What HOTAS are you using?
I've mapped the friction control 'slider' on my Warthog throttle to the scanner range using TARGET
KeyAxis(&Throttle,THR_FC,0,AXMAP1(10,PULSE+INCREASE_SENSOR_RANGE,PULSE+DECREASE_SENSOR_RANGE,0));
Basically mapped a 10 band range with scanner range increase/decrease across it. Works well except that it appears that ED doesn't maintain the last scanner range set when exiting out of SC, launching etc. so I have to rotate it forward back to get it back in sync.