I am anxiously awaiting part 2. My favorite part of this hobby is antenna building. I have wanted to build a mag loop antenna for a while and you have inspired me to get off my couch and do it. I also went back to some of your older videos and really enjoyed them. My father worked with the team that designed and built the Digital PDP-8. I remember the old memory cores like the one you showed in one of your videos. Subscribed and can't wait for more!
Wow! Glad you're doing videos again. You're a ham now, and you're doing a series on mag loops. This is the trifecta of awesome! Love the detail and video production work too. I look forward to the upcoming vids, and may tackle this in a scaled down QRP-ish in the future. Thank you, this is pretty rad!!!
Hi Jeri, good to hear that you uploaded a new video. Thanks. And also a video useful for radio listeners and radio amateurs like me. The magnetic loop has good properties, small/tunable bandwidth etc.
So very happy to see you posting videos again; you were quite an inspiration back when I was in undergrad :-) I have an unfinished loop of similar diameter, though I opted for a single turn comprised of copper foil wrapped around 4" flexible poly drain hose, with (in theory) all the seams soldered. I really ought to get back to it, as it worked very well for reception, and now I have a 1000pF vacuum variable good for a few kV...
Excellent work Jeri. I built my first magnetic loop in 1982. After I did and brought it to the local radio club meeting, an avalanche of loop home-brewing began. It is good to see some well-made contemporary loops.
Hi Jeri, I have enjoyed your in depth videos in the past and am happy to see you are posing once more. Your knowledge and subject expertise is very broad and informative. Please keep up the good work and know that it is appreciate by many. Regards, Don
I've been off air for about 3 years, and you are giving me motivation to get back to it, kb1pvm here, and I say thank you. I can't wait till we cross each other on the waves
Howdy Jeri, K4IVE, Kevin here... Your loop looks very similar to mine, except I used 3/4 inch copper water pipe and couplings to form a giant 6.5 foot octagon. I have 50 or so photos and videos of the build, so I know exactly how much work it is to chronicle a complicated build like this. It's amazing how well the modeling of the antenna system resembled the finished product. My capacitor is a massive homebrew contraption using 3/4 inch and 1/2 inch copper pipe in a compound trombone configuration. My tuning mechanism is all hydraulic, using all plastic components and water... What a crazy project, huh? 73! de K4IVE
Outstanding video. I'm starting to think I live at the North Pole or something, I've never seen your channel before. Excellent build and looking forward to the next one. 73 Julian oh8stn
Okay, I've been holding my breath for part 2 for over 3 years now. Fortunately, I have a cardiopulmonary bypass machine hooked up to my femoral artery that allows me to do this but I am still getting tired of waiting.
Hi, A slight improvement in the signal can be noted by pointing the "holes" of the loop to the generating source. The plane of the nulls of this antenna are parallel to the construction of the larger circle. You can use this feature to improve more good signal and attenuate noise source. Part of the noise can reach the tank tuned circuit by the coax cables through the common mode currents. A simple BALUN 1:1 installed before the smaller coupling loop can also greatly reduce noise. The balun must be BAlanced UNbalanced ... with turns ratio in 1: 1. Only producing the lag between the unbalanced antenna and the balanced coaxial line. 73 DE PU2SRZ
I think there needs to be more enforcement of shielding and drives to move back to the idea of fiber optic implementations and less wireless that isn't so well managed. Seems can create more jobs also that aren't so dangerous for enforcement operations. I suppose the JFK pervs next generation has taken hold and deviated systems to cause more jamming (not just Hollywood's), static, noise and interference. I'm sure there is more than one root cause.
The noise is lower for me using various loops than any other antenna. I usually have built full wave loops, some vertical, some horizontal. I have a decently sized piece of property. Could easily fit a 160 full wave loop. Dipoles have always been very noisy for me.
I built a Magnetic Loop back in 2004. It was awesome. It worked great on 40m. I have the parts to make another one with a Vac. Variable and a motor drive. It's my winter project. I have a 50 foot vertical but honestly, I want the best power and match. I also like how selective the loop is. I work Qrp and love weak signal. Thanks for the video ! I am also watching and brushing up on my electronic basics. It has been fun watching your channel. cheers.
Very nice work Jeri. I am a huge fan of the magnetic loop, I have built 4, and I am just getting started. The simulation work you did is really informative for people just getting into this special type of antenna.
Hey! Great to see you making videos again Jeri. I never cared much for radio but with was my Dad's obsession so ultimately it is how I got started in electronics.
Awesome! Looking forward to the next video. I once made an octagonal 21ft perimeter mag loop, but making a spiral is a great idea. Thanks. What's the efficiency on either bands?
Jeri, love your videos. One thing though I want to point out ( @ 3:26 in the video) is that Hams don't "broadcast", we "transmit". Broadcast is generally accepted as a one way transmission where there is no expected reply like in AM or FM radio stations that broadcast their signals. Hams are almost always looking for a reply or communication with another Ham thus we transmit to each other.
Cool - nice build! I've got just enough room for a 80m dipole, but not nearly high enough for DX. I'll be really interested to see what kind of Q (bandwidth) you get, especially on 160m. I'm liking it so far! 73 de Alan W2AEW
The Q was interesting because it changed radically with the coupling method I used. Using a gamma match was fairly high Q on both bands. I plan on exploring if I can get the 1/5th diameter loop and ferrite coupling method to behave better.
Hmm - that is interesting. I wouldn't have expected the coupling method to have that much of an effect. I hope you explore this in future videos - great job (and proud to have you among the ham community) 73 de W2AEW - Technical Coordinator for the NNJ Section of ARRL.
Great build. I can't wait for part 2 !! Please talk as much as possible about the math behind your design. I am currently working on loop made with 4" copper ribbon - hopefully maximizing surface effect but we shall see.
I've actually had pretty good luck with the 1/5-sized coupling loop, getting bandwidths similar to those predicted by, e.g., AA5TB's spreadsheet which can be found on-line. But, that calculator and my loops are all single-turn, and I'm not sure what the double-loop design does to the bandwidth. Good luck and 73, K7HKR.
Thanks for taking the time to show how to build this type of HF antenna. Being a condo dweller has made HF a non-starter for me, I see magnetic loop antennas for sale but more than what I want to spend. I didn't think of building my own (how I missed this concept as amateur radio is all about DIY/build/experiment). I see other youtube vids on building magnetic loops, your construction practices show how to make it look really nice along with pointers how to make it endure weather.
Dearest Jeri Ellsworth: Love your stuff, and want to build this antenna-but I'd like YOUR advice/dissent on sourcing a variable capacitor (I'd rather not fail often and buy the wrong parts over and over (fail often) as my time and funds are somewhat limited and I have to fish too). You speak of them, but not _about them_ it in this video. Hope you are well and we get to see a PART 2 sometime soon. I'd like to build, test and tweak before Winter of 2018. You make really great videos. Thanks so much, 73.
Hi Jeri, good to see you making more amazing videos about what you get up to. Just recently joined a radio club myself and hopefully should be licensed soon, I'll be following your build on the magloop for tips. Looking forwards to the next video!
carabela125 Is this figure based upon the assumption that 90 extra megawatts is the difference between mere time travel (1.21GW a la Doc Brown) and an intergalactic wormhole?
Awesome build! Some time ago I found a 1 inch rigid copper coax cable on a junkyard nearby and used it to experiment as magnetic loop. I never finished the project, but it had promising initial results.
Really really interested in building the antenna!!!! I hope part 2 construction and a part 3 use video are coming soon. Thanks for all the great info!!!!
Jeri, I've only just found out about your videos, you are absolutely amazing.the perfect example of what a radio ham should aspire to, I'm so happy to see so many young women in the hobby, thanks Scott 2E0 IOJ
