Joe, W4TV, wrote: 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". ----------- I rarely listen to the audio of digital signals since my brain cannot decode them, anyway. With a 3.5mm phone plug inserted the internal speaker is disconnected so I suppose you are using either headphones or ext. speaker. No need to hear the signal so volume on KX3 is adequate to set proper level for digital sw.
But one could provide for separated audio to speaker/headphone and computer with audio amp and pot for level setting. Final audio level is set with soundcard dialog box, anyway. In my case I use an ext soundcard that has pots for line-in level. ------------ Regarding serial connections to the computer this is easily handled by either a full RS-232 cable if you have RS-232 on your computer or by using a USB/RS-232 conversion cable (like what comes with the K3). One then connects DB-9 pins 2,3 for RXD and TXD to a cable to plug into the ACC-1 jack, and take off pins 4, 7, 5 to split out RTS, DTR and ground to supply PTT and CW keying, per one's needs. To provide fullest versatility I would provide both a DB9 serial port for full serial connection and the 3.5mm mini-phone jack for the KXUSB cable (RXD, TXD) for those not requiring RTS/DTR controls. One just uses whichever cable is suitable to their sw needs. If you use the KX3 VOX for audio-sensed PTT there is no need for any ancillary ckt. If you need hard switched PTT then use RTS/DTR per your sw. Audio interface should use isolation transformers, and the mic audio requires a pot for setting proper modulation level (using the ALC display). The four contact mic mini-plug is probably the hardest item to come up with. Such would satisfy all users, I believe (I do not use HRD or other control sw so perhaps they require addition controls?). 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 dubus...@gmail.com "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:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
