Month: July 2021

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Shed Workshop 1 August 2021: Four approaches to knowing whether a band is open

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.

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Presentation on four methods to determine whether a band is open

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Quick guide to Beacons and DX clusters with links

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Quick guide to Reverse Beacon and WSPR websites

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18 July 2021 Meeting – Trevor ZL2AKW and the Br 50 Projects Group

Our meeting on 18 July at the Johnsonville Library (Waitohi Hub Makerspace) attracted 10 members.

Trevor ZL2AKW gave a talk on the Projects Group that developed a wide range of projects for ZL amateurs during the 1970’s through to the 1990’s.   He covered “the why, the how, and the outcome”.  Kits discussed included the QT silent tune up kit, the Chelmsford transceiver and tuners. Trevor also brought along some of the completed kits.

The Projects group had some very talented and well qualified contributors.  One in ten active NZ Hams of the era bought at least one kit. The Chelmsford CW transceiver was a popular kit for portable operation.  While some maybe were never completed, none went wrong!

Tea and coffee (courtesy of the club)was available after the meeting in the cafe upstairs.

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Shed Workshop 4 July – High Current Switch Mode PS and Mixers in the Simple TXCVR

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.