quarter waver antenna ground plane

[lancerice]

i have 1/4 wave antennas up and are connecting ground planes to them, i have the lengths of what i need but i am unsure to how many ground radials i need 3 or 4 and to what angle they should be, horizontal or 45 deg down

thanks lance

[mike m]

EZNEC antenna modelling shows with 45 degree angled downward radials the antenna matches to 50 ohms when the lengths are properly adjusted for 50+-J0 ohms impedance.

The gain difference between 3 and 4 radials, when the radials are angled downward at 45 degrees, is withing a tenth of a dB at the same takeoff angle and the same arbitrary antenna height above ground or in free space isotropic conditions.

Cutting throw all the techno crap above; 3 radials should work fine.

Mike

[AEC]

The only other difference you would have with matching cable to a 1/4 wave atenna as you are using, is when the cable exits the base of the antenna at a 90 degree angle, then the feed imedance will be changed.