"Wyatt Emmerich" wrote in message
...
My Garmin 296 indicates 330 MSL at KHKS, which is correct. My Echo Flight
GPS indicates 140 MSL. Both are locked on to WAAS.

How can I have such a large discrepancy? Both units seem to be functioning
properly other than this.

Your Echo Flight GPS is not functioning properly. My guess is that it is not
processing the WAAS signal. The difference between the two units should be
no more than 50 feet.