HAM RADIO: Adding the CAPACITOR Building a Coaxial Magnetic Loop Antenna. COAX MAGLOOP:
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- เผยแพร่เมื่อ 30 ก.ย. 2024
- Building a Double Coax MagLoop Part 2, why part two because I have a Air spaced Capacitor. So this upload is all about the remaking of the double loop using plumbs plastic pipe. it is a simple job but you will need some spacers and a lot of time to get it right. there is NO set diameter for the loops as its a factor of 10th wavelength or there abouts...I decided on 75cm in diameter and ended up with 74cm but it still works so!!!
Parts:
6M of ridged Coax ( something like Andrew Heliax) 15mm
4 spacers (I used PVC Pipe)
2.4M 50mm plastic plumbers pipe
50cm 40mm plastic plumbers pipe
Variable Air Capacitor to finish the job
Special thanks to Andy M0JLY and Chris M1BZN
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Cheers
Mike M0MSN
Other channels for reference:
www.66pacific....
• RSGB 2020 Convention O...
www.nonstopsys...
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What's about dx? How good is the performance of these loops? I saw many of them on YT but I see people use them only for local qso's. What is your longest distance qso using magloop?
I made a loop using copper tubing using two 9m x 18mm and to form 2 half loops and bend them around a 700c bicycle wheel clamped in a black and Decker work mate and joined them together with a copper joint sleave .
The diameter is about 5ft resonated on 80 m and 40m band. using about 150 pf ?
Hi, nice video, I still have a few questions about the Magloop, the coaxial cable for the double loop is exactly 6 meters long, right? How long is the copper pipe that is bent into a small loop? And now the most important question, does the Magloop also make the 80 meter band 3.6 MHz or does it only start from the 40 meter band? Definitely a great project, thanks for showing it. 73 Jörg
Great video.
AliExpdess sells new AIR VARIABLE CAPACITORS if you can't find them.
Cool, thanks
Two pieces of PCBd back-to-back also makes a high voltage capacitor. Adjust the amount of overlap to change the capacitance.....cheers
You may want to trim or etch the copper back from the edge of the board to increase flashover voltage, but that's trivial to do. Beats the pants off gluing tin foil to window glass!
@@fletcherreder6091 Yes, that really is a given....cheers
@@ZL1BQDRoly Wait, are you _the_ Roly?
73, KD2TDE
@@fletcherreder6091 👍 I haven't been call "the Roly" before but yes i am the Roly you are probably thinking of.... cheers
squash the loop into a slight ellipse
do the test of putting horizontal the ring, in theory it will become omnidirectional and it will exclusively capture the signals (and noise) that arrive from "just above the horizon" (in theory the electrical noise of nearby towns will not be captured or will be captured very attenuated given the great directivity of these antennas)
I read about doing that but the information said you need to put the loop quite high for it to work well
Great Video, Mike. Thank you for that. 73 de Michael, DL2YMR
Many thanks!
Very nice build, though watching you cut that lovely capacitor in half was painful. It is perfectly shaped to fit inside an 18 inch length of 5 or 6 inch diam PVC pipe which would perfectly weatherproof the entire assembly. A short length of thinner pipe, such as the support pipe you used, could then be butt-joined to the top of the capacitor pipe to serve as the top support for the loop while also providing clearance for the coupling loop.
Great Idea, but now the single capacitor is making two loops work..👍👍
Capacitor envy
👍
I like the plumbing version Mike 👍🏻
Thank you - this is more of an education than the foundation course !
Thanks 👍
To my previous comment I used plastic pipe to keep a gap at the top of the mag loop this carbonizes. On ebay there are sellers selling PTFE rod various sizes hope this is useful info.
That mag loop set up with capacitor looks very much a fair weather set up. Tell me you rain proofed it, frost and snow likewise
So you coupling to both loops or just the front or just the back one?
There is only one loop. 😊
Hi Mike probably a daft question to the initiated, Am I correct in assuming the coax feeding the antenna connects to the small loop , And is physically not connected to the big loop? The capacitor is connected to the big loop as adjusts the swr ? If This is the case how is it possible for arcing to occur in the capacitor when things aren't right , I've been scratching my head for the last hour 😊👍
Hi, you have to look at this like a transformer the small loop inducts a larger voltage in the outer loop.
Ahhh the penny has dropped, thanks Mike makes perfect sense 👍
Great Build! I was fortunate to have a scrapped High power Ext. Tuner with the multi Channel tuning Components to use. Will try the Double loop with Heliax Coaxials (rigid )Thanks!
I was thinking about using the microbore central heating pipe for the main loop not sure how much it would change the calculations, I think for me might be easier to come by.
I've also heard that these loops are much quieter so maybe you can do a follow up video comparing the noise levels with your other antennas. Nice job Mike very enjoyable to watch!
Go for it. 😀
definitely less noise! 👍
Ah ha ha! Always gotta have a shot of special hot beverage.
I love the way these coaxial MagLoops look Mike 0 Mike.
Did you short the braid or ground to the center wire of the coax before soldering on the connecting wire?
Hi Mike hope you well ... which is the best loop the LDF450 or 22mm copper ... also have you seen VK5SFA Loop 160m 80m DXCC on 160m ... Mike M0CSI.
Not sure, my pref is the 22mm copper
Coffee. Don’t attempt anything before coffee.
Where is you tuner?
No tuner needed, the antenna is adjustable via the V/Cap
Learning a great deal watching this, going to attempt building one.
Another inventive solution. Good results interesting rebuild on the cap.
Mister Mike exelentes sus proyectos mis felicitaciones .muy practico.
Now that I could build, nice one.
Go for it!
@@mike-M0MSN I would but I would be told to take it down again. I am getting a bit frustrated, lack of money and not being allowed to put up aerials, though this I could sneak in the garden by the shed, but I would be told to take it down as soon as it is seen! :-(( I am going to fill up another permissions form this weekend, they will get fed up of me asking at some point 8-)
Another nice build Mike 👌
Blatant product placement of the DX Commander mug on the coffee machine 🤦♂️😂
Look forward to whatever the next build will be 👍👏👏
Oops 😅
Good job
Thanks
@@mike-M0MSN no probe im going to have to build me another when I have time
You culd have shorten the cap a couple of plates and decrease the capacity by adding spacers, something like chimneys. Just to get the voltage handling higher.
Also the mangnetich loop is challenging because the high voltage and current. So a clip like that on the capacitor might cause a lot off loses 🤔 great idea though
It's nice to watch you build your stuff and I'm getting good ideas for my own projects from you, thanks and keep up the great work. 73 de OH2FHJ
yes most of the projects here are improved on.. I have already upgraded the connections.. :)
Mike, I don't believe your copper coupling loop was too big. I think you just weren't getting good coupling. You need to have the loop eliptical in the west-east direction. 73 KD9PME
I will give it a try..👍
Well done, Sir! You've given me a number of ideas that should prove useful in my own experiments. 73 es DX de JB/k8os
Excellent!
Why not turn it into a 80m loop. Shame to waste the lovely coax.
I may do that as well
Looking good Mike! Certainly pulls in the signal and SWRs well, I can't get used to the narrow bandwidth on magloops! The capacitor was just the job too.
Thanks 😊
Nice one Mike the pvc drain pipe is a good move.
Well done.
Pete/ G0LVG
Cheers Pete
so i have a question ... why not use 3 loops or 4 or X loops of coax for the main loop ??? and or maximize the loop diameter ... more capture area means more gain and capture area no ? the cap could be changed for freq of interest ... your thoughts please ... thanks JF / N7WDF
You can use more than 1,2 or 3 loops but each loop adds to the circumference of the first so lowers the loops operating frequency.. read this website for more... www.nonstopsystems.com/radio/frank_radio_antenna_magloop.htm#top-of-page
Another way to attach coax feedline is to use short solid wire soldered to the tubing first, then solder the coax to the solid wire. This allows any amount of heat on the feed loop and minimum heat to the coax. Good video.
Good tip..
puff? Because picoFarads is to difficult to pronounce?
lol
I built a magloop too - it has an extremely small bandwidth.
yep!
Nice job Mike. And that is a TASTY Capacitor. Must admit to being a bit disappointed. I thought you did ALL your projects in the Kitchen :-)
Yes sometime my wife gets in the way...lol Thanks 👍
@@mike-M0MSN Thinking about it you make a very good point re the driven loop and the size. That might be what I am getting wrong with my loops. will have to have another experiment some time. When i try the analyser on it I am just not seeing anything at all :-(
You have no PLT in the neighbourship? And: How did you managed to get the motor running veeeery slowly? I have a diy Loop, too. But wvery motor I have is much too fast.
Slow motor and large gear wheel small drive wheel.
@@mike-M0MSN Mike You forget thanks to who build this capacitor GM0SDV
Mike, where can I buy one of those very pleasant VCs? I want to build one of those. My current fleet of shoddy antennas are not urban noise suitable...
No Idea, maybe eBay, I was given this one by a mate, I am going to make one soon.
@@mike-M0MSN Some nice people on Facebook sourced a company that sell them. It seems that it's quite a niche thing for whatever reason. It's almost more like metalworkers skills than electronics. Or plumbing for electrons.
wow great job mike it recieves brilliant aswell
Thank you kindly
Mike, which of your loops do you think is the best?
Early days each of them has it ups and downs..😅👍👍
Nice job Mike. Great video. de motfy
Thanks 👍
you are not suppose to use antenna tuner with mag loops ?
Yes you are right, what makes you think I am?
Hi, great videos, take my foundation a week today. Got directed here after watching Callum's videos - You must be an electrician Mike, 2 compartment trunking in your garage :)
Best of luck with your exam 👍
Passed :) Cant wait to get my call sign now!
@@GazzJ82 well done. 👍👍
What length of Coax did you use for that antenna? What bands can you get?
8M of coax. bands 40/80
I am wanting to do a similar build. Can you please show me a picture of how you have the capacitor connected?
Hello Mike it is possible to note the diameters of the small and large loop in the description?
Yes the Larger loop is 1.27M Dia, 4 Meters X 2 in circumference (8 Meters total) and the small loop is 20% = 50cm D 160cm C.
@@mike-M0MSN is there a benefit to having multiple loops as boosted to a single larger loop.....does it just same space?
Us aliens have loopy antennas
cool
Are you using flexible conduit for your loop?
Never mind, I say a previous vid that mentioned andrews coax cable... have never seen that before And it resembles flexible conduit...
Very true Joe, easy mistake. but a good idea if you only have bear flex you could twist together multiple lengths and feed it into the conduit.
Nice! What is the space between the loops?
10cm space between the loops.
@@mike-M0MSN tks Mike 👍
What a waste of LDF4-50
Why?
@@mike-M0MSN The price of that stuff i struggle to afford the 7 meters of it i needed plus connectors but i spose if you got it to throw awy then still a waste of it thou