Many people (including me) have some difficulty figuring out the Push-To-Talk button. The behaviour of this button depends on the setting of the "Mode" Switch.
1) When you are receiving audio, the Push To Talk button will refuse to push. Thus two people can never be accidently talking at the same time (doubling). You must wait until the frequency is clear before you try to transmit.
2) When Mode Switch is set to QRT ( also Keyer ), the Push To Talk button is dead and the rig will not transmit.
3) When Mode Switch is set to VOX, The Push To Talk button is operated only by the level of your voice. Adjust the Vox Level and Dwell while observing the Red Transmitting Light come on and off as you speak. Do not leave the mode set to VOX because the transmitter will be keying up and down whenever your dog barks. :)
4) When the Mode Switch is set to "PTT" or "PTT / PTL" a mouse click may be used to toggle (reverse) the current state between talk and listen. For technical reasons, we prefer that you NOT hold your mouse down on this button. Just click it and let go.Be careful you don't accidently leave your mic open:)
5) When the Mode Switch is set to "PTT", you can hold down the space bar to transmit and release the space bar to listen.
6) When the Mode Switch is set to "PTT / PTL", you can press the space bar quickly to toggle between talk and listen. Be careful you don't accidently leave your mic open:)
In summary, I prefer to use mode "PTT / PTL" and quickly touch the space bar as required. I tried the VOX mode and its nice, but I have never used a VOX before and need to get used to it.
I am quite successful in using VOX for digi-modes including CW with MixW digi-mode software. I would like to strongly recommend digi-mode lovers VOX for digi-mode operation as it can bring you totally emulated digi-mode world. Almost all setup of MixW can be used as it is with no additional complex operation/change. I have not confiermed this with other digi-mode software available now, but it should be work well. Please try! 73s de JA1SCW near Tokyo Japan