When compared to a stated db in a ground plane you should get at least
10db better with a 2 element quard. Go to:
http://www.signalengineering.com/ultimate/
and it will tell you all about it. Have made a 2 element quad on
3/8wave and have talked to Nova Scotia, Hawaii, Australia, New Zealand
on a SBE Console II 23 ch am/usb/lsb radio with a std ceramic mic. My
design came from a ham operator in No.Ctrl Tx that runs over 2Kw on it
and goes wherever he wants, and almost makes his own skip.
But this is the way to go.