Wednesday, July 08, 2009

QDFA Project Underway



The Quad Delta Flag Array (QDFA) which was tested with great success in Grayland, WA is going to be tested in Kongsfjord too this autumn. Supports are being bought and built, and 10 (!) 5-metre fishing rods were bought at a Finnish travel fair a few weeks ago. And the "Central Processing Unit", the phaser, arrived from the US today, thanks Dallas. Two 17Ah batteries are on their way, to power the 30mA Norton push-pull preamp (see photo). And lots of other stuff needs to be purchased, not least proper weather insulation. The Arctic winter only meters on shore is a hostile environment. Needless to say we are very excited as to how well this new antenna design will perform here.

The air photo shows the layout of the QDFA as a red line. My cabin is on the right.

July 11 Update! A high-res picture of the phasing box is here.

4 comments:

TK said...

Hi Bjarne!
All MW-DXers in Scandinavia are waiting for the results of the tests! Next MWDX season will begin sooner we can expect ...
73 Tarmo

Guy Atkins said...

Best wishes for success with the Grayland QDFA, Bjarne. The QDFA units I'm building for Walt Salmaniw and myself are just in the first stages. I am doing the tedious winding of the torroids soon.

What kind of wire will you be using for the delta loop elements? I am using 20 ga. Teflon insulated, silver plated copper stranded wire. Hopefully it is sturdy enough. You are probably using something heavier for the arctic conditions!

73, Guy

Bjarne Mjelde said...

16 awg pvc-insulated, silver plated copper stranded wire is my first choice. Lightweight and relatively sturdy. I'm less concerned with the wire than with the supports...

esn said...

It would be nice if you could post a more high resolution (the more the better... ;-)) image of the phaser so I can take a look more in detail how it´s constructed.

Thanks/Eric