Joe, That will work, BUT neither the KXSER or KXUSB cables could be used - they do not contain RTS or DTR signals.
73, Don W3FPR On 7/13/2012 12:30 PM, Joe Subich, W4TV wrote: >> Given that the KX3 supplied cables only have RXD and TXD signals, >> using the serial port to generate PTT requires that either you use 2 >> serial ports (one may be the KX3 USB cable and the other can be a >> real port or USB to Serial adapter), or provide a "Y" adapter to go >> to your interface. > Or simply provide a 3.5mm stereo jack on the interface for connection > to the KX3 CAT jack. Properly wired, TxD/RxD go to the KX3 while > DTR and RTS get split off (in the box) to a pair (or more) of NPN > transistors for CW and PTT. > > The difficulty in dealing with a computer interface for the KX3 is > the last of a fixed level audio output and the need to share audio > with the operator headphones/speaker. Levels for computer decoding > and operator comfort are not always the same <G> which means a > buffer/splitter amplifier, external speakers with separate volume > control and headphone jack or some other "extra box". > > 73, > > ... Joe, W4TV > > > > On 7/13/2012 10:12 AM, Don Wilhelm wrote: >> Bill, >> >> You may want to re-think using the serial port on your interface. >> >> Most data mode applications like to use the same COM port for rig >> control (OK, maybe just frequency display) as they use to activate DTR >> or RTS for PTT. >> >> Given that the KX3 supplied cables only have RXD and TXD signals, using >> the serial port to generate PTT requires that either you use 2 serial >> ports (one may be the KX3 USB cable and the other can be a real port or >> USB to Serial adapter), or provide a "Y" adapter to go to your >> interface. Use of the "Y" adapter precludes the use of the KX3 USB cable. >> >> There is nothing wrong with generating PTT from the audio stream, or >> just using VOX in the KX3. >> >> 73, >> Don W3FPR >> On 7/13/2012 9:51 AM, Bill Conkling wrote: >>> I am working on an interface in a box w/pcb. Once you use a box, you can do >>> anything. I plan to have full serial port and two audio cables from >>> computer. Transformers in the audio chain and a 10K/1k attenuator in mic >>> input to KX3. I will split the serial port to provide proper connections >>> for CAT, PTT, and CW as n1mm handles the K3. >>> >>> Whole thing in a 2.5X2.5X1 box. >>> >>> Big plans.... >>> >>> ...bill nr4c >>> >> ______________________________________________________________ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:[email protected] >> >> This list hosted by: http://www.qsl.net >> Please help support this email list: http://www.qsl.net/donate.html >> > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[email protected] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
