The DRA-45 and DRA-50 sound cards are nearly identical except for minor differences because of the DB9 radio interface connector on the DRA-45 as compared to the mini DIN-6 connector on the DRA-50. These sound cards were assembled from kits designed and marketed by Kevin Custer of Masters Communications. The sound cards have a wide bandwidth and a high output level which is required for my 9600 baud VARA FM Winlink node. The DRA-50 unit is interfaced to the Alinco DR-435 Mk III node radio and the DRA-45 is interfaced to the Kenwood TH-F6 that I use to test and maintain the node. Both sound cards are housed in custom enclosures and are powered by their USB connections to their associated computers.