Friday, May 18, 2012
The magic of an inverted V dipole and 100 watts
This screenshot tells a story. That story is the signal strengths at which I am being received around the world using just 100 watts of RF into my home made inverted V for 30 metres. Granted, conditions do help. Sometimes the figures aren't as good as this. However, it shows what a home made wire antenna can do in limited space. I have two inverted v dipoles, one for 30m and one for 40m, nested off the same feeder. There is no balun or twin line running to the antenna.
It consists of two wire dipoles made from 1.5mm wire bought for less than 40 euro for 100m, plus a dipole centre, a length of coax and some PL259s. There is a 20ft pole with another smaller 10ft pole bracketed on to give about 9-10m total height at the apex. They are cheap dipoles. I reckon the total cost, including pole, stand-off brackets and the other items listed above was less than 100 euro. Having made my own dipoles (with the help of my ham friends!) I can firmly say that anyone who shells out good money on buying commercially-made dipoles needs to see a psychiatrist! Either that or they have money to burn . . .
The first one to come back to my call, incidentally, was FM5BH in Martinique in the Caribbean. I also worked UN7LZ, Valery in Kazakhstan. Nice contacts with a small station. And I'm in the middle of a densely crowded housing estate! So you have no excuse !!
The signals above are from skimmer station on the Reverse Beacon Network.