Height of tower base

The concrete for the tower base has well and truly “gone off” or cured by now.
I put the GPS on it and it reads 1015 m (3330 ft) a.s.l. Later it said 1018 m (3340 feet), but I won’t quibble over such a small variation. Once the tower’s up, the topmost antenna will be at 1040 m (3400 feet). That sounds good to me!
