Remove top and bottom covers.
Remove 4 small screws holding front panel onto main chassis(2 per side).
Tilt up front panel(you may have to loosen and remove 2 connectors on lower left side of front panel) to expose the Logic Unit sitting vertically on the left side of the main chassis unit behind the front panel. You may find it easier to access the diodes by setting radio up on its right side.
Near the center of the Logic Unit (below and to the right of a processor chip) you will see 2 vertical rows of diodes / diode spaces. The bottom 4 diodes in each column are offset slightly to the right as pictured below. NONE OF THE DIODES IN THE RIGHT COLUMN ARE CHANGED!! The diodes in the left column must be configured exactly as shown below. This means that you may have to add or remove diodes in the left column depending on where you purchased your IC7800. USA radios are easy to modify as the only change is to remove D57. If you have to add diodes, try to use the ones that you had to remove(and make sure to install them in the correct direction-they ARE Surface Mount Devices):
LEFT RIGHT
D59 (no diode) 0 X (diode in)
D58 (diode in) X X (diode in)
D57 (no diode) 0 0 (no diode)
D56 (no diode) 0 X (diode in)
D55 (no diode) 0 - I forgot to note if there was a diode in this position.
D54(diode in) X 0 (no diode)
D53(diode in) X X (diode in)
D52(no diode) 0 X (diode in)
D51(diode in) X X (diode in)
Position the front panel unit back down into position in its proper place and then check to make certain that the connectors which connect to the front panel unit and to the logic unit are securely plugged in properly. Reinstall the 4 small front panel mounting screws(2 per side) and reinstall the bottom and top covers.
No radio reset is required. After this modification, there will be no band edge beeps if you had them turned on before, so be careful not to operate out of your band segment.
Enjoy your new General Coverage Transmit IC7800.
