Next event – Sunday 21 July 2019

The next Branch 50 event will be held at Mike ZL1AXG QTH on Sunday 21 July from 1pm – 3pm. Mike will talk about sunspots – what they are, what the next cycle may hold, and possible impacts on climate.

All Welcome. Afternoon tea/coffee will be available.

There will be no Shed Workshop in July, but Shed WOrkshops will return in early August with everybody getting to construct an Active Antenna. This will be spread across two workshop events. Costs will be covered by the Branch.

Shared lunch @ Mike ZL1AXG QTH

Branch 50 had its annual mid-Winter shared lunch on Sunday 23 June 2019 at Mike ZL1AXG’s QTH (2 Derry Hill, Churton Park, Wellington).

Plates of hot and cold food were shared alongside memories of Ralph ZL2AOH (now regrettably Silent Key as of Friday). There were also tales of the diminutive alternative to the Magnetic Loop, the Poynting Vector Antenna. When it was shared that the antenna was just 3/100 of a wavelength long, there was some disbelief about its properties. However, Bernard ZL2BD and Mike ZL1AXG noted that there seemed to be genuine research about this antenna, and given it is intended to receive magnetic waves (as opposed to electric waves) this may indeed improve reception. Also discussed were the challenges in making conical elements that are quite sizeable (albeit short).

There were also memory prompts from the past from members

  • A device of unknown purpose (Magnetron?, Phaser?)
  • A Creed latching relay (somewhat larger and heavier than you might think)
  • tales of great DX as a schoolboy when visiting the local ham radio operator in Cornwall, and a special QSL card from a Penzance Pirate
  • Two giveaways …
  • A tale of a repair of a Japan Radio Company (JRC) transmitter

Shed Workshop and RemoteDX AGM – 26 May

We held the June Shed Workshop a week earlier than usual on 26 May 2019. The event was held at Bernard ZL2BD’s QTH at 1 Winsley Tce, Churton Park, Wellington. The topic was Class D Audio Amplifiers. These audio amplifiers come very cheaply as modules and are incredibly small and light weight when combined with a switched mode power supply. They can also be scaled for different power outputs by simply changing the supply voltage. They have many good points, but there is a downside from an amateur radio perspective … they can generate a large amount of RF noise!

Bernard gave an excellent overview of the concept, the application and demonstrated the range of commercial modules available. His paper will be available here shortly to read.

The shed workshop was followed by a special afternoon tea at 2.30pm and then the AGM of RemoteDX Inc at 3pm. It was an excellent afternoon, with gorgeous late autumn weather.

Shed Workshop – Vintage Radio #2

At our shed workshop on Sunday 5 May, George ZL2AG opened up his garage and museum to the club to host the second shed workshop on vintage radios. The talk this time was given by Don ZL2BL.

Don first spoke about his restoration of a vintage Eddystone HF receiver. This had been somewhat hacked about by a previous owner, but he has restored it to near the status of the original.

He then talked about a couple of vintage AM radios – one he had restored and one still to be restored. They are illustrated in the photo below

George ZL2AG also had a mystery piece of electronic equipment for us to ponder on. This is clearly something developed for military or government purposes. Our guess is was that it is something like a range finder unit, since it is marked “E”, “N”, and “H” on the three banks of dials. Perhaps “East-West”, “North-South” and “High-Low”?