I see the TX duty cycle for the K3 is claimed to be 100W key down for 10 minutes. Does that really mean you could run RTTY, PSK31 or FM at 100W out without letting the smoke out?
What about the K3/10? The low power PA may not need to develop 12W to get 100W out of the high power PA, and there are no fans in the K3/10. so perhaps it would be wrong to assume 12W (or even 10W) key down for 10 minutes would be OK.