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.
What (like a dummy load or power meter) do you have available? Share public link
Older M700s drift like a lost buoy on a cold morning. Install a Temperature Compensated Crystal Oscillator (TCXO) module. Remove the stock 30 MHz crystal oscillator and drop in a 1 ppm TCXO unit (available from Icom dealers or eBay). This is critical for 10m and 15m operation. icom m700 mods
Note: The up/down buttons on the HM-114 will not function after this mod. IC-M700 Mods - Elliott Liggett - GitLab
Which do you have (e.g., original M700 with dial wheels, M700PRO, or M700TY)? Tap into the AF Out pin on the
The solution revolves around a single wire bridge. Examining the logic circuits section of the service manual reveals that IC1006 outputs mute signals for frequencies outside the marine bands to pins P40 and P41. These pins enable a voltage called "TMU" (presumably Transmitter Mute) via transistor Q1003. The schematics show a wire bridge, W1037, shorting the base of Q1003 to ground. With W1037 installed, the transistor is never engaged to release the TMU voltage, effectively muting non-marine frequencies. By cutting or removing W1037, the radio can transmit on all frequencies.
Originally designed with specific channel-based tuning for marine channels, the Share public link Older M700s drift like a
: If your factory knob spins freely without a physical feedback point, replacing the potentiometer with a center-detent model ensures you can quickly return to the exact calibrated frequency without looking at the dial. 3. Audio Quality and Microphone Upgrades