This seems a popular topic on the KX3. For computer interfacing the KX3 for running various soundcard programs a simple interface is needed for PTT, Keying, and transmit audio. It is assumed that one side of the IQ baseband will serve for connection of Rx audio to the soundcard.
A couple choices are given for PTT: 1) using the Mic-PTT 2) using GPIO input Transmit audio from a soundcard will have to be: 1) isolated 2) reduced in amplitude to drive the mic input properly. RS232 needs to be isolated from KX3 PTT and KEY. An external unit is what looks practical and will need the proper connectors: 1) Four contact mic connector w/ suitable length cord 2) ACC2 connector (if used) 3) standard 3.5mm phone jack for soundcard interconnect (get that from RS) 4) breakout of serial cable RTS line and DTR line 5) connector for KX3 KEY jack. 6) transistors to isolate RTS and DTR 7) resistive divider (pot) for setting Tx audio level 8) miniature pcb isolation transformer for audio A simple interface can be made "very tiny" using sm components, though may be more than will fit the standard DB9 (9-pin subD) jack shell. I'm giving some thought to manufacture such an item, but I need to receive delivery of my KX3 for development. What would folks like this to look like? How long should cords be? 73, Ed ------------------------- Date: Sat, 17 Mar 2012 20:29:41 +0100 From: Frode LA2RL <[email protected]> Subject: [Elecraft] KX3 and Data Mode Interface To: [email protected] Message-ID: <CADpT02T=Qw5TDWuv=Xev=2vr56gos52mor8ambxd+twmfrx...@mail.gmail.com> Content-Type: text/plain; charset=ISO-8859-1 The K3 Manual says clearly that the Line In and Line Out signals are isolated with transformers and that these ports therefore can be connected directly to a computer sound card. I have read carefully through the KX3 Preliminary Manual but I have not found any information about isolation of the input and output analog signals. I therefore suppose that the KX3 does not have any isolation on these ports, however on page 18 the manual says that you can connect the computer audio to the MIC jack and the KX3 phone jack to the computer's audio input. So I am still somewhat confused. 73 Frode LA2RL 73, Ed - KL7UW, WD2XSH/45 ====================================== BP40IQ 500 KHz - 10-GHz www.kl7uw.com EME: 50-1.1kw?, 144-1.4kw, 432-QRT, 1296-?, 3400-? DUBUS Magazine USA Rep [email protected] "Kits made by KL7UW" http://www.kl7uw.com/kits.htm ====================================== ______________________________________________________________ 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
