This cable works for the PRO-64, and possibly will work for most headphone jack programmed RadioShack scanners.
I tested it for the PRO-89 and it works. <G>
The cable consists of a stereo mini-plug at the scanner end, and a
female DB9 (or DB25) connector at the computer end. The connections are:
5->>>>?>>>>>>>> 5 ------------ -3--- -mc--
Base/GRND ring tip ) )
------------ ----- -----
DB9 STEREO PHONE PLUG
Stereo base to DB9 pin 5 (DB25 pin 7)
Stereo ring to DB9 pin 3 (DB25 pin 2)
I bought all the parts at Radio Shack for about six and a half bucks. I
saved a little work by buying a mini-stereo patch cord and cutting it in
half, so I have a nice factory boot at the plug end and only had to solder
stuff onto the DB9. Buy a second DB9 (or DB25) and hood and use the other
half of the patch cord to make yourself two cables for under ten bucks in
For what it's worth, the official Radio Shack spec for the cable has the
stereo tip connected to DB9 pin 2 (DB25 pin 3), and a 1K resistor between
pins 2 and 3. I have no idea why; if you're superstitious go ahead and
build it that way.
you also need to jumper DB9 pins 6,7,8 (DB25 pins 4,5,6) together.
The interface cable plugs into the headphone jack on the scanner. Make
sure that you insert or remove it ONLY when the scanner is OFF. Same for
plugging the DB9 (or DB25) into the computer if the scanner is attached.