WI7B – Radio Amateur Extra

an ARRL Registered License Instructor upto and including Amateur Extra

All things radio scientific





Latest issue of QEX

WI7B has a maximum output of 20 Watts SSB from the G90 SDR. It is made great by the artificial ground. The 1:9 unun (misnomer “balun”, because nothing is balanced about it) keeps the SWR in the range of the built-in autotuner. Unlike most set-ups, WI7B changes counterpoise wires to accomodate the various bands and tune up on them. The stealthy wire antenna stays the same. This maximizes the RF current emitted, as ground current must be reciprocal with antenna current, something for which many amateurs today have little understanding. Many only know “hundreds of watts” and “big antennas” and “SWR”, which have little impact on emission of RF photons beyond radiative resistance. So it goes.

Un ami de France

Christophe Picard, F11BAO, has been known as “The Shortwave Listener of The North” / A member also of REF (Réseau des Émetteurs Français) for many decades. Christophe Picard is listening, make no doubt!