Just a note: For those who do not have a serial port available and wish to use a USB to Serial to converter (for PTT purposes, etc.), the Belkin F5U409 model works terrifically well. It supports the entire RS232 protocol (not all converters do) and has LINK, TX, & RX indicator LEDS.
73, Bill Allen WA5PB -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Don Wilhelm Sent: Sunday, September 17, 2006 2:08 PM To: Jeff; [EMAIL PROTECTED] Cc: elecraft@mailman.qth.net Subject: RE: [Elecraft] K2 Crystal Filter Alignment Questions Jeff, If what you want to do right now is just receive PSK31 signals, use the same cable connection that you used for Spectrogram and run one of the PSK31 programs on your PC (DigiPan and Ham Radio Deluxe are 2 popular freeware programs - yes there are others). You may have better luck with the K2 external speaker jack and the soundcard line-in jacks than the headphone jack and the mic input, but try them both and see what works. Transmitting gets a bit more complex, but you only need to connect the soundcard line out to the K2 mic AF input - because the soundcard output is much greater than the mic input, you will need a resistive divider. Also at this point, you should consider isolating the lines between the computer and the K2 - I use transformers salvaged from defunct modems successfully. While you can change from receive to transmit by manually keying the transceiver after clicking the mouse, as a further step add automatic control of the PTT line. Add an optoisolator to connect the RTS and signal ground from a computer serial port and drive the K2 PTT line from the output of the optoisolator. You could use a simple transistor instead of the optoisolator, but the transistor does not allow ground isolation, and you could encounter RF feedback being picked up on the computer chassis and grounding system, etc., but for simplicity, it is worth a try. If you are stuck with no serial ports on your computer, a USB to Serial adapter could be used ahead of the PTT keying circuit. That is all there is to any PSK31 interface - some of the boxes available include microphone switching, and audio output switching, but those are add-on conveniences, the simple interface that I described (2 lines from the computer preferrably with transformers and an optoisolator for the PTT activation) is all that is needed for a full interface function, and can be built for less than $10 if you scrounge the transformers and don't have to pay much for an enclosure and jacks. 73, Don W3FPR > -----Original Message----- > > The problem that previously prevented me from using Spectrogram was that I > didn't know that getting the K2's audio into the PC was as simple > as running > a cable from the K2's headphone jack to the PC's microphone jack. > Instead, > I envisioned having to have an interface circuit of some kind and > wire up a > USB connector. > > As a side benefit, now that I have receiver audio going into my > computer, my > next project is to figure out how to decode PSK-31 signals. Cool stuff! > > 73, > Jeff > WB5GWB _______________________________________________ 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 -- No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.1.405 / Virus Database: 268.12.4/449 - Release Date: 9/15/2006 _______________________________________________ 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
