Hello Paul and Roger,

I wanted to tell you that tonight (about 2000 MST) my ancient ICOM
IC-260A is successfully accessing CTCSS-controlled repeaters! This is
due entirely to your help. I found easy access to the junction of R114
and C103, at the "upper" end of R114 (it is a 15K resistor on-end.) I
scraped away some of the insulation, and soldered in series a 10K and
0.1 uF capacitor, then from there a shunt 2.2K to ground, and out with
a piece of RG-174 coax. The coax is fed through one of the unoccupied
pins on the ACC connector, which I drilled out to about 3mm with a
drill bit (a tie-wrap is a strain relief to prevent pulling the coax
out from the radio.) The end of the coax is a 1/8" mono phone plug,
which goes into the audio output of my quite-ancient IBM Thinkpad 365,
running NCH Tone Generator tonegen.exe version 2.01. The output level
of tonegen is maximum (0dB) and the tone imposed on the output audio is
not very loud, but it is adequate to reach two different repeaters I
tested, and I imagine it will vary depending on the laptop and the
resistor values I used.

Anyway, this is really satisfying - with your help an old derelict
radio is now back in service in my shack, with my laptop doing duty as
the CTCSS generator. It wasn't necessary to create any T/R switching or
other controls on the tone - it just runs continuously from the laptop.

Again, very much thank you (and the manuals section you host proved
quite invaluable this time, and I'll look forward to improving my
library.)

Just as an aside, this project is actually a prototype for a ham friend
who was disabled a couple of years ago - I want him to get access to
IRLP, and I found a 2M transceiver (Kenwood TM201B) for USD 35, which
needs only CTCSS to bring it to life in a similar mode (he already has
the necessary laptop.) So your help has actually done double duty.

Thanks again,

73 Dave WB0GAZ