Icom IC-28A Instruction Manual page 21

3) Select 600kHz transmit offset.
4) Select VFO mode.
Б) Push DUP SWITCH то select
DUPLEX (+).
"DUPt+"
appears
6) Push SQL/CHK CONTROL to
check transmit frequency.
B SUBAUDIBLE TONE
ENCODER
(IC-28A U.S.A. version)
3) Push the front panel DOWN/UP SWITCH to select one of the two
methods for programming the transmit offset.
e The usual position is "Е" since most repeaters operate with a
600kHz split between the receive and transmit frequencies.
e |f the "P" position is selected, use the TUNING CONTROL to
choose your required transmit offset value.
4) Push the VFO side of the VFO/MR SWITCH.
5) Push the DUP SWITCH to select either the DUPLEX (-) or
DUPLEX (+) condition.
e DUP (—): The transmit frequency is lower than the receive
frequency by the offset amount.
e DUP (+): The transmit frequency is higher than the receive
frequency by the offset amout.
e Neither DUP (—) nor DUP (+) displayed:
The IC-28A/E is in the simplex mode with both receive and
transmit frequencies equal.
6) Push the SOL/CHK CONTROL in order to monitor the transmit
frequency when operating with the duplex mode.
e This allows checking of the signal strength of your contacted
station directly without going through a repeater. If the signal
is received strongly enough directly, both stations should move
to a simplex frequency.
The supplied tone encoder allows access to repeaters which require a
subaudible tone superimposed on the transmit signal in order to
open the squelch circuit of the receiver at the repeater station.
Without this tone being present, the repeater cannot be used.
ePROGRAMMING THE SUBAUDIBLE TONE ENCODER
Example: Program 88.5Hz in subau-
dible tone memory 3.
1) Select VFO mode.
2) Push SET SWITCH to select
subaudible tone programming
mode.
1) Push the VFO side of the VFO/MR SWITCH.
2) Push the SET SWITCH repeatedly until the TONE INDICATOR
appears flashing on the display.