Connecting and configuring an Elecraft KX3 for PSK, RTTY, CW, and Phone Operation
. de Rich, VE3KI
an audio cable from the KX3's headphone jack to an audio isolation transformer connected to the sound card's Line In jack
an audio cable from the soundcard's Line Out jack to an audio isolation transformer connected to the the KX3's microphone jack
a PTT connection, implemented by selecting the Xcvr Ctrl App option on the PTT tab of WinWarbler's Configuration window, with Commander configured to accomplish RX-TX switching by sending CAT commands
WinWarbler can transmit CW via the KX3 without any external CW interface; on the CW tab of WinWarbler's Config window, set the Keying Mode panel to Xcvr Ctrl App; note that the Esc key cannot be used to interrupt a macro message in progress
For PSK with WinWarbler, the KX3 should be in DATA mode, DATA A submode. In WinWarbler's Configuration window, under the PSK tab, I have the Receiver modulation and Transmitter modulation panels set to BPSK USB, and the transceiver mode panel set to Data-U. The optimal offset is set to 1500, which is where the KX3's filters are centred in DATA A submode.
AFSK RTTY Configuration
For AFSK RTTY, the KX3 should be in DATA mode, AFSK A submode. In WinWarbler's Configuration window, under the RTTY tab, set the Modulation and transceiver mode panel to AFSK LSB, the Xcvr mode to RTTY, the Mark offset to -2125, and the Optimal Offset to 2210 (that's with the KX3's Pitch control set to 2125 in AFSK A; for other pitch settings, set the Mark offset to the negative of the pitch and the Optimal Offset to pitch+85). On the General tab of Commander's Configuration window, set the RTTY sub-mode to AFSK.
The K3 can be directed to transmit CW, report decoded CW, transmit RTTY, and report decoded RTTY via CAT commands. Commander and WinWarbler can be configured to use this capability, permitting CW and RTTY operation without external interfaces.