I recently purchased the Avia/RS meter for my pio 53tx...The disc has all the instructions you need ,plus the members here have posted very useful tips on calibration ....just do a search , u would find them all
i was quite suprised that my pio MACC does what AVIA disc wants me to do, I used the avia / RS meter to fine tune the setup, little difference so far but am still playing with it. You may want to use avia to fine tune your setup if thats very very important cause the avia disc + RS meter will put u back by $70+
