Model: IC-765 Bulletin: B4002 Subject: Add PASSBAND TUNING to the transceiver 1. DESSOLDER AND LIFT CATHODE OF D63 FROM PCB. 2. ADD A 1N914 DIODE FROM THE CATHODE OF D63 TO THE ANODE OF D64. 3. DESOLDER AND LIFT W31 FROM PCB AND SOLDER TO JUNCTION OF THE 1N914 CATHODE AND D63 CATHODE. AFTER MODIFICATION: IF SHIFT BUTTON OUT = PASS BAND TUNING IF SHIFT BUTTON IN = IF SHIFT.