ICOM IC-725 MODIFICATIONS


                                                                           MARS MODIFICATION


DISCLAIMER:
This modification allows the radio to transmit outside of the designated
Amateur freq. Transmitting where you are not licensed to do so is
unlawful!

Disassemble radio following instructions on page 24 of Instruction
manual, steps 1 - 7, or as follows:

NOTE: All instructions with the radio's front panel facing you unless
otherwise specified!

1) Remove all black screws from top & bottom covers and remove both covers.

2) Remove the 2 flat head screws that hold the PA unit to the front unit.
(top front of radio - Not the screws that are in the plastic front panel.)

3) Remove the 2 screws that hold the PA unit to the rear panel.
(Looking at the rear of the radio, 1 is above the ext. speaker jack &
1 is above to ACC(1) jack.)

4) Unplug the 2 plugs from J11 & J12.

5) D
 

                                                                                ICOM IC-725A

                                                                                      EXPANDED RF
1- Remove power and antenna.
2- Remove screws open the case.
3- Locate PLL board and cut diode D5
4- Reset the microprocessor. ( Hold [ FUNCTION ] & [ MW ] and turn power ON
5- Reassemble the radio.
 

 ICOM IC-725

12) The radio will now transmit from 1.5 MHz to 33 Mhz. (It will transmit even lower but the power output drops off and I don't know if doing so will damage the transmitter.

ENABLE PREAMP Bye bottom cover.

2) Locate Q12 on Main Unit. 1/3 way from left side of board.

Q12 is the transistor that bypasses the preamp below 1.5 MHz to avoid overload when listening to AM Broadcast Stations.

3) Clip the lead of Q12 closest the front of the radio.

4) That's it, the preamp will now work below 1.5 MHz!

ENABLE NOISE BLANKER IN ALL MODES


1) Remove bottom cover.

2) Locate R44 on Main Unit (100 ohm 1/4 watt resistor).

3) Lift the side of R44 closest the front of the radio.

4) Solder a piece of wire to the end of R44 that you lifted.

5) Solder the other end of the wire to W54 which is located near the left
side of IC15.

This will supply a constant 8 Volts lly the 8 Volts is only present when in CW or SSB Modes, disabling the noise blanker in AM & FM modes.

I have done all of the above mods to my own 725 and they work great!
These mods should also work with the IC-726.
I'll let everyone know for sure when I get one!


P.S. If you have any good modifications for any radios, please pass them
along to me. I am starting a database of modifications for various
radios and I'm happy to pass along info to anyone who needs it.