The Kenwood TKM-707 is a rugged, 150-watt PEP marine SSB transceiver, widely used on commercial and recreational vessels. Its popularity among amateur radio operators (hams) stems from its robust build, high output power, and relative affordability on the used market. However, the unit is factory-locked to marine frequencies (1.6–30 MHz, primarily in 2 kHz steps for ITU channels). This report details the most requested modifications to expand frequency coverage, improve performance, and adapt the unit for general coverage and amateur bands.
For the AUX port mod, John wanted to use it to control an external device, a satellite receiver. He studied the AUX port pinout and discovered that with a simple modification, he could repurpose one of the port's pins to provide a PTT (Push-To-Talk) output. This allowed him to control the satellite receiver's PTT function directly from the TK-M707. kenwood tkm707 mods
The radio includes a protection circuit that activates if the SWR is greater than 3. For best performance, aim for an SWR below 1.5. hammadeparts.jivetones.com or specific component values for the PLL circuit? Articles for Kenwood 'TKM-707' - mods.dk The Kenwood TKM-707 is a rugged, 150-watt PEP
Some users modify the interface to use third-party automatic antenna tuners instead of the dedicated Kenwood MAT-100 . This report details the most requested modifications to
John identified several areas where he'd like to see improvements:
| D22 | D23 | D24 | D25 | Resulting Frequency Range | |-----|-----|-----|-----|---------------------------| | IN | IN | IN | IN | Stock Marine (2–27.5 MHz) | | OUT | OUT | IN | IN | (1.6–30 MHz RX, 1.6–24 MHz TX) | | OUT | OUT | OUT | IN | MARS/CAP + amateur (limited low bands) | | OUT | OUT | OUT | OUT | Experimental (not recommended – may lose VCO lock) |
Removing or clipping specific diodes can trick the microprocessor into allowing continuous transmit across the entire HF spectrum.