Designing Self Resonant Coils for Antenna Traps and Chokes

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 Off-Center-Fed Dipole Antenna – Design

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 [...]