Branch 50 (Wellington) NZART – Known as the Wellington Amateur Radio Club
Our final shed workshop session for the year was held on Sunday 5 December from 1pm – 3pm at John ZL2JPM’s QTH at 9 Ramphal Terrace in Khandallah.
John ZL2JPM talked in more detail about his portable microprocessor controlled QRP mag loop antenna that he briefly introduced to us at the October meeting. John won the annual Blackwood Cup for 2021 based on this entry.
Our monthly shed meeting was held at Mike ZL1AXG’s QTH in Churton Park on Sunday 7 November. Two topics were covered:
Bernard ZL2BD gave an update on experiments with receive only magnetic loop antennas including the differences between tuned and untuned loops (See the attached paper) and Mike ZL1AXG talked about his recently acquired MLA30+ Rx loop that can be used in conjunction with the portable Tecsun PL-330 receiver.
Mike ZL1AXG also gave his third talk on the Simple SSB TXCVR. The talk covered construction and testing of band pass filters and low pass filters (See attached powerpoint presentation for more details).
How do you know whether a band is open?
There are a number of different ways to know if there is propagation on an HF band. Listening for stations on a band is not necessarily the best way to determine whether there is a band opening. If everybody is listening, and nobody is calling then the band will still seem to be dead.
John ZL2XJ and Mike ZL1AXG demonstrated the use of beacons, DX clusters, the reverse beacon network, WSPR that can all help in determining the likelihood of a band being open.
The QTH for the Shed Workshop held on 1 August 2021 was that of John ZL2XJ at 9 Ridley Green, Churton Park.
Our July shed workshop was held on 4 July 2021 from 1pm to 3pm at the QTH of Mike ZL1AXG (2 Derry Hill, Churton Park, Wellington).
Mike ZL1AXG is building Charlie Morris ZL2CTM’s Simple SSB Transceiver. This is a modular design and as each module is completed it is tested. In this second session Mike discussed design and construction features and demonstrated the testing of completed modules. The module in the picture is one of two double balanced mixers constructed from scratch on veroboard (Photo from Charlie ZL2CTM)
Bernard ZL2BD also presented on high current Switched Mode Power Supplies suitable for driving Kilowatt amplifiers. He designed a system using two SMPS at 24 v to power a 2Kw linear for another amateur. The SMPS turned out to be very quiet electrically and they are available in 12v and 13.8v and other voltages as well ex China at very reasonable prices.
Tea and coffee were available following the workshop.
