Ubuntu New User (Audio Issues)

Hi, Have made the jump to Linux after years of love / hate relationship with Windows. Anyway, trying to make my ham computer talk to Signal Link Remote Sound Card that connects to Ham Radio Box Icom IC-7900 radio. Can not get Ubuntu Audio to talk to FLDIGI software. Am trying to use Port Audio. I wonder if I should be using PULSE audio. Any help out there. Tnx Rich KQ6EF