I heard CAS-6, but it required a couple of seconds of transmitting for the transponder to turn on. Then it would only stay on for a couple of seconds. It sounded like AO-7 getting knocked out by too much RX signal strength. I reduced power real low and that seemed to help, but there were others on the transponder who may not have been experimenting with power levels. I will have another pass in an hour or so. Thanks for the new bird! Red KC4LE