The Kenwood TKM-707 is a 150W HF SSB transceiver (RX: 0.5–30 MHz, TX: 1.6–27.5 MHz marine bands). Despite its commercial focus, amateur operators have developed several modifications to expand frequency coverage, improve performance, or enable external control.
Modifying your Kenwood TK-M707 can enhance its performance and tailor it to your specific needs, but always proceed with caution and respect for the device and regulations.
there is no single academic "paper" on the Kenwood TKM-707 modifications
, technical documentation and community modification guides describe several enhancements for this marine SSB radiotelephone. Technical & Modification Resources
The most critical documentation for this radio includes the service manual and specialized modification threads on community sites: Kenwood TKM-707 Service Manual
: Provides full circuit descriptions, PLL diagrams, and maintenance procedures. Mods.dk - TKM-707 Section
: A dedicated repository for user-submitted modifications, including discussions on VFO mods and amateur radio (HAM) band usage. Repeater Builder Manual Archive
: Hosts clear PDF copies of the instruction and service manuals for reference during hardware adjustments. Repeater Builder® Common Modification Categories
Based on community discussions and circuit descriptions, users typically explore the following: Frequency Expansion/Amateur Radio Conversion
: Because the TKM-707 is a marine radio, modifications are often sought to enable Lower Sideband (LSB) or to allow VFO-style tuning across amateur radio HF bands. Audio and Squelch Adjustments
: The service manual details internal potentiometers (VRs) for adjusting the beep tone level ( ) and alarm tone level ( Service Mode Access Kenwood Tkm-707 Mods
: Technicians use specific key combinations (often involving the
key) to access internal settings for tuning and frequency entry. Important Distinction Do not confuse the (Marine SSB) with the
(Dual-band Amateur Mobile). Many online "MARS/CAP" or resistor-removal mods—such as removing resistor 0 or 3 for extended TX/RX—apply specifically to the and are not compatible with the TKM-707 marine unit. pinout details for the TKM-707's antenna coupler or microphone connectors? ssb radiotelephone - tkm-707 - Manuals (Repeater Builder)
The Kenwood TKM-707 Go to product viewer dialog for this item.
is a high-performance SSB HF Marine Radiotelephone designed for durability in marine environments. While specific "mods" (modifications) for this marine model are often cited in amateur radio communities for expanded frequency use, they are frequently documented on specialized hobbyist sites like mods.dk. Core Features of the Kenwood TKM-707
High Power Output: Delivers a full 150 watts peak-to-peak RF output power in a compact package.
Broad Frequency Coverage: Covers marine bands from 2 MHz to 27.8 MHz and includes a general coverage receiver ranging from 500 kHz to 30 MHz.
Memory Capacity: Features 198 memory channels, including 136 preprogrammed ITU channels and 62 user-programmable channels.
Advanced Noise Reduction: Includes a dual-mode noise blanker (NB-1 for pulse-type noise and NB-2 for long-duty cycle "woodpecker" interference).
Rugged Construction: Built with a rustproof aluminum chassis and stainless steel screws to withstand harsh saltwater conditions. Kenwood TK-M707 — Common Mods & Practical Guide 1
Tuning & Stability: Equipped with a built-in clarifier for fine-tuning and microcomputer-controlled circuits for high frequency stability.
Scanning Modes: Supports ITU scan, memory scan, and VFO (general) scan. Common Modifications (Amateur Radio Use) Modification guides for the
typically focus on expanding its capabilities for non-marine or emergency use. Note: Performing these may void warranties or violate FCC regulations.
Expanded Transmit/Receive: Users often modify these units to transmit across the full HF range (0.5–30 MHz) rather than just marine bands.
Tuner Compatibility: It is frequently paired with the Kenwood MAT-100 or AT-300 automatic antenna tuners for optimal signal matching.
Internal Component Adjustment: Service manuals detailing circuit descriptions and alignment procedures are available for those looking to calibrate or repair the unit at the board level. ssb radiotelephone - tkm-707 - Manuals (Repeater Builder)
Kenwood TKM-707 is a 150W marine SSB transceiver originally designed for maritime communication. Due to its robust design and wideband capabilities, it has become a popular candidate for amateur radio modifications, particularly for the amateur bands. Core Modifications & Functionality
Modification data for the TKM-707 primarily focuses on expanding its frequency range and optimizing it for non-marine use: Frequency Expansion:
Mods for this unit typically allow for transmission outside of factory-set marine bands, enabling its use on various amateur HF frequencies. Amateur Band Adaptations: 160m Band:
The radio's broadband design makes it naturally suited for 160-meter amateur operations. Manuals and Guides: Look for specific guides related
Some modified units are reportedly used on the 80m band, though this requires specific hardware adjustments. 630m Band:
Recent community interest involves converting these older marine units for the 630-meter band allocation. Service & Reliability: Solder Joint Maintenance:
Common issues include "cold" solder connections on digital PCBs, which can often be resolved by careful resoldering with a low-wattage iron. Connector Cleaning:
Ensuring clean Molex connectors between PCBs is a critical maintenance step to prevent intermittent signal or power issues. Key Resources
For detailed technical schematics and step-by-step modification guides, refer to the following community repositories: Mods.dk - TKM-707 Repository
This is the primary archive for articles, frequency expansion mods, and service notes specific to the TKM-707. Fracassi.net - Kenwood Modification Collection
A comprehensive PDF compilation of service notes and hardware modifications for various Kenwood models, including the TKM-707. Performance Notes Power Output: In maritime setups, it is known as a reliable 150W station. Broadband Design:
Enthusiasts prize the 707 for its "neat" and broadband-capable circuitry, making it more flexible than some other rigid marine-only sets. required for frequency expansion? Articles for Kenwood 'TKM-707' - mods.dk
Disclaimer: This paper is a draft for informational purposes only. Modifications described may violate FCC/ITU regulations, void warranties, or damage equipment. Perform mods at your own risk.
The TKM-707 is excellent for digital modes because it has a stable oscillator. However, you need a proper interface (like a SignaLink USB or DigiRig).