OK Tony, here you go:
- find an aircraft on the ground, say the altitude readout is 300 ft - I think that you want it to read zero feet?
- First of all, click on the SmartView Tab to the right of MyFlight and Network. Where it says 'Auto set QNH' make hure that the box is NOT ticked
- Goto the RadarBox File menu item at the top left of the screen
- Left click on File and then left click on Preferences and then on the RadarBox tab in the Preferences window
- Look down to the Transition Altitude section middle left of the window.
- Set the 'Above this value altitude etc' and set 6000 here
- Go to the box below where it says 'QNH (to display etc')
- Divide the height you are seeing the aircraft on the ground by 30 (in our example we said that the aircraft was showing 300 ft on the ground) so 300 divided by 30 = 10
- Whatever figure you have now in the QHN box, say 1016, subtract 10 from this = 1006
- Enter this figure in the QNH box and click Apply and OK to exit the Preferences menu
- The aircraft that was reading 300 ft on the ground SHOULD now read zero
You will have to do this every day an the pressure changes all the time. You might even need to do this more than once a day if the pressure is changing rapidly.
Give it a go and see how you get on :-)