Comparing 20m dipole and magnetic loop

Did an interesting test today to compare the performance of my 20m multiband dipole and my MFJ magnetic loop. Both are in the attic of my very small detached house, the dipole is in the apex at a height of about 8m above ground.

With the help of Pat, F6IRF, I put WSPR into a 100% transmit cycle, and switched between the two antennas during the pause between each two-minute period. (That simply involved pushing the ANT button on the front of the K3, so it was not too hard!)

Conditions seemed to be changing quite rapidly at the time so it is difficult to be completely certain of the results, but it seemed as if Pat was receiving me about 3dB better on the magnetic loop. About half way through IV3NBD came on and provided some more reports. The dipole seemed to give about 3dB better results into Italy than the loop.

This pretty much confirms what I thought, that the loop and the dipole are pretty close. Sometimes one seems better, sometimes another. It depends on the signal, so one signal may be down on one antenna while another can be up. The advantage can even vary on the same station, from one minute to the next. It would be interesting to try diversity reception, should I ever get the second receiver option for the K3.

I suspect that the difference may have to do with polarization. The magnetic loop mounted vertically is reputedly favoring vertical polarization while the dipole is horizontal, of course.

It would be interesting one day to repeat the test with some DX stations from across the Atlantic. I remain convinced that for anyone in a restricted antenna situation, the magnetic loop just cannot be beat.