TX Data, RX Data, and Signal Ground are the only lines required for firmware loading.
However you may find it useful to also wire DTR and RTS so that computer logging / keying programs can use these leads for PTT and CW keying. Details of which pins are what are in the KIO3 section of the K3 Owner's manual (currently page 18). I generally would recommend a shielded "straight through" 9-pin M-F DB-9 serial cable. All 9 pins wired so that each pin on one end is wired to the same pin on the other. Avoid "crossover" or "null modem" cables. 73 de Dick, K6KR -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Don Wilhelm Sent: Friday, January 11, 2008 9:35 AM To: [EMAIL PROTECTED] Cc: [email protected] Subject: Re: [Elecraft] K3 serial cable Paul, Yes, but... it needs a DE9 male on one end, a DE9 female on the other. The computer port has a male jack and the K2 has a female jack. Look at the cable construction information in the KIO2 or KPA100 manuals. You have the pins correct, but the wire you have will not likely provide enough isolation - If you do not have the proper 4 conductor shielded cable, I would suggest that you use CAT-3 or CAT5 wire which has twisted pairs (you need two twisted pairs) to take advantage of the signal isolation the twisted pairs will provide - connect one side of a pair to pins 3, and the other side of the same pair to pin 5 - a second pair connects one side to pin 2, and that pair's return is also connected to pin 5. If the CAT5 or CAT3 cable is shielded, I would connect the drain wire to pin 1 at the K2 end only so it acts like a faraday shield - caution: pin 1 at the computer end is NOT the shield connection (it is carrier detect), if you want to connect a shield at both ends, connect it to the DE9 shell at the computer end (see RS-232 pinout for DE9 connectors) 73, Don W3FPR [EMAIL PROTECTED] wrote: > > > So the K3 F/F DE-9 serial cable only needs TX, RX, and SG? > > Pins 2, 3, and 5 only... > > Straight through... > > I've got some cable with one twisted pair inside a foil shield with an > un-insulated ground wire (I believe it's called the drain) in there > too, and it contacts the foil shield full length. Would that work? > > Should I slip some ferrites (which I already have) over the cable's > jacket before soldering the DE-9/F's on? > > 73, > _______________________________________________ Elecraft mailing list Post to: [email protected] 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: [email protected] 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
