Ok, runnning into a problem with the 3Dr radios.
I'm running firmware 1.9, a 1/2wl mono on the GS, and 1/4wl mono on the quad, both are at transmit power of 20 (100mw), both antennas are optimally placed and orientated but I cannot get more than 300m range, with clear line of sight. I've tried swapping antennas at both ends, and tried swapping radios on the aircraft - to no effect.
What's wrong? Shouldn't I be getting 2-3km with this set up?