I used Bob's "satgate antenna" page for my 145.825 igate.

http://www.aprs.org/aprs-satellite-igate-antennas.html

Not sure if that's what you're looking for, though.

--Roy K3RLD

Bob, when you say "big ground plane", how big is "big"? If you have a

link to the appropriate webpage on your APRS site, that would be great. Thanks! Steve AI9IN