Short 40/30/20m Antenna
FOR HAMS WHO DON'T HAVE 20m (67 ft.) OF SPACE
Much of the information on this page is based on 4 articles written by Alfred Kluess, DF2BC, for the German magazine CQDL. All pictures and translated excerpts are presented here with written permission from Alfred and the DARC Verlag.
Each page concludes with a DOWNLOAD of the original article (in German language).
ON THESE THREE BANDS, the antenna we have been using (see below) is no longer considered a short antenna. It is almost full size on 30m and 40% longer than a 20m dipole, but on 40m it is about 30% too short.
Normally most general purpose matchboxes will have no problem matching this antenna on those three bands and even higher bands.
This page describes an entirely simple, One-Knob matchbox that will match this antenna efficiently on 40, 30 and 20m, using a simple circuit that can be switched between series-resonant and parallel-resonant with just one banana jumper. It also requires moving one of the antenna legs to another banana connector when changing between series- and parallel-resonant circuits.
ONCE AGAIN THE ANTENNA:
THIS ANTENNA is used as pictured by Alfred, DF2BC. It was designed to match his environment, not optimized for any particular parameter. The two previous pages showed how Alfred matches this on 160 and 80m. This page presents a matchbox for 40/30/20m.
KEEP IT SIMPLE:
Honestly, it doesn't get much simpler than this.
One Coil + One Capacitor + One Jumper = One Simple Matchbox
Paticience please; Rome was not destroyed in a single day!