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...

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...

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...

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...

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...

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:...

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...

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