Magnetic loop: 'real' QSOs at the beach.

A couple of weeks ago, when it was much warmer, I took my car-portable magnetic loop down to the north coast of Anglesey for some WSPR tests.

Whilst I've done plenty of testing of magloops from home as well - showing extremely good results in comparison to full-sized wire antennas - there are always naysayers who claim that WSPR is, somehow, not a meaningful test of an antenna.

This claim is, of course, ignorant nonsense.  It is a plain refusal to accept objective evidence.  If my magnetic loop is better or equal to a full-sized wire antenna using WSPR, then, say the critics, it won't be better for 'real' QSOs, using other modes.

This silly reasoning also ignores the rather important fact that two-way contacts using WSPR mode actually qualify under the LoTW DXCC system.

Well, setting aside those stupid lines of argument, I wanted anyway to see how well my magloop - now kitted-out with a cheap homebrew remote tuning system - performed at the beach.

Cheap, simple remote magloop tuning (needs a longer cable!)

The brief answer is: extremely well!  Despite being too close to the car owing to a short remote control cable, I still managed to get the matching down to 1.3:1, the homebrew control working at a very fine, stable level towards resonance.

Magloop vertical pattern with seawater constants.  +3.1dBi peak gain at very low angles.

I made a contact (at 20W) with JA5QJD at -14dB SNR both ways on FT8.  I then managed to QSO with JA4LKB, giving him-04 and he giving me a less impressive -19dB SNR.

A magloop is definitely not a 'dummy load'!

I managed an EW station, a SV station and a few other European QSOs.  As usual, and with good propagation in effect, the main trouble in operating FT8 is finding a clear spot on the band where others are not transmitting over or very near to you.  This does make antenna performance assessment, especially at lower power, quite tricky.

Unfortunately, the tide was coming in rather quickly mid-morning, so I couldn't spend too much time testing things out further, as the higher one goes up the beach, the closer one gets to where most people park their cars, which magloops don't like much!

My magloop, aiming its vertically-polarised radiation to the NE horizon on a rather dull autumn morning.

The overall experience of operating the magloop, as compared to my vertical mobile stick antenna is that it is at least equal in performance, though I need a much longer period of testing to reach a firm conclusion. 

Certainly, looking out of the car window at a small copper tube loop making a connection between Wales and Japan at 9500km is a remarkable feeling!

Of course, for car-based operating, one might say a wind-resistant stick on top of the car, with no trailing cables to trip-up passing walkers, and no need to tune the antenna up or stop the whole antenna blowing over, is a much more convenient, rapid set-up proposition.  I would have to agree, whilst also noting that the loop, unlike the monoband stick, can be easily retuned anywhere from 7MHz to 14MHz.

But what this test shows is that a magloop is a very effective, efficient multiband antenna that, for those with little space but a reasonably good physical environment, offers a practical, ground-independent option.

Oh, and note that I never - ever - use a 'Faraday' (primary) loop feed system.  This is because that feed mechanism is not very mechanically (and thus electrically) stable, and usually much harder to achieve a good match.  Instead, I use a 4:1 balun, one side connected to the lower centre tube, and the other side connected to an insulated wire running parallel with and close to one side of the loop, where the wire is soldered about 2/3 the way up a vertical side.  If you make the last image full-size, it's easy to see the detail.  I consistently achieve 1.05:1 SWR or better with my loop if it's not too close to a car!