All change!

The figure of eight loop, as earlier reported, has done very well in WSPR performance, and showed itself able to tolerate strong winds up to, so far, about 110km/h.  Tuning is stable in all weather - a satisfying vindication of my simple, very cheap approach to remote tuning).

Having gathered about a month's worth of data with the 10mm pipe, figure-of-eight loop (total tube perimeter of 3.67m), I decided I might as well see how a single loop of 15mm tube, 3.9m total perimeter (1m per side, minus 10cm gap where the cap sits) compares from exactly the same location and height (noting the single loop base is the same height, but its top is only half as high as the top of the 'meight' loop).

Single loop test.

In fact, I had stopped running the 'meight' loop a day or so previously.  I had been running my vertical delta loop at 1W from the rig overnight (shaded period in the graph below).  At 08:06UT, I switched over to the single magnetic loop running 200mW.  The outcome is surprsing:

Of course, my delta loop might well have seen its spots graph increase after this period; it usually slightly outperforms GI8YJV most of the daytime.  But that doesn't really matter, because the magloop running 200mW is certainly reaching as far as the delta running 1W, and doing as well at this moment as the full trapped wire dipole at GI8YJV, who is one of or often the best WSPR performer on 14MHz from the UK.

At the time of writing, as it's possible to see on the extreme right, the magloop has started - and has so far maintained - a significant distance advantage over the wire dipole.

I will now continue to run the magloop for at least several days, to see how it compares to that figure-of-eight loop, which is of almost identical perimeter (though, again, the single loop is of 15mm, not 10mm pipe as in the case of the 'meight').

Other than that, this Sunday, it's time to go flying (using VHF AM radio). 

Image: Wiki Commons.