Branch 50 (Wellington) NZART – Known as the Wellington Amateur Radio Club
Branch 50 members, were present at the 2019 Maker Faire which took place at Queen’s Wharf in downtown Wellington on 20 October (10am – 4pm) . We participated in the NZART stand, along with members from branches 42 and 63. NZART brought amateur radio to the people. We gave away brochures about the branch, engaged with a wide range of people and talked about our hobby.
Note that there was no regular branch meeting in October, due to the Faire.
Bernard ZL2BD gave a talk on how to safely switch between RX and TX antennas on your rig and demonstrated the circuit (which is probably not suitable for break-in keying). This circuit would allow us to use our active antenna or mag loop antenna on RX and our standard antenna on TX. The MFJ unit above is an alternative approach.
He also demonstrated a simple phasing circuit that works with two RX antennas to reduce noise levels or to peak a signal. Steering of a two antenna array throughout 360 degree is possible. Two active antennas can be used, or in fact, any two antennas spaced less than 1/4 wavelength apart can be steered (on RX) to reduce unwanted noise and maximise forward gain.
The following articles relate to the workshop:
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.
