[Elecraft] K2, FD, and N1MM

[Jim Brown]

On Fri,7/8/2016 10:17 AM, Robert G Strickland wrote:
> So, as Guy states and Don infers, using an interface device is 
> probably preferable to a direct computer-radio setup. YMMV and OMD. 

When I used a K2 for contesting, I made up a simple adapter that split 
out the DTR line from the computer to an NPN transistor that keyed the 
radio. Details begin on page 51 of this set of Power Point slides. The 
NPN inverter is shown on page 53. Following slides suggest how to get 
varying degrees of fancy.

http://k9yc.com/HamInterfacing.pdf

As has been noted, the K2 does NOT have a standard RS232 interface, and 
a standard DB9 cable wired for RS232 CANNOT be used directly. The K2 
uses pins 2, 3, and 5 for serial interface. Other pins are used for 
other functions. When you build a K2 accessory that has a DB9 connector, 
clear instructions are provided for building a suitable cable to 
interface to a standard RS232 port.

One thing that was WRONG about K2 accessory kits was that Elecraft 
provided parallel wire cable for the interface. That cable SHOULD use 
twisted pairs, one pair for each signaling circuit between the K2 and 
the computer. Ordinary CAT5 cable is an excellent choice. This is shown 
on pages 53-55.

I successfully used this setup to control and key the radio both with 
WriteLog and N1MM.

73, Jim K9YC