Chuck, When the radio is in CW mode, it is keyed via on-off key closures at its CW key input. It does not accept audio input when it is in CW mode. As far as I am aware, this remark applies to all amateur transceivers, certainly not just the K3.
However, unlike most other CW software, fldigi does not have any on-off keyed output. Its only output is audio from the sound card. To transmit in CW from fldigi, you must put the radio into an SSB mode that accepts audio input (such as DATA A). Fldigi uses the sound card to generate an on-off single-frequency tone, like a code practice oscillator, and this tone output from the sound card is fed into the radio's audio input and transmitted. When the radio is in a single-sideband mode (including DATA A), the net result is in theory the same as transmitting true CW, assuming of course that there is no hum, noise, distortion, etc. on the sound card's output, and also assuming complete suppression of the opposite sideband in the radio. There is a way to use fldigi to transmit true CW with the radio in CW mode, but it requires that you provide an external circuit to detect the audio tone produced by fldigi and generate an on-off keying signal which can then be fed into the radio's CW keying input. An example circuit to do this is described in the fldigi on-line help at <http://www.w1hkj.com/FldigiHelp-3.20/CWkeying.html>. When receiving in DATA A mode, the K3's internal CW decoder does not work. This should not be surprising, since DATA A is the mode that is used for arbitrary digital modes (every mode that fldigi can decode plus many others), and the K3's firmware has no way of knowing what mode you are trying to decode. To decode CW on receive, the K3 must be in CW mode. Fldigi, on the other hand, can decode CW even with the radio in DATA A mode, since you can tell fldigi via its menu system which of its many supported digital modes (including CW) you want it to decode. If you want to take advantage of the K3's CW decoding and other CW-specific features, you will have to either use different software that is capable of true CW keying, or provide an audio tone-to-keyed output converter such as the one in the fldigi help file. 73, Rich VE3KI af4xk wrote: > Hello folks. > > I'm trying to get cw going with the K3 connected to a PC running a cw > program for both decoding receive and cw xmit via the keyboard. I'm using > the line-in/line-out jacks on the K3 for the audio and the fldigi program on > the pc. > > The decode works decent when the k3 mode is set as CW but I can't transmit > on that mode. But when I change the K3 mode to DATA, I can transmit fine but > the receive/decode is garbage. > > Anyone have the above working?..... what PC program works?..... K3 in CW or > DATA? Any other advice?? > > thanks and 73. > chuck > af4xk ______________________________________________________________ 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
