: To achieve continuous transmit capability, you must locate and clip a specific diode. The Process : Disconnect the power supply and antenna from the radio. Remove the top and bottom covers of the transceiver.
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.
Adapting the radio for modern digital modes like FT8 or PSK31.
Page 3. SECTION 1 SPECIFICATIONS. GENERAL. Frequency Coverage: Receive. Transmit. 1.6MHz ~23.9999MHz. 2.0MHz - 2.9999MHz. 4.0MHz ~ IC-M700 - Single Sideband Radiotelephone - ICOM Canada icom m700 mods
: The stock clarifier usually only allows a swing of ±150 Hz to ±1 kHz. By altering the resistor values inline with the Clarifier potentiometer on the Main Board, you can expand this range to ±3 kHz.
While the radio works well on amateur bands, it lacks the narrow filtering found in dedicated ham rigs, which may make it sensitive to nearby interference during contests.
The original IC-M700 uses a channelized system or a relatively clunky front-panel frequency entry system compared to dedicated ham radios. : To achieve continuous transmit capability, you must
When opening your IC-M700 for modifications, perform these preventative maintenance steps to ensure long-term reliability:
In this mode, you can change the channel/memory settings to match your required frequencies rather than fixed factory marine channels. 3. Digital Mode Mods (PC Interface)
: The digital interface can easily trigger transmission by pulling the PTT line on the rear accessory jack to ground. Important Warnings and Best Practices Push-to-Talk (PTT) must be triggered via a virtual
Swapping the factory electrolytic capacitor with a lower value (e.g., changing a 10µF to a 4.7µF) quickens the AGC release time.
To enable continuous transmit across the entire frequency range (1.6 MHz to 24 MHz), remove specific diodes based on your exact sub-model revision.
A notable "interesting report" from the community highlights the risks of buying used M700 units. One restorer found that a previous owner had replaced the original microphone with a 1971 vintage rotary telephone "T1" carbon element, which severely degraded signal quality. This serves as a warning that used marine gear often contains decades of "jury-rigged" repairs that must be reversed for proper operation. Key Resources for Step-by-Step Guides
: The IC-M700 has a few production variations (such as the M700PRO). On some older M700 models, removing D26 or D28 achieves the same effect depending on the country destination code (e.g., US vs. Europe). Always cross-reference your specific board layout with the official Icom Service Manual schematics.
Locate the inline coupling capacitor on the mic element line.