The transmit signal is very clean as the oscillator is always running. There are no key clicks. Power output is in the 200 to 300 milliwatt range. You'll be amazed what happens at this power level with a decent antenna. This rig makes contacts spanning hundreds of miles on 80 meters.
Band changing is simply a matter of pi-network and crystal changing.
If you build one, I'm sure you'll have fun with it. Complete parts kits are available for those of you who are interested. He has modified his rig to operate at this higher part of the 75-meter band. You can use Walkman style headphones, with a mono adapter. There is even enough audio power to drive a speaker.