Icom Ic-78 Hf Tranciever Instruction Manual

4OPERATION
19
nFunctions for receive
•RIT function
The RIT (Receive Incremental Tuning) function com-
pensates for off-frequencies of communicating sta-
tions. The function shifts the receive frequency up to
1.2 KHz without moving the transmit frequency.
qRotate the RIT control to cancel the off-frequen-
cies.
¥ Ò Ó appears on the display.
¥ The transmit frequencies are not shifted.
wTo cancel the RIT function,
rotate the RIT control to the
center position.
¥ Ò Ó disappears.
•Preamp
The preamp amplifies...

20
•Meter peak hold
The meter peak hold function freezes the highest dis-
played bar segment in any meter function for about
0.5 sec. so that you can more easily read the meter.
This function can be turned ON and OFF in 
initial set
mode
. (p. 31)
Initial reception of a signal 
results in an S-meter reading 
of 40 dB.
The highest indicated bar 
remains displayed for 0.5 sec. 
even when the signal strength 
decreases.
The IF shift function electronically narrows the pass-
band frequency of the IF...

21
4OPERATION
nFilter selection
The Þlter selection switches the IF passband width as
shown in the table at right.
The Þlter selection is for temporal setting.
qSelect the desired mode programmed channel.
(p. 13)
wPush [SET] for 1 sec. to enter 
quick set mode.
ePush [UPY] or [ZDN] several times until ÒFILTERÓ
appears on the display.
rRotate the channel selector to select desired pass-
band width.
¥ Either Ò Ó or Ò Ó does not appear while the nor-
mal Þlter is selected.
¥ Ò Ó appears when the wide Þlter...

22
4OPERATION
When an optional Þlter is installed, set the optional Þl-
ters in 
initial set mode. Optional filters are not se-
lected by default. (p. 33)
DOptional Þlter setting
qWhile pushing and holding [SET], push [PWR] to
enter 
initial set mode.
wPush [UPY] or [ZDN] several times until ÒFILÓ ap-
pears on the display.
eRotate the channel selector to select the installed
Þlter.
¥ Òno,Ó Ò52A,Ó Ò53A,Ó Ò96,Ó Ò222Ó and Ò257Ó indicate no op-
tional filter, FL-52A, FL-53A, FL-96, FL-222 and
FL-257,...

23
4OPERATION
nFunction for CW
•Connection for CW
12348 7 6 5 910 11 1213
Paddle [ELEC KEY]
[MICROPHONE]
See p. 25 for connection details: 
Paddle operation from front panel 
MIC connector.
Straight key
Microphone
Initial set mode setting (p. 32)
48
12
[ACC]
1237 6 5 9
10 1113
For no break-in operation:
Connect an external switch such as 
a foot switch; or use the RTTY 
SEND terminal for all bands. 
(See p. 25)
: normal
: reverse
: off
: UP/DN key
•CW operation
qConnect a paddle or straight key as...

4OPERATION
24
•CW pitch control
The received CW audio pitch and monitored CW
audio pitch can be adjusted to suit your preferences
(300 to 900 Hz) without changing the operating fre-
quency.
qPush [SET] for 1 sec. to enter quick set mode.
wPush [ºUP]/[ÃDN] one or more times until ÒCW
PITCHÓ appears, then rotate the main dial to set
the desired pitch. (p. 29)
•CW reverse mode
The CW-R (CW Reverse) mode receives CW signals
with a reverse side CW carrier point like that of LSB
and USB modes. Use this mode...

4OPERATION
25
nFunction for RTTY
•Connection for RTTY (FSK)
Rear panel
TU or TNC 
Personal computer
Rear panel 
 
      viewUse either the ACC or one of the two 
1⁄8² plugs. 
*
1Connect SQL line when required.
SQL*1 
AF out 
SEND  
GND 
FSKK  GND AF2-conductor 
1⁄8² plug[ACC]
[EXT SP]
1234 5678910111213
•Connection for AFSK
To a TU or TNC 
and personal computer.
Use either the ACC or microphone connector. 
SQL*
1 
AF out 
AF in 
SEND
GND
1234 5678910111213
Rear panel 
 
       view
*1Connect SQL line...

4OPERATION
26
•RTTY (FSK) operation
qConnect a terminal unit as at p. 25.
wSelect RTTY (or RTTY-R) mode with [MODE].
eSelect the desired FSK tone and shift frequencies
as below.
rSet the desired frequency with the channel selec-
tor.
tOperate the connected PC or TNC (TO).
PRESETTING FOR RTTY
¥ Tone frequency
qPush [SET] for 1 sec. to enter 
quick set mode.
wPush [ºUP]/[ÃDN] several times until ÒTON 2125Ó
appears, then rotate the channel selector to select
the desired tone frequency.
¥ Shift frequency...

27
4OPERATION
nChannel comment programming
The IC-78 has a capability to assign up to 8-character
channel comments for each operating channel. This
provides easy recognition of channel usage, or station
names, etc.
qSelect the desired channel by pushing
[ÃDN]/[UPº], rotating the channel selector, or
using the keypad. (p. 13)
wPush [FC] to select channel comment indication, if
desired.
ePush [ENT] for 1 sec. to enter channel comment
programmable mode.
¥ 1st digit blinks
rPush corresponding keys to enter...

5
28
SET MODE
nGeneral
Set mode is used for programming infrequently
changed values or conditions of functions. The IC-78
has 2 separate set modes: 
quick set modeand initial
set mode
.
DQuick set mode operation
qWhile power is ON, push [SET] for 1 sec.
¥ Quick set mode is selected and one of its items ap-
pears.
wPush [UPY] or [ZDN] to select the desired item.
eRotate the main dial to set the values or conditions
for the selected item.
rRepeat wand eto set other items.
tTo exit quick set mode, push...