Think several times before doing this. Pin 7 on the IO connector, labelled RF, is indeed connected to the main MCU. Imposing RS-232 voltages on it will probably cause very bad things to happen in your K2, as others have discovered.
If you want to break out pin 7 of the cable from the computer before it reaches the KIO2 connector, you can do that - it can provide the PTT (or CW) signal you need. You will also need the signal ground off pin 5 of that same connector (from the computer). In any case, ALL pins of the KIO2 IO connector are used, and imposing RS-232 voltages on any except the two communications pins (TxD and RxD) WILL cause failures in your K2. Thus you want to be very careful about what you let near your K2... -----Original Message----- >From: cloud runner <[EMAIL PROTECTED]> >Sent: Apr 26, 2007 9:20 AM >To: elecraft@mailman.qth.net >Subject: [Elecraft] KIO2 and serial keying > >I use N1MM contest logging program. At present, I communicate between the PC >and the K2 with its KIO2 using a serial cable, and I key the K2 using a >parallel cable with Tom's (N0SS) keyer built into the parallel cable housing. >With parallel ports absent from many laptops, and in the interest of fewer >cables... > >My question(s): > >The KIO2 uses pin 2 and pin 3 for RXD and TXD communication with the radio, >and pin 5 for the ground connection. > >1) Can I use pin 7, on the KIO2 labeled RF but appears that nothing is >connected to it, to drive transistor keying of the radio instead of the >parallel port? > >2) Will N1MM recognize the same com port for keying that it is using to talk >to the radio? > >73, Fred - kt5x >K2 # 0700 >_______________________________________________ >Elecraft mailing list >Post to: Elecraft@mailman.qth.net >You must be a subscriber to post to the list. >Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > >Help: http://mailman.qth.net/subscribers.htm >Elecraft web page: http://www.elecraft.com _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com