Icom M700 Mods Jun 2026

A peculiar quirk of some M700 variants—particularly the IC-M700D and certain German-market units—is the absence of Lower Sideband capability despite the mode switch having two J3E positions that both do the same thing. These radios are USB-only from the factory.

: To enable transmit across the entire covered range (roughly 1.6 MHz to 23 MHz), ensure jumper W37 (W1037) on the Logic Board is installed.

: If the channel lock is intermittent, cleaning flux residue from the discrete PLL circuit boards can resolve many stability issues.

Replacing the stock dynamic element with a high-quality electret condenser element significantly improves transmit clarity. This requires adding a small resistor and capacitor inside the mic housing to tap into the radio's 8V DC phantom power line on the mic jack. icom m700 mods

If you want to proceed with a specific project on your rig, let me know:

Given the IC-M700 was released in the mid-1980s, basic restoration is often the best "mod":

The primary goal for ham operators is to unlock the radio's frequency flexibility and improve its interface for non-marine use. A peculiar quirk of some M700 variants—particularly the

For the classic IC-M700, clipping or removing a specific diode (typically or D28 , check your specific schematic variant) disables the factory frequency lock.

: Modern operators frequently wire a digital Direct Digital Synthesis (DDS) VFO chip (like the AD9850 or AD9851) directly into the first local oscillator (LO) injection port.

: Closing a specific internal jumper typically allows transmit coverage from approximately 1.6 MHz to 23 MHz SRAM Upgrade : If the channel lock is intermittent, cleaning

These modifications unlock the radio's full potential by allowing it to operate outside restricted marine bands. Transmit Frequency Expansion (MARS/CAP):

: To unlock transmission across all covered frequencies, locate the Logic Board and ensure jumper W37 (W1037) is installed. If it has been cut to restrict the radio to marine bands, simply solder it back together. Memory & Programming Lockout :