Hi Peter, > Newbie question : why do I need 4(!) in-/outputs on this card ? > I got from Leifs site that only one Hpol and one Vpol input is required. > What did I miss ? If you do not want to build crystal filters, you have to use "direct conversion" which will give you I and Q, two audio channels for each antenna. 73 Leif / SM5BSZLINRADDARNIL