Chameleon F-Loop 2.0 / 3.0 vs AL-705 on WSPR with IC-705 Comparison
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- Опубликовано: 22 май 2022
- 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! 
Развлечения
Nice video, Frank. The wider bandwidth, easier tuning and rugged construction makes the F-Loop the winner in my book. 73
Hi John, I agree, the F-Loop is a quality product. Thanks 73
Great comparison video! Thx for all the hard work
Hi AJ, It was very interesting, thanks for the comment! 73
Nicely done! 73, Dave, KEØOG
Thank you Dave for the comment and also for providing excellent videos on your channel.73
Fantastic video. Thank you very much for all the explanations.
Great JJ, glad you liked it!
Great info Frank.. I've been curious about these loop antennas.. your demo does a great job of comparison.. Thanks for sharing.. k0klb
Thanks Kevin, I have learned a lot about these antennas with these tests, glad you liked it, All the best! 73 👍
Well done Frank !
Hey Thanks Gilles!
tnx for all.👌
Great video,thanks,you help us so much
Glad to help, thanks for the comment, 73!
Thank you, it was a pretty good analysis , I enjoyed it to the last second. I'd like to see those two loops compared to Pavol Timkovic MC-20 Loop antenna !!
Hi Andrea, I am pretty sure the MC-20 Loop antenna is very good, thanks for enjoying and the comment! 73!
Excellent video and thank for showing the inside of both models! Do you know if Chameleon is using the same variable capacitor int he F-Loop 3.0? And do you have any info on the switch they use? Couldn't quite make out the part number on the side from your video.
Hi ben_r_ I have no idea about the loops using the exact same Capacitors, based on tuning with both I would says it is pretty close/similar. I believe the switches are standard electric ones, both models use a different type but basically it is a switch with no particular attribute. I believe Chameleon downsized the 2.0 to a smaller form factor (3.0) with the same specifications, either one are great. I have used the 2.0 and now own the 3.0. Thanks for the questions!
I am trying to build a Magloop here as importing them from US / Europe is like paying through my nose.... hence your video will surely help me in my steps towards building a antenna like Chameleon but at half the cost probably!
Yea, they are expensive, but they are good and proven. Building your own requires a lot of research and understanding, may be trials and errors. I have build many loops based on a commercial Capacitor. Loops are fun and surprising! Good luck! 73!
@@VE2FGJ Thank you for your encouraging words. :-) Everyone has to start somewhere... Chameleon also did so let me start and see where it goes! 🙂
👍👍✌️
Can you mention what the Alex tune does for the Chameleon FLoop. I have the same 2.0 and now that Chameleon has their remote tuner for sale, I may start using it again.
Hi, the Alex Tune allows to tune by seeing the led glow, reach peak brightness. The illumination range changes from band to band. It serves as a visual cue. It works on many loops,
nice viiseo what tuning led are you using I saw the alextune but the other one??? 73 qro HB9GUR
The other one is a custom made RF sensing circuit with a LED in a 3D printed box attached to a paper clip. I did not make it, got it from a friend. Thanks for the question! 73
Now that I live in a city environment, I have been using a Moonraker WhizLoop for the high bands with great success. A magnetic loop is a good compromise...it's never going to be as good as a beam or a vertical, but many QSOs are possible
For 20M and above, Loops can be sometimes as good as a Dipole on reception, plus able to rotate but for TX efficiency it is more limited. They perform better on narrow signals (CW, Digital...). It is a great compromise antenna but it does not appeal to everyone. It as its purpose.
I use the al-705 indoors with my ic-705. Rfi is a concern. I have ferrite rings on the antenna coax and on the usb cable. However with transmit power above 5w wsjt-x can throw an error about interface 'crash'.
I was able to TX 10W digital on the AL-705 indoors, ensure SWR is below 1.5, may be try different locations.
Move the rig further away from the antenna. That should help.
These small loops are a real compromise. I found an end wire in a tree or laying on a bush far more effective and faster to tune. Plus super cheap. 73 WA6MOW
Yes indeed, at the same time, each antenna type have their own advantages. Thanks for the comment! 73
That sounds nice, but I'm going to be stuck in a hotel 250 days out of the year. In that situation it seems easier to not have an end wire? Let me know if I'm wrong :)
73 Frank de Gérard F5MOX QRP PARIS FRANCE.
Salutation Gérard! Bons contacts sur les ondes! 73 Frank
I think the best realistic test would be SSB voice..............................................................
SSB would be difficult to compare, subjective. Retrospectively I think WSPR with DB signals would be best, then complete with SSB.
For $20 or less anyone can build better loops using surplus parts. Any loop the same size with a larger diameter conductor (meaning a higher Q,) is BETTER. A wider bandwidth is NOT better. That's the sign of a lower Q, which implies lower transmit efficiency and more receive noise. A wider bandwidth mag loop is only 'better' in the sense that it is more convenient. It requires less tuning. Again, it is NOT better in performance. It's worse. The higher the Q, the narrower the bandwidth, the better the performance on both transmit and receive. Such loops are just less convenient to use.
Loops are very forgiving when homemade, since they are tunable. They are almost as easy to build as wire antennas. One thing some folks forget is that they are directional, so should be built with ease of rotation in mind, because they can be turned for a stronger transmitted signal along a line edge to edge of the loop, or they can be turned for the lowest local noise on receive. Also, leaning the loop can further reduce local noise. So control of those variables makes a loop much more useful, again, less convenient, but more useful.
@John West Building a Loop, there are alternatives for sure. I think the bandwidth difference may be linked to the loop size (AL-705=3ft vs F-Loop=4ft) the 4ft may bring in more signal. Since this video I made tests with a 5ft loop and the bandwidth is even wider. I may in the future build a loop with a sealed capacitor and be able to output 100W. More projects!
@@VE2FGJ I had good fun with a MFJ-935C, I made up a loop with 13 feet of copper pipe and make contact from Ireland to Canada on 20m with 20 watts, the video is on my youtube channel if you want to take a look.
I used a smaller loop around 7 feet and made contacts around Europe in 20m.
The loop was on a table outside around 3 feet off the ground I was amazed, no vertical with loads of radials.
I really must use it more as I haven't really used it outside since because this Summer has not been nice.
The MFJ-935C can take 100 Watts too without Issue, it's a lot of fun to experiment with.
@@o00scorpion00o Yes Mag Loops can be fun, I am still amazed of how it works, and have fun with new loop contacts! 73