Hi Paul, Very nice craftmanship again. Version 3 is also very solid build. Hope to hear you on the Bands as soon as the weather is better here in Germany. 73's de Stefan
Hello my friend! Thank you. It's the same construction as 3th ver. just is used bigger main and coupling loop diameter and wider and longer tubing. ;-) I hope to hear you on the air. Maybe QRP to QRP or MLA to MLA :-) Paul
This antenna is great, i work QRP on 20M band from forest in Czech Republic, stations from USA etc. Luxury quiet noise floor and signal quality!!! I recomended it !!!! 73!! OK1TCM.
Hello Richard ;-) Thank you for the nice comment! I am your subscriber and i like your videos. Btw One your video helped me to decide to buy my IC7610 ;-) You are doing good job... 73, Paul
Vďaka! Áno máš pravdu. Aj ja ju používam hlavne na portable do hôr. Väčšinou išlo o ver.3 ale často bol problém s podmienkami na 20M a vyššie tak som myslel že 40M pásmo by sa celkom hodilo. To bol hlavný dôvod prečo som ju trochu obmenil a hlavne zväčšil. No i napriek tomu sa dá stále jednoducho zložiť a prenášať. A hlavne je veľmi ľahká. Váži necelé kilo, bez trojnožky samozrejme :-) Tak 73 a veľa štastia na kopcoch! Paľo OM0ET
Ahoj, pekna antenka, nejake pokusy s prenosnym magloopom som robil v 2015 a 2016, koncepcia priblizne rovnaka ako tvoja, tvrdy koax a PLka, navyse pripinatelny paralelny kondenzator pre 80m a 4 kusy 25mm PVC elektrikarskej rurky. Na prijem je antenka na dovolenku super, odskusane v 9A, na vysielanie na 20m na svoj rozmer tiez vyhovie, ale na 40m to bola s 3m smyckou bieda o 80m ani nehovorim. Na SOTA v 9A som s nou totalne pohorel, 20m zavrete, na 40m jedno QSO, nastastie bol v batohu obycajny dipol a natiahnuty na krikoch 2m nad zemou som bez problemu dal 8 QSO za 10 min. Niekedy tomu dam este sancu, zohnal som ladicak s velkymi medzerami ale malou kapacitou, tak skusim zvacsit rozmer smycky. Tiez ma laka prevedenie PEX-AL a ladenie koaxom vnutri, ale to nie je do batoha :) . Na tvojej verzii by som koax pripajal do budiacej smycky BNC konektorom, je to rychlejsie ako skrutkovat cokoladu ;) Prva verzia mojej portable MLA, rok 2015: photos.app.goo.gl/jUnFHx1iWHcHEkUCA
Ahoj Tono, moja antena chodi celkom slusne aj na 40M ale musia byt samozrejme aj vhodne podmienky. Predsa len ucinnost 1 metroveho loopu na 7MHz musi byt logicky nizsia ako polvlnny 20m dlhy dipol. Problem vsak je ze nie vsade na portejbli su stromy alebo bod kde sa da drot ukotvit. Kazda antena ma svoje vyhody aj nevyhody. Nedavno mi napriklad protistanica z Ruska davala na 40M pasme 57 report ked som vysielal zo zahrady a s 5W. Co sa tyka tvojho loopu tak je otazka ako si ho mal zladeny, ake min.SWR, ako bol zapojeny kondenzator ci ako bol zapojeny hlavny loop. Ci to cele nevytvaralo v obvode tvojej anteny niekde odporove prechody a tym padom dramaticky znizovalo ucinnost celej anteny.
@@OM0ET Ahoj, zladeny bol dobre, na MiniVNA Pro, PSV pod 1:1,5, PLka ku kondiku pripojene 15mm CU paskou, kondik so 4 zberacmi a vytrhanymi plechmi pre vyssie napatie. Na 20m som dostaval o 2 - 3S horsie reporty, ako som na FT-817 pocuval, co je v pohode QRP vs 100W. Ale na 40m to uz fungovalo pri TX slabo. Hral som sa s tym par dni a vznikla aj V2 :). Problem moze byt mala smycka alebo nevhodne sa spravajuci paralelny kondik. MLA som chcel hlavne porovnat z pohladu SOTA aktivacii a toto riesenie som zavrhol, neprinasa to voci 3 pasmovemu trapovanemu dipolu ziadnu vyhodu, vaha, cas pre zlozenie + nasledne nutne ladenie, moznost pouzitia na WWFF s 60W a hlavne nizsia ucinnost. Zatial som dipol vsade natiahol, doma si pozriem foto kde idem vysielat a podla toho beriem 6m ultralight alebo 10m teleskop alebo spagat na strom :). Ale su QTH, kde je MLA vhodna, balkon na dovolenke, zameriavanie rusenia, priestor kde nie je mozne natiahnut drat. V robote mi pribudol VN generator do 4kV AC aj DC, tak viem otestovat aj ladicak, kolko znesie a s MLA sa este planujem pohrat :)
@@om1aeg Napadlo mi ze by si este mohol zapojit kondenzator do split stator modu pre vyssiu ucinnost anteny. Stratis sice mozno 40M pasmo ale vies to dolozit pridavnym paralelnym kondenzatorom, len stale pozor na prechody. Ja vo svojich antenach pouzivam iba split stator zapojenie. Zvysuje to ucinnost anteny, takmer zdvojnasobuje VN odolnost takze nemusim zasahovat do plechov a tiez aj antena nieje tak citliva na priblizenie ruky k ladiacemu gombiku a jednoducho sa naladi na pozadovanu frekvenciu.
Great neat job Paul! I want to make one too, I just need to calculate and find the right cap for at least 60W, as my military rig (Qmac HF90) puts out some 50+W LOL :) I have 15m of coax, so I can be safe enough from the antenna on the exposure point of view ;)
Thank you Chris. Then I recommend to you use the remote controled tuning system. Bluetooth or trough coax. On chinese webshops you can find plenty of wireless solutions how to do that with DC motor ar use Arduino if stepper motor. Good luck! 73 Paul
Paul, Very good video. Your craftsmanship is excellent. Glad you made the loop for the 40-30-20 meter bands. Need to know the PVC diameter please. I really enjoy all your videos. Thanks. 73's KJ4YM Mark.
Thank you! Currently my UltraLight MLA's works from 7MHz up to 28.8MHz so all the 7 SW bands + CB with just one loop antenna. Versatile design too. 73, Paul
Could I ask you a serious question? What is the total lengths (in either inches, or centimeters) of all the loops in this video, if they were all straightened and laid out flat on a floor in a straight line, and measured? For some reason, people can't get the right measurements, by just going only by the diameter of a loop, because no hand -made loop has the same dimension at every point around the loop, once made into a circle. Parts of the loop, will flatten out if hung up, making it wider, and shorter in places around the loop. The straight, flat length of the loop material, is required, before it is even made into a circular loop.
I would like very much to install a 40M loop antenna in my house but I need to know the following: 1. Can you change the capacitor to one that can handle 100 watts? 2. Is it weatherproof enough to mount on the roof of a house? 3. Can your antenna be tuned remotely? Thank you for answering these questions.
Hello! 1. For 100W capacitor you will need different and much bigger enclosure. I don't recommend use 100W in the house. 2. Is rain proof but not fully waterproof. Not for permanent base installation. ( portable antenna ) 3. After some modifications it can be tuned remotly. 73, Paul.
@@OM0ET Thank you for your quick reply. I understand that a larger capacitor will need a larger enclosure. Can you supply or recommend such a capacitor? Also, I have no room inside my house so it will have to go on my deck, but the deck is not waterproof. That is a minor inconvenience. The big problem for me is the capacitor. My old boat anchor radio could be damaged with too small a capacitor. I therefore am looking for one I can build, buy or modify into handling 100 watts. Can your antenna be modified to handle 100 watts? Thank you very much for your help.
@TheBrasilcowboy hello GM it's very simple the length of the major passive circle couldn't more then 2,40 meters the best is 1,80 to 2 meter's and the the active circle is 1/5 of the major. The active circle is connected normally directly to the coaxial cable no more then 2,5 meters length. The capacitor is connected to the major passive circle, when you do this job, connect to the radio put it in AM, sintonize the antenna with capacitor when you listen more qrm and the signal is high you have the antenna sintonized, then with careful sintonize to 1:1:1 of SWR. That's it. 7351.
You just cannot build these antennas with high output for cheap. At higher wattage the main loop produces thousands of volts on the capacitor gap. Thus only good vacuum variable capacitor will make $150 alone. I guess :)
Hi, really enjoyed watching your video, I get frustrated when there is endless waffle & the whole video could have been done in a tenth of the time. I have built my own mag loop using RG213 for the two loops, it receives fine but I can’t make any contacts on it, also a QRP station. Encouraged to keep trying! Ps, you didn’t say how you tuned your loop. I’ve been peaking the Rx signal & trying watching SWR as well. 73, Bill G6ATO
Unless the calculator I used is wrong, this simply isn't true Sure, the inductance rises by around 50%, but both antenna circumferences fall nicely in the range of required capacitance with the variable capacitor used here. Notably, the antenna's efficiency decreases by about 50% with the smaller model. I'd be careful how you throw around the term resonance when talking about small loop antennas, it could mislead someone.
Hi pole, Ashortwave bigger here. You ham experts always stress upon construction of antenatal itself and most of the time you neglect to explain the antena loop end connections. I am always confused about how to make end connections. We have two end of big outer magnetic loop and two two ends of small coupling loop. Now how the connections are made to gang capacitor, how to earth and how to feed the connection to the radio. Can someone explain this please. M Yaqoub Khan Islamabad Pakistan.
Hello Kari, thank you very much for watching! I love MLAs and QRP operations, but some HAMs should have more patience with QRP operators with low signals. Very often happend to me that they won't to make QSO because it's not so comfortable for them to listen noisy signal :-D That's a pity sometimes... But there are also many good operator who when hear QRP so they call for QRP first in front of all other strong stations calling him. 73 and greetings from Slovakia! Paul.
@@OM0ET I agree Paul, but that has not changed much in the 33 years that I have worked QRP. Often I don't tell up front that I am QRP. If the contact lasts more than a couple exchanges I will slip in that I am QRP and wait for their reaction. 72 KB8AMZ
Using a magnetic loop with a small diameter coax loop as qrp is extremely qrp because such an antenna has a low efficiency assuming there is zero added resistance.... with 5 watts in you are looking at less than 1 watt radiating from the antenna.
@@M0GLU hello! what do you mean, by saying "traditional version"? where do i get such information for mag loops, to leave a gap at the upper center of the main loop?
Hi! Nice work, again! In your instruction you said nothing about that the shield of the coax is splitted at the top. Where did you get the information to do so? Greetings from OE!
Thank you. The construction of the main loop doesn't changed from ver.2. It's still splitted in the middle. It's hybrid between traditional shielded design and classic non-shielded deaign. I had the best results by using this type of construction. 😉 73 and thanks for watching! Paul
Very well done Paul and very good English too including calling the Connector Chocolate we also call it Choccy Block here in Liverpool UK short for Chocolate Block. 73 de Steve M0BFM
Lol 😃 thank you very much Steve! I still make many mistakes in english that's because I didn't learn this language at the school. I'm just a self-learner. btw. My brother live near you - in Manchester 😊 And yes we call it "čokoládka" that's the short of small chocolade in our language. All the very best Steve and 73! 😉👍Paul OM0ET
Hi Paul, I love the antenna and as I would like to sometimes use it indoors in my attic (for rx only) it is ideal (my attic door is small, too small for a 1m rigid loop!!). My question is as it will be there for some time I have some concern about the loop losing shape. Is it possible to make a cross frame to preserve the circular aspect? I had an idea to manufacture a rigid cutaway pipe and cable tie the loop in. Anyway thank you for your work and I will be looking to purchase one soon.
Hello! To preserve the circular shape you can use a copper pipe as the main loop ;-) But my H1000 coax hold the shape very good too :) It have 2,5mm solid copper core inside.
Где-то читал, что надо снимать чёрную изоляцию с кабеля петли, потому что она с примесями ферромагнетика. Чистая оплётка меди без изоляции должна работать лучше.
Thank you for this information Evgeny. But still PVC isolation protect the inner copper shield of the oxidation and mechanical stress. Especially if is antenna portable ;) 73 Paul
Ahoj. Vdaka! V pohode je viditelne cele pasmo, akurat v strede je vsetko silnejsie. Na vysielanie je uzka - tak 5-10kHz, to zavisi podla pouziteho pasma. 73, Palo
Awesome video Paul. When I used AA5TB's calc for 7.1 MHZ design frequency and 1m Loop Diameter and 10mm conductor diameter, I get 7.8% Efficiency only. You mentioned here it is 60+ %. Can you clarify please?
Your videos are interesting. Please let us know how you came out with the efficiency figure of 74% on 40 meters. I used the same calculator and got much lower figure.
I see that AA5TB MLA calculator link is no longer available so sorry I can't do the same calculation again. But of course I can't be sure that this calculator was 100% realistic.
Ciao, I have several videos on my channel in reception as you can see ... with my loops self-built I also made several links that I have not filmed only and always in qrp ... I transmit only up to 5 w with my Yaesu 817 . I hope to do some videos in transmission like years ago and film it. You are really good. 73 de Giuseppe.
@@qrpradiolistner7232 Thanks for your reply Giuseppe. I see that you are listener and you have many own videos in your channel. I have also Tecsun receiver no. 600. It's a great receiver and I like it very much. So enjoy this perfect hobby Giuseppe and I hope you will hear me once too sometimes in the future ;-) 73 Paul
Paul, what surprises me is that your tuning capacitor is small compared to other mag loops I've seen. Could the reason for this be purely because your transmit power is low? i have not attempted to build a mag loop because others that have built this antenna indicate that a vacuum tube capacitor is required even for QRP power. 72 KB8AMZ
Hello Terry. Yes this capacitor is small for just couple of hundreds volts. I connected it in to the "Split stator mode" and power increased. Unfortunatly the capacity decreased to half, still OK for my magloops ;-) Split stator mode also dramatically decrease the resistance in the circuit and increase effectivity and Q of this magloop. 73, Paul.
@@OM0ET Thank you for that. I was just wondering because I have a chameleon f loop with compensator and was running 60watts sitting only 6 feet away, after reading the dangers I backed it back to 5watts lol
Unfortunately no. It's all about the size of capacitor. But on 40M band this antenna can handle 40W SSB. I tested it. And also is very dangerous to transmit 100W with Magloop so close to the human body. I plan to the future some 100W version for base installation.
Hello my friend! Thank you for watching my video. I never had a SSB QSO with China. It's very exotic country for me personally. I hope to work China sometimes. 73 Paul OM0ET
@@danielmartin7674 I think that larger version made of this coax (Nordix 10/50) would be mechanically unstable. Is possible that "circle shape" wouldn't be possible to create. Theoretically it is possible to build larger version, but we need to change main loop material. 73, Paul
Very very nice! 5W QSO Slovakia-USA!!!! Very good!
Hi Paul,
Very nice craftmanship again.
Version 3 is also very solid build.
Hope to hear you on the Bands as soon as the weather is better here in Germany.
73's de Stefan
Hello my friend! Thank you. It's the same construction as 3th ver. just is used bigger main and coupling loop diameter and wider and longer tubing. ;-) I hope to hear you on the air. Maybe QRP to QRP or MLA to MLA :-) Paul
Interesting video. Contemplating making a mag loop and your dimensions are very doable for me. Thanks very much!
Thank you! 😉👍
Отличная антенна, я пользуюсь уже 8 лет. US7ITC 73!
Спасибо за комментирование и просмотр этого видео. :-) Удачи вам в вашем MLA.
This antenna is great, i work QRP on 20M band from forest in Czech Republic, stations from USA etc. Luxury quiet noise floor and signal quality!!! I recomended it !!!! 73!! OK1TCM.
QRP on magnetic loop. You is hero ) good luck, 73
Thank you andrey! ;) 73
Very nice Paul. Thank you for the demonstration. Nice job on the antenna and nice job on the QSOs. 73
Hello Richard ;-) Thank you for the nice comment! I am your subscriber and i like your videos. Btw One your video helped me to decide to buy my IC7610 ;-) You are doing good job... 73, Paul
Nice slim down 👌, and as always, I enjoyed the video
Hello Paul, after the QSO with you and I did at 18.140 MHz, I redesigned my MLA and ordered some spare parts, I hope to see you in the on air again.
Very good. TH-cam has the best video about the LUP antenna. 73!
Parádna, jednoduchá, skladná, uvažoval som nad niečim podobným na SOTU,..
Vďaka! Áno máš pravdu. Aj ja ju používam hlavne na portable do hôr. Väčšinou išlo o ver.3 ale často bol problém s podmienkami na 20M a vyššie tak som myslel že 40M pásmo by sa celkom hodilo. To bol hlavný dôvod prečo som ju trochu obmenil a hlavne zväčšil. No i napriek tomu sa dá stále jednoducho zložiť a prenášať. A hlavne je veľmi ľahká. Váži necelé kilo, bez trojnožky samozrejme :-) Tak 73 a veľa štastia na kopcoch! Paľo OM0ET
Thanks for making the video and all the information. I have started to collect parts to build one myself now.
Thanks! I wish you good luck with your own project! 😉
Great job very nice setup looking forward to building one just like yours
Great! Let me know when you done with your magbetic loop and thanks for watching! 73 Paul 😉👍
good job from Belgium
great job paul , and antena very good working
Thanks Velin! I will let you know when send you as soon as possible. 😉👍 73
Ahoj, pekna antenka, nejake pokusy s prenosnym magloopom som robil v 2015 a 2016, koncepcia priblizne rovnaka ako tvoja, tvrdy koax a PLka, navyse pripinatelny paralelny kondenzator pre 80m a 4 kusy 25mm PVC elektrikarskej rurky. Na prijem je antenka na dovolenku super, odskusane v 9A, na vysielanie na 20m na svoj rozmer tiez vyhovie, ale na 40m to bola s 3m smyckou bieda o 80m ani nehovorim. Na SOTA v 9A som s nou totalne pohorel, 20m zavrete, na 40m jedno QSO, nastastie bol v batohu obycajny dipol a natiahnuty na krikoch 2m nad zemou som bez problemu dal 8 QSO za 10 min. Niekedy tomu dam este sancu, zohnal som ladicak s velkymi medzerami ale malou kapacitou, tak skusim zvacsit rozmer smycky. Tiez ma laka prevedenie PEX-AL a ladenie koaxom vnutri, ale to nie je do batoha :) . Na tvojej verzii by som koax pripajal do budiacej smycky BNC konektorom, je to rychlejsie ako skrutkovat cokoladu ;) Prva verzia mojej portable MLA, rok 2015: photos.app.goo.gl/jUnFHx1iWHcHEkUCA
Ahoj Tono, moja antena chodi celkom slusne aj na 40M ale musia byt samozrejme aj vhodne podmienky. Predsa len ucinnost 1 metroveho loopu na 7MHz musi byt logicky nizsia ako polvlnny 20m dlhy dipol. Problem vsak je ze nie vsade na portejbli su stromy alebo bod kde sa da drot ukotvit. Kazda antena ma svoje vyhody aj nevyhody. Nedavno mi napriklad protistanica z Ruska davala na 40M pasme 57 report ked som vysielal zo zahrady a s 5W. Co sa tyka tvojho loopu tak je otazka ako si ho mal zladeny, ake min.SWR, ako bol zapojeny kondenzator ci ako bol zapojeny hlavny loop. Ci to cele nevytvaralo v obvode tvojej anteny niekde odporove prechody a tym padom dramaticky znizovalo ucinnost celej anteny.
@@OM0ET Ahoj, zladeny bol dobre, na MiniVNA Pro, PSV pod 1:1,5, PLka ku kondiku pripojene 15mm CU paskou, kondik so 4 zberacmi a vytrhanymi plechmi pre vyssie napatie. Na 20m som dostaval o 2 - 3S horsie reporty, ako som na FT-817 pocuval, co je v pohode QRP vs 100W. Ale na 40m to uz fungovalo pri TX slabo. Hral som sa s tym par dni a vznikla aj V2 :). Problem moze byt mala smycka alebo nevhodne sa spravajuci paralelny kondik. MLA som chcel hlavne porovnat z pohladu SOTA aktivacii a toto riesenie som zavrhol, neprinasa to voci 3 pasmovemu trapovanemu dipolu ziadnu vyhodu, vaha, cas pre zlozenie + nasledne nutne ladenie, moznost pouzitia na WWFF s 60W a hlavne nizsia ucinnost. Zatial som dipol vsade natiahol, doma si pozriem foto kde idem vysielat a podla toho beriem 6m ultralight alebo 10m teleskop alebo spagat na strom :). Ale su QTH, kde je MLA vhodna, balkon na dovolenke, zameriavanie rusenia, priestor kde nie je mozne natiahnut drat. V robote mi pribudol VN generator do 4kV AC aj DC, tak viem otestovat aj ladicak, kolko znesie a s MLA sa este planujem pohrat :)
@@om1aeg Napadlo mi ze by si este mohol zapojit kondenzator do split stator modu pre vyssiu ucinnost anteny. Stratis sice mozno 40M pasmo ale vies to dolozit pridavnym paralelnym kondenzatorom, len stale pozor na prechody. Ja vo svojich antenach pouzivam iba split stator zapojenie. Zvysuje to ucinnost anteny, takmer zdvojnasobuje VN odolnost takze nemusim zasahovat do plechov a tiez aj antena nieje tak citliva na priblizenie ruky k ladiacemu gombiku a jednoducho sa naladi na pozadovanu frekvenciu.
Good job ,congratulation fron Brasil !
Thank you ;-)
great antenna. I need her circuit for connecting the cable and capacitor as well as the antenna power circuit
Good stuff paul. Love the idea of the loop antenna. 👍 shame you still wont part with 1 haha
Heh :-D yes true, I agree... :-D
Great neat job Paul! I want to make one too, I just need to calculate and find the right cap for at least 60W, as my military rig (Qmac HF90) puts out some 50+W LOL :)
I have 15m of coax, so I can be safe enough from the antenna on the exposure point of view ;)
Thank you Chris. Then I recommend to you use the remote controled tuning system. Bluetooth or trough coax. On chinese webshops you can find plenty of wireless solutions how to do that with DC motor ar use Arduino if stepper motor. Good luck! 73 Paul
@@OM0ET Good idea Paul, thanks, i will have a look at the chinese on line solutions :) 73, de ha7wx
Paul, as always - nice video! and nice construction! . congrats -73 de fredy HB0BB
😉 thank you very much! I am happy that this mini magloop really works 😊 73 Paul 🙋♂️
Paul,
Very good video. Your craftsmanship is excellent. Glad you made the loop for the 40-30-20 meter bands. Need to know the PVC diameter please. I really enjoy all your videos. Thanks. 73's KJ4YM Mark.
Thank you Mark. PVC tubing diameter is 25mm. Soon will be all dimensions available on my website.
Thanks Paul. I will look on your website. Keep up the good work. 73’s.
Thank you for the video and also the spread sheet 73 Ron VK2DQ
Thank you Ron for watching my video! 73 from Europe ;-) Paul
Great antenna and explanatory video Paul.
Can you let us know when the motorised version comes out to the market? Keen to buy it!
Thanks
A great job Mr. Paul ... Thanks for your video, good idea of the loop antenna, small dimension and simple for 40 m band. 73 Sudarmanto - YD1WDL
Thank you! Currently my UltraLight MLA's works from 7MHz up to 28.8MHz so all the 7 SW bands + CB with just one loop antenna. Versatile design too. 73, Paul
Great video Paul and I am thinking about building a magnetic loop. Where did you get your building information from? 73 KV5P
Could I ask you a serious question? What is the total lengths (in either inches, or centimeters) of all the loops in this video, if they were all straightened and laid out flat on a floor in a straight line, and measured? For some reason, people can't get the right measurements, by just going only by the diameter of a loop, because no hand -made loop has the same dimension at every point around the loop, once made into a circle. Parts of the loop, will flatten out if hung up, making it wider, and shorter in places around the loop. The straight, flat length of the loop material, is required, before it is even made into a circular loop.
GREAT video..how to i buy the capacitor in US
I would like very much to install a 40M loop antenna in my house but I need to know the following:
1. Can you change the capacitor to one that can handle 100 watts?
2. Is it weatherproof enough to mount on the roof of a house?
3. Can your antenna be tuned remotely?
Thank you for answering these questions.
Hello!
1. For 100W capacitor you will need different and much bigger enclosure. I don't recommend use 100W in the house.
2. Is rain proof but not fully waterproof. Not for permanent base installation. ( portable antenna )
3. After some modifications it can be tuned remotly.
73, Paul.
@@OM0ET Thank you for your quick reply. I understand that a larger capacitor will need a larger enclosure. Can you supply or recommend such a capacitor? Also, I have no room inside my house so it will have to go on my deck, but the deck is not waterproof. That is a minor inconvenience. The big problem for me is the capacitor. My old boat anchor radio could be damaged with too small a capacitor. I therefore am looking for one I can build, buy or modify into handling 100 watts. Can your antenna be modified to handle 100 watts? Thank you very much for your help.
I like it small QRP аид antena.
Thank you! :) 73
super! i want to build one. at present using an alpha antenna loop.
Very nice job. Bravo Paul.
Thank you 😊
Very nice Paul, I´m using an home made Magnetic Loop for 27 Mhz with very good results too, working 10 watts Cobra 148 GTL. Nice contacts. 7351.
@TheBrasilcowboy hello GM it's very simple the length of the major passive circle couldn't more then 2,40 meters the best is 1,80 to 2 meter's and the the active circle is 1/5 of the major. The active circle is connected normally directly to the coaxial cable no more then 2,5 meters length. The capacitor is connected to the major passive circle, when you do this job, connect to the radio put it in AM, sintonize the antenna with capacitor when you listen more qrm and the signal is high you have the antenna sintonized, then with careful sintonize to 1:1:1 of SWR. That's it. 7351.
Nice job!
Nice videos. Very educational. Thank you for taking the time.
Where do you buy your air capacitors?
Thank you very much 😊 you can buy it mostly on ebay. 73 🙋♂️ Paul
@@OM0ET Thank you. N2OWM 73s Jim
Is the dipole you built yourself good for both reception and trasmissione? Thank you,
Antonino Lo Coco from Italy, Sardinia
Paul, Nice job. The antenna looks great. What is the approximate power handling capacity for the 40 m and 20 m antennas for CW and for SSB?
I recommend max.10W continous CW and SSB due to a small capacitor inside 😉
You just cannot build these antennas with high output for cheap. At higher wattage the main loop produces thousands of volts on the capacitor gap. Thus only good vacuum variable capacitor will make $150 alone. I guess :)
@@rodrigoroaduterte9415 yes cap is the biggest problem of MLAs
Paul do you sell Them ..Danny South Australia ..?
Hello Danny, yes I do. Here you can visit my website: www.sk-tech.sk/om0et/ 73, Paul.
Great job bro, it´s vary nice and PRO video ;)
Thanks bro 😉👍
Hi, really enjoyed watching your video, I get frustrated when there is endless waffle & the whole video could have been done in a tenth of the time. I have built my own mag loop using RG213 for the two loops, it receives fine but I can’t make any contacts on it, also a QRP station. Encouraged to keep trying! Ps, you didn’t say how you tuned your loop. I’ve been peaking the Rx signal & trying watching SWR as well. 73, Bill G6ATO
All is well explained in many folowing videos and livestreams 😉
You're always the best
The main factor about the loop size is resonance. The 40 metre one needs the extra size to reach resonance with the available tuning capacity.
Unless the calculator I used is wrong, this simply isn't true Sure, the inductance rises by around 50%, but both antenna circumferences fall nicely in the range of required capacitance with the variable capacitor used here.
Notably, the antenna's efficiency decreases by about 50% with the smaller model.
I'd be careful how you throw around the term resonance when talking about small loop antennas, it could mislead someone.
Hi pole,
Ashortwave bigger here.
You ham experts always stress upon construction of antenatal itself and most of the time you neglect to explain the antena loop end connections. I am always confused about how to make end connections. We have two end of big outer magnetic loop and two two ends of small coupling loop. Now how the connections are made to gang capacitor, how to earth and how to feed the connection to the radio. Can someone explain this please.
M Yaqoub Khan
Islamabad
Pakistan.
Hi Paul Making contact with VK7LJ in Tasmania on 5Watts, where are you located? that was incredible. Thanks Tim VK8LLA
Thanks for the video, Paul. Manetic loops rock! 73 de Kari, oh2gqc
Hello Kari, thank you very much for watching! I love MLAs and QRP operations, but some HAMs should have more patience with QRP operators with low signals. Very often happend to me that they won't to make QSO because it's not so comfortable for them to listen noisy signal :-D That's a pity sometimes... But there are also many good operator who when hear QRP so they call for QRP first in front of all other strong stations calling him. 73 and greetings from Slovakia! Paul.
@@OM0ET I agree Paul, but that has not changed much in the 33 years that I have worked QRP. Often I don't tell up front that I am QRP. If the contact lasts more than a couple exchanges I will slip in that I am QRP and wait for their reaction. 72 KB8AMZ
Using a magnetic loop with a small diameter coax loop as qrp is extremely qrp because such an antenna has a low efficiency assuming there is zero added resistance.... with 5 watts in you are looking at less than 1 watt radiating from the antenna.
congratulations SV2YJ
Thank you ;-)
WOW! It's very nice video! 😁 ❤️
Thank you 😊
Very nice...
Hi Paul. Good job. Are you use the center wire of the coax or use the shield or both? Thank you. 73' Tony
Thank you! I use the center wire. Shield is splitted in the center of the loop - in the point where is located small coupling loop.
@@OM0ET Thank you. This is the traditional version.
@@M0GLU yes correct. It's shielded version of magloops.
@@M0GLU hello! what do you mean, by saying "traditional version"? where do i get such information for mag loops, to leave a gap at the upper center of the main loop?
Very nice... this is vy good antenna For Portable... TNX Paul 72 de in3ufw...
Thank you too 😉👍 73 from Slovakia! Paul
Hi! Nice work, again! In your instruction you said nothing about that the shield of the coax is splitted at the top. Where did you get the information to do so?
Greetings from OE!
Thank you. The construction of the main loop doesn't changed from ver.2. It's still splitted in the middle. It's hybrid between traditional shielded design and classic non-shielded deaign. I had the best results by using this type of construction. 😉 73 and thanks for watching! Paul
@@OM0ET sorry, missed the 2nd version, now i know
@@spotzgeil np ;-) 73 Paul
Very well done Paul and very good English too including calling the Connector Chocolate we also call it Choccy Block here in Liverpool UK short for Chocolate Block.
73 de Steve M0BFM
Lol 😃 thank you very much Steve! I still make many mistakes in english that's because I didn't learn this language at the school. I'm just a self-learner. btw. My brother live near you - in Manchester 😊 And yes we call it "čokoládka" that's the short of small chocolade in our language. All the very best Steve and 73! 😉👍Paul OM0ET
@@OM0ET in finnish it is called sugar cube. 73 CU de Jukka OH4MFA, OG4T
Hi Paul, I love the antenna and as I would like to sometimes use it indoors in my attic (for rx only) it is ideal (my attic door is small, too small for a 1m rigid loop!!). My question is as it will be there for some time I have some concern about the loop losing shape. Is it possible to make a cross frame to preserve the circular aspect? I had an idea to manufacture a rigid cutaway pipe and cable tie the loop in. Anyway thank you for your work and I will be looking to purchase one soon.
Hello! To preserve the circular shape you can use a copper pipe as the main loop ;-) But my H1000 coax hold the shape very good too :) It have 2,5mm solid copper core inside.
Где-то читал, что надо снимать чёрную изоляцию с кабеля петли, потому что она с примесями ферромагнетика. Чистая оплётка меди без изоляции должна работать лучше.
Thank you for this information Evgeny. But still PVC isolation protect the inner copper shield of the oxidation and mechanical stress. Especially if is antenna portable ;) 73 Paul
The little loop is about 1/3 of the principal loop. The general rule for little loop is 1/5 of the principal loop, really?
Здравствуйте! Напишите пожалуйста точные размеры основной петли и петли связи! Из какого кабеля сделанно полотно петель? Спасибо!
Perfekt. Aku zhruba sirku pasma pasma "vidis" po naladeni anteny?
Ahoj. Vdaka! V pohode je viditelne cele pasmo, akurat v strede je vsetko silnejsie. Na vysielanie je uzka - tak 5-10kHz, to zavisi podla pouziteho pasma. 73, Palo
Awesome video Paul. When I used AA5TB's calc for 7.1 MHZ design frequency and 1m Loop Diameter and 10mm conductor diameter, I get 7.8% Efficiency only. You mentioned here it is 60+ %. Can you clarify please?
Yes, agree, his percentages are suspect
@do7425 not mine percentages, it's maybe due to faulty calculator.
Hello could you tell me if the 40m version is very directional? Could it be used to null out local noise for example?
Yes, but is not 100% noise cancellation
Your videos are interesting. Please let us know how you came out with the efficiency figure of 74% on 40 meters. I used the same calculator and got much lower figure.
I see that AA5TB MLA calculator link is no longer available so sorry I can't do the same calculation again. But of course I can't be sure that this calculator was 100% realistic.
effıcıency should be about 10 out of 100 on 40 mt...consıdaring coax diameter 1.5 cm. and dıameter of maın loop about 1 mt.
Fantastic. Where can I buy the capacitor ??
There is the link on ebay somewhere in the comments 😉
ITS UPSIDE DOWN. THE CAPACITOR SHOULD BE AT THE TOP. KEEP THE HIGH VOLTAGE AND HIGHER RADIATING PARTS FURTHEST FROM THE GROUND AND NEARER TO THE SKY.
Hezké. Tripod vypadá jako homemade. Je to tak? Hodně hezkých qso´s, 73, Kamil
Ahoj Kamil. Nie ten tripod som kupil z rybarskych potrieb 😁 je fajn a je hlavne pevny a lahky. Dakujem za sledovanie 😉 73. Palo OM0ET
@@OM0ET Díky. 73, Kamil OK2HBY
For QRP and a Mag Loop antenna I think you did FB on the contest conditions. 73 de John - G0WXU.
Thank you John! ;-)
A great job my friend ... I love the loops too and I use them a lot even inside the car ... A greeting.
Giuseppe iz0gzw qrp.
Thank you Giuseppe! Inside the car?? Really? :-) Wow I was never tryed transmitting with MLA in the car. Have you some QSOs from car already?? 73
Ciao, I have several videos on my channel in reception as you can see ... with my loops self-built I also made several links that I have not filmed only and always in qrp ... I transmit only up to 5 w with my Yaesu 817 .
I hope to do some videos in transmission like years ago and film it.
You are really good.
73 de Giuseppe.
@@qrpradiolistner7232 Thanks for your reply Giuseppe. I see that you are listener and you have many own videos in your channel. I have also Tecsun receiver no. 600. It's a great receiver and I like it very much. So enjoy this perfect hobby Giuseppe and I hope you will hear me once too sometimes in the future ;-) 73 Paul
If luck helps us we can connect on 20m. sometimes ... I hope so, qrp and qrp ...
Greetings.
Giuseppe.
Paul, what surprises me is that your tuning capacitor is small compared to other mag loops I've seen. Could the reason for this be purely because your transmit power is low? i have not attempted to build a mag loop because others that have built this antenna indicate that a vacuum tube capacitor is required even for QRP power. 72 KB8AMZ
Hello Terry. Yes this capacitor is small for just couple of hundreds volts. I connected it in to the "Split stator mode" and power increased. Unfortunatly the capacity decreased to half, still OK for my magloops ;-) Split stator mode also dramatically decrease the resistance in the circuit and increase effectivity and Q of this magloop. 73, Paul.
where can I get one from and how much are they
I can made one for you. Send me an email.
cannot find your Email address
@@OM0ET
@@bigphil6980 write me please on hamradioslovakia@gmail.com
👍👍👍👍👍👍💎
Are they safe to sit beside during use ?
Hard to say.... but I use only 5W. Smartphone runs max. 2W and on much much higher frequencies... I think it's not so bad ;-)
@@OM0ET Thank you for that. I was just wondering because I have a chameleon f loop with compensator and was running 60watts sitting only 6 feet away, after reading the dangers I backed it back to 5watts lol
@@ronangsr read this site: translate.google.sk/translate?hl=sk&tab=wT&authuser=0&sl=sk&tl=en&u=http%3A%2F%2Felektrosmog.voxo.eu%2Fmobilne-telefony
Its a QRP antenna
If you built it they will sell.....
Where can I find the capacitors..?? Thankyou. :)
You can find it on ebay. There are links in some older comments. 😉 73
The adjust swr its manual ??
yes it's manual tuning :)
hello pal...how can i get that antenna
Hi Ayub! 👋🙂 Here is the link for this antenna: om0et.com/ultralight-mla-mc-20.html
Do you do a 50w or 100w version?
Unfortunately no. It's all about the size of capacitor. But on 40M band this antenna can handle 40W SSB. I tested it. And also is very dangerous to transmit 100W with Magloop so close to the human body. I plan to the future some 100W version for base installation.
73 From CHINA.
Hello my friend! Thank you for watching my video. I never had a SSB QSO with China. It's very exotic country for me personally. I hope to work China sometimes. 73 Paul OM0ET
Maybe we can test FT8 QSO in next. even if I am still obsessed with SSB. ： ）
@@qwb0330 LOL yes I am too SSB operator but I have FT8 capability too... We should make a sked. How can I contact you directly?
Hi, Paul, You can send email to me qwb0330#gmail.com Then we can test at some weekend time
Thanks
@@qwb0330 great! OK i will send you mail. 😉👍
where can I buy a unitra 2x243pF.? Thanks.
I bought it from a HAM meetings, from bazaar or from an old HAMs :-)
and ebay :)
yes from ebay too :)
Nice video mate 😁👍
Oh thank you! 😃👍
What video camera are you using?
Daniel I use Samsung Galaxy S9 and the FHD camera setting. Why you ask? 😊
I do some video myself and I think your video looks good. Your antenna works well. Could it be made in a larger version ? 73. KA8P
@@danielmartin7674 I think that larger version made of this coax (Nordix 10/50) would be mechanically unstable. Is possible that "circle shape" wouldn't be possible to create. Theoretically it is possible to build larger version, but we need to change main loop material.
73, Paul
OM0ET thx 73
It's looks like a copy of the Alexloop :-)
No, it is not a copy. When I designed this loop I didn't know about some Alexloop. 🙂