drkirkby@kirkbymicrowave.co.uk said: > I assume it wont start until it has tracked sufficient number of satellites. There is a chicken-egg problem with getting started. The satellites tell you where they are, but you need to know where they are and where you are in order to calculate the Doppler offset so you know what frequency to listen to. The difference between warm start and cold start is that for a warm start the receiver has a 32KHz clock and has saved its last position and the satellite orbit data in battery backed RAM. -- These are my opinions. I hate spam.