HAM RADIO: Building a Coaxial Magnetic Loop Antenna. COAX MAGLOOP: Double Loop: 

Another great and very interesting video Mike, Thank You! 73

You Sir are the David Attenborough of ham radio! ha! Love the videos - keep up the good work homebrewing antennas!

Nice one Mike... I have been looking for something to be used in my apartment and mag loops seems like the only solution... nice bit of work there and looking forward to an update. 73's

I have a few meters of some 7/8 in Andrews in the rafter of my garage. I may try this as well. Thanks for the inspiration.

Great work Mr Mike.

Great job mike,I used micro boar copper for my loop and you are right the variable caps are bloody expensive now

Nice build and video as always Mike 👍👏👏

Thanks Mike 👍🇬🇧❤️

Nice Work Bless Up Fella

Mike, you make it look so simple. I just might try this one.

Another nice loop Mike. Very informative on build methods 👍🏻 Maybe nylon chopping board spacers for those without printers.

Ciekawa, interesująca seria filmów. Pozdrowienia z Polski

Top work.

Brilliant

Greetings from Belgium 73 Albert. Vidéo very nice thanks. 👍👍

That’s big $ coax amazing !!

Hi Mike, well done! It‘s another great video and it looks so simple! vy 73 de DK7- -

Very well Mike, at next time on the air (F1PBT)

Great job! 73

Mike: I built a 2-turn magnetic loop from CATV RG-11 here. My cap for 10 watts is a dual receiver 365/365 pf cap with the sections series connected. The loop covers 80/60/40 meters and is rectangular to fit in the family car for portable outings. It's102cm x 90 cm and the loop conductors are separated by 7 cm center to center. A fun project loosely based on your RU-vid videos! Lots of fun, and looking forward to some air time... de WB2VUO

Mike, great looking antenna did you have a plan you were working from laying out the loop sizes and wiring layout. I am thinking of creating one to try in the attic. I would want to set one up for 80m-10m and maybe another for 2m & 70cm running barefoot out of a Yaesu Ft 991a (100w or less) I would be looking to do remote tuning as it would be in the attic and the shack is in the basement

Bravo tres belle réalisation 73's

Nice work as usual Mike! I'll be watching this build with particular interest as I've been considering a magloop build myself for some time and that large heliax seems the best stuff by far. I want mine to be able to handle respectable input power, Have you considered using a vacuum capacitor? Expensive but very reliable or an air spaced cap but immersed in oil again capable of greater power handling but also far less susceptible to corrosion for a permanent outdoor install. Keep em coming, Great down to earth proper ham radio vids nicely done! Many thanks. Tom, 73!

Love your videos and they've inspired me to make my own. I noticed the loops spacing get tighter at the bottom, I don't think the 10cm spacing is kept. Was that on purpose or what is the reason? I made my mag loop using PVC pipe step by step by your instructions and I can get it to tune on 40/80 but haven't been able to tune to the 20 meter band. I am using a 20/250pf variable.

Saludos y felicitaciones, me podrías indicar cuantos metros de cable usaste para formar las dos circunferencias y en que frecuencia resuena mejor. Un abrazo desde Lima, Muchas Gracias ,

Ray at the Radio Workshop in Worthing might have a capacitor.

Be interested to see you make a variable capacitor. I wondered if you could make the plates via designing pcb’s. Dual layer, heavier copper with plenty of vias.

Nice job. However i’d have been hung drawn and quartered had I attempted that in the kitchen. I have some Andrew’s Ldf4-50 in the garage. Can only cry the amount of those capacitors i threw away many years ago 😢

All antenna building takes place in the kitchen 😂

The colloquial term we use for that type of coax in the US is 'hardline'. Primarily for repeater installations and so forth.

très bien et un travaille très propre merci pour tous 73 q r o

Can you tell me what kind of coaxial cable you used here? I’d like to take a stab at making one of these antennas. Thanks!

I made a Magnetic Loop out of 6 feet of RG8. Worked well 15 through 40 meters. KG7IRJ Ohio Extra

wow that looks like real heavy duty coax nice work mike looking forward to see how it tunes with a capacitor. pete G0LVG

Are you soldering with silver or tin-lead? 6:36 Tin-lead is bad idea when you will TX with more than 10w

Hi Mike. Did you find a variable air capacitor.

so that the 2 terminals of the loop are not connected, but prepared for the variable capacitor ?.

Great video . I am studying for my Foundation and one of my post licence projects will be to make one of these. I wonder how long before the Chinese start knocking these out in volume and low cost though ?

may I please have the SLT for the printed spacers?

Besides the flexibility, wx proof coating, and just cool factor, does using coax for the big loop add any other benefits? Does the center conductor help it be more wide banded? There is a fridge on the curb, and the copper is still there, would like to mimic this, but no broadcast or cell tower scrap around here.

awesome build, any plans to share the printed part designs?

Mike. I have to ask. Why do they use coax for the main loop? Would small-bore copper tubing or 4 gauge power cable do the same?

For attaching a terminal to the outer of the coax, Could do with a more powerful soldering iron .. de John G4XJC

Hello Mike, I did Bild the large loop. That one does his work great. But, now I want to bild this one, but before I cut the Andrew wire, what frequency's work this small loop. Grtz Gerrit.

You said without a cap it was resonant at 15mhz. How did jt receive on other bands?

I can get a similar cable. All I need now is a transceiver and 3D printer :-)

While I applaud all efforts to learn by experimentation, my "gut feeling" is that any multi-turn magnetic loop antenna is likely to be retrograde by comparison with the conventional single-turn. It appears that the single-turn loop is *more* than just an inductor. In effect it is a centre-fed half-wave dipole where the ends of the dipole have been pulled round to form a circle. And the ends of this "half-wave dipole" are connected together with a variable capacitor. So the entire loop radiates into free space. There is high voltage (across the variable capacitor), and a high current (near the feed point). It may not look like a half-wave dipole, but it works very much the same way. (However, unlike a half-wave dipole the circumference of the loop is *not* determined or constrained by the transmitted wavelength). The important consideration is that there is a *voltage standing wave* around the loop, where maximum voltage is across the variable capacitor. But this "pure" arrangement is severely upset if the loop is multi-turn.

when you transmit I would love to see a ft8 pskreport of it and your copper tube version

Really interesting and well made video as always. At some point it would be good to hear the pros and cons of trombone, air variable and vacuum capacitors in your practical experience.

This looks like a useful antenna where can I get the plans for it ?

Hello ... Interesting design of the antenna ... I have a question ... What type of coaxial cable is used on the main loop. What is the capacity of the variable capacitor. I do not understand English very well. Witam... Ciekawa konstrukcja anteny... Mam pytanie... Jaki typ, rodzaj kabela koncentrycznego jest zastosowany do wykonania głównej pętli. Jaka jest pojemność zmiennego kondensatora. Nie rozumiem zbyt dobrze angielskiego. Pozdrawiam

Us aliens like soldering

5:00 soldering core with the shield together on both ends will give you less resistance. Have you tried to use flux? Try to find "no clean" one. Works better than resin cores inside the solder.

Yes....i'm the 450 thumbs up heheheh nice video and very informative..thanks and keep them rolling love the magnet loop for SWL.....have a good life

Be interesting to see you show us how to build an 8 band mag loop like the one sold by 2E0ERO. I would love one of his 8 band magloops but the capacitance switch being at the loop is no good and the price is far to high.

Fancy. What did u use for plastic spacers? What was your fill %? Just curious. Haven’t used my printer in a while. I use Fusion 360. Great antenna project. Would like to see this antenna with a capacitor. Are you planning on using a vacuum variable?

Have you got the stl files. And would 213 fit the holes OK do you think. I would love to build one and have a 3d printer and some 213 lying around.

i don't undestand some mesures , if the coupling loop 32 Cm diametre= 100Cm , it's a half wave ? so it's (32 * π) /2 and main loop is 94 *2π (lenght of coax ) .

Shouldn’t the exciter loop be positioned at the center point of the two loops (the bottom, in this case)?

What kind of capacitor you used? I can't see in this video. Thanks.

Mike, have you go this lovely bit of kit to tune on 80? If so, did it work well? I'm keen to build one, but specifically for 80, since it's an utter pig to fit in an 80 long wire here. Hoping you can find the time to reply!!!!

Search on Ebay for 'Eddystone' - you'll find airspace caps there.

Do you have a link to get the STL files? I have some Hardline jumpers here that size. Great stuff! Thanks! 73 K4RJJ

Is there anyway to get the 3D stl files for the printed parts I would like to make one of these antennas!

What diference does having the 2 loops make as oposed to just one?

Dou you have the stl files handy or the dimensions so I can create them?

Hi, is the location of the capacitor critical? Ie, any option/possibility to have it further away from the antenna?

Question : will RG213 coax work as well ? Q2 = solder the connections to the braid ? what to do with the coax core. ? pls some more details as i got plenty of RG213 laying arround. No 3 d printer unfortunatly. 73s from PD0ROH

I only need a three D printer Lol. 73 KQ4CD Paul

Are you single or very brave, soldering over that nice kitchen counter top??? 😎😇

Mike how did you make a dia mtr at 32 cm when you write the coupling loop is 51 cm 🤔

You should have used a little bit of washing up liquid to get the spacers on

Mike, i have a couple of Air spaced capacitors you are welcome to look at / borrow.

Why not electrically shielded feed loop?

I'm not sure how these kitchen activities aren't met with repercussions....

Hey dr op. Is it usable for 80m to 10m band?

Should not the driving loop be 1/5 of the electrical length of the resonant loop, not the diameter?

Forgive my ignorance, but why can you NOT transmit on the Coax Magloop?

LOL! My cheapo MLA30+ can pull in more!

Mike, I built your 5/8 wave "Sirio Gainmaster Type" a few weeks ago and it worked quite well, straight away. Kudos. I know that your video states that your multi-turn loop is 94 cm in diameter. From what I read the Faraday coupling loop is 32 cm in diameter. So, the ratio of coupling loop to main loop (for this particular multi-turn loop) is around 1/3 (34%) ? Keep posting!

No antenna is complete without some cable ties! Mine are made entirely out wire and (mainly) cable ties.

I can't afford a 3D printer :-( Have to chop up the white plastic chopping board and spend the next few nights sleeping in the shed! :-((

Wouldn't the small loop diameter be 1/5 of the large loop diameter?

Hi Mike, I have some LDF2-50

Have you tried to couple the larger loop with a toroid, FT 240-43 or FT140-43 a simple 1:1 would give you a really low SWR.... some people use an ATU on their radio to help out with the matching. A toroidal match or a gamma match really work better than a small coax loop.

Is a double loop better than only one loop?.

Complete novice here. Can we make them for 15 - 50 kHz? If yes what dimensions might work? Thank you.

if two loops are better than one then why not 3 or 4 loops ???

i dont understand how does it get so low swr without variable capacitor.

I think you would have been better making a mechanical joint with the wires you soldered on for the capacitors, then soldered them. Relying on just the solder strength could lead to a future failure

Is that LMR600?

What type of coax is it?

Surely circumference is 294. C=2*pi*R.

Can you share the 3D spacer file ?

So why No set diameter for the magnetic loop antenna. I find it frustrating to communicate with Ham radio Humans. I am aware that the modulated electric field works best at resonance with element length. So what about the magnetic field?? Please provide a straight answer.

It appears you are having some fun and are indeed enjoying yourself with this project. I am pretty sure that you having any sort of fun in the UK would be quite illegal and considered anti-social. I hope that you are not caught.

Hard line?

why wont you share your 3d print files so others can build this project???

Why doesn't anyone show a loop fed with a gamma match?

I recently got the MFJ-935C loop tuner and made a loop for 20M up of 4 meter long 10mm Copper Pipe, not the straightest loop either lol but first contact was on 20m with 20 watts from Ireland to Canada, very impressed and think I'm going to have a lot of fun with this tuner. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-GgHE2hcZzHc.html