I recently changed my antenna from pod mounted to king post mounted because I wanted to use a/c power to the vhf and gps, Icom A6 radio and Garmin 196 GPS. When I had the pod mounted antenna reception was excellent like perhaps 200 nautical, now with king post aerial flat out getting 30 I guess, the antenna is micro avionics where you have to refurb the bnc end so you get the right coax length, could this be the problem to limited range. Also when I transmit to Brisbane Centre for a radio check I believe they cannot hear me, interface is also micro avionics, like I said before connecting to a/c power for the gps never had a problem but want to stick with a/c power.