Building a Magnetic Loop Antenna For My Apartment, Part 1.
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- Опубликовано: 17 мар 2019
- The only way I can get on HF in my small apartment now is using a magnetic loop antenna. Follow the build and learn more about this awesome and efficient small antenna.
Link to Part 2: • Building a Magnetic Lo...
Mag loop calculator:
www.66pacific.com/calculators/...
RJELOOP1: zerobeat.net/G4FGQ/rjeloop1.exe
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Great project looking forward to seeing how well it works
I'm anxious to see part 2 Gil. It is always fun as well as interesting to watch you tinker and conceive new antenna systems. I wish you great success with this one. de KM2U
Thank you :-)
Another really good vid Gil. Looking forward to part 2.
Your joint prep looked quite good and so did your soldering so I wouldn't worry too much about joint resistance.
The source of 'HIGH' resistance is usually at the Capacitator's connections and/or the shaft's bushings/slip rings. Your VacCap circumvents that problem.
I'm also in an appartment but on the ground floor. I'm in the process of fabricating a 40 Mtr Spiral Loop based on the N4SPP/SM0VPO design. It will get me airborne with my QCX rig. The cap will be cylindrical and fabed from tall and different dia sized beer/soft-drink alu cans.
Will post here when I get a reading on the cap's range.
If the beer cans fail, I'll fab a ButterFly cap using foam-board and alu foil.
BTW: Can't wait for Han's QSX All Mode/All Band kit.
Regards/73
Russ/KA1RUW
Interesting, I'll look that up, thanks!
Love your "Cousin IT" WInd-Sock👍
Hi Gil,
One more awesome video, a lot of hints and tips.
A good source of inspiration for a similar project here.
Thank you :)
Thanks!
Looks great so far! I have used mag loops for several years - mostly on 40M. I never had a good enough capacitor to tune other bands. I have also used coaxial cable as a capacitor - not practical as you are limited to maybe +/- a few khz, but that works too. I guess I'm still waiting for a vacuum variable to drop into my lap. Since I work in communications, I have had access to scrap elliptical waveguide - it naturally bends into a nice circle for mag loops! Can't wait for part 2. I hope it works well for you (I have lived antenna/space challenged for many years myself).
You can find one on EBay for around $150..
Beautifully done!
Thanks!
i cant wait to see part 2,magnetic loop antennas are best for single band that way lower capacity capacitor used so tunes easier also they work better close to ground you can make it better buy having two the same spaced one in front of the other at a bit of distance all the best for the project 😃
Thanks!
Great job Gill on the apartment loop =) You have one advantage over me as you have a balcony =) I would love a balcony and the size of loop you end up with is great =) I need to shop for a a Vac CAP as Hamfest season is here again =) Looking forward to part II =) de N5VMO Pat
Thanks :-)
Great work Gil, 73 de HB9/F1VNO. I was looking forward to see this interesting project and apply it for my tiny-winy Swiss conditions :)
Thanks!
Regarding the brackets that you need- brass is so expensive, I wonder if a thinner plate with a larger ring that matched the capacitor mating surface would work, the two parts soldered together. That could be made with hand tools. I see 1/8" copper sheet scraps available on that auction site. Excellent video and very inspiring!
Thanks, that is a good idea..
if you use grey flux for plumbing and a stronger hand torch (the ones you screw in a gascan), when heating the flux, as soon it switches color you can add the solder and it will suck it in completely between the joints. On the outer edge there will only be a small film visible and the excess flux can be wiped of. Much cleaner results :) Cheerio! I have to get a variable capacitor, I need a loop here at my home because nothing else seems to work because of the QRM.
Grey flux, noted, thanks!
Hello Gil, realy nice Loop! Still waiting for Part II.
Best Greets,
Jan / Germany
Me too ;-)
me three ! :-)
I still need to solder the clamps...
berry nice gil ,look berry good.RAMON 73,FLORIDA.
Nice.
To cut out the piece you need most probably you can find a shop in the area where they are cutting metals with water jet. You will just have to drill the hole for the tightening screw. If not if you have a drill press, vice, some files and other basic tools could be made by hand. Best 73 de s57rw!
Will look for that, thanks.
3D printing to the rescue! Good luck with your project! Looking forward to more!!
I wish I had access to a metal printer!
Thanks for such a great video.. Many of us only have limited space and our neighbours don't always think that antennas are beautiful to look at :) Andy - G7MJV
Well the balcony is bigger than my whole house. My car or out buildings, I depend on. That aside. Wire antenna is main stay. Incrochment puts me in to looking for smaller foot print. It's study time.. knowledge is power
Tks for show de kv4li
I really appreciate you leaving the problems and errors in your vids they are very useful Gil. Is the clamp acrylic or something less brittle?
Thanks Marc, it's the 3D printing filament stuff, not sure..
@@RadioPrepper Cool, that stuff is used to make the lower receiver of AR-15's so it should be fine lol
Right, LOL.
I am still wishing you good luck with the clamps that don't break the bank. I've never seen anyone paint a loop, yet always wondered about that. I wonder how the skin effect is affected by corrosion or insulation like paint. Any thoughts people?
Thought of trying some copper strap to connect whilst using the plastic bracket?
I did, we'll see...
*Very Interesting.* I've heard guys praising mag. loops, and this looks to be a mag. loop done correctly.
Most commercial models are too small. A 5m perimeter is ideal...
What barber shop did you get that deadcat from? haha. Very knowledgable video, thank you.
Oh this is going to be fun! Thanks for doing this video. Are those vacuum caps very expensive? And where do you get them? Thank you
Hi, about $150-180, on Ebay.
I didnt consider using a toroid instead of using a 1/5 diametre driving loop instead.
Great video ! Thanks for posting. What primer do you use to prevent oxidation ?
Thanks, not sure, nothing special, and in fact it doesn't work too well...
Radio Prepper I had considered using the Krylon “fusion” product for my loop. I am using 4” wide copper ribbon. I m concerned that oxidation would lead to dramatically elevated resistance via essentially messing up the surface effect conductance of the ribbon.
Flange is good but the Jennings one I am getting has flange mounts My big loop is circle of flex l 3/4 and inner loop 3/8 flex l 2 ft. My crisis is nolocal stock for small variable speed motor to make control so gasp-hand tuning?
Nice. I tune it by hand but it is a pain..
Bonjour cher OM .très belle construction ,mais un conseil n'acheter pas les fournitures en magasin de bricolage mais plutôt en quincaillerie professionnel ,le tube cuivre est en 5 ml et est moins cher que a la coupe 👍.
73,
F4fee
Merci!
I initially thought aluminum might be a good idea, but after reading more about galvanic corrosion - it's not a good material choice. Brass or copper are both good on that front. See the anodic index chart at en.wikipedia.org/wiki/Galvanic_corrosion. The resistance of brass is higher than Aluminum and Copper. Looks like the price of scrap brass is higher than scrap copper. Sounds like copper is very difficult to machine. Brass is reported "good" to machine depending on the alloy. A solid brass or copper bracket is looking less and less appealing. I like the "strap" idea. I think we could easily redesign the bracket to work that way.
Could you use 3d printed brackets and use a heavy copper flat braid strap for the connection. Really I'm just curious.?
Probably...
Gil, do you still have your Sark 100? It was giving you issues and since I have one too I am a bit curious. Otherwise, love your videos and keep truckin.
Hi, yes, still use it... Though trying to calibrate it messed it up a bit..
That windscreen for your mike makes it look like you have a very oddly colored beard...or like you're chewing on a Tribble! ;)
I made a small transmitting loop about 3 feet in diameter, using plastic pipe strap. (It turned out to be too soft and flimsy, but I made it work.) I applied 1/2" wide copper foil with conductive adhesive to the plastic strap and connected the ends to the tuning capacitor. I made another loop 1/5th the size of the main loop and hung it inside the top of the big loop, connected to my feedline. It tunes up great on 30, 20, 17, 15, 12, and 10 meters, but barely tunes on 40 and has horrible efficiency. It was very good on 30m, however, so I used it inside my house to run FT8. It handled 50 watts just fine, and even 100w for short periods with no heating. I made good contacts from eastern Pennsylvania to Fargo, North Dakota, about 1800km!
Excellent!
Hi, my Chameleon doesnt work. I wonder as it is inside or under the porch, if in both cases it could be because the ceiiling is low (about 7 feet) and NVIS isnt possible ( m'y friend is 40 miles ahead and my tripod is 3 feet height). Cordially, Milos F4IIP
(Above the porche is a balcony and above an advanced roof ; as it rains I cant no more give a try in the tiny garden)
You can't really do NVIS with a vertical, it won't work well. Are you using the whip? A short whip on 40m will not work well on top of that...
@@RadioPrepper I have a F loop
what is function of the hair on the mic? Does it increase the db?
No, it's to remove wind noises.
Could you paint this, without affecting performance?
I would think so, yes.
Unrelated question, as a Prepper do you protect any of your gear from EMP? I just saw a documentary about what the sun or a EMP bomb could do. We are moving towards solar Max should we as hams start hardening our gear?
Oh yes... Faraday cage...
Fantastic, looking forward to part 2. ON9CJD
Thanks!
Did you use plumbers or electrical solder? And for ones using plumbing flux, are you using plumbing or electrical solder? I have always needed to ask ones who have build these magnetic loop antennas from copper pipe.
Hi, plumbing solder and flux.
Check out pages 30-36 in the April 2019 QST Magazine. There's several pictures of a mounted vacuum variable capacitor tuning assembly for a 160 s 80 meter loop. Hope this helps. 73's
Thanks, I'll search for it..
Hi, do you share the CAD file for the clamp? I have the same capacitor and want to make a loop with the Loftur E. Jónasson - TF3LJ / VE2LJX automatic tuner. 73 PA1RP.
I will put it on thingiverse...
@@RadioPrepper OK thanks, let me know the filename after you stored it on Thingiverse.
How much power will it handle?
Honestly, no idea! I've put 30W through it.. At least 100W I would think.. I'd have to check the online loop calculator to find out..
yikes, don't paint it yet Gil! The success (or failure) of the octagonal pipe loop depends alot on very (very) low resistance solder joints. I went down this road and the results were not very good for me. (Neither are my soldering skills so that doesn't mean anything!!) But I'd leave the paint for later - if you haven't already completed that. Good luck, they can be very good!!! In the end I made the loop from some very nice silver plated coax from LMR.
Good point thanks. I should mention that in part 2.
lacquer would have made a gold look
Wow 🇩🇿🙏🏼❤️🇫🇷
It looks like you’re talking into the top of Geri Haliwell of the Spice Girls’ head. 😆
I wish, LOL.
I thought that was your beard, at first...lol (MIC hair thing)
LOL!
Showed it to my radio friends living in a city.
Nice project. May we get a parts list?
73 DO1OH
Not much to it... A variable capacitor, tubing, 45deg angles and an FT-140-43 toroid.
Do you still need the parts?
Sorry, I'm swamped, please remind me next payday, 30th!
12:36 AHAHAHAHAHAHAHAHAHA...SURE !!!
That calculator is not working.
It worked well for me..
@@RadioPrepper when I hit "calculate", I get:
Validation of viewstate MAC failed. If this application is hosted by a Web Farm or cluster, ensure that configuration specifies the same validationKey and validation algorithm. AutoGenerate cannot be used in a cluster.
See go.microsoft.com/fwlink/?LinkID=314055 for more information.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.
Exception Details: System.Web.HttpException: Validation of viewstate MAC failed. If this application is hosted by a Web Farm or cluster, ensure that configuration specifies the same validationKey and validation algorithm. AutoGenerate cannot be used in a cluster...
(And a lot more...)
Feet? What's wrong with meters?
Metric is much easier...
Cool.
73 de 4Z5UY
Neat Loop. Use Mapp Gas next time. It's quicker and hotter. This is way better than following a woman around with a bunch of shopping bags all day. 73. KB2QQM
LOL.
Radio Prepper I built a 40 M loop like yours about a decade ago. It worked great. Used a metal clothes hangar as a gamma match. Before that I had an AEA Isoloop when I lived in NY in my attic. I remember busting a pileup with that and 25 watts. So many great memories. Small Transmitting Loops are so much fun to play with.
Yep, really efficient!