With continuing warm and fairly dry weather, attention has turned, once more, to magnetic loop work at Copper Mountain HQ!
This time, the focus is on simple portable deployment, with a loop that (just) fits in the back of the car and will go down to at least 30m, and a timber stand that gives reasonable height whilst still being fairly simple to build and light to carry around.
I'll post details on the build later. For now, I'm starting to think about a more permanent magnetic loop for the /P station location, which will require remote tuning.
I recently bought, for £11, a 6:1 planetary (manual) drive to test on a butterfly capacitor. Despite the fairly low degree of drive reduction, I was surprised at how very much easier it is to tune a magloop with this than without it. With the aid of an antenna analyser, or simply a SWR meter, one can make controlled, accurate approaches to the perfect matching 'dip' without overrunning, as is almost inevitable with a 1:1 drive.
All the same, the 6:1 remains too fast a ratio. For much finer control, this seems a good place to start. I'm quite excited to find a simple 12V, 5300:1 unit for just £23, and will let you know how I get on with it in due course.
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