[Elecraft] K2 - KPA100 RS232 interface repair

[Jim Brown]

On Sat,8/22/2015 10:21 PM, Richard W. Solomon wrote:
> Not to flog this horse any further, but I direct you to page 85 of the K2
> Manual where the DB-9 connector is labeled ..."RS-232 and AUX I/O"... .
>
> Is it RS-232 or not ??? Is it mis-labeled ????

The fact that it says RS-232 AND AUX I/O should be a clue -- a full 
RS-232 interface requires the use of all 9 pins, leaving nothing for AUX 
I/O. All of the ham gear I've ever interfaced to uses only two circuits 
and three pins  -- 2 (RXD),3 (TXD), and 5 (Sig Gnd) for control, leaving 
the other pins and lines for other uses. Pins 4 (DTR) and 7 (RTS) are 
used by many logging programs to send CW and PTT. There's a piece in QST 
from 10-15 years ago showing how to build an ICOM interface getting 
power from either DTR or RTS (I don't recall which).

73, Jim K9YC