Tkm-707 Mods: Kenwood

Implement one modification per unit per test round

Repeatability

Safety checks

Blind audio evaluation

Field test

The TKM-707 is a marine radio. Marine HF uses Upper Sideband exclusively (except for some inter-ship on 2 MHz, which sometimes uses J3E - similar). Amateur radio uses LSB on 160, 80, and 40 meters. Without LSB, you can only listen to half the conversations.

The TKM-707’s clarifier is great for fine-tuning marine nets, but it lacks the range for SSB phone rag-chewing where operators might drift. Kenwood Tkm-707 Mods

The Fix: Locate the trimmer capacitor (TC1) on the PLL board. By tweaking this or replacing a fixed resistor in the clarifier circuit (R158), you can expand the adjustment range from ±50Hz to ±200Hz. Implement one modification per unit per test round

Why you need it: This turns the clarifier from a "fine tune" into a proper "voice finder." No more asking the other station to re-tune their Drake. Repeatability