Kenwood Tkm-707 Mods Portable Official

The TKM-707 has a reputation for slightly muffled receive audio due to aggressive IF filtering meant for noisy boats. The transmit audio is fantastic (the Kenwood "warmth" is there), but you can make it better.

Open the radio up and locate jumper JP5 on the main control board (near the front panel ribbon cable). On most units, removing this jumper opens the TX from 1.6 MHz to 24 MHz continuous (some later models require a diode matrix change).

Enable transmit on amateur HF bands (e.g., 80m, 40m, 20m).

If you want, I can provide: wiring diagrams for a specific mod, service/manual links, recommended replacement parts, or a step‑by‑step guide for one of the mods above — tell me which mod you want. Kenwood Tkm-707 Mods

: Gain access to the digital control board (which houses the primary CPU chip and the EEPROM).

After performing your mods, always test into a dummy load first. Never modify for 11m (CB) operation—it’s illegal, and the radio will bleed harmonics across entire bands. Keep it clean, keep it ham, and enjoy the sleeper classic.

Once D313 is clipped to enable VFO functionality, you can activate the VFO mode by pressing a specific key combination. The TKM-707 has a reputation for slightly muffled

What is your for this radio? (e.g., Ham Radio use, Marine use, Digital Modes)

to transmit outside marine channels and within the amateur radio (Ham) bands (e.g., 80m, 40m, 20m).

Modifying marine equipment requires caution, as these devices are life-safety tools. On most units, removing this jumper opens the TX from 1

| Feature | Modification Type | How to Achieve | Result | | :--- | :--- | :--- | :--- | | | Hardware | Clip Diode D312, D313, D314 | Transmit on LSB, USB, and AM across wider frequency range, including ham bands. | | Activate VFO Mode | Hardware + Key Combo | Clip Diode D313, then press C + 84 ENT | Switch from channelized operation to continuous frequency tuning. | | Configure for Ham Use | Hardware | Set DIP switches S301-1: OFF, -2: OFF, -3: ON, -4: ON | Enables full ham band operation with dealer mode and US destination. | | CPU Reset (Clear Memory) | Key Combo | C + Power On | Clears all stored memory channels and performs a full reset. | | CPU Reset (Keep Memory) | Key Combo | ENT + Power On | Resets the CPU but retains programmed memory channels. | | Adjust Power Output | Hardware/Alignment | Internal realignment via service manual. | Potentially boost output from 150W to 180-200W PEP. | | Enable/Disable Key Beeps | Key Combo | C+80 ENT or C+81 ENT | Turn confirmation tones on or off for silent operation. |

:The Kenwood TKM-707 Service Manual identifies several internal potentiometers for user-preferred "soft" mods:

Factory 8V and 5V regulators run hot and can crack their solder joints.

, the general principle involve manipulating internal jumpers or resistors to bypass regional or service-specific software locks. VFO and Sideband Mods : Users frequently inquire about enabling Lower Sideband (LSB) Variable Frequency Oscillator (VFO)