controlled
by
the
protection
voltage
which
is
developed
when
the
transmitter
output
locks
into
an
incorrect
load,
continuously
reducing
output
power.
The
SSB
signal
from
the
crystal
filter
is
amplified
about
30
dB
by
the
3SK74
IF
amplifier
(Q1),
and
is
fed
to
the
transmit
3SK74
MOS
FET
balanced
mixer
(Q5
and
Q6),
where
it
is
mixed
with
the
VCO
output
and
converted
to
the
final
transmit
frequency.
Unwanted
spurious
components
are
eliminated
by
the
transmit/receive
BPF
circuit,
and
the
signal
is
wideband-
amplified
by
Q7,
Q8
(2SC1815),
and
Q9
(2SC2086).
In
the
final
unit,
the
signal
is
amplified
by
the
2SC2075
driver
(Q1),
and
by
the
2SC2509
push-pull
power
amplifiers
(Q2
and
Q3)
TS-120V,
and
plus
2SC2290
push-pull
power
amplifiers
(Q4
and
Q5)
(TS-120S).
The
signal
then
passes
through
an
RF
filter
and
is
fed
to
the
antenna.
Antenna
output
is
toroid-sampled
to
detect
the
forward
and
reflected
power.
The
forward
power
is
used
for
ALC
and
the
reflected
power
for
protection.
Forward
Power
is
fed
to
the
second
gate
of
the
3SK74
transmit/receive
IF
amplifier
(Q1),
with
a
time
constant
determined
by
R7
(1
MQ)
and
C40
0.47
uF).
For
CW
operation,
block
bias
keying
controls
the
base
circuit
of
the
2SA1015
switching
transistor
(010)
in
the
RF
circuit.
Q10
controls
the
first
and
second
gate
voltages
of
the
transmit
mixer
(Q5
andQ6)
and
the
base
voltage
of
the
predriver
(Q9).