Altimetry is a real headscratcher sometimes!
When QNH is 1000mb the transition level (first available flight level above transition altitude) is FL 65 (assuming transition altitude is 6000 feet), ie you've lost half a flight level.
If you've climbed to 7000 feet QNH 1000, you're actually at FL74 (as near as dammit).
On a radar display, you will show as FL 074.
If the QNH was 1026 and you climbed to 7000 feet you would show at FL 066.
Most radars will show you at an altitude when you are below the transition altitude and a FL when above it regardless of what you have set on your altimeter.
I hope this is of some help.
[ 13 July 2001: Message edited by: cossack ]