On 21 Aug 2006 17:50:21 GMT, Ed
Its all a matter of reference. I was thinking in terms of dBi.... a
vertical has 3dBi gain, a ground plane, 2 dBi.

Here is a ground plane with a free-space gain greater than 2.9 dBi and
an SWR less than 1.2 at its design frequency (as given by NEC2):

CM Groundplane antenna for MURS (151.8 Mhz)
CE
GW 1 19 0 0 0 0 0 0.444243 0.000813863
GW 2 21 0 0 0 0 0.163546 -0.4506 0.000813863
GW 3 21 0 0 0 0 -0.163546 -0.4506 0.000813863
GW 4 21 0 0 0 -0.163546 0 -0.4506 0.000813863
GW 5 21 0 0 0 0.163546 0 -0.4506 0.000813863
GE 0
FR 0 31 0 0 145 0.33
EX 0 1 1 0 1
RP 0 31 73 1001 0, 0, 3, 5, 10000, 0
EN


It uses 14 AWG wire and consists of a 17-1/2 inch vertical, and 4
18-7/8 inch radials symmetrically placed at about 20 degrees with
respect to the vertical axis:

|
|
| A A = 17-1/2 in
| B = 18-7/8 in
| T = 2*19.95 degrees
/ \ C = 12-7/8 in
/ T \ B
/ \ (only 2 radials shown)
/ \
-- C --

--John