[amsat-bb] LH or RH in unswitched?

I am building my first set of crossed yagis for sat work. I have the option when connecting to setup the "unswitched (without DC applied)" to either Left Hand or Right Hand Circular Polarization.

Which one do I want the unswitched set to? Is there any explination out there somewhere of how you know what to set it as and when to change it as a sat flies by?

Thanks for the help BB,

Mike kb8zgl