Push-to-Talk (PTT) must be triggered via a virtual COM port using a USB-to-RS232 adapter wired to the radio's PTT ground line.
: The IC-M700 relies on a massive passive heatsink. If you plan on operating high-duty cycle modes like FT8, RTTY, or continuous AM, you must install an auxiliary 12V cooling fan over the rear fins to prevent thermal runaway.
Most marine HF communication is USB only. For lower ham bands (like 40m or 80m), LSB is the standard. Mods often involve adding a toggle switch or internal circuitry to flip the sideband. Technical and Connectivity Mods icom m700 mods
Here is a quick reference guide to answer the most common questions about the Icom M700 series:
These capacitors form high-pass filters in the receive audio chain. By increasing their capacitance, you lower the cutoff frequency to approximately 80-100 Hz, allowing natural voice fundamentals and low-end richness to pass through. Push-to-Talk (PTT) must be triggered via a virtual
: Available on the Icom Japan Support site, this is necessary for identifying board locations like the Logic and Matrix boards mentioned above. IC-M700 Mods - Elliott Liggett - GitLab
This radio draws significant current (up to 30A at peak). Ensure your power cable is heavy-gauge (at least #6 for runs over 10 feet). Do you have the original IC-M700 or the IC-M700PRO? Most marine HF communication is USB only
Sharper speech articulation and increased average talk power without over-modulating. Audio Low-Pass Filter Mod
Carefully clip or desolder one leg of the restriction diode. Insulate the cut leg so it cannot short against other components.
Let’s break down the top three modifications that will change your M700 experience.