Thanks for the suggestions. The s80 is the only instrument taking gps from the oudie igc. I did try taking the bench test outdoors to eliminate poor signal considerations. I've been advised by Paul Remde that I need to update the s80 firmaware. The rev. date is pre 5.5 and definitely should be updated.

One other thing I noticed is that the oudie draws down a lot of power recharging. It blew the 3 amp inline fuse between the s80 and the +battery. The oudie battery was at about 40% charge. The voltage as read by the s80 was 12.5 to 12.2 over the test runs.