On Sunday 30 March 2008 01:56:46 pm Lyle Johnson wrote: > A cosine is shifted by 90 degrees, starting at -1 for 0 degrees, > building to +1 at 180 degrees, and dropping again to -1 at 360 degrees. The cosine of zero is +1 and the cosine of 180 degrees is -1. Ian, G4ICV, AB2GR, K2 #4962 --