This year there were three entries in the Blackwood Cup contested at the October meeting ( Wednesday 17 October) at the Lutheran Church Hall, King St, Mt Cook, Wellington.
Bernard ZL2BD showed off a couple of SWR meters. One of these covered both HF (using a standard pair of toroids in a bridge circuit) and VHF/UHF (using a stripline circuit). Bernard separates the sensor components from the metering components so that the bridge can be located somewhere remotely as required.
Mike ZL1AXG showed off his completed “Hiland” 0-30v 0-2A power supply and talked about a couple of the glitches he uncovered. Occasionally when turning the unit on, the supply will not move off zero volts. This is thought to be a function of the slightly different specs for the op amps, which were substituted. The other fault is in the cheap $2.70 Aliexpress digital volt/ammeter. The ammeter reports double the actual current!
Doug ZL2AOV talked to his uBITx transceiver and an extensive range of modifications, including built in battery, VOX and S-meter.
The Blackwood Cup moves on from Mike ZL1AXG’s shack to Doug ZL2AOV’s shack, as he was declared the winner by Malcolm ZL2UDF.
Over the summer we are having informal shed workshops. No set topic, but all are welcome to come along, preferably (but optionally) with your soldering iron and a project to work on. That might be a uBITx transceiver, a magnetic loop antenna, a power supply, an arduino nano keyer project, or whatever takes your fancy. There are eight magnetic loops under construction for a start!
#1 in the summer series kicked off at Bernard’s QTH, 1 Winsley Terrace, Churton Park, from 1pm – 3pm, on Sunday 7 October 2018. Eight turned up, with George ZL2AG and Don ZL2BD talking about their regenerative and super-regenerative receivers.
At the last “formal” workshop for the year on 9 September 2018, held at ZL2XJ’s QTH, we were given tips on the construction of power supplies by three members (Don ZL2BL, Bernard ZL2BD, and George ZL2AG). This included:
a foolproof (but weighty) bench power supply for valve circuits (short circuits no problem) using readily available transformers and valves (Don ZL2BL)
two different kits for variable voltage bench power supplies, acquisition of low cost 13.8v switched mode power supplies, and tips on how to quieten down RF noise from these power supplies (Bernard ZL2BD)
low cost 13.8v transformer-based power supplies built into older desktop computer cases (George ZL2AG).
Over the summer we will have informal workshops, where you are welcome to “bring along the soldering iron” to work on projects, whether that be a uBITx transceiver, a magnetic loop antenna, or a power supply or whathaveyou.
Power Supply Shed Workshop Notes September 2018 103.87 KB