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:
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.