An online expert helped recently helped his Small Transmitting Loop (STL) disciples with:
Also remember that the bandwidth given by the calculators is the half power point. That’s equivalent to an SWR of about 4.3 at the ends.
Whats that?
Most STL, and lots of other resonant antenna systems exhibit a classic VSWR curve being that of a approximatly constant resistance in series with an ideal capacitor and inductor.
Above is that classic VSWR curve. Continue reading Extrapolating VSWR of a simple series resonant antenna