## GROUNDPLANE ANTENNA

This is the antenna I have found to be the most effective limited space radiator that I have ever used.

The main requirement is to get it positioned in the clear, away from buildings if possible. Having said that, it is possible to hang a groundplane from the limb of a tree, this also works very well. The diagram below shows the basic design:

The Formula for calculating the length of the Radiator is given by:

L in feet) = 234/(Frequency in Mhz)
There is a school of thought which holds the view that the RADIALS should be 5% longer than the Radiator, but I have found, together with others, that the Radials should be the same length as the Radiator.

IT IS MOST IMPORTANT THAT THE LENGTH OF THE RADIALS ARE EXACTLY THE SAME AS EACH OTHER

The Table below is a good guide to antenna lengths

 1.8Mhz 130 ft 3.5Mhz 66ft 9in 7Mhz 33ft 5in 10.1Mhz 23ft 2in 14Mhz 16ft 9in 21Mhz 11ft 2in 28Mhz 8ft 4in

Construction of the self supporting radiator is usually 3/8 to 3/4 in alum. tubing, the radials of 14swg wire.

The hanging radiator can be of 14swg wire as well as the radials.