HAM RADIO: FINISHED 80M Band Wire Spiral Loop - Magnetic Loop, Small Gardens,
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- เผยแพร่เมื่อ 30 ก.ย. 2024
- Well this has been a stop and start project, due to work commitments it has taken me over 6 weeks to complete this antenna, but the time spent, was worth it.
I have to take my hat off to Frank and thank his for a great website (linked below) without his research and brilliant record keeping this project would not have got off the ground.
Please check it out at :
www.nonstopsys...
Now for a list of what is needed and measurements please refurbs to Franks website, I have followed the plans and instructions to the letter and have manage to produce a fantastic working Spiral Loop antenna for the 80 metre band that works.
I have changed one or two parts of the design, this was to allow the introduction of a home made capacitor for higher power handling unto 200Watts and also the frame has been updated for products available today.
I managed to get some good results from this antenna and over the next month or two I will compare it with my Twin Copper Magnetic Loop.
something too look out for....perhaps.
Thanks for watching my take on this build.
Please subscribe and like.
Cheers
Mike - M0MSN
P.S. do not take my word for it, give it a go for yourself.
What is of REAL interest is watching the back ground noise drop away when you switch to the loop and still have a good received signal.....It would be very interesting to see the same comparison with a very weak signal....cheers
Yes that the next challenge Roly, and the weekend is coming. cheers mate.
This is what separates the serious DXers from the rest of us; focus on the RX side of things as Roly is doing here...this is why Roly has the DXCC totals he has. 73! de WX0V
I wonder if you ran 2kW into it, would it become a Stargate ?? Or would it just open a portal to the realm of demons ???
Yes Stargate lol
Hi MIke - this is such a cool video, and nice to see how this mag loop performs on RX - very well it seems, will you test TX? The graphical illustration of the loop going in and out of resonance was particularly interesting. I said on a Cal video earlier that he keeps this "new" hobby alive for me. The same goes for your channel. I will never be a great DIY builder / (like you), but I did build my DX Classic and look forward to buying and building the 12.4. Perhaps you and Cal could offer the sorta Mag product you have shown in this video in kit form? A kit version of this build is something I would certainly have a go at. Anyway, thanks for a great video. Mark, 2E0MSR, 73.
Hi Mark, many thanks for the flowers, this coming weekend will be the true test of the wire loop
Wow...... I need this antenna for my 705!!! Sell it!!! Make antennas and sell it.... beautiful work... ✅ 73.s Dl3PWR.
Hi Mike,
I have been a ham since 1991 but I've never tried making a loop - and I have a question you might have come across.
Is it possible / makes sense, to make a long coil antenna. Like a "slinky" but scaled up. Say 10m long, 30cm diameter, wide spaced coil. I have a relative small garden and would love to have a decent 160m antenna like that.
If it works it would be cool to try using it as 630m reception antenna too.
Haven't found any calculations online for such and antenna. Any ideas?
Cheers SM3TTZ
You’re a ham. Try it. Share the results on TH-cam. :-)
If you’re talking a vertical helix style. It should work. Narrow band though.
Mag loops work best between 1/8 & 1/4 wavelength in circumference. Anything less and they’re efficiency drops. Anything longer it losses it’s electrical noise rejection characteristics on RX,
The efficiency is related to the area inside the loop with respect to the wavelength, so a circle works the best, square is not quite as good at around 78% of the surface area for the same length of loop material.
You also want low ohmic resistance at RF so surface area, not thickness. 1/2” copper would be the minimum, but 1” aluminium is fine, and much cheaper and lighter.
I have a small back yard and I run a 10m end fed vertical for 20m with a 2m trap and extension for 40m
I have a semi portable loop that has lengths of aluminium strap that are 3m, 4m, 5m and 8m long. I can use them individually for coverage of 40-10m or I can join them to go lower, which I have yet to try.
The vertical takes up the least room, but is noisy on RX with the hash peaking at S8 with no filter and S3 with the CW filter. On TX it punches a good signal. The loop, on the other hand is only S3-S4 with no filter, and, provided it’s pointed in the right direction, is negligible in its difference on TX.
I use a push up lighting stand to get it 3.5m off the ground. And a shot bag to weigh it down do it doesn’t blow over when there is a breeze.
Given I’m on an inner city block, 5m wide and not that deep, (the residence is incredibly long) the mag loop and vertical have served me well, until I can figure out how to get something on the galvanised steel sheet roof 2 stories up :-)
I built one for 20m with a capacitor made of two pcb's, a dry sponge and a 3d printed bolt / nut to adjust the capacitance. Touchy, but it worked :-)
2 PC boards and a dry sponge! LOL That sir is the spirit of ham radio! Nice.
i built it for 11 m en i try it dry sponge and 2 pieces of a Coke can and a plastic bold from a toiletbril later i try it with a coax capacitor you can trim it to resonant freq it was a fun and educational project for me
I'll be trying with a jam-jar (OK, Aldi black olives jar, nice straight sides) capacitor, brass sheet rolled to fit halfway around inside and outside, supposed to be good for 10 kv or so!
Nice build -
Two points:
Nylon nuts and bolts - very useful for mounting hardware and not causing too much trouble.
You tinned the wires then put them into the connector block. This is rather unreliable. The connection will work loose over time. The pressure of the screw contact slowly causes the solder to flow away from the contact point making the connection become loose. In power situations the connection can then arc and get hot / catch fire. I have a nice example of this happening from a pre-made 4 way extension socket. One day when I unplugged it, the plug was almost too hot to touch. The wires in the plug had been tinned, and had blackened with the heat.
Just use a hard metal ferrule (brass) and crimp the wire into that. It's also ok to solder it in as well. The hard metal will not flow in the same way and the contact will be more reliable.
I'll send you a photo of the wires!
Andy
Agreed Andy, but if I needed the antenna to last as long as the need to use ferrules, I would have soldered the wires and done away with any mechanical joints altogether, the ferrules would have introduced another impedance point making the antenna less sensitive, however I do like the idea of Nylon.
thanks for your input.
And so they would be 11 Meter magic? explain please
you need to wind 2.5 meter on a smaller loop
I vote that Mike's channel is BY FAR, the best amateur radio build channel on TH-cam.
Many, many little tips on how Mike builds things have found there way into my humble efforts. Even just the attention to detail is entrancing.
This is a woefully undersubscribed channel for the quality (yet still nowhere as underappreciated as my book - but that's a different story I guess...)
Thanks again!
Yes it is very talanted
Mike, If it's working that well indoors so near to the ground and with all the in-wall wiring, I can't imagine the performance you'll get once it's mounted a bit higher and out of doors. Fantastic video, mate!
I would have drilled 2 more holes in the vertical pole. Fed the 2 ends of the loop in, and taken the cap off the centre joint.
Terminal block inside the joint, and coax cable inside the leg pole.
@ 9:40 OMG that was disgusting, I use my screw drivers as chisels and drifts but using flush cuts as a crimper is next level shit.
You could make some money selling these! I’d certainly buy one as moving to a terrace house with no garden or space to put a wire or vertical antenna with only a balcony on the second floor. I work very long hours so don’t have time to try to build one myself. I wonder how much you’d charge to make me one for 80m with postage to Australia… also what’s the power rating and could I use an auto tuner for other bands?
Tinning wire that will be used with a compression type connection is a bad idea. Solder cold flows under pressure. You once tight connection becomes loos over time . This applies to connections under screws as well as grub screw connections
Could you go to the band with no station, so we can actually see the noise levels.
Also pick weak stations, rather than the S9...
Seems a common mistake everyone does, when testing antenna.
Personally i pick a station in the noise, or a weak beacon.
Good work on the loop, Mike
Yep will do, :)
Maybe a dumb question but could you connect the radio directly to the main loop and use the radio's tuner instead?
Very smart talented I agree best d.i.y.s. Build channel on youtube
Great job! The homemade capacitor is really cool!
thank you
You do incredibly neat work Mike, congrats. It would have been interesting to see, if you gave the loop a better chance by doing the test with the loop outdoors and then turning the loop for max signal, then switching between the antennas
next video ...... I think!
How did it respond when you transmitted ? Very impressive indeed! Would you be able to listen and transmit on 40 m and 20 m with the same antenna? If not, with a higher valued capacitor allow you to do that?
bet he wont post a vid of the tx test as it will be crap!.
Hi Mike,
Thank you very much for your very good comments on building your 80M Band Wire Spiral Loop.
What are your experiences today between the two antennas
“80M Band Wire Spiral Loop” & the “Twin-Loop Antenna”.
Is there already a report on this, or can you write something about it here?
Thank you for the great inspiration.
73, Ingo
The copper twin loop is my preferred loop and is still in use today
Hi. Is it possible to use 1.5mm plastic covered steel wire instead of copper wire? like a washing machine. If you share the project drawing on paper, it may be more useful for those who do not know the language like me. thanks. TA5MEX QTH TÜRKIYE
Steel wire would be a poor choice. The resistivity of steel would add considerably to the feedpoint impedance making the moderately low efficiency even worse.
@@RobB_VK6ES Hi. I use 40-80 1/6 balun and plastic coated braided steel wire. I am not very satisfied. Likewise, having copper should be a great advantage.
click the website link and print the pages..
Wow fantastic project thanks for sharing this video I am trying to make my antenna thanks so much for your class 73 from kb2uew
Have fun
Can it used for transmission ??
congrats Mike
on all your 11k + subscribers if only we could get at least 1000 subscribers we would be happy
You've got one more (just subscribed)
@@mike-M0MSN thank you so much i love watching your channel and you building stuff in the kitchen and coffee in hand you and callums channels are very informative
Just wondering the performance differences of variable capacitor in various weather conditions. Specially when it's open like that outside.
Not to be used in the rain.
Wouldn't the Tuning Capacitor mounted at that Location (Possibly) be affecting your VSWR ?? - What if it were mounted slightly below the (Multi-Turn) Tuned Loop. ??
probably not
@@mike-M0MSN I want to try and make a Loop Antenna like this.. Supposedly they work very well, better than an "End Fed Long Wire".. For me I would only be using it for Shortwave Listening.. No TX Required. So VSWR won't be an Issue. (However.. Building a Wide Band version) for 500 KHz to 30 MHz not sure if Possible. thanks for posting as it helps with construction methods.. 👍🏆
Hard to understand what your saying when the guys were talking on the radio. Great video and another great capacitor build. And you gotta love the mfj analyzers.
Sorry about that
Hmmm was this built to be used as a receiving antenna? How directional is it?
I expected that you were going to try an on the air check to see how it worked transmitting.
73 de w8nsi Jim
Both Transmit and receive, with upload the next video Transmitting soon.
The spiral pattern looks cool but does it really make any difference if it is a sprial or all in one loop?
Yes simply put it is frequency dependant given the size of the loop.
Hi Mike, where do you get the capacitor plates from?
Etsy.com (SnowistCorner)
Neat Job....73s
I bet your wife loves
Mike did you make your plates for the variable capacitor
In this case yes, however you can purchase the same plates from Etsy.com
Look up videos of baking soda and super glue. The combination makes a VERY strong bond. Nice build, btw. IMO that antenna would be a good for dx'ing the MW band.
👏👏
I don’t recall you transmitting on the accept to tune. Is this a receive only antenna?
yep that's this coming weekend
good work .... salute from Chile.
It"s Frame antenna.
It just occurred to me that the loop directly fed with a MFJ-936b loop tuner would work great without the coupling loop. This would get a station on 75/80 in a very compact space. Now I really wonder how it works transmitting.
super
It looks great, portable and not too large. I'm guessing it's not to be used if it's raining with the external variable capacitor.🤔
Fantastic antenna. Thank you for posting. You probably do not have to have it very high above the ground for receive. The lower the less noise it will pickup. Also, the strength of the signal is not very important. It is the signal to noise ratio what matters. I use LoG antenna for Rx and I like it very much with SDRPlay. Have you tried to Tx with the antenna? I would like to see WSPR at 10mW.
Hello Mike, what did you use as end caps? Cheers
I 3d printed them
I'm glad that the superglue is not rock solid. 😃Otherwise it was impossible to remove the incorrectly installed strip connector (4:13) and glue it again in the right direction.(5:03) Otherwise a very nice video as always
Fabulous result mate. Well done and well built too. It works!!
thanks Tom
What kind of DB gain do you think it has
-3db maybe I don't know
Nice design! And it even works indoors.
Yep so far so good Paula
Your 3d printing talent is as good as your capacitor build talent.. love your capacitor build video's.
Glad you didnt build it any taller Mike :-)
yes!!
Very nice & clean design Mike - I might have to try making one of those.
Go for it, cheers
Beautiful work as always Mike.
Thanks
I see the PVC comes from CastleHAM. Greatest...PVC...ever. Enjoyed the video...73! de WX0V
Thanks for the info!
Putting the amateur into radio.
Thanks Ade :)
👍👏👏
Good job Mike 👍 Vy 73 stay safe Mabuhay🌺
Great Build Mike, as Always.
Would changing the orientation, change the radiation pattern - instead of having the vertices at ( Clock Face position ) 12, 3, 6 ,9. rotating 45deg to 10, 2, 4, 8. can't explain any other way without drawing a picture lol.
Thanks for sharing. 73 Barnie de M7PBX.
Great question, possibly, build it and let me know.
After talking to you in CG this morning I laughed when I heard my callsign as the first thing you played from the radio....mind you I did have an extra W added... Nice one Mike! Dr m0tfy
Love that!
Thank you for this video and interesting project. Will we see another video about this antenna, showing us some real SSB or CW qso signal reports from your tx-signal? Reverse Beacon Signal Report data for example? I think, showing a low SWR is not telling us anything about the practical usability of any antenna ;) all the best to you and yours, vy73 from Hamburg/Germany, Dietmar, DL4HAO
Thats the plan ..:)
This is the exact antenna I am planning to build, and it's great you just built one Mike.
I'll be very curious to see what it does as a TX antenna (I guess it will be similar to the RX performance) ; I am also curious about 2 things actually :
1) if performance is better with the antenna at say 10m AGL vs 1.5m AGL
2) what is the recommended safe distance from the antenna when it's transmitting at 100W (since you have a nice capacitor that should at least handle that amount of power).
So thanks for that, Mike, and for all the entertainment you provide us through your channel.
73, Chris VA3KWX
Well hopefully I may get time to try it soon.
Fun job , enjoy the fruits of your labour. Thanks for making the video . 73 Leo K
Thank you
Great video Mike, keep them coming bud. 73 for now. Tappy
Thanks 👍
Really interesting build. One of the simplest 80metre loops I have seen. Gonna have to try and build one. Was you comparing the loop with the shortened 80mtr EFHW as per your earlier TH-cam video build?
Ivan G0BON
Yes Ivan, I was.
Just crudely modelled this antenna, although the jX was 58R the Imp was 0R???? but maybe a mmana gal quirk. I found it gave a nice bubble at low levels, I.E. floor level, but once you give this height the dB gain increased but it gave weird patterns at given heights on the Fairfield plot. Might get one in my loft in a few weeks time. maybe try remote tune the cap via a servo...
Something I should do MMANA. :)
NICE!! Sounds like a winner!
Your the best Mike keep up the great work and great videos
Love when you and Cal get together you have me rolling on the floor
Chow from the states Mike N2dbi Ny
Thanks 👍
Very interesting video as always Mike.
Any idea what the max safe power the capacitor will stand.
Also will you try rotating it, manually would be ok to see if is directional and can null out noise.
That's the plan! maybe this coming weekend
Job well done, Mike. That's a nice looking antenna. It seems like it receives pretty good... Does it radiate equally well?
hopefully that this weekends plan
Would love to build one of these but I'd not know where to store it. That leads me into an interesting question. If you replaced the lines on a rotary washing line with antenna wire, I wonder if that would still work as some sort of an antenna? How do you make the fins of the capacitor?
interesting idea
Cool build thanks for sharing. Your wife has to be a Saint letting you work in her kitchen. My wife would skin me and feed me to the hogs in the back pasture.
Yes she a good egg. :)
Your work is neat and brilliant. Looking forward to your weekend video on TX with this amazing antenna
73
New Delhi
Many thanks!
Well that’s a damn fine looking antenna.
Always impressive Mike, i wish i had the confidence and ability to make these projects but alas, until i can honestly say "i can do that" I'll just watch the master in action. 73 Mike.
Hi Mat, give it a go you may surprise yourself.. :) 👍
Great stuff Mike . lot less noise with the loop .
Does it tune better outside in the garden, away from the window frames?
Does the cat affect the SWR?
The Cat helps but by just a whisker
Excellent ant, and great for small qth, apartments etc, well done Mike. Did you try tx, and if so, what pwr is it rated for.
Not yet this weekends work
Brilliant Mike, you're right onto these loops just now huh 🤔 as always thanks for sharing.
Glad you like them!
Nice work Mike. How far have you been able to have a QSO? 73 Joe
I have only done some short QSO around 300 miles this coming weekend is when I will give it a go.
Brilliant mate, cheers!
Yes dear trust me it's a new style garden umbrella - would I lie to you ? Great job Mike.
Yes! Thank you!
Good Job Mike. I really enjoy your loop antenna builds. 73
Cheers Steve
Nice. Thanks for the second part lol. I have been madly calculating lengths. Could the tunable range be extended upward in frequency using additional capacitance?
Edit: what voltage rating wire was used? (Insulation breakdown) I know there can be high voltages on transmit and was wondering how much to spend on higher voltage ratings.
Do you also figure the spiral loop is better than a parallel loops with spacers like many others have done, in particular, does it seem to affect the bandwidth due to the differing loop sizes?
Thanks from Canada 🇨🇦.
The more capacitance the lower the Frequency, if you need it to work on 5MHz say you need to remove a turn of the wire......
@@mike-M0MSN I put some thought into that and am more confused. As I understand it, an antenna longer than resonant (resonates at a lower frequency) is inductive and requires capacitance to bring it into resonance at the (higher) frequency. Similarly, the short antennas are capacitive and require an inductor to bring them into resonance.
Perhaps I have something upside-down in my learning. I'm great with computers, networks and autos, even medicine, but antennas seem to escape me!
Edit... more reading and cogitation overnight (I normally work nights... night off) and I think I realize my mistake after reading a manual for (of all things) a MFJ loop tuner. They recommend cutting short and using their capacitor to resonate the loop at a lower frequency. I think the difference in the various discussions is whether the capacitor (or inductor) is in parallel or series it seems...
Nice build..............👍👍
Thanks 👍
Amazing, if I would not see it build by you I could swear it was a commercial product. And better than that, it works fantastic! 73
I've bought a LOT of commercial antennas that are not built remotely as well as Mike's work. No where close.
He takes pride in what he's doing. That much is obvious.
Oh wow thanks guys.
Excellent stuff!
Brilliant!
what was the catalyst spray you used Mike?
Silversil Cyanoacrylate activator
very interesting Mike, now subbed 👍
Awesome, thank you!
AMARAL PW8BR/ RO
I was curious if you experimented with your feeder loop Covering the top and bottom half so that it was in a diamond shape rather than in a triangle and if that would’ve made any difference also did you try to transmit if so how did that turn out
Great idea with the feeder loop may try that, transmitting this coming weekend
@@mike-M0MSN I’m considering getting a power out for my Yaesu 991 a - Just wondering if you have any recommendations
Хороший результат, Mike! Good!
Спасибо
Well done!
What is the wire and where you get it from?
@DX Commander Might have to buy some for the one I tried a few years back. Never got it working as a antenna transmitter, but as a receive it worked well.
You know if you turn on your radio without a antenna and tune the loops wit hit in the middle it will bring up the signal on the radio. Quite a neat trick .
Thank You very much!
No worries!
Nice work mike very neat.
Thanks 👍
Nice work.
Thanks!
I have an 80M - 30M magnetic loop, 6' (2 meter) diameter. 500pF Vacuum Variable Cap for tuning. Very high Q, SWR rock steady at operating frequency (after tuning, of course). Mike, I like how the noise floor dropped when you switched to the loop...and the received station was more intelligible. Mine exibits the same behavior. The DX Commander was bringing EVERYTHING in....including band noise. I am going to be feeding mine with an amp soon, as the VVC will allow 700+ watts. So far, only 100W. Great job on your magloop, my friend!! I love these things. I'm building another one now for 20-10M...only ~1 meter diameter. Same VVC-type tuning system.
thanks.