Trouble with a Magnetic Loop Antenna

[@Chameleon_Antenna]

Previous owner probably dropped the tuning box on the knob which is directly connected to capacitor.

[@OutdoorsOnTheAir]

Thank you! I was hoping you might see this and give me your thoughts. 73 from VE3TWM.

[@Chameleon_Antenna]

@@OutdoorsOnTheAir don’t be shy to email us! 👍

[@opsprey3]

There is at least as much to learn from an unsuccessful trial or test as a successful one. You just have to put the time in on the back end whether it's mag-loops or moon rockets. I really enjoy your videos and always find something worth learning.

[@OutdoorsOnTheAir]

Thank you for the feedback!

[@Steven_VE9SY]

I've had mine for about 10 years. Never had an issue. But then again I bought it new and it has never seen more than 5 watts go through it. I've looked at the compensator, and that should get you 60.. Only issue I've had with the steel loop, was that the connections where not tight enough. Could be whom ever had it previously figures that with the compensator if it can handle 60 heck it should handle 100! Had a friend that bought one after seeing mine and liked it. But he hated tuning it so he added an auto tuner to it and would run 100 watts into it. Then one day he noticed that the plastic was melting. Took it apart and it was scorched. Were talking apocalyptic scorched. Said they here a piece of just. Then Told me how he set it up. Mine still works great. Love the Champollion. Would still like to try a few others on the market. as it isn't the easiest on to take portable in the woods due to the weight!

[@Chameleon_Antenna]

Very simple - if you've issue with a second hand LOOP antenna - the capacitors is damaged because tune the metal loop or the LMR-400 coax loop is very easy!

[@KD9ZHF]

I have the same issue with mine.

[@MI7DJT]

I love my 2E0ERO 6 band Magloop. They're amazing for a tiny antenna.

[@ben2e0omr]

I don't, I sold mine....

[@MI7DJT]

@@ben2e0omr They take a little getting used to but once you get the hang of them, it's a pleasure to use. I live low down in a valley and can easily hit the USA and Russia with it indoors with 20W from the UK.

[@OutdoorsOnTheAir]

I'll have to look that one up, thank you for letting me know about it.

[@MI7DJT]

@ Any time pal. They are fascinating antennas.

[@ky4rod]

Tracy - I have the F-Loop 3.0 and it works flawlessly with my IC-705. I was surprised by how well it worked with my QRP setup. It appears that your have the older F-loop 2.0 model by the images in your video. I cannot speak to the version 2.0 F-Loop since mine is a 3.0 and there are I am sure there are some differences between them. In the instructions for my 3.0 F-Loop it states to use the 7" coupling loop (and not the larger 8" loop) with the rigid aluminum radiator loop and to leave a 1/4" gap between the 2 loops. It appears in the video that you are using the correct smaller 7" loop, however in the video I cannot see if there is a gap between them. With using the coaxial loop, the coupling loop is insulated from the radiating loop by the coax jacket and the gap probably isn't as critical. I am wondering if the 2 aluminum loops were touching your case and this was causing incorrect coupling, maybe thats why it didn't tune up with any dips on the rigid loop but you did have dips on the coaxial loop... just a thought to consider maybe? I love your videos, hope you figure the issue out and its not an issue with the variable capacitor being damaged where you have to send it in for repair. Good luck, hope you figure it out! 73, Rod - KY4ROD

[@DPTrainor1]

Thank You

[@barrykery1175]

What a shame. I made two magnetic loops. One was 3-1/4 feet in diameter and the other was 4 foot in diameter. Both worked from 17 meters to 40 meters. Yes, they have a very high Q. But both of mine worked great. Now I'm not talking a DX pileup buster, but I was able to work a lot of stations. Barry, KU3X

[@stephensussman-fort5786]

If you achieved resonance with the 2-turn coaxial loop on 40M, but not with the single-turn aluminum loop, it is because the aluminum loop has insufficient inductance to resonate with the capacitor on 40M, even with the capacitor set to maximum. Open up the box and look at the capacitor to check for any blades being bent or missing. It would be interesting to know the lowest frequency you could achieve resonance with the solid loop. Also, upon opening the box, check the connections from the where the solid loop is attached to the capacitor terminals. Good luck. 73, Steve, AB2EW

[@alzeNL]

brilliant video as ever ! I'm thoroughly spoiled with the alexloop hampack, my word, that makes getting out, getting on the air, so easy - i now feel guiltry i've not been out since Ocotober 2024... I WILL CORRECT THIS ! a brilliant inspiration as ever :D

[@OutdoorsOnTheAir]

Thank you...now hurry along and get outside 😀

[@johnk8091]

It's certainly not the aluminium loop - that is a solid conductor, no breaks in it, except for the join at the top. There is very little that can go wrong with the loop. My guess is the jumper connection point inside the box where the loop makes contact with the capacitor. I bet there is a dry joint on the connection, and the weight of the aluminium loop puts pressure on that dry joint allowing it to lose connection to the capacitor. Open up the box, I'm sure you will find the issue

[@OutdoorsOnTheAir]

This is the best guess I've come across, thank you very much.

[@menajemh]

@@OutdoorsOnTheAir i have that loop and that is the first thing i thought also, i'm sure will be an easy fix. don't overpower it or will arch. also keep good distance from the loop when tx. it's high impedance and radiating right next to you.

[@abdulal-hodl8861]

Now you have to do a vid where you crack that open

[@Philip-KA4KOE]

Use a VOM. check for shorts while rotating the cap.

[@nr3rful]

If it is the capacitor, the coax loop would not work either ???

[@OutdoorsOnTheAir]

True, unless the issue is intermittent.

[@WECB640]

Looks to me like that aluminum loop simply does not have enough INDUCTANCE to resonate with the capacitor in the box. When you exchanged the single turn aluminum loop for a TWO TURN coax loop, you gained 4 times the inductance (the square of the number of turns) and also added a bit lossy resistance (coax braid). Together, these allowed the variable capacitor to resonate the "tank circuit" (loop and capacitor in parallel). In any case, despite achieving a low SWR, the loop will only give a very small efficiency at that band due to the loop size. It may be only 2-5% of the power going in that's actually being radiated. You'll still make contacts. That's been my experience. 73 OM

[@Chameleon_Antenna]

Magnetic loop use ZERO inductance because it's 100% capacitance tuning!

[@WECB640]

@@Chameleon_Antenna I respectfully disagree. Any conductor has inductance. Without inductance in the loop, the variable capacitor would have nothing to make resonant. The magnetic antenna is an LC tank circuit. 73

[@Chameleon_Antenna]

@@WECB640 it’s marginal compared to the actual capacitor itself. We know because we made 12K+ of those.