Kenwood Tkm707 Mods //top\\
The Kenwood TKM-707 is a highly modifiable platform. The frequency expansion mod is the most sought-after, transforming a marine-only radio into a capable general coverage and amateur transceiver. However, operators must respect legal band allocations and ensure RF safety. The power and clarifier mods further enhance usability. Given the age of these units (1990s–2000s), recapping the power supply and checking for dry solder joints is also recommended.
: If you are comfortable completely removing the final power amplifier transistors, replacing the dried-out factory thermal paste with high-grade computer ceramic compound drastically improves heat dissipation. Essential Safety & Compliance Warning
The most frequently reported technical issue is the radio being slightly off frequency, a problem often described as "偏频" (off frequency) in community forums. The TKM-707 uses a single reference oscillator for both transmit and receive; if one is off, both are off. This is almost always due to the aging of the master TCXO (Temperature Compensated Crystal Oscillator).
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): kenwood tkm707 mods
You must perform a full CPU reset (hold MR + Power On) for the changes to take effect. 📻 12.5 kHz Step Modification
By default, the TKM-707 is often locked to specific maritime bands (2, 4, 6, 8, 12, 14 MHz). To use it across the full 2–30 MHz range
requires a precise balance of electronic skill and technical understanding. Unlocking the VFO and Amateur Radio Bands By default, the Kenwood TKM-707 Go to product viewer dialog for this item. The Kenwood TKM-707 is a highly modifiable platform
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.
To open the transmitter for continuous coverage across the HF spectrum, developers and operators utilize the official Kenwood Modification Database on Mods.dk .
Perform mods only if you hold the appropriate amateur license. Use a dummy load and spectrum analyzer to verify purity of emissions after modification. The power and clarifier mods further enhance usability
A common complaint about the TKM-707 is that it sounds "quiet" on the air. This is because the microphone amplifier circuit often needs to be adjusted for optimal deviation. The manual details the procedure for adjusting the microphone gain, which involves speaking into the mic while transmitting into a dummy load and adjusting a trimmer resistor (VR) on the TX-RX unit until you see the desired ALC (Automatic Level Control) action. Proper adjustment ensures a loud, clear signal that fully modulates the transmitter.
+--------------------------+ +-------------------------+ +---------------------+ | Kenwood TKM-707 Rig | Control | MAT-100 / KAT-1 Tuner | Hi-Volt | End-Fed Wire / | | (Modified for VFO/HAM) |=========>| (Antenna Coupler Unit) |=========>| Long Whip Antenna | | [50-Ohm Coaxial Out] | Cable | [RF Impedance Match] | RF Out | [Wideband Tuning] | +--------------------------+ +-------------------------+ +---------------------+ || || Heavy Copper Strap \/ +-------------------------+ | Dedicated RF Ground | | (Hull / Ground Rod) | +-------------------------+ Kenwood TKM-707 SSB Radio Telephone - Cruisers Forum
