Radio Shack sells a cable, listed in their 1999-2000 catalogue as part number 26-149, that can be easily modified for connecting an ICOM IC-207H dual band mobile transceiver to a packet TNC. It is a PS/2 keyboard extension cable with a male connector on one end (this end plugs into the IC-207H on the rear apron of the rig) and a female connector (which we don't need … now - so it went in my junk box).

I removed the female plug from the end of the cable and replaced it with a hooded connector (male. DB-25) suitable for my TNC (PK232). Other brands/models of TNCs frequently require a different connector, so check your TNC's manual to determine what your TNC uses.

Here is a brief table describing the pin-out of the RS 26-149 cable and each wire's function.

Pin. No.	Signal Name	Insulation Colour	Comment
1.	TX Audio	Black
2.	Ground	Brown
3.	PTT	Red
4.	Data out - 9600 bps	Orange	ONLY used with 9600 bps capable TNC
5.	Data out - 1200 bps	Yellow	* Standard - used 90% of the time
6.	Squelch	Green	Not used in most cases
Shield  Frame		bare	bond to Pin 2

Also, Radio Shack lists a separate male PS/2 style plug in its 1999-2000 catalogue which must be soldered onto the end of a cable. Save your nerves and hair, use the indicated cable instead because this connector's solder point dimensions and spacing are so small and close together that you'll either need a magnifying glass, or wish for one, while you fight with the separate plug.

My PK232 worked the first time when I attached the modified cable (very unusual, hi)!