ICOM
IC-4GAT EXPANDED RF
1 REMOVE BATTERY AND ANTENNA.
2 REMOVE SCREWS AND OPEN RADIO.
3 REMOVE D506 (THIS PART IS ALREADY REMOVED ON US VERSION)
4 ATTACH DIODE AS SHOWN (USE 1N914 OR EQUIVALENT DIODE)
MAKE SURE DIODE LEADS WILL NOT SHORT ANYTHING. COVER THEM IN TAPE.
5 REASSEMBLE THE RADIO.
6 RESET RADIO. (TURN RADIO ON,HOLD [LIGHT] & [FUNCTION], TURN RADIO OFF
AND
BACK ON)
ICOM
IC-4SAT EXPANDED RF
1- REMOVE BATTERY AND ANTENNA.
2- REMOVE SCREWS AND OPEN RADIO.
3- LOCATE AND REMOVE DIODE D9 ON
LOGIC A UNIT (SEE DRAWING)
4- SOLDER INSTALL A CHIP DIODE
(DA114 T107) IN POSITION D6.
5- REASSEMBLE RADIO.
6- RESET THE MICROPROCESSOR. (PRESS
& HOLD [#],[B] & LIGHT, TURN POWER
ON)
Optional commands: Push [LAMP] &
[Keyboard key, and power ON.
[1] Enter 4 digits. [5] See timer
scan.
[2] Enter 5 digits. [7] PS off.
[3] Enter 6 dugits. [8] PS 1:4 125
msec on/500ms off.
[4] Pause Scan. [9] PS 1:16
[0] PTT disable. [*] PTT enable
[#] PTT disable. [A] Reset.
[D] display test
ICOM
IC-4SRA EXPANDED RF
1 REMOVE BATTERY AND ANTENNA.
2 REMOVE SCREWS FROM BACK PANEL AND
BATTERY PLATE AND OPEN RADIO.
3 REMOVE PL DECK AND POWER PLATE.
4 UNPLUG VHF & RECEIVER DECKS.
5 ATTACH CHIP DIODES LOCATION POINT
D19 POINT A (MA133).
(DIODE MA133 - ICOM # 1790000860)
6 REASSEMBLE THE RADIO.
7 RESET THE CPU (PUSH AND HOLD [3] &
[B] [#] AND TURN ON
(PUSH ANDHOLD [FUNCTION] & [A] & [CLR]
AND TURN RADIO ON)
Model:
IC-4GAT
Division: Amateur
Note: This service
bulletin is meant for technical per-
sonnel with
experience working on solid state
com-
munications
equipment. Damage caused by im-
properly installing
this modification may cause
ICOM to charge for
subsequent repairs to the
product. ICOM does
not warrant this modification.
Bulletin #: 00389-001
Date: January 3, 1989
Subject: When servicing the
radio, the technician may cause
failure of the +5 V
source by improperly replacing
crystal X-3. We
have seen cases of this occur-
ring.
Information: When replacing
reference crystal X-3, the physical
location of the
crystal is critical due to close
spacing of coil
L-17.
Procedure
1. Make sure the leads of X-3 are
insulated with tubing to
prevent shorting. If a short
does happen the VCO buffer
signal will be shorted to
ground and cause PLL unlock.
2. It is suggested that the body
of the crystal as well as the
leads be insulated to prevent
contact with L-17 in the VCO
circuit.
3. Do not trim the leads of the
replacement crystal as all of
the supplied length is
required.
®
