Icom M700 Mods 'link' Direct

: The original HM-28 microphone is often replaced with the modern HM-114 . Note that this requires replacing the internal connector (53) on the MIC-C-UNIT board.

The stock Icom hand microphone uses a dynamic element. Converting the radio to accept an electret condenser microphone drastically improves transmit clarity.

The Icom M700 is a classic. With the right knowledge, patience, and respect for the technology, these modifications can give this old radio a new and fulfilling life on the ham bands. Good luck and 73!

This technique is universally applicable to a huge range of modern Icom radios, including the M700. The core concept is that Icom often uses a set of surface-mount diodes on the main logic board to restrict transmit frequencies based on the target market. Removing specific diodes disables these restrictions.

While the standard 8-pin microphone connector can be used, many users choose to solder an interface directly to the board or use a specialized adapter to allow an audio interface box to connect for input/output, according to discussions on ⁠Reddit's ShortwavePlus . icom m700 mods

The ICOM M700 (and its variants like the M700PRO and M700TY) was designed for marine use on ITU channels. For amateur radio operators, its stock frequency coverage is limiting. This guide covers the most popular, proven modifications—from simple jumper changes to advanced filter upgrades.

By running this 8V line through a 1k-ohm resistor to isolate the DC, and using a 0.1µF capacitor to block DC from entering the audio line, you can power a high-fidelity electret mic element.

Look for a row of programming diodes labeled D23 through D32 . Modify for Open Transmit:

Hold the and SQL buttons simultaneously and turn the radio ON . : The original HM-28 microphone is often replaced

A common mod involves adding a DIN plug lead emerging from the back of the radio to interface directly with a Pactor modem or PC sound card.

Description: NEW HM-180 replace old model EM-101 Hand Microphone For IC-M700 IC-M710 IC-M700PRO IC-M600 (equal EM-48 or HS-50 mic, Go to product viewer dialog for this item.

For advanced users, the ultimate modification involves replacing or overriding the internal synthesizer reference with an external Direct Digital Synthesis (DDS) VFO kit.

Before snipping any component, you must locate the correct service manual for your exact version of the M700 (e.g., M700, M700TY, M700PRO, M700D). The diode location differs, and removing the wrong one can permanently disable the radio. The service manual is an essential tool for any serious modification work. Converting the radio to accept an electret condenser

The IC-M700 is rated for a massive 150W PEP output, which generates significant heat during prolonged transmissions, such as digital mode operations (FT8, JS8Call, or Winlink). Fan Mod for Digital Modes

Older HF radios can drift in frequency as they warm up.

The Icom IC-M700 (and its variant the IC-M700TY) is a legacy HF marine transceiver. While robust, it is an older analog radio. Most modifications performed today fall into two categories: (bringing the radio back to spec) and expansion (enabling HAM band usage or replacing obsolete components).