They say nothing is new in life and surely this is true of amateur radio! However I hope someone will find this old chestnut useful.
It's a dipole set up whereby three (or more!) parallel dipoles are fed from one coax. The one I am using at the moment is for 14, 18 and 21 Mhz, but you can choose your own bands.
The centre piece is made as shown from a piece of PCB material (single sided). A suitable size might be about three inches by four. Cut a groove down the centre to isolate the two halves, or etch a strip of copper off the board. Drill holes for the wires as shown and solder each pair.
Spacers are made from PCB board without any copper, or another idea is to use strips of Formica laminate. With the wires under tension, thread the spacers on about a foot apart and secure by using plastic garden ties as shown. End pieces can be made of bare PCB again (use the glass fibre type thoughout, which is very strong and light).
Start tuning with the shortest dipole first (21 Mhz in my case) and end up with the longest (eg: 14 Mhz). Tuning is best done away from objects, trees, etc and in the clear. Use your preferred method, noise bridge, GDO, antenna analyser, SWR etc.
Water proof the centre piece with your favourite way; I use Finegan's Waxoyl.
Work the DX! And, don't forget to let me know you've had a look at my offering and how you get on.
Watch this space for more ideas!