Icom Ic-78 Hf Tranciever Instruction Manual

							PROBLEM POSSIBLE CAUSE SOLUTION REF.
RECEIVE
POWER
TRANSMIT
DISPLAY
8
39
MAINTENANCE
nTroubleshooting
The following chart is designed to help you correct
problems which are equipment malfunctions.If you are not able to locate the cause of a problem or
solve it through the use of this chart, contact your near-
est Icom Dealer or Service Center.
Power does not come
on when the [PWR]
switch is pushed.
No sounds comes out
from the speaker.
Sensitivity is too low,
and only strong signals
are audible.
Received audio is un-
clear or distorted.
Your signal does not
reach as far away as
usual.
Transmit signal is un-
clear or distorted.
The displayed channel
does not change prop-
erly.¥ Power cable is improperly connected.
¥ Fuse is blown.
¥ Volume level is too low.
¥ The squelch is closed.
¥ The transceiver is in transmitting condi-
tion.
¥ The antenna is not connected properly.
¥ Antenna is not properly matched to the
operating frequency.
¥ Wrong tuner condition is selected in set
mode.
¥ The attenuator is activated.
¥ Wrong type of mode (emission) is se-
lected.
¥ Noise blanker is turned ON when receiv-
ing a strong signal.
¥ The [RIT] control is rotated too far clock-
wise, or counterclockwise.
¥ Antenna tuner is improperly matched to
the operating frequency when manual
tuning is selected.
¥ CW or RTTY mode is selected for voice
transmission.
¥ Wrong type of mode (emission) is se-
lected.
¥ Microphone is too close to your mouth.
¥ The dial lock function is activated.
¥ A quick set mode is selected.¥ Re-connect the DC power cable correctly.
¥ Check for the cause, then replace the fuse
with the spare one.
(Fuses are installed in the DC power cable
and the internal PA unit.)
¥ Rotate [AF] clockwise to obtain a suitable
listening level.
¥ Turn [RF/SQL] to the position which opens
the squelch.
¥ Check the SEND line of an external unit,
if desired.
¥ Re-connect to the antenna connector.
¥ Push [TUNE] to tune the connected an-
tenna tuner.
¥ Set the proper condition for the connected
tuner.
¥ Push [ATT] to turn the attenuator OFF.
¥ Push [MODE] to select the proper operat-
ing mode (emission).
¥ Push [NB] to turn the noise blanker OFF.
¥ Adjust the [RIT] control to receive proper
audio output.
¥ Push [TUNE] to tune the connected an-
tenna tuner.
¥ Push [MODE] to select USB, LSB, or AM
mode.
¥ Push [MODE] to select the proper operat-
ing mode (emission).
¥ Speak into the microphone naturally and
do not hold the microphone too close to
your mouth.
¥ Push [LOCK] to turn the lock function
OFF.
¥ Push [SET] to exit the quick set mode.p. 10
p. 40
p. 15
p. 15
p. 5
p. 9
p. 18
p. 32
p. 19
p. 15
p. 19
p. 19
p. 18
p. 15
p. 15
p. 15
p. 14
p. 28 
						

							40
CIRCUITRY FUSE REPLACEMENT
The 13.8 V DC from the DC power cable is applied to
all units in the IC-78 through the circuitry fuse. This
fuse is installed in the MAIN unit.
qRemove the top cover as shown on p. 48
wReplace the circuitry fuse as shown in the diagram
at right.
eReplace the top cover.
FGB 4 A
PA unit
nFuse replacement
If a fuse blows or the transceiver stops functioning, try
to Þnd the source of the problem, and replace the dam-
aged fuse with a new, rated fuse.
CAUTION:DISCONNECT the DC power cable
from the transceiver when changing a fuse.
The IC-78 has 2 types of fuses installed for transceiver
protection.
¥ DC power cable fuses ................................ FGB 20 A
¥ Circuitry fuse ................................................ FGB 4 A
DC POWER CABLE FUSE REPLACEMENT
20 A 
fuse
nResetting the CPU
Returns programmed values in both quickand ini-
tial set mode
to their defaults.When Þrst applying power or when the function seems
to be displaying erroneous information, reset the CPU
as follows:
qMake sure transceiver power is OFF.
wWhile pushing [UPY] and [ZDN], push [PWR] to
turn power ON.
¥ The internal CPU is reset.[PWR] [Ã][º]
8MAINTENANCE 
						

							9REMOTE JACK INFORMATION
41
¥ CI-V connection example
The transceiver can be connected through an optional
CT-17 
CI-V LEVEL CONVERTERto a personal computer
equipped with an RS-232C port. The Icom Communi-
cations Interface-V (CI-V) controls the following func-
tions of the transceiver.
Up to 4 Icom CI-V transceivers or receivers can be
connected to a personal computer equipped with an
RS-232C port. See p. 32 for setting the CI-V condition
using set mode.
¥ Data format
The CI-V system can be operated using the following
data formats. Data formats differ according to com-
mand numbers. A data area or sub command is added
for some commands.
CONTROLLER TO IC-78
FE
FEFE 62 E0 Cn Sc Data area FD
Preamble code (fixed)
Transceiver’s default address
Controller’s default address
Command number
(see table at right)
Sub command number
(see table at right)
BCD code data for frequency or
memory number entry
End of message code (fixed)
OK MESSAGE TO CONTROLLER
FE FE E0 62 FB FD
Preamble code (fixed)
Controller’s default address
Transceiver’s default address
OK code (fixed)
End of message code (fixed)
NG MESSAGE TO CONTROLLER
FE FE E0 62 FA FD
Preamble code (fixed)
Controller’s default address
Transceiver’s default address
NG code (fixed)
End of message code (fixed)
IC-78 TO CONTROLLER 
FE E0 62 Cn Sc Data area FD
Preamble code (fixed)
Controller’s default address
Transceiver’s default address
Command number
(see table at right)
Sub command number
(see table at right)
BCD code data for frequency or
memory number entry
End of message code (fixed)
qwert y u
qwert y u
nCI-V remote control
9–15 V DC
personal
computer
ct- 17
BC-25
(optional)
mini-plug cable IC-78 
						

							9CONTROL COMMAND
42
¥ Command table
Command Sub command Description
00 Ñ Send frequency data
01 Ñ Send mode data
02 Ñ Read Upper/Lower frequencies
03 Ñ Read frequencies
04 Ñ Read operating mode
05 Ñ Set operating frequency
06 Ñ Set mode
08Ñ Set memory
Ñ Set memory channel
0E00 Scan stop
01 Memory scan start
11 Ñ AT T
01 AF gain
14 02 RF gain
03 Squelch level
1501 Read squelch Open/Close
02 Read S-meter level
02 PREAMP
16 22 Noise blanker
44 Microphone compressor
19 00 Read ID
nData cloning between transceivers
¥ Data cloning
The IC-78Õs data (programmed frequencies, channel comment, both quick and initial set mode conditions, etc.) can
be copied to the other IC-78. This function is useful when exactly the same setting of the IC-78s is required.
¥ Cloning operation
qTurn power OFF.
wConnects a mini-plug cable between two IC-78Õs
(master and sub) [REMOTE] jack.
eWhile pushing [TXF] and [FC], turn the master IC-
78 power ON.
rWhile pushing [SET] and [FC], turn the sub IC-78
power ON.tPush [TONE] of the master IC-78 to start cloning.
¥ After cloning complete;
yTurn power OFF 
Master transceiver
indicates “M”.
[REMOTE] jack
Mini-plug cable to [REMOTE]
to other IC-78’s 
[REMOTE]
Master transceiver
indication
Daughter transceiver
indication
Daughter transceiver
indication 
						

							43
SPECIFICATIONS
nGENERAL
¥ Frequency range : 
Rx 0.030000Ð29.999999 MHz*1
Tx 1.600000Ð29.999999 MHz*2
*1Guaranteed range: 0.5Ð29.999999 MHz
*2Not guaranteed for some frequency bands
¥ Mode : USB, LSB, CW, RTTY, AM
¥ No. of memory channels : 99 
(Duplex)+1 call
¥ Frequency stability : 
Less than ±200 Hz from 1 min. to 60 min. after
power ON. After that rate of stability less than
±30 Hz/hr. at +25ûC 
(+77ûF). Temperature ßuctua-
tions 0ûC to +50ûC 
(+32ûF to +122ûF) less than
±350 Hz
¥ Power supply requirement (negative ground)
13.8 V DC ±15 %
¥ Current drain 
(at 13.8 V DC):
Receive Stand-by 1.3 A
max. audio 2.0 A
Transmit max. power 20.0 A
¥ Operating temp. range: Ð10ûC to +60ûC
; +14ûF to +140ûF
¥ Antenna connector : SO-239 
(50 ½)
¥ Dimensions : 240(W)´95(H)´239(D) mm
(projections not included)97Ú16(W)´33Ú4(H)´913Ú32(D) in
¥ Weight (approx.): 3.8 kg; 8 lb 6 oz
¥ ACC connector : 13-pin
nTRANSMITTER
¥ Modulation system : 
SSB Balanced modulation
AM Low level modulation
¥ Output power : 
SSB, CW, RTTY 2Ð100 W
AM 2Ð40 W
¥ Spurious emissions : Less than Ð46 dB
below peak
output power
¥ Carrier suppression : More than 40 dB
¥ Unwanted sideband : More than 50 dB
¥ Microphone connector : 8-pin connector 
(600 ½)
nRECEIVER
¥ Receiver system : Double-conversion 
superheterodyne
¥ Sensitivity 
(10 dB S/N): 
SSB, CW, RTTY
0.16 µV (1.600Ð29.999999 MHz)
(0.5 µV at 12 dB SINAD)
AM 13 µV (0.5Ð1.599999 MHz)
2 µV (1.600Ð29.999999 MHz)
¥ Selectivity : 
SSB, CW, RTTY More than 2.1 kHz/Ð6 dB
Less than 4.5 kHz/Ð60 dB
AM More than 6.0 kHz/Ð6 dB
Less than 20 kHz/Ð40 dB
¥ Spurious and image rejection ratio:
(1.600Ð29.999999 MHz)More than 70 dB
¥ Audio output power : More than 2.0 W
at 10%
(at 13.8 V DC) distortion with an 8 ½load
¥ RIT variable range : ±1200 Hz
¥ PHONES connector : 3-conductor 6.5 (d) mm 
(1Ú4²)
¥ Ext. SP connector : 2-conductor 3.5 (d) mm (1Ú8²)
/
8 ½
All stated speciÞcations are typical and subject to
change without notice or obligation.
10 
						

							SP-7 EXTERNAL SPEAKER
Compact speaker for base station op-
eration. Height can be adjusted for
your convenience.
FL-52A, FL-53A, FL-96, FL-222
and FL-257 455 KHz FILTERS
¥ FL-52A: 500 Hz/-6dB 
(CW/RTTY narrow)
¥ FL-53A: 250 Hz/-6dB (CW narrow)
¥ FL-96: 2.8 KHz/-6dB (SSB wide)
¥ FL-222: 1.8 KHz/-6dB (SSB narrow)
¥ FL-257: 3.3 KHz/-6dB (SSB wide)
CR-338 HIGH-STABILITY
CRYSTAL UNIT
Contains a temperature-compensat-
ing oven heater and crystal unit for
improved frequency stability.
¥ Frequency stability: ±0.5 ppm
AH-710 FOLDED DIPOLE 
ANTENNA
Covers from 1.9Ð30 MHz bands. Has
an SO-239 connector. 30 m (98.4 ft)
coaxial cable with PL-259 connector
is supplied.
approx. 24.5 m; 80.3 ft
11
44
OPTIONS
AH-4 AUTOMATIC ANTENNA
TUNER
Specially designed to tune a long wire
antenna for portable or mobile HF op-
eration. The PTT tuner start function
provides simple operation.
¥ Input power rating: 120 W
SP-20 EXTERNAL SPEAKER
4 audio filters; headphone jack; can
connect to 2 transceivers.
¥ Input impedance: 8 ½
¥ Max. input power: 5 W
AH-2b ANTENNA ELEMENT
A 2.5 m long an-
tenna element for
mobile operation
with the AH-4.
¥ Frequency 
coverage:
3.5Ð28 MHz
bands with the
AH-4
PS-85 DC POWER SUPPLY
Light weight switching regulator sys-
tem power supply.
¥ Output voltage: 13.8 V DC
¥ Max. current drain: 20 A
SP-21 EXTERNAL SPEAKER
Designed for base station operation.
Input impedance: 8 ½
Max. input power: 5 W
AT-130/E AUTOMATIC 
ANTENNA TUNER
Matches the transceiver to a long wire
antenna with a minimum of insertion
loss.
MN-100 ANTENNA MATCHER
Match the transceiver to a dipole an-
tenna. Covers all HF bands from 1.5
to 30 MHz. 8 m´2 antenna wires
comes attached.
MN-100LANTENNA MATCHER
Match the transceiver to a long wire
antenna. Covers all HF bands from
1.5 to 30 MHz. 15 m´1 antenna wire
comes attached. 
						

							11
45
OPTIONS
CT-17 CI-V LEVEL CONVERTER
For remote transceiver control using a
personal computer. You can change
frequencies, operating mode, memory
channels, etc.
OPC-4204-CONDUCTOR SHIELD CABLE
For the connection between transceiver and antenna tuner.
Compatible with the control cable, that is supplied with the
AT-120, AT-130 and AH-4. Cable length: 10 m (32.8 ft)
OPC-599ADAPTER CABLE
13-pin, ACC connector to 7-pin + 8-pin ACC connector.
MB-23 CARRYING HANDLE
Carrying handle, convenient for
portable operation.
IC-MB5 MOBILE MOUNTING
BRACKET
Transceiver mounting bracket for mo-
bile operation.
HM-36 HAND MICROPHONE
Hand microphone equipped with
[UP]/[DOWN] switches.
Same as supplied.
SM-8 DESKTOP MICROPHONE
Including 2 connection cables for si-
multaneous connection of 2 trans-
ceivers. Has [UP]/[DOWN] switches. 
SM-20 DESKTOP MICROPHONE
Unidirectional, electret microphone for
base station operation. Includes
[UP]/[DOWN] switches and a low cut
function.
SM-6 DESKTOP MICROPHONE
Electret condenser-type desktop mi-
crophone. 
						

							1-1-32 Kamiminami, Hirano-ku, Osaka 547-0003 Japan
A-5658H-1EX-w
Printed in Japan
© 2000 Icom Inc.