On the Low-Pass Filter unit (near the PA), locate R28 . This resistor sets the ALC threshold. Replace the stock value (often 22k ohms) with a 50k ohm linear potentiometer in series with a 10k ohm fixed resistor.
The radio's internal 13.8V regulator is underrated. If your external power supply is stable at 13.8V (e.g., a switching supply), you can bypass the internal regulator entirely. Warning: Desolder the input to the pass transistor and jumper the collector to the emitter. This reduces heat inside the radio and improves stability. Do not do this if you ever use a battery (12.6V nominal) or an unregulated supply. icom m700 mods
: Users often modify the microphone gain or add a speech compressor to improve signal punch on SSB. Modern replacements like the HM-180 8-pin microphone are frequently used to replace aging EM-101 models. On the Low-Pass Filter unit (near the PA), locate R28
References: Mods.dk, Icom M700 Service Manual (ICOM Inc.), Repeater-Builder.com M700 forum posts, YouTube user "M0UKD" M700 restoration series. The radio's internal 13
This guide covers everything from unlocking the frequency bands to improving audio clarity and adding modern features like the CI-V computer control.
Users often report "off" audio in used units, leading to mods that replace poor-quality third-party microphones (like 1970s telephone elements) with modern high-fidelity ones to restore clarity. Digital Mode Adaptation: