[Elecraft] K3- cw- pc program problems??

[Richard Ferch]

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