Thanks, @Dave, yes, I agree, ham radio is a hobby that is open to lots of creativity. Personally, I like to do things based on "Keep it simple" :) Thanks for your feedback, 73!
What a fantastic design - you are really a great credit to the amateur radio community just sharing all the info on how to build this, its amazing ! I can see this being very popular !
Thank you! Yes, I do get lots of questions and requests from all over the world about that. I'm happy that it can help the ham radio community. I appreciate your feedback, 73.
I was excited about your wanting to show us how to build a mag loop ant. I am a beginner, I don't understand the speak in acronyms and in this case all I want was instruction on how to build the ant. just for listening. I don't have a ham license yet, but I want to listen so I can learn what is going on. The equipment is expensive, cheapest MFJ SWR meter is $169 plus the transceiver which appears to be any thing from $500 up. I have a Eton 750 listening radio. Will some one show me how to build the mag loop ant. just for listening so I can learn more. Thanks very much. I appreciate the videos very much, keep them coming.
Thanks so much for your comment, @Mogul. I hope that the video gave some more knowledge, even if not all the terminology is clear at this point. You will get it soon. The best way is just by... "doing it!" :) I tried to show how to build that Mag-Loop as simple as I can and with the minimum cost as not everything needs to be expensive. Good luck with your ham radio journey and hope to found you on the air someday! Welcome to the club :) Happy holidays, 73!
The best demonstration of building a stepper driven magnetic loop yet. Your format was so easy to follow. Congratulations!!! I too have built a stepper driven magnetic loop using an inexpensive stepper motor. Your means of coupling the sm to the variable cap was very useful... I will now change out the spiral couplers I was using. I chose to use a pulse encoder to manually tune my mag loop. Thank you!!
Thanks for the video. Can a variable capacitor be made with a sliding copper tube inside a larger ID copper tube? Plastic pipe sleeve in-between to act as an insulator. Very fine adjustment created by a fine threaded machine screw with appropriate insulation. Your servo motor driving the bolt would be great. Directional control could be supplied by a linear actuator from a lift chair or using your servo idea above. The Antenna would be mounted on a swivel mount to allow motion without rocking.
Thanks for your feedback. The capacitor is always the part that is hard to find, but just be patient and search on eBay, from time to time you will find interesting surprises. Good luck.
Yes. I already have the idea to add an automated tune feature that will be based on the field strength of the antenna. I hope to work on that in the near future. But audio is also an option, even though it will not be so precise.
The controller is configured for micro-steps, which means 6400 steps per revolution. From my experience it's more than enough, but it also depends on the capacitor type as well.
@@reHamRadio I will use a Palstar C600 capacitor, which is 20-500 pf or so at 5,5 KV, Not sure what power the antenna will handle, but that is the one. Thanks.
Excellent well done. I want to try something like this myself. I recently got the MFJ-935C and with just 13 feet of 10 mm copper pipe I made an SSB contact @20 Watts on 20m from Ireland to Canada, I was very impressed, the antenna was just on a patio table outside a few feet off the ground, I was not expecting this DX contact with just 20 Watts. The MFJ loop tuner is strange in the fact it doesn't have the coupling loop. It works on 20m also with 9 feet of copper, I made contacts around Europe, I haven't used it much yet but will experiment more when the weather gets finer. It also handles 100 Watts. The MFJ tuner has made me very interested in loops, it would be great if it could be controller remotely.
Thanks for sharing that information. Yeah, it's amazing what these tiny antennas on a balcony or patio can do even with low power. I'm working on another version of that remote tuner and hope to release a movie soon. 73.
I found your video very interesting and I want to build by myself such an antenna. Please send me the precise schematics of the butterfly capacitor, because what I have found does not tell all the distances of the margin holes of the wings. Thank you in advance 73
Thanks for your feedback, @Nicolae. I'm not sure that I understand the question, so please elaborate if needed. But for clarifying, just connect the edges of the loop to the capacitor that you have. In my case, the distance between the screws is 7.5cm, but from my experience, it's really minor, as it will just change a bit the frequency up or down, based on your capacitor and loop measurements. I hope it helps, 73.
There are lots of differences but the main idea Is that with my loop we are using induction between the small loop and the main loop, while in dipole the load is direct in the middle of the antenna. There are so many more differences and the best will be to read about that online, there are so much knowledge out there. I hope it helps and answers your question.
@@reHamRadio , that was just it. I don't understand how a magnet can be used as an antenna. I was hoping you could point me to something explaining it. You're teaching the advanced class. I need to learn what it is first. I found your video very interesting by the way. Can I just Google "magnetic loop antenna?"
Very good demonstration of how the antenna is constructed. I am going to have to build one. I do have to ask, if there is no balun at the feed point of the small loop, does the length of the feedline come into play? 73 WA4QGA
Ideas for your next version: as you know, the radiation resistance of the loop is very low. So to improve efficiency you can reduce the RF resistance of the circuit by using a butterfly capacitor which doesn't require a wiping contact. Also, you can solder or braze the connections of the loop to the capacitor to reduce resistance there. I have thought of polishing the copper and coating it with lacquer to reduce the skin effect resistance when the copper oxidizes, but I don't know how much that would help. MFJ sells a butterfly capacitor that they use in their loop, but the capacitance is much lower than that of the one that you have, so you would need to make the loop bigger if you want it to cover 7 and 10 MHz. I've had good luck with this kind of antenna, but the need to retune every few kHz is annoying. DE 4X6GP
Thanks Victor, for the tips and for sharing your experience. Yes, I'm aware of these options to lower the resistance. Believe it or not, I built this version as an experiment to make sure that I'm on the right track. I do have more ideas for the next version, for example an auto tune feature, that should solve that time issue you mentioned. I really appreciate your feedback! 73. Toda!
Victor, a split-stator or "butterfly" capacitor essentially puts two identical variable capacitors in series, and uses the capacitor's rotor to couple between them to avoid the wiper contact on the rotor. This is great, and increases the cap's voltage rating, but it means maximum capacitance is reduced in half for a given physical size. As they say, there is no free lunch!
Agree, there are more options. As a note, the app that is shown in the video based on and old version of Blynk, which is not supported currently. Please keep an eye on the channel as I will publish a newer version.
Nice video! I need to watch your controller video now. When I built my 30-80 magnetic loop I used a bias-T network, at each end, to put DC control voltage on the coax to rotate my gear motor/tuner mechanism. I'd like to know, does RF ever cause your tuning cap to move?
Thank you! Nope, I didn't have any RF issues. You can also see in the video, that I placed the controller on one of the tripod legs, no so close the capacitor.
Hi.... Thank you so much for the videos you provide.. I've watched the remote unit you have made but I'm unable to find the type of stepper motor you have used and where to purchase one... I'm in the UK... M1bsz
Hi @Francisco, for the physical plan of the antenna, please review the video again as I provided all the details about the parts. If you are asking about the WiFi controller, please check my website and/or my GitHub repository as I put their full details about the electronic schema and the software code. Please check the description of this video for all the links. Thanks for contacting and asking. Good luck, 73.
Excellent. Wood actually is not so good isolator. I use 10kV fence and wood posts even when dry are conductors. Usually snail or fly goes between isolator and wood post and it starts to arc. It's max 10J generator and some wire inductance
What you wrote is true. That's why I built the capacitor inside a plastic box. In addition, each of us needs to make sure that the isolation fits in his/her own environment.
Thanks Michael, the only thing that you'll need to take into consideration is that a Vacuum capacitor has turns limits, while the provided solution is using an Air capacitor with no stops and it can turn around unlimited.
No, the capacitor range should fit the frequency range that you plan to use. The best will be to use an online free magloop calculator and check the options.
Please clarify: 1. How did you make or obtain the white snap clamps on the back of the plastic box? Are those made from the next size up thin wall PVC pipe? 2. What are the 4 red "washers" between the variable capacitor and wood strip? Are they fiber washers or possibly ceramic, and are they simply spacers or are they put in for safety, heat, or isolation reasons? 3. Is it OK for this antenna to become grounded through the shield/PL259 when connected to a radio that is grounded? Thank you for this excellent video and I am looking forward to starting the project.
Thanks again, @Todd. 1. The snap clams are the following parts: www.amazon.com/Snap-Clamp-Inch-Inches-White/dp/B00C7DPO4K/ref=pd_bxgy_1/131-0507706-1910934?pd_rd_w=TsZ0M&pf_rd_p=c64372fa-c41c-422e-990d-9e034f73989b&pf_rd_r=7JRVFVGC3PMR1HV0FRDB&pd_rd_r=f6b5abcf-e449-4ce2-8423-23f838f4d7ae&pd_rd_wg=UcEUV&pd_rd_i=B00C7DPO4K&psc=1 But any similar 1" PVC snap clams parts should be good. 2. Good question - these 4 red washers are made of rubber, and in my case i just needed a tiny spacers to align the capacitor shaft with the motor. I needed ~2mm to align that ;) 3. This is exactly my setup and I don't have any issues. My radio is grounded. Remember that the coax that goes to the Antenna, is connected "directly" only to the small loop. There is no physical contact between the main loop or the capacitor and the coax/radio. I hope it helps. Good luck!
@@reHamRadio Thanks for the link for the snap clamps and for the other answers. It's all starting to come together now. Whenever I need spacers like that I now turn to my 3D printer and it is quite a timesaver to be able to quickly make exactly what I need instead of rummaging through parts bins or trying to cut small pieces of wood etc. Best regards to you.
Excellent job. Amazing workmanship. I read somewhere if you give the small loop a more oval shape (side to side, not top to bottom) it will increase the induction area between the two coils. But if it's not broke, don't fix it!😅
I just have a small question, how can a magnetic loop antenna be calculate for more than one band. Let's say that I'd like to have one to 40 & 80 meters band. The first calculated, the one you recommend only allow us to enter one frequency, so how can we put both together? And thank you for sharing your ideas. 73's / ct1bsd
Hi @Filipe, thanks for your feedback. When using the calculator, you should use both the capacitor's minimum and maximum values, one at a time. These calculations will give you the frequency range. If the range that you get is not what you are looking for and you don't have another capacitor, you can change the value of the loop diameter. Try to change the values up and down, and check the difference. I hope it helps. 73.
Great video! I really like your remote turner as well. Have you thought about making a remote auto tuner? That would eliminate the hassle of manually tuning every time you change frequency. 73 and Shalom!
Thanks 👍 Yeah, Auto Tune is one of the features that I have in the features list to develop. The latest version supports Vacuum capacitors (will be released very soon), and the next version will support "memories" and more. Please stay tuned and visit the website for more news. I appreciate your feedback. 73.
It's a combination of the size of the loop and the capacitor range. I would recommend checking the options using an online mag loop calculator, and set the target frequency to 10M and see what are the needed parameters of the loop and capacitor. Good luck.
Made something similar, but just for listening and testing. I tune it with an arduino similar to a rotory encoder with a switch to set the stepper step size from 1/2 to 1/16. the best result I get from the 1/16 step step. You use blynk by the look of it. I have a blynk server, but this is a better solution if you're out and about. What stepper size do you run on fine tune?
The Blynk v1 is not available anymore so I decided to provide an independent solution. You can see another video that explains that. In my configuration I'm using 1/32 thanks to the DRV8825.
hi om Tamir , tu fer nice es informative video , from were the supply voltage comes ? do you have a battery under the antenna ? or do you use a bias-t and feed the supply through the coax ? 73 de Amir 4z1ar
Thanks Amir. Yep, I'm using a battery that is located underneath the antenna. In the movie, around minute 1:08, you can see the antenna on the balcony, and the orange battery near the tripod leg. Thanks for stopping by :)
*HOW TO CALCULATE FOR BUILDING A RECEIVING MAG LOOP*---I need a calculator or formula that can show the measurements for building a mag loop for receiving a frequency range. Is there any formula or a calculator for that?
What does prevent you from creating a A/D to detect power of SWR and then automatically "maximise" the position of the motor, on the basis of maximal output power (or minimal SWR)? I am thus proposing to go "closed loop" as opposed to "open loop" control that you demonstrated.
Thanks for your comment, I do have ideas to add this feature and I already mentioned that in previous comments. This was only my first version of the antenna. I hope to provide an update soon. Thanks again.
Wow, Tamir, this is an outstanding video! I’m going to check out your video on the remote tuning. I’m interested in (watch out) a magnetic loop for 160m since I am unable to use an L or other kind of antenna due to HOA restrictions. The mag loop will have to be how I do it. Again, excellent video. I have subscribed to your channel. Jeff, KF5KWO
Great video. moving to a condo with HOA's. Will be building your antenna. Best explanation I've seen. Can you tell me what the max voltage specification is for your variable capacitor? Thanks, Terry, N7TB
Hi Terry, Thank you. And enjoy the building. I don't know exactly about the max voltage that this specific capacitor can handle but the spaces between the plates is wide, and the plates themselves are heavy, so I can just assume that few thousand volts. The max power that I tested was 100W and without any issue at all.
The best will be to check which capacitors you can get, and then, check what frequency range you will get by using the Online MagLoop Calculator. If you have only a single capacitor and you don't get the exact frequency range that you want, you can try to change the loop "size", smaller or larger, and then see what you can get. I hope it helps, good luck.
Nachon! Todah! How do you power the tuning unit? Do you power it with 12v over the coax? That would seem to be the most convenient way to do it. 73 de Arnie W8DU
Hi @Arnie, I do use 12V but from a battery. Please review the video at minute 1:08. In that frame, there is a picture of the antenna on the balcony, and it's easy to see the battery near the tripod legs. I separated the remote unit from the Antenna and from the tuning unit. I found it the best way to avoid RF issues and for safety. And Todah as well for the question ;) 73, Tamir.
I'm curious, in witch way the mag. loop works better, with the capacitor up, or down. A couple of years ago I make my loop with the capacitor on top and the small loop at the bottom.
friends, I have tried to make an antenna like your instructions, using a 1/4 in copper pipe for the main loop, after I tried it, I couldn't catch the signal at all, please advise what the problem is, thank you Haryoso
Hi, there are so many options that can cause you to not get any signal. From problem with the connectors, failure coax, capacitor that is in short, soldering, and more... Please try to isolate each component to make sure that they are good. It's very hard to help remotely with this kind of issue. I would recommend to contact a local ham that may help to check that with you. I hope things will be ok soon. Good luck, 73.
I am VU3SQM, Ameer Khan from India. Would you advise what is the usual gap between the main loop and the feeding Loop in this design. Thank you for providing us with magnificent design.
Thanks Ameer for your feedback. As for the gap between the loops, you can see in my design in the video, that only a PVC in a T shape is in between them. I would say it's around 1 cm at the top. As you can see, the small loop is not a real circle but an oval, because you want as much space close to each loop, to get a better SWR. Good luck, 73.
Nice build. By the way, your use of the word torsion is off. I think you mean "torsional backlash" in the case of couplers that have springiness where rigidness is desired.
Nice wireless control option! I am looking for one for my loop 10 15 20 40 mt. Can you give me the purchase link of the pieces contained in the box? Can you give me indication for the tuning app from Iphone? I appreciate it! 73's de Alex IK0TOM from Rome Italy
Hi @Alex, Thank you for your feedback. As for the parts, please take a look at the description of the video, I already put links to all the parts and apps. Good luck, 73.
Thanks! Yeah, already asked for that. I may release this kind of feature in the future but it may be tricky from the type of the motor as it needs to be more stronger, which means a stronger power supply. Will see.
Hi John, yeah, I mainly agree, less people are in the center, but still, it looks very quiet there as the wave just skipped that area, at least this is my theory. Thanks for your feedback, 73.
Thanks for the good question @Randon. When I thought about the design, Coax was one of the considerations. But I wanted something wide, for better bandwidth, but also something that will be not heavy and strong. The flexible copper is soft enough to work with, but strong enough to hold itself without any special support. See the pictures how it stand by itself and keep it shape. Also, it's very cheap!
@@reHamRadio Yes, seems too good to be true! So many videos where hams go through elaborate pipe-bending or elbow-joint-making in order to use copper pipes. Great find.
A very elegant and intelligently realized magnetic loop with a nice wireless control option. Inspirational this is what Amateur radio is all about.
Thanks, @Gavin for the kind words. Comments like yours inspiring as well and provides more motivation to create more.
I appreciate your feedback. 73!
I love how you integrated so many home brew systems. This is what attracted me to amateur radio!
Thanks, @Dave, yes, I agree, ham radio is a hobby that is open to lots of creativity. Personally, I like to do things based on "Keep it simple" :)
Thanks for your feedback, 73!
What a fantastic design - you are really a great credit to the amateur radio community just sharing all the info on how to build this, its amazing ! I can see this being very popular !
Thank you! Yes, I do get lots of questions and requests from all over the world about that.
I'm happy that it can help the ham radio community.
I appreciate your feedback, 73.
Awesome. That capacitor housing killed me. Kudos for that build. Wait - you have a dedicated app? You’re the man. I’m speechless
Thanks, Ohne, for your feedback. Yep, everything is possible :), 73!
Thanks for creating this video... I like the actual DIY instructions.
Thanks for your feedback, good luck with your project. I hope the instructions will help. 73.
I was excited about your wanting to show us how to build a mag loop ant. I am a beginner, I don't understand the speak in acronyms and in this case all I want was instruction on how to build the ant. just for listening. I don't have a ham license yet, but I want to listen so I can learn what is going on. The equipment is expensive, cheapest MFJ SWR meter is $169 plus the transceiver which appears to be any thing from $500 up. I have a Eton 750 listening radio. Will some one show me how to build the mag loop ant. just for listening so I can learn more. Thanks very much. I appreciate the videos very much, keep them coming.
Thanks so much for your comment, @Mogul.
I hope that the video gave some more knowledge, even if not all the terminology is clear at this point. You will get it soon. The best way is just by... "doing it!" :)
I tried to show how to build that Mag-Loop as simple as I can and with the minimum cost as not everything needs to be expensive.
Good luck with your ham radio journey and hope to found you on the air someday!
Welcome to the club :)
Happy holidays, 73!
What a good explanation about magnetic loop,,, thank You so much..
Thanks, @Vianney, I'm happy that it was helpful, 73.
The best demonstration of building a stepper driven magnetic loop yet. Your format was so easy to follow. Congratulations!!! I too have built a stepper driven magnetic loop using an inexpensive stepper motor. Your means of coupling the sm to the variable cap was very useful... I will now change out the spiral couplers I was using. I chose to use a pulse encoder to manually tune my mag loop. Thank you!!
I'm so happy to hear that, Ron. Yes, I like to keep things simple :) I appreciate your feedback, 73.
Just love this antenna ,this is what I think I will build "good ***** job"
It's a great antenna, good luck!
Thanks for your video and great explanation. It is so helpful for HAMers.
Glad it was helpful!
Thanks for the video. Can a variable capacitor be made with a sliding copper tube inside a larger ID copper tube? Plastic pipe sleeve in-between to act as an insulator. Very fine adjustment created by a fine threaded machine screw with appropriate insulation. Your servo motor driving the bolt would be great.
Directional control could be supplied by a linear actuator from a lift chair or using your servo idea above. The Antenna would be mounted on a swivel mount to allow motion without rocking.
There are so many possibilities and options... Yeah.
Great video. I am impressed. Greetings from Germany.
Thanks, Florian. I appreciate your feedback, 73!
You just inspired me to make one. My main issue is the capacitor which is just impossible to find in my country . 😊
Thanks for your feedback.
The capacitor is always the part that is hard to find, but just be patient and search on eBay, from time to time you will find interesting surprises. Good luck.
Magnificent! 💜 Thanks for the explanation!
Thanks, you're welcome, 73.
Very good!
Is it possible to add a kind of automated function using microphone input on mobile phone, for maximum noise level?
Yes. I already have the idea to add an automated tune feature that will be based on the field strength of the antenna. I hope to work on that in the near future. But audio is also an option, even though it will not be so precise.
Fantastic video Tamir!
I appreciate your feedback, thank you, 73.
What is the spacing of the capacitor? And what type capacitor? Nice video!finding good capacitors is the hard part of building
Loops.
It's 5mm between the same polarity plates, so 2.5mm between each plate. Thanks for your feedback.
Wondering if a vernier reducer will add some advantage or controller will be enough.
The controller is configured for micro-steps, which means 6400 steps per revolution. From my experience it's more than enough, but it also depends on the capacitor type as well.
@@reHamRadio I will use a Palstar C600 capacitor, which is 20-500 pf or so at 5,5 KV, Not sure what power the antenna will handle, but that is the one. Thanks.
That was absolutely great , and I am going to have to build 2 , one for me, and one for my son. Thanks for the great video. 73’s Dave
Thanks, Dave. Good luck to you and you son. Should be a great family project! 73.
What a brilliant video 👍
Thanks 👍
Really nice job,maybe a future project I will try
Thank you, good luck.
Impressive antenna and build suggestions. Thank you.
Thanks!
Excellent video. Thank you.
Thanks, Robert!
Very interesting and impressive, simple and elegant antenna design.
I appreciate your feedback, Marlon. I like the "keep it simple" approach. Thanks, 73.
Never thought I'd extend my Working Magnetic Loop Antenna Peoject to now include Remote control for better ease of Operations!
Excellent well done. I want to try something like this myself.
I recently got the MFJ-935C and with just 13 feet of 10 mm copper pipe I made an SSB contact @20 Watts on 20m from Ireland to Canada, I was very impressed, the antenna was just on a patio table outside a few feet off the ground, I was not expecting this DX contact with just 20 Watts.
The MFJ loop tuner is strange in the fact it doesn't have the coupling loop. It works on 20m also with 9 feet of copper, I made contacts around Europe, I haven't used it much yet but will experiment more when the weather gets finer. It also handles 100 Watts.
The MFJ tuner has made me very interested in loops, it would be great if it could be controller remotely.
Thanks for sharing that information. Yeah, it's amazing what these tiny antennas on a balcony or patio can do even with low power. I'm working on another version of that remote tuner and hope to release a movie soon. 73.
wow that's cool. subbed
Thank you
Nice antenna! Great video. Concise. I hit subscribe.
Thanks, Charlie for your feedback and for subscribing! Welcome to the club, 73!
That is top shelf work all the way. Congradulations!
Thanks for your feedback, Virgin, 73!
Where did you get the variable capacitor and what is its voltage can cap rating?
Ebay, keep an eye on what people are selling. Mine can hold a few KV.
I found your video very interesting and I want to build by myself such an antenna. Please send me the precise schematics of the butterfly capacitor, because what I have found does not tell all the distances of the margin holes of the wings. Thank you in advance 73
Thanks for your feedback, @Nicolae. I'm not sure that I understand the question, so please elaborate if needed. But for clarifying, just connect the edges of the loop to the capacitor that you have. In my case, the distance between the screws is 7.5cm, but from my experience, it's really minor, as it will just change a bit the frequency up or down, based on your capacitor and loop measurements. I hope it helps, 73.
How does a magnetic loop work vs a regular loop or dipole?
There are lots of differences but the main idea Is that with my loop we are using induction between the small loop and the main loop, while in dipole the load is direct in the middle of the antenna. There are so many more differences and the best will be to read about that online, there are so much knowledge out there.
I hope it helps and answers your question.
@@reHamRadio , that was just it. I don't understand how a magnet can be used as an antenna. I was hoping you could point me to something explaining it. You're teaching the advanced class. I need to learn what it is first. I found your video very interesting by the way. Can I just Google "magnetic loop antenna?"
Very good demonstration of how the antenna is constructed. I am going to have to build one. I do have to ask, if there is no balun at the feed point of the small loop, does the length of the feedline come into play? 73 WA4QGA
Ideas for your next version: as you know, the radiation resistance of the loop is very low. So to improve efficiency you can reduce the RF resistance of the circuit by using a butterfly capacitor which doesn't require a wiping contact. Also, you can solder or braze the connections of the loop to the capacitor to reduce resistance there. I have thought of polishing the copper and coating it with lacquer to reduce the skin effect resistance when the copper oxidizes, but I don't know how much that would help. MFJ sells a butterfly capacitor that they use in their loop, but the capacitance is much lower than that of the one that you have, so you would need to make the loop bigger if you want it to cover 7 and 10 MHz.
I've had good luck with this kind of antenna, but the need to retune every few kHz is annoying. DE 4X6GP
Thanks Victor, for the tips and for sharing your experience. Yes, I'm aware of these options to lower the resistance. Believe it or not, I built this version as an experiment to make sure that I'm on the right track. I do have more ideas for the next version, for example an auto tune feature, that should solve that time issue you mentioned. I really appreciate your feedback! 73. Toda!
Victor, a split-stator or "butterfly" capacitor essentially puts two identical variable capacitors in series, and uses the capacitor's rotor to couple between them to avoid the wiper contact on the rotor. This is great, and increases the cap's voltage rating, but it means maximum capacitance is reduced in half for a given physical size. As they say, there is no free lunch!
You can add pan and tilt base to select reflection angle from sky. Nice app. Did you do it your self?
Agree, there are more options. As a note, the app that is shown in the video based on and old version of Blynk, which is not supported currently. Please keep an eye on the channel as I will publish a newer version.
Nice video! I need to watch your controller video now. When I built my 30-80 magnetic loop I used a bias-T network, at each end, to put DC control voltage on the coax to rotate my gear motor/tuner mechanism. I'd like to know, does RF ever cause your tuning cap to move?
Thank you! Nope, I didn't have any RF issues. You can also see in the video, that I placed the controller on one of the tripod legs, no so close the capacitor.
WoW..Even got all the way down to us in New Zealand
Indeed. It's really impressive with this kind of antenna size and power.
Thanks for your feedback, Kris, 73.
Hi.... Thank you so much for the videos you provide.. I've watched the remote unit you have made but I'm unable to find the type of stepper motor you have used and where to purchase one... I'm in the UK... M1bsz
I put the list of parts in the description. Any compatible motor should work
buenas tardes quisiera saber si me puedes compartir los planos para la contruccion de la antena porfavor gracias
Hi @Francisco, for the physical plan of the antenna, please review the video again as I provided all the details about the parts.
If you are asking about the WiFi controller, please check my website and/or my GitHub repository as I put their full details about the electronic schema and the software code.
Please check the description of this video for all the links.
Thanks for contacting and asking.
Good luck, 73.
Genius re. the flex copper pipe.
We need to be creative ;)
Very nicely demonstrated and explained. Enjoyed the video.
Thank you @Rob for your feedback! I appreciate that. Good luck, 73!
Excellent. Wood actually is not so good isolator. I use 10kV fence and wood posts even when dry are conductors. Usually snail or fly goes between isolator and wood post and it starts to arc. It's max 10J generator and some wire inductance
What you wrote is true. That's why I built the capacitor inside a plastic box. In addition, each of us needs to make sure that the isolation fits in his/her own environment.
Thank you for this wonderful video. You implemented some great ideas. I want to try building my own now. Much appreciated!
Thanks for the feedback, @David, and good luck with yours.
Excellent design and well explained
Thanks a lot, 73!
Nice. You're an inspiration. Now for the motivation! And yes, I subscribed.
Awesome! Thank you! Good luck!
Very nice antenna build and a great video. Thank you.
Thanks, Jason. 73.
Thank you this was a very nice video to help. The wireless tuning is a very nice and I will look at that video as well.
Thanks for your feedback. Enjoy with the next video, 73!
Excellent! Thank you for sharing.
Your welcome, John. Thank you, 73.
Fantastic job on the build!!!
Thank you for your feedback! 73!
4X1LM : Very nice and helpful ! will it work with a 10 turns vacuum capacitor??
Thanks Michael, the only thing that you'll need to take into consideration is that a Vacuum capacitor has turns limits, while the provided solution is using an Air capacitor with no stops and it can turn around unlimited.
Fantastic video. I really enjoyed it i like to mess around with mag loop antennas. Looking to remote tune mine also. Keep up the great work
Thank you and good luck with your mag loop. 73!
What variable capacitor did you use
All the parts are in the description of the video. It's an air capacitor. You can choose anything you have just calculate the size of the loop itself.
Hello does the capacitor have to be 40-430 pF?
No, the capacitor range should fit the frequency range that you plan to use. The best will be to use an online free magloop calculator and check the options.
Please clarify:
1. How did you make or obtain the white snap clamps on the back of the plastic box? Are those made from the next size up thin wall PVC pipe?
2. What are the 4 red "washers" between the variable capacitor and wood strip? Are they fiber washers or possibly ceramic, and are they simply spacers or are they put in for safety, heat, or isolation reasons?
3. Is it OK for this antenna to become grounded through the shield/PL259 when connected to a radio that is grounded?
Thank you for this excellent video and I am looking forward to starting the project.
Thanks again, @Todd.
1. The snap clams are the following parts: www.amazon.com/Snap-Clamp-Inch-Inches-White/dp/B00C7DPO4K/ref=pd_bxgy_1/131-0507706-1910934?pd_rd_w=TsZ0M&pf_rd_p=c64372fa-c41c-422e-990d-9e034f73989b&pf_rd_r=7JRVFVGC3PMR1HV0FRDB&pd_rd_r=f6b5abcf-e449-4ce2-8423-23f838f4d7ae&pd_rd_wg=UcEUV&pd_rd_i=B00C7DPO4K&psc=1
But any similar 1" PVC snap clams parts should be good.
2. Good question - these 4 red washers are made of rubber, and in my case i just needed a tiny spacers to align the capacitor shaft with the motor. I needed ~2mm to align that ;)
3. This is exactly my setup and I don't have any issues. My radio is grounded. Remember that the coax that goes to the Antenna, is connected "directly" only to the small loop. There is no physical contact between the main loop or the capacitor and the coax/radio.
I hope it helps. Good luck!
@@reHamRadio Thanks for the link for the snap clamps and for the other answers. It's all starting to come together now. Whenever I need spacers like that I now turn to my 3D printer and it is quite a timesaver to be able to quickly make exactly what I need instead of rummaging through parts bins or trying to cut small pieces of wood etc. Best regards to you.
@@stolz5573 I am wanting to get a 3D printer. Do you have any recommendations for printing up to about 12" square?
Excellent job. Amazing workmanship.
I read somewhere if you give the small loop a more oval shape (side to side, not top to bottom) it will increase the induction area between the two coils.
But if it's not broke, don't fix it!😅
Tests shows that the SWR is going down when the two loops, large and small, have more area in parallel. Not going to break it now :)
Nice antenna, very well done! Thank you.
Thank you, @Derek, for your feedback! 73!
I just have a small question, how can a magnetic loop antenna be calculate for more than one band. Let's say that I'd like to have one to 40 & 80 meters band. The first calculated, the one you recommend only allow us to enter one frequency, so how can we put both together? And thank you for sharing your ideas. 73's / ct1bsd
Hi @Filipe, thanks for your feedback.
When using the calculator, you should use both the capacitor's minimum and maximum values, one at a time. These calculations will give you the frequency range. If the range that you get is not what you are looking for and you don't have another capacitor, you can change the value of the loop diameter. Try to change the values up and down, and check the difference.
I hope it helps.
73.
Great video! I really like your remote turner as well. Have you thought about making a remote auto tuner? That would eliminate the hassle of manually tuning every time you change frequency. 73 and Shalom!
Thanks 👍
Yeah, Auto Tune is one of the features that I have in the features list to develop. The latest version supports Vacuum capacitors (will be released very soon), and the next version will support "memories" and more.
Please stay tuned and visit the website for more news.
I appreciate your feedback. 73.
I can see you hit 40M-20M, what change would be needed to get good SWR at 10M?
It's a combination of the size of the loop and the capacitor range. I would recommend checking the options using an online mag loop calculator, and set the target frequency to 10M and see what are the needed parameters of the loop and capacitor. Good luck.
Made something similar, but just for listening and testing. I tune it with an arduino similar to a rotory encoder with a switch to set the stepper step size from 1/2 to 1/16. the best result I get from the 1/16 step step. You use blynk by the look of it. I have a blynk server, but this is a better solution if you're out and about. What stepper size do you run on fine tune?
The Blynk v1 is not available anymore so I decided to provide an independent solution. You can see another video that explains that.
In my configuration I'm using 1/32 thanks to the DRV8825.
Great Video
Thank you, 73.
What tripot is that? Is made of aluminum?
Standard that you can find on Amazon, mainly for speakers. It is made from steel.
hi om Tamir , tu fer nice es informative video , from were the supply voltage comes ? do you have a battery under the antenna ? or do you use a bias-t and feed the supply through the coax ? 73 de Amir 4z1ar
Thanks Amir. Yep, I'm using a battery that is located underneath the antenna. In the movie, around minute 1:08, you can see the antenna on the balcony, and the orange battery near the tripod leg. Thanks for stopping by :)
*HOW TO CALCULATE FOR BUILDING A RECEIVING MAG LOOP*---I need a calculator or formula that can show the measurements for building a mag loop for receiving a frequency range. Is there any formula or a calculator for that?
Just Google it, you will find a set of different calculators the one will fit your needs.
Hello, Where did you buy the couplers and the shaft? Thank you
Hi, please check the other video about the controller. I wrote a list of all the parts in the description. It was from Amazon.
What does prevent you from creating a A/D to detect power of SWR and then automatically "maximise" the position of the motor, on the basis of maximal output power (or minimal SWR)? I am thus proposing to go "closed loop" as opposed to "open loop" control that you demonstrated.
Thanks for your comment, I do have ideas to add this feature and I already mentioned that in previous comments. This was only my first version of the antenna. I hope to provide an update soon. Thanks again.
Hi, Is the 40m loop very directional? Can it be used to null out noise from neighbours led lights for example?
It is definitely directional, but about the null... It will depend on the strength of the signal
Very strong accent 💪
Born like that ;) ,73.
Dear OM thanks for interesting info.Congrats-very fb Your antenna.Vy 73 from SP9DTI
Thanks, 73!
Very Nice 👍, Congratulations
Thank you, @Carlos
Wow, Tamir, this is an outstanding video! I’m going to check out your video on the remote tuning. I’m interested in (watch out) a magnetic loop for 160m since I am unable to use an L or other kind of antenna due to HOA restrictions. The mag loop will have to be how I do it. Again, excellent video. I have subscribed to your channel. Jeff, KF5KWO
Thanks, I'm going to release a new video with a new software version. Stay tuned.
Hi @Herr, I just released the new video with the new software version that will replace Blynk. Good luck.
@@reHamRadio thank you, Tamir, I will check it out immediately! Happy New Year to you!
Great video. moving to a condo with HOA's. Will be building your antenna. Best explanation I've seen.
Can you tell me what the max voltage specification is for your variable capacitor?
Thanks,
Terry, N7TB
Hi Terry,
Thank you. And enjoy the building. I don't know exactly about the max voltage that this specific capacitor can handle but the spaces between the plates is wide, and the plates themselves are heavy, so I can just assume that few thousand volts. The max power that I tested was 100W and without any issue at all.
Great job congratulations
Thank you!
what value capsitor can you use, the one you mentioned is not availeble here
The best will be to check which capacitors you can get, and then, check what frequency range you will get by using the Online MagLoop Calculator. If you have only a single capacitor and you don't get the exact frequency range that you want, you can try to change the loop "size", smaller or larger, and then see what you can get.
I hope it helps, good luck.
Please sell us the auto-tuning version once it’s available!
Thanks for your feedback, Robert, I really appreciate your comment. I'll see what I can do. 73.
Very nice job! 73.
Thank you, 73!
Nachon! Todah! How do you power the tuning unit? Do you power it with 12v over the coax? That would seem to be the most convenient way to do it.
73 de Arnie W8DU
Hi @Arnie, I do use 12V but from a battery. Please review the video at minute 1:08. In that frame, there is a picture of the antenna on the balcony, and it's easy to see the battery near the tripod legs. I separated the remote unit from the Antenna and from the tuning unit. I found it the best way to avoid RF issues and for safety.
And Todah as well for the question ;)
73, Tamir.
I'm curious, in witch way the mag. loop works better, with the capacitor up, or down. A couple of years ago I make my loop with the capacitor on top and the small loop at the bottom.
There are lots of articles out there about that. I personally didn't test that yet.
Thanks very much! It’s a very fine description, I hope the article is very useful for construction of the antenna
Kind Regards! 73!
4S7LF
Thanks Leonard!
73.
friends, I have tried to make an antenna like your instructions, using a 1/4 in copper pipe for the main loop, after I tried it, I couldn't catch the signal at all, please advise what the problem is, thank you
Haryoso
Hi, there are so many options that can cause you to not get any signal. From problem with the connectors, failure coax, capacitor that is in short, soldering, and more... Please try to isolate each component to make sure that they are good.
It's very hard to help remotely with this kind of issue. I would recommend to contact a local ham that may help to check that with you.
I hope things will be ok soon. Good luck, 73.
Wow. Amazing project. I must make something similar 🙂 . But no free time . I am mobile only
Thank you! Please check my website, it may help you to build it. Good luck, 73.
I am VU3SQM, Ameer Khan from India.
Would you advise what is the usual gap between the main loop and the feeding Loop in this design.
Thank you for providing us with magnificent design.
Thanks Ameer for your feedback.
As for the gap between the loops, you can see in my design in the video, that only a PVC in a T shape is in between them. I would say it's around 1 cm at the top. As you can see, the small loop is not a real circle but an oval, because you want as much space close to each loop, to get a better SWR.
Good luck, 73.
Do you use a choke on the RF feed-line?
Hi Peter, no, I don't use a choke yet. The coax is connected directly to the coupling loop and it works without any issue.
Can’t find any links to anything where are they
Click on the "Show more...", Good luck!
Nice build. By the way, your use of the word torsion is off. I think you mean "torsional backlash" in the case of couplers that have springiness where rigidness is desired.
Yep, that's a better way to explain that :) , Thanks, 73.
Perfect for Me that Lives here in New York City,
Thank you, Manuel. Yes, it's a great option for HF operation inside the city. Good luck, 73!
I would love to see a version that could handle 1KW across the band.
As for now, I'm not using any amplifier ;)
Nice wireless control option! I am looking for one for my loop 10 15 20 40 mt. Can you give me the purchase link of the pieces contained in the box? Can you give me indication for the tuning app from Iphone? I appreciate it! 73's de Alex IK0TOM from Rome Italy
Hi @Alex, Thank you for your feedback. As for the parts, please take a look at the description of the video, I already put links to all the parts and apps. Good luck, 73.
Nice, how about adding a motor to the pole as well to rotate the antenna ! VU2INL
Thanks! Yeah, already asked for that. I may release this kind of feature in the future but it may be tricky from the type of the motor as it needs to be more stronger, which means a stronger power supply. Will see.
Very nice video and great antenna. Thank you for sharing your work.
73 de S56RLU
Thank you, Luka. 73.
The area in the center of the US simply doesn't have that many people. - John, in CO
Hi John, yeah, I mainly agree, less people are in the center, but still, it looks very quiet there as the wave just skipped that area, at least this is my theory. Thanks for your feedback, 73.
Thanks for sharing! VK2AOE 73
You're welcome, 73
Yours is the first mag loop build I've seen to use flexible copper tubing. Why go that route as opposed to just shorted thick coax? 73 KN4YRM
Thanks for the good question @Randon.
When I thought about the design, Coax was one of the considerations. But I wanted something wide, for better bandwidth, but also something that will be not heavy and strong. The flexible copper is soft enough to work with, but strong enough to hold itself without any special support. See the pictures how it stand by itself and keep it shape. Also, it's very cheap!
@@reHamRadio Yes, seems too good to be true! So many videos where hams go through elaborate pipe-bending or elbow-joint-making in order to use copper pipes. Great find.
very big capacitor for 430 pf
Indeed, but an Air capacitor that can hold a few KV. It's needed for 100W.
1000 !
Haha! :)
The best comment! Thank you, 73.
Traductor. En. Español
In RUclips, you can enable "CC" for Spanish captions
VK4CP Very Interesting!!
Thanks, Terry, for your feedback, 73.
saludos desde chile CD3FZS y gracias por la informacion
Thanks, @Francisco, I hope that it will be helpful for you. 73.
יפה מאוד! 4X4MN בישראל בונה אנטנה כזאת בדיוק אולי כמה עצות יהיה נחמד אבל לא מצאתי מייל שלך גם בQRZ יום טוב
Nice to meet you Micha :) I just emailed you. Thanks
New sub. Really enjoyed your build.
73
Julian oh8stn
Thanks, Julian. I appreciate your feedback. I watched your videos few times in the past. Thank you. Good luck, 73.