Portable Vertical Antenna for 20M and 40M

The idea for this antenna came from the qrpguys.com website.
This one is built to handle 100W on ssb. The box has one T157-2 powered iron toroid with 24 turns of 18ga. enameled wire. For 20m the core is bypassed as the antenna wire is already a 1/4 wave on 20m- 16′-5″. For 40m , the connection uses the core that provides the inductance to make the wire electrically appear to be a 1/4 wave on 40 meters. The core has around 12uH of inductance.
It could be modified to work on 30 meters if the windings were tapped at around the 8uH point and another connection made from the tap to the outside.
For more info I’m good on QRZ. Km4slw

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