The Ramsey TD-1 is a great low-cost source for parts when looking for a tone generator/decoder. Unfortunately, it's missing a buffer stage, so the output usually isn't "loud" enough to sufficiently deviate the transmitter output (causing the tone squelch to open on the repeater). If you don't need tone decode, here's a simple, step-by-step way to modify it for tone encode only:

1. Assemble TD-1 kit per Ramsey's instructions, EXCEPT:
   • Omit resistor R2
   • Omit capacitor C5
2. Cut the PC trace between R2 and IC1-8