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Icom M700 Mods [hot] Site

Icom IC-M700 is a classic marine HF transceiver that has become a popular project for radio amateurs due to its rugged build and relatively low cost on the used market. To make this commercial-grade radio suitable for hobbyist use, several internal modifications are commonly performed by the amateur community. Core Amateur Radio Modifications

Digital Modes (FT8/SSTV): Enthusiasts often install an external audio interface box. This allows for PC connections via an XLR output for high-quality dynamic mics or direct interfacing for digital modes like FT8. icom m700 mods

  • Once opened, the radio will transmit outside its tuned passband. You must perform a full alignment of the low-pass filters and transmitter tuning to ensure the output is clean and does not produce spurious emissions.
  • Do not crank the power screwdrivers. There are "power output" pots (R265, R266). Turning them blindly will cause harmonic distortion and splatter across the band. Use a spectrum analyzer or a good quality wattmeter with a dummy load.
  • Do not ignore the PLL unlock variations. Some early M700s use a different synthesizer chip (the MB8719). Unlocking those requires a different diode matrix. Always look up your specific board number (e.g., 02-214-xxxx).
  • Watch out for "MARS/CAP" mods. Many online guides list a MARS mod. That is similar to the ham band unlock but may not cover 630m (472 kHz) or 60m (5 MHz). The M700 is not stable below 1.6 MHz without major work.

Programming Unlocking: If memory banks A and B are locked out from user programming, remove jumper W33 (W1033) on the Logic Board. Icom IC-M700 is a classic marine HF transceiver

(and its successor, the M700PRO) is a legendary marine HF transceiver prized by mariners and amateur radio operators alike for its rugged construction and 150W output. While originally designed for marine SSB channels, a few key modifications can transform this workhorse into a versatile HF rig for the ham bands or specialized data use. 1. Transmit Frequency Expansion (MARS/CAP Mod) The most common modification for the Once opened, the radio will transmit outside its