Icom Ic-703 Hf/50mhz All Mode Tranciever Instruction Manual

							6
1PANEL DESCRIPTION
DS1 functions
MEMORY WRITE (p. 57)
Push for 1 sec. to store the selected
readout frequency and operating mode
into the displayed memory channel.
MEMO PAD WRITE (p. 60)
Push to store the the selected readout
frequency and operating mode into a
memo pad.
MEMO PAD READ (p. 60)
Push to call up a memo pad.
DS2 functions
DURING VFO MODE:
DURING MEMORY MODE:
SCAN (pgs. 61–63)
Push to start or stop the scan function.
PRIORITY WATCH (p. 63)
Push to start or stop the priority watch.
VFO/MEMORY
➥Push momentarily to toggle between VFO
and memory modes. (p. 56)
➥Push for 1 sec. to transfer the frequency
and operating mode in the selected mem-
ory channel to a VFO. (p. 58)
SELECT SCAN (p. 61)
Push to toggle the select setting ON and
OFF for the selected memory channel.
DS3 functions
QUICK BAND CHANGE FUNCTION (p. 22)
This item provides access to the band stacking regis-
ter. By default the 7, 14 and 21 MHz bands are dis-
played. Push [F-1], [F-2] or [F-3] for 1 sec. to select a
new band if desired.
• A mode is memorized along with the frequency for each
band.
DS4 functions
(UT-106 is required for some version)
AUTOMATIC NOTCH FILTER (p. 50)
This function automatically attenuates
beat tones, tuning signals, etc., even if
they are moving.
NOISE REDUCTION (p. 50)
This function reduces noise components
and picks out desired signals which are
buried in the noise.
NOISE REDUCTION LEVEL DISPLAY(p. 50)
This switch displays the noise reduction
level when pushed.
F-3
NRL
F-2
NR
F-1
ANF
MENU
S4
F-1
ANF
F-2
NR
F-3
NRL
MENU
S3
F-1
7
F-2
14
F-3
21
F-2
SEL
F-3
V/M
F-2
PRI
F-1
SCN
MENU
S2
F-1
SCN
F-2
SEL
F-3
V/M
MENU
S2
F-1
SCN
F-2
PRI
F-3
V/M
F-3
MPR
F-2
MPW
F-1
MW
MENU
S1
F-1
MW
F-2
MPW
F-3
MPR
1 
						

							7
1PANEL DESCRIPTION
Rear panel
qANTENNA CONNECTOR [ANT] (p. 13)
Accepts a 50 Ωantenna with a PL-259 connector.
wGROUND TERMINAL [GND] (p. 11)
Connect this terminal to a ground to prevent electri-
cal shocks, TVI, BCI and other problems.
eDATA SOCKET [DATA] (pgs. 8, 14)
6-pin min DIN socket to connect a TNC (Terminal
Node Controller), etc. for packet operation.
• See page at right for socket information.
rACCESSORY SOCKET [ACC] (pgs. 8, 14)
Enables connection to external equipment such as a
TNC for data communications, a linear amplifier or
an automatic antenna selector/tuner, etc.
• See page at right for socket information.
tEXTERNAL SPEAKER JACK [EXT SP] (p. 14)
Accepts a 4–8 Ωspeaker.
y
CI-V REMOTE CONTROL JACK [REMOTE] (p. 71)
➥Designed for use with a personal computer for re-
mote control of the transceiver functions.
➥Used for transceiver operation with another Icom
CI-V transceiver or receiver.
uMICROPHONE CONNECTOR [MIC] (p. 13)
Accepts the supplied microphone (connected in par-
allel with the front panel’s [MIC] connector).
• See p. 2 for microphone notes.
• See p. 10 for microphone connector information.
iELECTRONIC KEYER JACK [KEY] (p. 28)
Accepts a paddle to activate the internal electronic
keyer.
• Selection between the internal electronic keyer and
straight key operation can be made in keyer set mode.
(p. 32)
If you use an external electronic keyer, make sure
the voltage retained by the keyer is less than 0.4 V
when the key is ON.
oTUNER CONTROL SOCKET [TUNER] (p. 14)
Accepts the control cable from an optional AH-4
HF/50MHzAUTOMATIC ANTENNA TUNER.
!0DC POWER SOCKET [DC13.8V] (p. 15)
Accepts 9.0–15.87 V DC through the supplied DC
power cable.
NOTE: DO NOTuse a cigarette lighter socket as a
power source when operating in a vehicle. The plug
may cause voltage drops and ignition noise may be
superimposed onto transmit or receive audio.
When connecting
a straight key
When connecting
a paddle
(dot)
(com)
(dash)(⊕)
w
qr
etyui
o!0 
						

							8
1PANEL DESCRIPTION
DDATA socket
DACC socket
ACCPIN No.NAME DESCRIPTION SPECIFICATIONS
1 2 3 4
8765
9
10 11 12
13
Rear panel view
qbrownigray
wredowhite
eorange!0black
ryellow!1pink
tgreen!2light
blue
yblue
upurple!3light
green
1 8 V Regulated 8 V output.Output voltage : 8 V ±0.3 V
Output current : Less than 10 mA
2 GND Connects to ground. ———
Input/output pin. 
(HF/50 MHz only)Ground level : –0.5 V to 0.8 V
3
HSENDGoes to ground when transmitting. Output current : Less than 20 mA
When grounded, transmits. Input current (Tx) : Less than 200 mA
4 BDT Data line for the optional AT-180. ———
5 BANDBand voltage output.
Output voltage : 0 to 8.0 V
(Varies with amateur band)
6 ALC ALC voltage input.Control voltage : –4 V to 0 V
Input impedance : More than 10 kΩ
7 NC ——— ———
8 13.8 V 13.8 V output when power is ON. Output current : Max. 1 A
9 TKEY Key line for the optional AT-180. ———
“High” level : More than 2.4 V
10 FSKK Controls RTTY keying “Low” level : Less than 0.6 V
Output current : Less than 2 mA
11 MODModulator input. Input impedance : 10 kΩ
Connects to a modulator. Input level : Approx. 100 mV rms
AF detector output.
Output impedance : 4.7 kΩ
12 AF Fixed, regardless of [AF] position in
Output level : 100–300 mV rms
default settings.
13 SQLSSquelch output. SQL open : Less than 0.3 V/5 mAGoes to ground when squelch opens.SQL closed : More than 6.0 V/100 µA
DATAPIN No.NAME DESCRIPTION
1 23 45 6
Rear panel view
1 DATA IN Input terminal for data transmit. (1200 bps: AFSK/9600 bps: G3RUH, GMSK)
2 GND Common ground for DATA IN, DATA OUT and AF OUT.
3 PTT P PTT terminal for packet operation. Connect ground to transmit data.
4 DATA OUT Data out terminal for 9600 bps operation only.
5 AF OUT Data out terminal for 1200 bps operation only.
Squelch out terminal. Becomes ground level when the transceiver receives a signal
which opens the squelch.
6SQ• To avoid unnecessary TNC transmission, connect squelch to the TNC to inhibit trans-
mission when receiving signals.
• Keep audio output at a normal level, otherwise a “SQ
”signal will not be output.
Color refers to the cable strands of the supplied cable.
ACC 1 ACC 2q FSKKt AF
w GNDy SQLS
e HSENDu 13.8 V
r MODi ALCq 8 Vt ALC
w GND
y VSEND
e HSENDu 13.8 V
r BAND1 2 3 4
88
765
9
10 11 12
131
2 3
4 76
5 1
2 3
4 76
5
Connect to ACC socket • When connecting the ACC conversion cable (OPC-599)
1 
						

							9
1PANEL DESCRIPTION
Function display
qNARROW/WIDE FILTER INDICATORS
➥“ã” appears when selecting AM narrow or FM
narrow modes.
➥When installing an optional narrow filter, narrow
mode can be selected in CW, RTTY and SSB
modes.
• When the SSB wide filter is installed, “ç” appears
during wide mode selection.
wMODE INDICATORS
Show the selected operating mode.
•“å” appears when CW reverse or RTTY reverse mode is
selected.
eSPLIT INDICATOR
Appears during split operation.
rPROGRAMMABLE/1 MHz TUNING STEP
INDICATORS
➥
ra appears when the programmable tuning step
is selected.
➥
rb appears when the 1 MHz quick tuning step is
selected.
tFREQUENCY READOUT
Shows the operating frequency.
yBLANK MEMORY INDICATOR
Appears when the displayed memory channel is not
programmed (blank channel).
• This indicator appears both in VFO and memory modes.
uVFO/MEMORY INDICATORS
➥VFO A or B appears when VFO mode is selected;
MEMO appears when memory mode is selected.
iSELECT MEMORY CHANNEL INDICATOR
Appears when the selected memory channel is set
as a select memory channel.
oMEMORY CHANNEL READOUT
Shows the selected memory channel.!0DOT MATRIX INDICATORS
These alphanumeric readouts show a variety of in-
formation such as current functions of the “F” keys
[F1] to [F3], memory channel names, set mode
items, etc. See p. 94 for an overview of these indi-
cators.
!1METER READOUTS
➥Shows receiving signal strength while receiving.
➥Shows one of transmit power meter, ALC or SWR
meter while transmitting.
!2FUNCTION INDICATORS
➥“NB” appears when the noise blanker is activated.
➥“VOX” appears when the VOX function is se-
lected.
➥“F-BK” appears when full break-in operation is se-
lected and only “BK” appears when semi break-
in operation is selected.
➥“COM” appears when the speech compressor is
activated.
➥“F
AGC” appears when the fast AGC function is se-
lected.
!3DSP INDICATORS
Appear when the (optional*) DSP unit UT-106 is (in-
stalled and) activated.
* UT-106 DSP unit is optional for some version.
NWRLSB
NB VOX F-BK COM F
CH VFO A
VFO B
MEMO
AGC
ALC
SWR P
O
S1
1 1.5 2 3 55 379
20 40
10 60dB
USB CW RTTYAM    FM TSQLSPL
S
∞
NR NR
ANF
BLANK
DSP
qw
t r e
y
i
!0 !1 !2 !3
u
o rb
M1  SPL  A/B  XFC
a 
						

							10
1PANEL DESCRIPTION
•MICROPHONE CONNECTOR
Microphone (HM-103)
qUP/DOWN SWITCHES [UP]/[DN]
Change the operating frequency.
• Push and hold to change the frequency continuously.
• Tuning step is 50 Hz when no TS indicator appears.
wLOCK SWITCH [LOCK]
Locks the [UP]/[DN] switches.
ePTT SWITCH [PTT]
Push and hold to transmit; release to receive.
DN UPLOCK
OFF ON
q
we
TECHNICAL INFORMATION
PIN NO.FUNCTIONDESCRIPTION
1+8 V DC outputMax. 10 mA
2Frequency upGround
Frequency downGround through 470 Ω
8Squelch open“LOW” level
Squelch closed“HIGH” level
r PTT
y Microphone input w Frequency up/down
u GND q +8 V DC output 
i Squelch switch t GND (Microphone ground) e AF output
Rear panel view
1 2 3 4 5 6 7 8
•HM-103 SCHEMATIC DIAGRAM
4700p 4700p
10µ
0.33µ
+ +
MICROPHONE
MIC
ELEMENT2k
2.2k
470 DOWN
LOCK UP
PTT
RECEIVE
TRANSMITMICROPHONE
CABLEMICROPHONE PLUG
12345678
CAUTION:DO NOTshort pin 1 to ground as
this can damage the internal 8 V regulator.
1 
						

							2
11
INSTALLATION AND CONNECTIONS
Unpacking
After unpacking, immediately report any damage to the
delivering carrier or dealer. Keep the shipping cartons.
For a description and a diagram of accessory equip-
ment included with the IC-703, see ‘Supplied acces-
sories’ on p. ii of this manual.
Selecting a location
Select a location for the transceiver that allows ade-
quate air circulation, free from extreme heat, cold, or
vibrations, and away from TV sets, TV antenna ele-
ments, radios and other electromagnetic sources.
The base of the transceiver has an adjustable stand
for desktop use. Set the stand to one of two angles de-
pending on your operating conditions. (see description
at right page)
Grounding
To prevent electrical shock, television interference
(TVI), broadcast interference (BCI) and other prob-
lems, ground the transceiver through the GROUND
terminal on the rear panel.
For best results, connect a heavy gauge wire or strap
to a long earth-sunk copper rod. Make the distance be-
tween the [GND] terminal and ground as short as pos-
sible.
RWARNING: NEVERconnect the [GND] ter-
minal to a gas or electric pipe, since the connection
could cause an explosion or electric shock.
Antenna connection
For radio communications, the antenna is of critical im-
portance, along with output power and sensitivity. Se-
lect antenna(s), such as a well-matched 50 Ωantenna,
and feedline. 1.5:1 or better of Voltage Standing Wave
Ratio (VSWR) is recommended for your desired band.
Of course, the transmission line should be a coaxial
cable.
CAUTION: Protect your transceiver from lightning
by using a lightning arrestor.
ANTENNA SWR
Each antenna is tuned for a specified frequency
range and SWR may be increased out-of-range.
When the SWR is higher than approx. 2.0 : 1, the
transceiver’s power drops to protect the final transis-
tors. In this case, an antenna tuner is useful to match
the transceiver and antenna. Low SWR allows full
power for transmitting even when using the antenna
tuner. The IC-703 has an SWR meter to monitor the
antenna SWR continuously.
30 mm
10 mm (soft solder)
10 mm
1–2 mm
solder solderSoft
solder Coupling ring
PL-259 CONNECTOR INSTALLATION EXAMPLE
q
e
r w
Slide the coupling ring 
down. Strip the cable 
jacket and soft solder.
Slide the connector 
body on and solder it.
Screw the coupling 
ring onto the connector 
body. Strip the cable as 
shown at left. Soft 
solder the center con-
ductor. 
						

							2
12
INSTALLATION AND  CONNECTIONS
To raise the stand:
With the transceiver upside down, pull the stand to-
wards the rear panel and then upwards, as illus-
trated below. 
Installation
DSingle body mountingDStand
Nut Spring washer
Flat washer
*CAUTION: Non-supplied screws (longer than 8 mm)
may damage the internal units. MB-62
(optional)
Supplied with
the MB-62*
Pull backthen up
DFront panel separation
DFront panel mounting
qWhile pulling the panel release button towards you,
slide the front panel to the right (fig. 1).
wAttach the optional OPC-581 to the main body and
tighten the supplied screw as in fig. 2.
eAttach the other end of the OPC-581 to the de-
tached front panel as in fig. 3.CAUTION: NEVERdetach/attach the front panel
when connecting the DC power supply (or battery).
Make sure the disconnecting DC power cable from
the [13.8 V] receptacle on the transceiver rear
panel.
qAttach the MB-63 to a flat surface using the two
supplied screws (fig. 1).
wFix the detached front panel to the MB-63 as illus-
trated in fig. 2.
BE CAREFULof the orientation of the MB-63, oth-
erwise, the front panel may become attached in the
opposite direction.
fig. 1fig. 2
fig. 3
Latch
Separation cable
Separation cable
fig. 1
fig. 2
2 
						

							13
2INSTALLATION AND  CONNECTIONS
Required connections
BAND
BAND
MODE
TS
DISPLAY
LOCK
F 1 F 2 F 3
AF RF SQL
RIT
SHIFT M-CHSUB
PHONESTUNER P.AMP
AT T
Y
Z
POWER
MENU
TX RX
MICROPHONE (p. 10)
HF/50 MHz ANTENNAGROUND
 (p. 11)
HM-103
CW KEY (p. 28)
Use the heaviest gauge wire or 
strap available and make the 
connection as short as possible.
Grounding prevents electrical 
shocks, TVI and other problems.
Connects to DC 9.0–15.8 V 
power supply. See p. 15 for 
details. 
						

							14
2INSTALLATION AND  CONNECTIONS
Advanced connections
BAND
BAND
MODE
TS
DISPLAY
LOCK
F 1 F 2 F 3
AF RF SQL
RIT
SHIFT M-CHSUB
PHONESTUNER P.AMP
AT T
Y
Z
POWER
MENU
TX RX
OPC-589 (p. 92)
DESKTOP(p. 91)
MICROPHONE
 
Selectable with the [PHONE/SPEAKER] switch
on the back of the front panel.SPEAKER
ACC SOCKET (p. 8)
DATA SOCKET
 (p. 8)
6-pin mini DIN socket to connect to a
TNC, etc. for packet operation.
AH-4
  (p. 16)
AH-2b
EXTERNAL
SPEAKER
 (p. 91)
HEADPHONES
SP-7/SP-10SM-20
or
REMOTE (p. 71)
Used for computer control 
and transceive operation.
2 
						

							Use a 13.8 V DC power supply with at least 3 A ca-
pacity. when operating IC-703 with AC power. Refer
to the diagram below for connection.
CAUTION:
Before connecting the DC power cable, check the
following important items. Make sure:
• The [POWER] switch is OFF.• Output voltage of the power source is 9.0–15.8 V
when you use a non-Icom power supply.
• DC power cable polarity is correct.
Red: positive (+) terminal, 
Black: negative (–) terminal
DC Power supply connections
15
2INSTALLATION AND  CONNECTIONS
Battery connections DC Power voltage
Depending on the applied voltage from the connected
power supply, a boarder voltage of 11.0 V is set as the
point where the IC-703 switches between normal op-
erating mode (over 11.0 V), and battery operating
mode (under 11.0 V: power save mode).
However when the connected voltage decreases from
13.8 V to 11.0V, the IC-703 switches from normal
mode to battery mode. Conversely the IC-703
switches back to normal mode from battery modewhen the voltage reaches 11.5 V. This 0.5 V voltage
difference prevents irregular switching between nor-
mal mode and battery mode, caused by the voltage
drop which are current capacity, receiving or transmit-
ting.
When 11.3 V voltage is applied, the IC-703 may acti-
vate the battery operating mode depending on the
current capacity of the power supply.
AC cable
AC
outlet
A DC power
supply**13.8 V; at least 3.0 A
continuous
Black
 _Red
+
CONNECTING A DC POWER SUPPLY CONNECTING PS-125 DC POWER SUPPLY
PS-125
DC power cableGround
4 A fuses Transceiver
to DC power
receptacleSupplied
OPC-1229 Optional
OPC-1248
Connect to an AC 
outlet using the 
supplied AC cable.
•RWARNING NEVERconnectto a battery
without supplied DC fuse, otherwise a fire hazard
occur.
•NEVER connectthe transceiver directly to a
24 V battery.•DO NOT use the cigarette lighter socket for power
connections. (See p. 7 for details)
•Attach a rubber grommet when passing the DC
power cable through a metal plate to prevent a
short circuit.
Grommet
CONNECTING A VEHICLE BATTERY
Note: 
Use terminals for
the cable connections.
Crimp
Solder
Supplied
DC power cablered
black
12 V
battery