Kenwood TM-631A User manual

GOONS)
144/220MHz FM DUAL BANDER
TM-631A
144/440MHz FM DUAL BANDER
IM-731A
144/430MHz FM DUAL BANDER
IM-731A
TM-731E
INSTRUCTION MANUAL
KENWOOD CORPORATION
©PRINTED IN JAPAN B50-8295-00(K, M, P, W)(T)
90/12 1110987654321 89/121110987654

Thank you for purchasing this new transceiver.
IMPORTANT:
Please read this instruction manual carefully before placing
your transceiver in service.
SAVE THIS INSTRUCTION MANUAL.
CAUTION:
Long transmission or extended operation in the HI power
mode might cause the rear of this transceiver to get warm.
Do not place the transceiver where the heat sink (rear panel)
might come in contact with plastic or vinyl surfaces.
This Instruction Manual covers the following models.
TM-631A : 144/220 MHz FM DUAL BANDER
TM-731A : 144/440 MHz FM DUAL BANDER
(U.S.A. version)
TM-731A : 144/430 MHz FM DUAL BANDER
(Other market)
TM-731E : 144/430 MHz FM DUAL BANDER
The following explicit definitions apply in this manual:
Note : If disregarded, inconvenience only, no risk of
equipment damage or personal injury.
: Equipment damage may occur, but not per-
sonal injury.
Caution
CONTENTS
Poe
BEFORE OPERATION ...i..00:scscceccsecccneneneroes 3
SPECIFICATIONS and ACCESSORIES io
INSTALLATION INSTRUCTIONS .. 6
IPERA TIONS. cvcrcteexsegetistacrsentvevesvacrasansneind 9
OPERATING CONTROLS
RECEIVER'OPERATION. .iscscsscessccriscoesstuaeens 15
Reception
Frequency Selection
Frequency Step Selection...
A.B.C. (Automatic Band Change) ...
TRANSMITTER OPERATION
REPEATER OPERATION
Transmitter Offsets
REVErse|FUNCHON scssicvsiesieneveuaisooruwiaveone 20
Tone Operation
Autopatch (U.S.A. version only)......ssseseeee 22
MEMORY 55 sseccdhtcacatea cocaxtercssane atveesaunsee 23
Microprocessor Memory Back-up
Microprocessor Initialization
Memory Channel
Memory Contents
Memory Entry sresesisscusecessreransxcestacaniecuan 24
Simplex/Normal SHIFT
Odd Split Channels
Call, CHANNEL ses ovsenaedes os sseasnancescewene 26

Memory Recall
Memory Shift
SCAN cscnanvesnarsascdawsnanaasnienrnsastensienpebendace 27
Scan Options
Hold Resume Programming
Programmable Band Scan/Band Scan
Memory Channel Scan....s.scsseceseneeeeeeeeees 28
Double Scan
Priority Alert
Memory Channel Lockout.....esssseeesseereneee 29
Tone Alert System
BLOCK DIAGRAM
and SCHEMATIC DIAGRAM""""""" another sheet
MAINTENANCE
In Case of Difficulty ....
OPTIONAL ACCESSORIES ............csceeeeseeees 32
CTCSS unit TSU-6
REMOTE CONTROLLER RC-10
ACCESSORIES wvcsisinssinisvnnsncnontessseinas’aeciase 35
1. [A waRNiNe] BEFORE OPERATION
TO PREVENT ELECTRIC SHOCK, FIRE AND OTHER INJU-
RY. PLEASE NOTE THE FOLLOWINGS:
To avoid risk of electric shock, under no circumstances
should the unit be opened:
Do not place this unit, where it will be exposed to direct
sunlight or close to heating appliances.
To ensure good ventilation, do not put anything on top of
the cabinet and allow at least 15 cm (6 inches) of space
behind the unit.

The power requirement is 13.8 VDC.
Never attempt connection to a 24 VDC source.
Do not place the unit in areas of excessive dust, high hu-
midity or on unstable surfaces.
Do not drop pieces of metal, needles, coins and other elec-
trically conductive materials into the unit.
Do not pull the power cord, when disconnecting it from the
AC wall outlet. Grasp the plug and ensure that your fingers
do not touch the live pins.
If an abnormal odor or smoke is detected, immediately turn
the power off and pull out the power plug. Contact the
KENWOOD service station or your dealer.
CLEANING
1. Turn the power off, before cleaning the unit.
2. Do not use any type of abrasive pad, thinner, benzine
or any substances which may damage the unit.
3. Wipe the front panel and other exterior surfaces of the
unit with a soft dry cloth or a soft cloth lightly moistened
with water.

2. SPECIFICATIONS AND ACCESSORIES
2-1. SPECIFICATIONS 2-2. ACCESSORIES
lode! 1-731,
Giharmakes| TM7aIe TM-631A J
Specifications
U.S.A,
version
Version
Unpack
your
new
transceiver
carefully,
and
con-
744 to 148 MHz|144 to 148 MHz|144 to 146 MHz|144 to 148 MH; i i i j
Frequency range PES tape bia beep a ia ten eee firm that the accessories listed below are included
Mode — F3€ (FM) in the box.
‘Antenna impedance 50 ohms
Pe it it! 13.8 VDC +15% .
ct es a MC-44DM Microphone....791-0380-15 .....1 ea.
§ [E | Tranamit mode Less than 11 A (U.S.A. and CANADA)
= [5s Besene mode with no Less than 0.6 A or
Operating temperature =20°C to +60°C (-4°F to +140°F) MC-44E Microphone....... 7T91-0382-15.....1 ea.
Dimensions (WH 201 160x 60x 219 mm (8.97 x2" x 8.6") (U.K. and Europe)
Weight 1.8 kg (3.97 Ibs) oF
Output Hi 744 MHz: 50 W, 220 MHz: 25 W, 430/440 MHz: 35 W Microphone ..........csseeeeee T91-0379-15..... 1 ea.
‘
aa
Low
=
ae
(Other
market)
lodulation feactance modulation r
Sauna Taaavon leer Seas Microphone Hook..........« J20-0319-24......1 ea.
Maximum frequency deviation £5 kHz (U.S.A. and CANADA)
F* | Audio distortion (at 60% Less than 3% (300 to 3000 Hz) Self tapping Screw......... N46-3010-46.....2 ea.
Microphone impedance 500 to 600 ohms (U.S.A, and CANADA)
Circuitry Double conversion superheterodyne Bracket iiiiisiicssscasceas -..J29-0418-03.
144 MHz: 16.9 MHz/455 kHz, i i i - |
U.S.A. version 220 MHz: 30.825 MHz/485 kiiz, Mobile Mounting Kit .......N99-0318-05 .
Intrmeckat 440 MHz: 21.6 MHz/455 kHz Wrench -W01-0414-05 ....1 ea.
juency 144 MHz: 10,7 MHz/455 kHz,
5 Other market Ano the so aoptic/abe Kriz DC Power Cable -E30-2111-05 .....1 ea.
3 Sensitivity(12 dB SINAD) 144 MHz: Less then 0.2 nV, 220 MHz: Less than 0.18 2V, Fuse (15A) -FO5-1531-05...... 1 ea.
iz:
Less
than
0.16
.
€
%
| cores ZG ilaiddera than TZkHz, Instruction Manual -B50-8295-XX ..1 copy
letteavity — 80 dB: Less than 24 kHz Warranty Card. 1 ea,
Spurious response Better than 60 dB (U.S.A. CANADA and Europe)
‘Squelch sensitivity Less than 0.09 »V J 4
Output More than 2 W across 8 ohms load (5% distortion) i
External speaker impedance 8 ohms After unpacking
Notes: Shipping container:
1. Circuit and ratings are subject to change without notice due to ad- Save the boxes and packing in the event your unit
vancement in technology. needs to be transported for remote operation, main-
2. *Recommended duty cycle:
ri St, * . tenance, or service.
1 minute Transmission, 3 minutes Reception -

3. INSTALLATION INSTRUCTIONS
3-1. INSTALLATION
Mounting Bracket
When installing the transceiver in a vehicle consider the ease
of operation and safety when selecting the location for the
mounting bracket.
Ts
Install the bracket using
the supplied flat washers
and self tapping screws (4
pcs. each).
. Attach the transceiver
loosely using the SEMS
screws (4 pcs.).
. The angle of the bracket
may be adjusted to any of
9 possible viewing angles.
Select the desired angle.
(Fig. 2)
. Hold the transceiver in
place and tighten the 4
SEMS screws using a
wrench or screwdriver.
Flat
washer
Self tapping
screw
[}
3-2. CONNECTIONS
3-2-1. Mobile Installations
External Speaker
The SP-41 or
TM-731A/731E:
The MA-700 dua! band
antenna is recommended.
To 144 MHz
To 144 MHz antenna
the SP-50B is
Duplexer
To 220 MHz To 430/440 MHz
A
+
t TM-631A: y TM-731A/731E:
antenna — antenna
To 430 MHz
Cautions: —
te
2.
Before installing the power cable, be sure to remove the
negative lead from the battery for safety.
After installation and wiring, be sure to double check for
correct installation before reconnecting the negative lead
to the battery terminal.
. If the fuse opens, be sure to check that each conductor
has not been damaged by short-circuiting, etc.
Then replace with a new fuse of the same rating.
. After completing the wiring, wrap the fuse holder with
heat resistant tape to protect against heat and moisture.
. Do not remove the fuse even if the power cable is too
long.

A. Battery Connections
Connect the power cable directly to the battery terminals.
Use of the cigarette lighter socket can lead to poor connec-
tion, and result in poor performance. Pay close attention to
the polarity of the cables when connecting them to the
battery.
Make sure the positive (+) and negative (—) lead polarity is correct
when connecting to the battery.
Engine compartment Th Passenger compartment
Fuse
Red
y
To the
transceiver
Select a location where
the power cable is pro-
tected from heat, mols
ture or abrasion when
securing the cable.
Make sure the cable does
not directly contact the
edge of the hole by using
4 ‘a grommet.
Chassis or
fire wall
Battery
™ f the wiring hole in the fire wall or chassis is too small, disas-
semble the fuse holder to thread the wire through the hole.
From passenger
compartment
Thread like this
B. Ignition Noise
This transceiver has been designed to suppress ignition
noise; however, if excessive noise is present, it may be
necessary to use suppressor spark plugs (with resistors).
3-2-2. Fixed Station
A regulated DC power supply (13.8 VDC capable of sup-
plying at least 10 Amperes) is required. The PS-430 and the
PS-50 are recommended.
CAUTION:
1. Never connect the AC power cable to the AC outlet un-
til all other connections have been made.
2. Before connecting and disconnecting the power connec-
tor, be sure to turn off the POWER switches of both the
transceiver and the DC power supply.
3. Observe polarity of the DC power cable. The transceiver
operates on 13.8 VDC, negative ground. Battery polari-
ty must be correct. The power cable is color coded:
Red -— + (Positive polarity)
Black — — (Negative polarity)
\o/ (a SP-430
HGOUUNONNONGONGA
Pin nIniUATOO ARON
+
TM-631A + To 220 MHz antenna 3
TM-731A/731E : To 430/440 MHz antenna —

3-2-3. Antenna
The type of antenna that is used will greatly affect the per-
formance of the transceiver. Use a properly adjusted anten-
na, of good quality, to enable your transceiver to perform
at its best. The antenna input impedance is 50 ohms. Use
50-ohm coaxial cable such as RG-8U or 8D-2V for this con-
nection. If the antenna is far from the transceiver the use
of low loss coaxial cable, such as RG-8U is recommended.
Match the impedance of the coaxial cable and that of the
antenna so that the SWR is less than 1.5 to 1. The protec-
tion circuit in the transceiver will activate if the SWR is par-
ticularly poor (greater than 3 to 1).
High SWR values will cause the transmitter output to drop,
and may lead to TVI or BCI reports.
CAUTION:
For protection against fire, electric shock, personal injury,
or damage to the radio, use a lightning arrester in your an-
tenna lines.

4.
OPERATION
i L
+t
CONTROLS
PS
==
wes
agé
©
4-1-1. Front Panel Hen a
F Lak ST 19h oa gh ABE — = eee ®@
Main Tuning control
This control is used to select the desired transmit/
receive frequency, Memory Channel, Frequency Step,
Tone Frequency, and Scan direction of the MAIN fre-
quency band.
CALL key
The CALL key selects the CALL channel of the MAIN
frequency band. The frequency may be reset to any
desired frequency. (See CALL Channel P26.)
VFO key
This key is used to return to VFO operation after oper-
ating in the MR (Memory Recall), or CALL Channel
mode. The MAIN tuning control will increase frequen-
cy in the selected step size, the tone frequency, and/or
the frequency step.
Press and hold the key for longer than 1 second to in-
itiate VFO scan. Press the key after scan has been in-
itiated will cause scan to stop.
MR key
This key is used to select Memory Recall operation af-
ter operating in the VFO or CALL channel mode. The
MAIN Tuning control may be used to select the desired
2)
@ Microphone audio—_
@ PTT (STBY) switch
memory channel in this mode.
Press and hold the key for longer than 1 second to in-
itiate MR scan. Press the key after scan has been in-
itiated will cause scan to stop.
VOL control/Power switch
The volume control and power switch are combined.
Rotating the control clockwise will turn ON the tran-
sceiver.
Advancing the control further clockwise will increase
the total volume of two bands.
The BALANCE control proportions the volume among
the two bands.
MAIN SQL control
This control is used to select the desired SQL threshold
level of the MAIN frequency band.
Microphone connector
Plug the standard or optional microphone into this jack.
GND (PTT)
@ GND (Microphone)
RX Audio output
(Approx. 100 mV/10 kQ)
@
DOWN
©
8
V/Max.
50
mA
@ up
Front view

10
®7= ®= @
ALB. C. DUAL BAND
CTCSS. SEI
A ae eee 58 edie Oe pee
., 3... E9 GO re Nee
©) o) ® ®
MHz key
This key is used to change frequency in 1 MHz steps
during VFO operations.
Pressing and holding the key will continuously change
the frequency in 1 MHz steps.
Sub Tuning control
This control is used to select the desired receive fre-
quency and Memory channel of the SUB band.
LOCK switch
This key will deactivate all functions except the PTT
switch.
BALANCE control
This control proportions the total audio volume among
the two bands.
MAIN position : Audio only from the MAIN band
Center position : Equal audio from both bands
SUB position : Audio only from the SUB band
SUB SQL control
This control is used to select the desired SQL threshold
level of the SUB band.
LOW key
This key is used to select the transmit output power
level as follows:
HI (no indicator): 144 MHz:50 W/220 MHz:25 W/
430 MHz:35 W
LOW : 5W
DIM key
This key is used to select either high or low intensity
of both the LCD display and control's illuminations.
For the key to function, it must be pressed within 5 se-
conds after pressing the F key.
A.B.C. (Automatic Band Change)
When this key is pressed, the contents of the SUB band
will be transfered to the MAIN band whenever a signal
is received at the SUB band antenna, which is strong
enough to open the squelch. The contents of the MAIN
band are transfered to the SUB band at the same time.
DUAL band
This key is used to turn the SUB band ON or OFF.
CTCSS SEL (With the TSU-6)
Pressing the key within 5 seconds of pressing the F key
will switch the CTCSS function alternately between the
UHF band and VHF band. (To activate the CTCSS func-
tion use the CTCSS key.)
During scan press the key to initiate double scan.
BAND key
This key is used to change the contents of the MAIN
band.

@ T.ALT Key
This key is used to
turn the Tone Alert
function ON or OFF.
@ SHIFT key
This key is used to
select the desired
transmitter offset dur-
ing repeater opera-
tions. When the key is
pressed the shift
mode cycles from +
to — [— to — — (Eu-
ropean version)] to
simplex (no indicator).
@ TONE key
This key is used to ac- |
tivate the subaudible |
tone encoder.
@ REV key
This key is used to
reverse the transmit/
receive frequencies
during repeater opera-
tions. This will allow
you to check the input
of the repeater or to
operate on a reverse
repeater pair.
© MUTE key
This key is used to
reduce the volume of
the SUB band (Ap-
proximately 20 dB).
v v v v v
The F key is activate these keys below for 5 seconds after pressing the key, and during the “‘F’’ indicator is ON.
@L. OUT key AL key @ T. SEL key STEP key @ CTCSS key
This key is used to This key is used to This key is used to This key is used to With the TSU-6: This
temporarily skip un- check Memory Chan- switch to the tone fre- | | switch to the frequen- key is used to activate
wanted Memory nel 1 at approx. 5 se- quency _ selection | cy selection mode the CTCSS function.
Channels during the cond intervals. If the mode. | | during VFO operation.
Memory Channel channel is busy, a The MAIN Tuning The MAIN Tuning
Scan mode. beep will sound. control can then be | | control can then be
used to select the
desired tone fre- |
quency. |
used to select the
desired frequency
step.

Display panel = The MAIN band
indicators , The SUB band indicators
® 9® 69 @|@®
|
= 4 ineagber| wale
Fy 8. sags g. 8. ces 5! EEECELD
be g ca teemegeenealtL
TASC. | MUTE
rv + +
The MAIN band Indicators
Flashes when scanning
Displays the operating frequency to
the nearest kHz, the frequency step,
and/or the tone frequency.
—This level meter indicates the relative
receive input signal strength or trans-
mitter RF output.
ON whenever the squelch is open.
ON during transmit.
Fr ON whenever the F key is depressed.
* fa) jc
(Always displays the last Memory
Channel number that had been
selected.)
Displays the current Memory Channel
number.
The * indicator is ON when the
Memory channel will be skipped dur-
ing Memory Channel Scan.
ON when the CALL channel is ON.
+ Displays the selected transmitter off-
- set direction.
(TM-731E)
REV
ON
when
the
Reverse
function
is
active.
T
ON
when
the
Tone
function
is
active.
g
ON
when
the
Tone
Alert
System
is
active.
The
indicator
will
flash
when
a
signal
is
received
on
the
MAIN
band.
LOW
Indicates
low
power
has
been
selected.
AL
ON
when
the
Priority
Alert
system
is
active.
2G ® 68 ©
Common indicator
<
CTCSS
»
With
the
TSU-6;
ON
when
the
{ t CTCSS function is active.
Displays the selected CTCSS band.
©
asc.
ON
when
the
A.B.C.
(Automatic
Band
The SUB band indicators
Flashes when scanning.
o~ andibwiea relative signal strenght dur-
ing reception.
Displays the current Memory Channel
number.
«ff
Memory channel will be skipped dur-
ing Memory Channel Scan.
Change) function is ON.
Displays the receive frequency.
bo 52 on whenever the squelch is ON.
The * indicator is ON when the
ON
when
the
CALL
channel
is
ON.
(0)
g
ON
when
the
Tone
Alert
System
is
active.
The
indicator
will
flash
when
a
signal
is
received
on
the
SUB
band.
@
mute
ON
when
the
volume
of
the
SUB
band
is reduced.

4-1-2. Rear Panel @_ SP (Speaker) jack
These jacks are for connection of 8-ohm external
speaker.
© When connect a speaker to MAIN/SUB jack, audio
signals from both bands will be heard only from the
external speaker. (Fig. 1)
© When connect a speaker to MAIN jack , audio from
MAIN band will be heard from the external speaker
and audio from SUB band will be heard from the tran-
sceiver’s internal speaker. (Fig. 2)
¢ When connect two speakers to both jack, audio from
the MAIN band will be heard from the external speak-
er connected to the MAIN jack. Audio from the SUB
band will be heard from the external speaker con-
nected to the MAIN/SUB jack (Fig. 3)
@ _ ANT (Antenna) connector
Attach an antenna with an impedance of 50 ohms to
this connector.
A
for
144
MHz
Internal
speaker
B for 220 MHz (TM-631A) Internal speaker SUB band
430 MHz, 440 MHz (TM-731A/731E) OFF
@ 13.8 VDC power input connector
Connect the supplied DC Power Cable to this connec-
tor. Pay close attention to the polarity (the DC Power
Cable is color-coded; red is positive and black is nega- MAIN &
tive), when connecting the cable to the power source. band ~~!
External
speaker
Internal speaker
OFF
@ Fuse holder
Contains a fuse (15A).
Fig. 3
13

Microphone
ed —— “f ‘e
3 Se eS =
ba
ia
hid
¥
European U.S.A,
yyy version version
@ @ UP/DWN switches
(2)
14
These switches can be used to increase or decrease the
VFO frequency, the Memory channel number, and the
Tone frequency, ect.
PTT (Push to Talk) switch
The transceiver will transmit whenever this switch is
depressed. Scan operations may be cancelled by press-
ing this switch without transmitting.
CALL key (Except European Version)
This key functions just like the CALL key on the front
of the radio.
1750 key (European version)
The transceiver will transmit with 1750 Hz repeater ac-
cess tone whenever this switch is depressed.
VFO key
This key functions just like the VFO key on the front
of the radio.
@
MR key
This key function just like the MR key on the front of
the radio.
PF (Programmable Function) key
This key can be programmed to perform any of the fol-
lowing functions:
BAND key (Initial setting from the factory); or T.ALT,
SHIFT, TONE, REV, MUTE, A.B.C, DUAL, or LOW key.
To program the key use the following procedure:
1. Turn the POWER switch on the transceiver OFF.
2. Press and hold the key on the front panel of the
set that corresponds with the function you wish
to program the microphone key to perform.
3. Turn on the POWER switch while the key on the
front panel is held in.
4. Release the front panel key.
One additional function can be programmed that is not
included on the front panel of the transceiver. This is
known as the MONITOR function. This will allow you
to open squelch of the MAIN band, to check the band
for a clear frequency. This will function even if you are
operating in the CTCSS decode mode.
MONITOR programming
Press and hold the F key on the front panel as you turn
on the POWER switch of the transceiver and then
release the F key.
16-Tone DTMF keypad (U.S.A. version only)
These buttons are used to activate the DTMF encoder.
See 4-4-4. for further information on their use.
LOCK key
This key will deactivate all functions of the microphone
except the PTT function and DTMF keypad.

4-2. RECEIVER OPERATION
The transceiver will supply audio confirmation whenever a
function is activated.
\f you would not like audio confirmation when a function
(except Priority Alert) is activated, turn the POWER switch
OFF. Then press and hold the CALL key and turn ON the
power switch, then release the CALL key.
Repeating this procedure will turn the function back ON.
4-2-1. Reception
1. Connect the power supply and antennas, and then set
the switches and controls as follows:
POWER (VOL) control : OFF (Fully counterclockwise)
POWER switch of the DC power supply (Fixed Station)
> OFF:
MAIN SQL control : Fully counterclockwise
SUB SQL control : Full left
BALANCE control : Full left (MAIN) POWER/
LOCK
switch
:
OFF
(VOL)
control
oO
veouey mann Lr .
CC) = vygo0a Ricco) HF mann
Loud = ——=
LOCK switch| BALANCE corto} SUB SQL control
ig.
2. Turn ON the DC power supply and then turn the tran-
sceiver’s power switch ON. The display panel will indi-
cate as shown in Fig. 1. Additionally some control and
key lights will turn on.
Note:
If the display is not as shown Fig. 1 reset the micropro-
cessor using the procedure give in Microprocessor
memory Initialization Page 23.
3. Turn the VOL control clockwise until a signal or noise
from MAIN band frequency is heard.
4. Rotate the MAIN Tuning control and select an open chan-
nel. Then, turn the MAIN SQL control clockwise until the
noise disappears and the BUSY indicator goes OFF
(Threshold point).
5. Slide the BALANCE control full right (SUB).
6. Rotate the SUB Tuning control and select an open chan-
nel. Then slide the SUB SQL control to the right until the
noise disappears and the indicator goes OFF.
Dual band reception | (Simultaneous reception on both bands)
1. Slide the BALANCE control to the middle.
2. Select the desired frequencies in each band. When each
signal is received, the BUSY or the } indicator will turn
ON and each S-meter will deflect.
3. To distribute volume among MAIN band and SUB band,
slide the BALANCE control to the desired point.
The VOL control regultate the amount volume of two
bands.
Single band reception
Press the DUAL key. The SUB band frequency display will
turn off.
Caution:
Turn off the transceiver’s POWER switch before you turn
off the power supply, or if in a vehicle, before you stop the
engine.
15

4-2-2. Frequency Selection
Frequency can be changed in the VFO mode. The selected
frequencies of the main band can be stored in the Memory
channels, and the Call channel.
(See Memory Entry page 23, CALL CHANNEL page 25.)
You can select the VFO mode, MEMORY Channel mode,
and CALL Channel mode using the following keys.
VFO mode
MR key CALL key
VFO key VFO key
CALL key
MEMORY Channel mode | ———————|_ CALL channel mode
MR key
It is impossible to change the mode directly in the SUB band.
It is possible to transfer the mode of the MAIN band to/from
SUB band.
Exchange the Band
Press the BAND key. Each time the BAND key is pressed,
the contents of the SUB band are exchanged with the MAIN
band.
@
MAIN
BAND
ius
© VFO mode i \ine
1.
Press
the
VFO
key
to
select
the
VFO
|i\
Ys
ee
mode.
aa
2. Rotate the MAIN Tuning control, MHz
keys, or Microphone UP/DWN swit-
ches to select the desired frequency.
16
® Memory Recall mode
. Press the MR key. The previously
selected memory channel will be dis-
played on the LCD display.
2. Rotate the MAIN Tuning control or
Microphone UP/DWN switches to
select the desired Memory Channel.
3. To return to the VFO mode press the
VFO key.
=
@ CALL Channel mode
. Press the CALL key to select the CALL
Channel mode. The CALL indicator and “= G
the call channel frequency are dis- 5 4 J
played on the LCD display.
2. To return to the previous mode press
the CALL key again.
Note: —
The
Memory
Channel
number
will
not
disappear
during
the
CALL Channel mode, if the call channel is selected from the
MR mode.
=
@ SUB BAND
° If the current frequency is in VFO
mode; Rotate the SUB Tuning control
to select the desired frequency.
e If the current frequency is in MR mode;
Rotate the SUB Tuning control to select
the desiréd Memory Channel.
© Current frequency is in CALL Channel mode; Frequency
can not be changed in the SUB band.

4-2-3. Frequency Step Selection
The frequency step is factory-set to the following;
TM-631A TM-731A TM-731E
144 MHz Band 5 kHz 5 kHz 12.5 kHz
220 MHz Band 20 kHz = =
430/440 MHz Band = 25 kHz 25 kHz
procedures:
1. Press the VFO key to select
the VFO mode.
lf you are already in the
VFO mode you can skip
this step.
2. Press the F key. The F in-
dicator will be displayed on
the LCD display.
Press the REV/STEP key wi-
thin 5 seconds. (If the in-
dicator goes off, you must
press the F key again.) The
current frequency step will
be displayed on the LCD
display.
vrone
The frequency step can be selected by using the following
3. Rotate the Tuning control
or press the Microphone
UP/DWN switch to select
the desired frequency step.
The accompanying figure
shows how the Tuning|_
=
5+10-15--20.-25..12.5—
control will increase or
decrease the step size.
. To complete the Frequen-
cy step selection press the
VFO key or any other key.
Automatically return 5 se-
conds of the selection.
SUB Band
(Hz)
Microphone
MAIN Tun- | UB/OWN
ing control j
switches
| Rotate Press UP
clockwise | key
teed Press DWN
counter- key
clockwise id
It is impossible to select the Frequency Step directly while
in the SUB Band. It is possible to transfer the selected Fre-
quency Step of the MAIN band to the SUB band. Press the
BAND key.
17

4-2-4. A.B.C. (Automatic Band Change)
The A.B.C. function allows you to exchange the contents
of SUB band to the MAIN band automatically whenever a
signal is received in the SUB band and SUB squelch is open.
1. Press the A.B.C. key. awe
The A.B.C. indicator will —
turn on displayed in the nn =...
LCD
display.
494BOO
y35su0
2. As soon as a signal is
received in the SUB band,
exchange the bands. *
Caution: —————————-_ |y
* The Tuning controls are
not effective during this
exchange.
The A.B.C. function can always be released by pressing the
PTT switch.
Note: :
When using A.B.C. function with the T.ALT system press
the PTT switch twice to release the A.B.C. function.
fer :
If press the PTT switch,
A.B.C, function is released.
signal goes off, the MAIN
band return to SUB band.
If does not press the PTT
switch 3 seconds after the
3.
If press the BAND key the
MAIN band return to SUB
band and all the keys and
Tuning control are ef-
fective.
18

4-3. TRANSMITTER OPERATION
Caution:
1. Ensure that an antenna with a low standing wave ratio
(SWR) is attached to the antenna connector before at-
tempting to transmit. Failure to provide proper termina-
tion may result in damage to the final amplifier section.
2. Always check to ensure the frequency is clear before
transmitting.
Note:
The use of LOW power is recommended, whenever possi-
ble, to avoid interfering with other stations.
Transmit
1. Select the desired operating frequency in the MAIN band
using any of the methods previously discussed.
2. Check the frequency to see if it is occupied before you
transmit.
3. Press the PTT switch. The ON AIR indicator will light,
and the RF meter will deflect to the right.
Note:
If you have selected the LOW power position, the low
indicator will appear in the display and the RF meter will
only deflect slightly. When HI power has been selected
the RF meter will swing full scale.
re ail
We MAES rca, nt
mo
et i ie
4. Speak into the microphone. The recommended distance
to the microphone is 5 cm (2 inches).
Note:
Talking closer may result in overdeviation of your trans-
mit signal, which might be reported as a loss of clarity
or of an excessively wide transmit signal. Talking too far
away may result in reports of weak audio.
5. Release the PTT switch to return to the receive mode.
The ON AIR indicator should go out, and the RF meter
will return to zero.
Duplex Operation
Pushing the PTT switch on the microphone allows the simul-
taneous reception in the SUB band frequency and sending
in a MAIN band frequency.
Note:
With certain relationship between the sending and receiv-
ing frequencies, the receiver sensitivity may be suppressed.
4-4. REPEATER OPERATION
4-4-1. TRANSMITTER OFFSETS
All
amateur
radio
repeaters
utilize
a
separate
receiver
and
transmitter
section.
The
receiver
frequency
may
be
either
above
or
below
the
transmitter
frequency.
19

For most repeaters offsets are as follows:
Band 144 MHz 220 MHz 430/440 MHz
Model| TM-631A
TM-731A TM-631A TM-731A TM-731E
Display TM-731E
+ +600 kHz +1.6 MHz +5 MHz +1.6 MHz
= —600 kHz — 1.6 MHz —5 MHz —1.6 MHz
a = —7.6 MHz
* Offset Direction
To select the desired transmitter offset direction press the
SHIFT key. Each time you press the key the transceiver will
advance from one offset to the other, i.e. + to —
(- to —- — with European version) to no offset
(simplex).
The transceiver allows you to store the frequency, and off-
set in memory, or you can select these functions directly
from the keyboard.
° Auto-Offset (TM-631A/731A, U.S.A. version)
The TM-631A/731A have been programmed according to
the standard ARRL Band Plan, regarding transmitter offsets.
Please see the accompanying chart for additional informa-
tion. You can, of course, override this by using the SHIFT
function, if desired.
144.00 145.10 146.00 146.60 147.40 148.00
‘ n
s s = sis] = T+isi=
7 r + 1
145.50 146.40 147.00 147.60
220.000 223.920 224.995
sc 5 — sta lS
20
4-4-2. REVERSE FUNCTION
Some repeaters utilize a ‘‘Reverse pair’’, i.e. the transmit/
receive frequencies are exactly the reverse of another
repeater. For example repeater A uses 146.000 for a trans-
mit frequency (OUTPUT) and 146.600 for receive (INPUT).
Repeater B uses 146.000 for its receive and 146.600 for
its transmit frequency. It would be inconvenient to have to
reprogram the transceiver each time if you were in range
of both repeaters.
The REV key allows you to reverse the transmit and receive
frequencies. To use the REVERSE function press the REV
key. The offset indicator( + or — / — or — —)
will light in the display to remind you that you are working
a reverse repeater pair.
To return to normal offsets press the REV key again. This
function is also useful to check the input frequency of the
repeater, so that you can determine if you are within SIM-
PLEX communications range.
4-4-3. TONE OPERATION
Some repeaters require the use of a control signal to activate
the repeater. Several versions are currently in use worldwise.
In the United States sub-audible tones are sometimes used.
38 different sub-audible tone frequency selections are
possible.
With the use of the optional sub-audible tone encoder/
decoder (TSU-6) also allows for CTCSS (Tone Squelch) oper-
ations. Wher this option is activated the squelch will only
open when the proper sub-audible tone is received.