Modifying radio equipment requires solid soldering skills and test equipment. Working inside electronic hardware can damage sensitive components through electrostatic discharge (ESD). Additionally, transmitting on unauthorized frequencies or exceeding legal power limits may violate national telecommunications regulations (such as FCC rules). Proceed at your own risk. 1. General Coverage Transmit Mod (Frequency Expansion)
: Contains a technical write-up and SRAM schematic for the memory expansion and jumper mods.
: By clipping the line that senses the Push-To-Talk (PTT) switch on the Clarifier circuit and tying it to a constant 8V DC source inside the radio, the Clarifier will remain active during transmission. This allows you to "net" perfectly onto an amateur radio frequency. 3. Microphone Audio & Compression Upgrades
Before you attempt any mod, assemble this toolkit: icom m700 mods
Adding an internal speech compressor can significantly improve audio punch during poor band conditions. Pactor Modem Interfacing:
For amateur radio use, the standard SSB ceramic filter can be broad, allowing adjacent channel interference to bleed through.
: The rear connections provide a fixed-level receive audio output (unaffected by the volume knob) and a direct modulator input that bypasses the microphone pre-amplifier. Proceed at your own risk
The frequency restrictions are controlled by a diode matrix on the (usually located behind the front display panel or on the bottom main board, depending on the exact M700 sub-model like the M700PRO).
A modern resource focusing on making the M700 more user-friendly for ham use, including video demonstrations of active mods.
You can modify the mic socket to accept newer microphones or high-quality dynamic mics with XLR outputs. Speech Processor: : By clipping the line that senses the
Tap into the AF Out pin on the rear external speaker jack or accessory plug for clean receive audio. Tap into the Mic Input pin for transmit audio.
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