[ForSale-Swap] garmin gps 18 or motorola oncore nmea rs232

[normn3ykf at stny.rr.com]

Hi,
Subject line says it all. Prefer NY state or PA driving distance from 18840.
Needs to be either one of the two models OR one that is known to operate above 65535ft.
(we're launching a balloon!!)
Most gps units don't do this.
Thanks,
Norm n3ykf