[Elecraft] KIO2 and serial keying

[Jim Brown]

On Thu, 26 Apr 2007 15:03:35 -0400 (EDT), Jack Brindle 
wrote:

>If you want to break out pin 7

Yes. I use Writelog as a contest logger and have always set 
it up to send CW on pin 4 of the computer's serial port. I 
break it out of the serial cable, make an inverter/level 
shifter for it (a transistor and a resistor), and use that 
to key the K2 (and othe rigs). It works VERY well on every 
radio I've ever hooked it up to, including my K2's, TS850, 
and OmniV. With the K2, of course, I feed it through the 
two isolation diodes so that I can also use the paddle. 

The transistor inverter/level shifter is the one that 
Writelog shows for the parallel port. Collector to the key, 
emitter to key return, base thru resistor to the keying 
line from the computer. 

All this works MUCH better if you rebuild the serial cable 
using twisted pairs for the computer to radio part, one 
pair for each signal circuit. No changes to the wiring 
between a KPA100 and a K2. Details on my website for the 
serial connection. 

http://audiosystemsgroup.com/RFI-Ham.pdf

73,
Jim Brown K9YC