Hi this is Frank, I was wondering if there was a big difference between the Chameleon F-Loop 2.0 / 3.0 and the AL-705 magnetic loop antennas.

Timeline
00:56 WSPR Setup
01:23 WSPR Results
02:38 RX Bandwidth comparison
03:37 Results comments
04:22 Which is better?
04:59 Inside F-Loop 2.0
05:37 Inside AL-705
05:56 AL-705 custom reduction gear
06:25 Indoors RX comparison

Chameleon has released a new F-Loop 3.0 which has similar specifications as 2.0 but in a smaller package. In this video we will:
-Compare the F-Loop 2.0 and the AL-705 using WSPR on 20M,
-Compare the receive bandwidth,
-Look at the tuning capacitors / how they are connected,
-And a quick comparison of using a Magnetic Loop indoors vs a Fan Dipole
-So sit back and enjoy the comparisons!

For the WSPR tests, both antennas are connected to an antenna switch then to an IC-705 which is set at 500mW on the 20M band. You will see a dozen comparison maps over the span of 2 days. This is by no means a professional comparison of the 2 antennas performance but is simply for curiosity!

Overall both antennas performed well and initially I was expecting the F-Loop to out-perform the AL-705, but these results showed that the AL-705 is very much capable.
While the AL-705’s SWR was around 1.2:1 it sometimes went over 2:1 and also seemed to fluctuate with direct sunlight, so I had to re-tune it 4 or 5 times during these tests. Also the AL-705 used to be affected by the wind, as the loop wobbled, it was reflected in the SWR. So that is why I added a PVC pipe to hold the loop straight. As for the Chameleon F-Loop, it remained stable all the time in the same conditions.

So which is better? My personal choice for this comparison is the Chameleon F-Loop, either an older 2.0 or the newer 3.0 because they have similar specifications. The F-Loop provides a wider bandwidth, is easier to tune and did not fluctuate with direct sun light or the wind. At the same time the AL-705 could perform as well on the WSPR tests but it did require occasional re-tuning.

In this F-Loop 2.0, the internal capacitor is a dual gang 10-365 pF. The SO-239 connectors are connected to the outer shield of the Coax. Using the toggle switch in the "B" position, the capacitor gangs are connected in series to achieve an effective capacitance of 5-182 pF with twice the voltage rating of a single gang. The tuning mechanism uses a 6:1 planetary reduction drive and is very pleasing to operate.

In this AL-705, the internal capacitor is a 10-313pF, the SO-239 connectors are connected to the center pin. Tuning with a 1:1 ratio can be very difficult at times, that is why we added a custom 6:1 reduction gear and 3D printed the related parts. While you may tempted to ask me questions about this setup, it was a long process of measuring, 3D printing, multiple times until everything fits together. So the only information I can really give you are these videos and pictures to inspire your own customization.

Operating a Magnetic Loop indoors, in a house or apartment may sound convenient, but the main issues I have found are reduced signal strengths and local noise…Video… Surprisingly, sometimes the loop could perform as well on reception as my dipole because I could change the orientation of the Loop, but most of the time using a Loop indoors is a compromise. The best performance I had was outside, in a park or at the top of a mountain.

Well this was an interesting series of tests, it took several hours to make this video, if you liked it click the Like button. I would like to see what are your comments and experiences with both antennas? I invite you to leave your comments down below.

Well, that’s it for me for today, thanks for watching, 73!

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