A Growing Concern
A lowly coil of wire can be surprisingly difficult to understand and model correctly. I use coils of wire or coils of coax cable as trap inductors for various antenna designs that I have built. In the low frequency limit, the traditional inductance calculations work okay and can give you a pretty good estimate of [...]
The bamboo Moxon I built for the 20 meter band earlier this summer convinced me of the power of compact two element antennas. When I was showing the Moxon to a friend, he pointed up to a nearby tree and said "There's the place to pull from," pointing to the crotch of a tall branching [...]
As much as I love all of the wires up in my trees, I've come to realize that a little real gain and directivity would be nice. However, my trees are really in the way for a a typical tower and a beam antenna, so I am left to consider what resources I have and [...]
There are a few ways to build multi-band HF antennas. These include multiple resonant dipole arrays, trapped dipoles, resonant loops and the off-center fed dipole, OCFD. I'm going to look at the OCFD because it is relatively simple to construct, yet gets quite decent performance. I also am fortunate to have some nice tall trees [...]
Squash Practice 