Nope, it'll transmit in CW WITHOUT a key attached when you flip "send". In sideband, if you have a microphone plugged in you'll be able to talk just like pushing a PTT, but without one attached you'll be transmitting but no audio. I do it all the time with my TS-520. There's no key connected to it, but I can xmit in CW mode into a dummy load just by flipping the send switch. The send switch works for ALL modes, at least on my 520. The 830 could be different, but I doubt it. I don't think it does work in CW with a key plugged in, though. Try it.