Bernard ZL2BD and John ZL2XJ launched the first of a pair of shed workshops covering the construction of an active antenna.
Bernard discussed why amateur operators should be interested in active antennas, the basic design elements that underpin the electronics, and the nature of the kit construction that members will be undertaking.
The designs all incorporate a FET followed by a bipolar transistor. They must transfer the very high impedance of a short whip antenna to the 50 ohm input of a typical receiver. They may also include filtering to reduce broadcast interference (BCI). They are fed using 12v over the coax, so they require a filtering system to separate RF from DC back in the shack.
We will meet on 1 September from 2pm -4pm since it will be Father’s Day and some may want to go out to lunch with family. We will be constructing our devices, so members will need to bring a soldering iron. The kits will be provided free of charge to members. If you didn’t attend the first session, please contact one of the committee to confirm you are coming to be sure we have sufficient kits available.