> -----Original Message----- > Writelog keys the K2 VERY nicely using their serial port method. > To make it work, you need to make a very simple interface. > > 1) Pin 4 of the serial cable (from the computer) thru a 1K > resistor to the base of a generic NPN (I use a 2N4123 because I > have a lot of them, but any general purpose NPN will work). > > 2) Collector of the transistor to both sides of the key jack > through diodes (just as you would do with a straight key, per the > manual). > > 3) Emitter of the transistor to the shell of the key jack. > > You can now use both your paddle and the computer to key the > radio. Very nice in a contest. >
Jim and all, If you have the physical space, use two transistors - base and emitters in parallel, conect one collector to the dash input and the other to the dot input - the diodes can be eliminated since the transistors take care of switching the dot and dash inputs at the same time. It would also eliminate the problem caused by higher diode forward voltage that was mentioned on the reflector late last week. 73, Don W3FPR -- No virus found in this outgoing message. Checked by AVG Anti-Virus. Version: 7.0.308 / Virus Database: 266.11.8 - Release Date: 5/10/2005 _______________________________________________ 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
