After 25+ years, the small electrolytic caps on the audio and control boards are drying out. Symptoms: distorted receive audio, low TX output, humming.
Out of the box, the TKM-707 is limited to marine bands (2–27.5 MHz, mostly USB). To enable TX on all HF ham bands (160–10m including WARC):
Result: TX from 1.6–30 MHz continuous, modes USB/LSB/AM/CW (LSB needs separate mod).
Difficulty: Easy (internal pot)
Procedure: kenwood tkm707 mods
Note: Exceeding 150W may damage final transistors (2SC2879). For higher power, external amplifier is recommended.
The Kenwood TKM-707 is a legend. Designed as a rugged, commercial-grade marine HF SSB transceiver, it has found a second life in the hands of amateur radio operators (hams), overlanders, and long-term cruisers. Its 150-watt PEP output, robust construction, and relatively simple architecture make it a coveted rig—if you know how to unlock it.
Out of the box, the TKM-707 is locked to the marine bands (2–27.5 MHz in simplex/half-duplex). For amateur use, it’s almost useless. For marine operators, there are still performance tweaks that can bring this 1990s workhorse into the modern era. After 25+ years, the small electrolytic caps on
This article covers every major modification (mod) for the Kenwood TKM-707, from the essential “MARS/CAP” frequency expansion to power adjustments, audio upgrades, and display brightness fixes.
Warning: Modifying your TKM-707 may violate FCC or local regulations if used on unauthorized frequencies. It may also void any remaining warranty (unlikely) or damage the radio if done incorrectly. Proceed at your own risk.
The TKM-707 is basically a rugged TS-50 with a marine faceplate. All TS-50 schematics apply. After mods, it’s a killer 200W field radio. Out of the box, the TKM-707 is limited
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You're looking for modifications (mods) for the Kenwood TK-M707, a popular amateur radio transceiver. Here are some in-depth details on various mods that enthusiasts and users have explored:
The most common search leading to “kenwood tkm707 mods” is the need to open the TX/RX frequency range. By default, the TKM-707 transmits only on ITU marine channels. For amateur bands (160m, 80m, 40m, 30m, 20m, 17m, 15m, 12m, 10m) and MARS/CAP frequencies, you need to perform a simple diode mod.
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