11 Feb 2016 – Construction Contest Winners Talk

The 10 to 2 Antenna Switch
The Major Project winner, the 10 to 2 Antenna Switch

As the winner of both the Weekend Special and the Major Project sections of the contest, Don, G4LOO spoke about his projects.

The Weekend Special was a self imposed challenge to build a high Amperage power supply for under £50. Don provided a cost breakdown which included numerous items purchased on the internet. The main power was supplied by the Dell Poweredge,
Server supplies. While many are listed on the popular auction site, the cost of shipping can be a deal breaker! Two were found that met the criteria and were incorporated into the twin 12v, 2x 47A supply. Don explained how a voltage nearer to 13.8v was obtained and
how over voltage and power was controlled and monitored.

The idea for the Major Project came during Don’s visit to Friedrichshafen where he saw a PCB for build a switching control for six antenna inputs to two rigs. Don build this unit but then decided he would like ten inputs to two rigs and set about designing one. After producing his own PCB, Don used 36 relays to control the ten inputs and also the inputs from his Four Square antenna. Measurements show the connection isolation to be equal to or better then commercially manufactured units.

Victor, who won the Kit Competition, was unable to attend on the evening and will present his story of building  the ‘PIXI’ at a later date.