49:1 End Fed Half Wave Multi-Band HF Antenna 80m - 10m
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- เผยแพร่เมื่อ 28 มี.ค. 2020
- Here we take a look at an End Fed Half Wave antenna which is resonant on many HF bands due to a 49:1 matching unit being used.
Antenna Design Plans:
www.m0dqw.com/2022/06/28/491-e...
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#TechMinds #efhw #49:1 - วิทยาศาสตร์และเทคโนโลยี
After some extensive background research and a final push of encouragement from this excellent video I decided to try this antenna system. I made the transformer with two T240-43 toroids for an alleged efficiency increase and power handling. I used the same Sotabeams thin wire for the antenna and the coil by wrapping approx. 92 turns on 40mm PVC pipe I got the desired 110uH. I hung the wire very much like you have, using a 10m pole and fastening the coil end up the rooftop. The system has been tested only on receiving as I'm waiting for a vna analyser and it seems to work very well, it receives in all the claimed bands with relatively low qrm and good voice quality. I really like it 😊
Very useful thank-you. I am just about to put up an antenna for my first HF rig so this information was spot on. :-)
I will be putting one together for my home in Boston MA USA. Thanks for putting this together!
Very good / Clear Explanation and demonstration!
I'm using a non-resonant end fed as an inverted V strung over my house. I've been considering a resonant EFHW and this antenna looks brilliant. I'd be tempted to design the trap coil so I could wind it from the same wire as the antenna to eliminate those connections. Thank you for the excellent video. Very well presented - educational and morivational!
ThankYou for sharing your system Tech Minds, I do have in a box an end fed 80-10 from MyAntennas soon to go up.
I built the transformer last weekend. I just got a delivery of antenna wire and feed line. Next is the loading coil. This baby is going up this weekend! Thanks!
That’s great! It’s an extremely popular design and works very well for what it is. Let me know how you get on!
Really interesting thanks .
You’re welcome 😊
Played with half waves for use on single band but never tried multi bands. Thanks for the video. 73's
Thanks for watching!
I'm using a 35m horizontal end-fed,with a 9:1 unun.I have some counterpoise,but I get a really nice amount of rf coming back to the shack..will need to make a choke.
Except for that,the antenna works on almost all bands even without a tuner,my old FT-757 can handle a 2:1 SWR with a fan on top of it.And performs really good,especially on higher bands in Es
I have this antenna as commercial - it's the Hyendfed 5 band efhw. Looking forward to reinstalling it properly this time when i move to my new QTH - from flat to house with small garden. With the current pandemic, it's going to be a slightly longer wait though. Stay safe people. 73 MM0SDK.
I have same antenna. Very good. I also have monoband antennas from www.lambdahalbe.de that use no matching transformer but rather an ajustable matching stub. the 20 meter band antenna is great for portable work!
Hi,informative video,didn't understand everything, but thanks from Rotterdam, 👍👍
Glad it was helpful!
good informative video, just finished building my 49:1 - 2x ft240-43 Fair-Rite cores, 14 AWG Enamelled wire. gave it a quick test with an analyser and all good. the induction build for 80m was of real interest, as was your SDR test- well done. 73 M7PBX
Thanks for watching! This antenna has been a life saver for me with my small garden. 73 M0DQW
@@TechMindsOfficial Update: Yes this worked really well for me. 40m -10m- only. Made a contact in St Petersburg And Luxembourg soon after.- chuffed!
I'm now re-building it with the 80m addition, so I'd like to ask did you tune the 40m first then add the coil and extra wire then tune the 80m portion. thanks again for this informative video. M7PBX.
No, I put it all together and then tuned the 40m part, then the 80m. Bit of a pain as had to trim and remove the coil, but got there in the end
yes my friend it's been a long time since I was looking for this solution. you deserve a diament 73 qro of cn8mm
Thanks you!
Nice work Matt! I've been playing around with the EFHW design for about the last 6-8 months now for going portable and having built a heavy duty 49:1 transformer to feed a full sized 130ft element I have found it the best /P antenna thus far. I wish I had enough room to put one up at the home QTH as well but alas at the moment thats not posible. 73, Tom, G2NV.
Thanks Tom! I wish I could test the full size version without then loading coil but my garden is small. Maybe in the summer if we’re allowed out I might try it portable! Good luck 73
@@TechMindsOfficial & Tom, I have recently had permission to use the roof of one of my works buildings- 60ft high & 190 ft long. The Future is Bright - The Future is Radio.
Very good! I ordered a commercial End Fed by a company called HyEndFed in combination with their line isolator, nonetheless your video gives a good insight, thank you!
Hi Matt,
I bought a ready made EFHW-8010 from myantennasdotcom. It has a 49 to 1 matching transformer and a coil 78 inches from the transformer and 124~ ft more wire to the end insulator. I have the transformer ten feet off the ground and the end insulator about 20 ft off the ground.
I did not have any analyzer available when I started using it and the internal tuner was not sufficient so I bought an external tuner. I now have an analyzer and found the low SWR below all of the bands so I shortened the wire at the end and now have this low SWR at the bottom of each band. I do not use a wire counter poise as the manufacturer says that is recommended as long as my outer shield of the coax is grounded. I think it has performed well but have nothing to compare it to except for my vehicle mobile unit which seems to perform just as well.
Thanks for sharing!
73
Kevin KA0KAE
That’s great news Kevin, and I’m in a similar position. I don’t have much to compare my EFHW to apart from some verticals which I have been testing lately. I think for a multiband antenna it’s great! Have fun! 👍
Great job and sure is great when when VNA shows you that it actually works as designed !
73 N8AUM
New subscriber to the channel really great stuff here! Thanks so much!
I have a 49:1 balun wound, and the fiberglass mast, but need to build that loading coil. I haven't started using the mast I've got so I'm in the prep phase.
I also have a small 9:1 that works but I haven't tried that vertical either.
I never considered running the wire up through the inside of the mast. I'd have to either remove the top section or cut it, but it saves trying to band the wire to the outside
73 de N2NLQ
Welcome to the channel, and thank you for watching. That’s what I did, I removed the top section, it’s so thin anyhow and bends too much so wasn’t an issue for me to remove it. Hope it works well for you. 🙏
Very nice video
Thanks
currently building a home brew shorty forty EFHW completely scatch built and it is my first antenna build. new ham but electronics background, the 49:1 is easily built if you have a suitable torroid on hand, wouldnt recomend bigger than 1.25mm wire as i used 2mm and it was tough to get it nice and tight. look forwrd to getting it all finished and setting up my FT 857
I've built several and they work really well. Having built several identical transformers I hooked them back to back and ran it into a dummy load but I noticed about a 1.5dB loss in the transformer (3dB total with the pair hooked up back to back) with 43 mix cores so it's worth bearing in mind how much power you lose as heat in the transformer so you don't cook it.
That's quite a lot. Probably need a bigger core or different material.
@@rogeronslow1498 it's 1/4 of an s-point so in practical terms it's barely noticeable on the air. This was with 43 mix cores but I also tested -2 and -52 cores and the loss with those is almost total. I could barely get a deflection on the power meter at the far end with those. I also tried it with larger -43 cores and the results were the same (up to 10w). Where this does matter is when using high power as you're going to be dissipating this as heat. For QRP I use a couple of FT114-43 cores stacked which results in a nice small build can easily handle a couple of watts being turned into heat however. The largest cores I've used are a pair of FT240-43 stacked which seemed to handle 100w just fine. I think it becomes hard to scale it much above 100-200w but if you're running that sort of power then there's not much point making any compromises on the antenna. With the EFHW at low power what you lose in power is worth it for the ability to operate on multiple bands with one simple antenna. I want to test some other cores but I need to order them in
@@binky_bun Pretty much agree on all comments. If you really wanted to reduce the loss you could probably use an L- network. Of course, the network values will have to change from band to band which is an annoyance.
I also use an EFHW with a switchable L network between the rig and the antenna.
In my opinion it allows you to operate HF on several bands with a single low visibility length of wire. Perfect for small gardens etc.
.
@@binky_bun Have you tested type -61 cores, I have made one for portable use with a FT140-61 and find the losses through two cores back to back extremely low, turns ratio is 3 primary 24 secondary, I only use it on 40 & 20m with 65 feet of antenna, using type -61 wont cover 40-10m but i only built it for 40m so 20m is a bonus
My coil is 1mm wire, wraped 54 times, around a 5.5cm former, giving roughly 110.340uH.
Its all I had so will see how it works out
Steve Ellington has done extensive experimentation and testing on EFHW. He personally has the space to use the full length 80M half wave and uses a relay to switch out the impedance xfmr to allow operation at 1/4 wavelength on 160M.
Well worth checking out his channel th-cam.com/users/n4lq
Excellent video description!. I have built the 49:1 quite recently using a fair-rite 240-43. Have it hooked up on the soffits outside bedroom window and 65 ish feet of 18swg wire sloping down to far end corner post in the garden with insulator etc. Trimmed for minimal vswr on 20m and 40m, but strangely the swr seems to be very low on 80m too without any additional loading coil. Around 1.3:1 mid band. I also have a choke with 12 turns on another core as it enters the window before radio. No earth connected at this point. So from transformer in plastic box to radio is a 10 ft length of coax with a good foot of that wrapped around the choke and straight into rig, no ATU. Should it actually be resonant on 80m without the loading coil and extra wire? Maybe I have done something wrong!!
The magic EFHW
Thanks for this! I love watching your videos. This design looks perfect for my QTH. I currently have steel pipe that is 6 meters high that I can extend to 8 meters with a fiberglass pipe. My question: will the steel pipe be a problem with the vertical wire being parallel (close) to the steel pipe? I so, I could run this down leg in an inverted V fashion with the the end of the short leg being about 4 meters horizonal from the base of the mast. This would keep the wire from being close to the pipe. Thoughts?
I have just put one of these end-fed antennas up and was surprised how well it works in my small garden.
I just finished building one of these end-fed's to cover 10, 15, 20 and 40 m. I installed it horizontally about 40 ft up from the ground with the Balun up at 40 ft. Question; how important or necessary is to add a counterpoise wire? how long should it be? How important is it to ground the shield side of the coax?
Thanks,
JL
Nice built and video. Is the actual length actually 20m, or did you have to adjust it, due to the L-shaped angle of the wire? There must be some capacitive loading at the bending section which should change the overall length for being in resonance.
It will likely need a tuner on 12 and 17. Only the full 130 odd foot version gives you a less than 2:1 match on 10 12 17
Yup, I have to use a tuner for those bands but to be honest, I rarely use those bands.
Tim G5TM .....And results on 30 meters? Is that the oddball band that is near impossible to tune to resonance?
What if you could make the wire 133 feet and get rid of the 110uf inductor?
Any URL that is too long, TH-cam just cut. Please use short URL of any kind instead. Antenna Design Plans just not work anymore because URL is cut and leaved with '...' Thanks.
That's incorrect, the URL is still good, its just that the host removed the content. I have now changed the url and hosted the plans on my own personal site: www.m0dqw.com/2022/06/28/491-efhw-antenna-plans
@@TechMindsOfficial Thanks!!!
@@TechMindsOfficial It is very useful, since most of us having short backyard, or in my case good one, but oriented east-west, so any dipole will result mainly in north-south radiation. Currently I have WSPR listening and my inverted V antenna not performing well. Also, on Raspberry Pi 1 (original version) unable to properly build WSPR transmitter - it constantly crashes. It is due to not compatible GCC and G++ installation (requires maybe GCC 6.0 but I have 10.something installed). Since I am NOOB for Linux, no hope for me. :(
Great video, have an multi band end fed planned for my garden. Question from a newbie, what did you use to anchor the wire to your chimney?
It was just looked through a bracket that was already there for another mast.
got my wire and balun ready . thanks for this video . one question do you take the earth from the antenna coax connector
Yes, from inside the transformer housing. Try it without earth as well, but make sure you use a choke if you do :)
Do you have any static discharge protection when using this wire antenna and SDRplay.
consider zooming in on sections of the band where your aerial is resonant. The number of samples spread over such a large range is losing resolution at the resonant dips. its possible your 80m dip is better than shown. This is a great range for the overview - maybe then make a new sweep for each band... ?
Ahhh yes, I have done this many times for each band personally, but didn’t want to stretch the video too long so I just put in the whole sweep for the video.
@@TechMindsOfficial ok great. and did you get a lower dip on 80m or is the excellent nanovna representative where it sampled ?
Congrats for the video! I have a general question about the Power dissipated by a balun. If I operate in QRP with 5watt, which balun dissipate less Power? 9:1 or 49:1?
plus if u using on sdr as a recive antenna it dont really matter on the swr
Can you use this to pick up TV channels?
I made 4 of these 49:1 transformers with the antenna described here. They work. There is no difference with or without an earth. I used 2 x T240-43 stacked toroids with another T240-43 toroid with 10 turns of RG316 for a current choke which is important. I run 400watts on 40 and 80 no problem. It is not as effective as my 80 horizontal loop but not far behind. Worth building. VK5SRP described the build very clearly. Google VK5SRP. Cheers VK5LB.
Cool man. Thanks. Not entirely sure how a 49:1 matching unit does not need a tuner.
JMTAUL impedance at end of a half wave is between 2000 and 4000 ohms. Threrefore a 49:1, 50:1 or 60:1 are usually used to transform impedance to near 50 ohms to give a good match. Harmonic bands usually match in the same way hence no tuner on harmonically related bands. In the case of this antenna 80 40 20 15 10 should all be within a good 2:1 bandwidth so very useable without a tuner.
Amateur Radio - Tim- G5TM ohh. Right. The bands are resonate. Like a virtual fan dipole with those frequencies cut. Sorta. Kinda.
JMTAUL yep
I am definitely building one of these. Thanks for pointing me to this video.
Of course I have another question. 😬
Which SDR are you using that works down in the HF range? Also what software was this?
Thanks so much.
You probably already got this, but SDR Play, and the software is their branded SDR Uno software
Am I missing something ?? A total of 16 turns around the torroid, gives a step down impedance of 8 squared or 64:1 .. Do the bifilar turns not effect the impedance step down ??
i notice you still have that rx antenna up still in the video . how does it compare to the wire antenna
Well, the RX antenna is pretty low down compared the top section of my EFHW, but the EFHW outperforms the RX Only antenna.
I have Par EndzFed quad band from Vibroplex 10,15,20,40, and it's shockingly good for dx ssb.
Ooohh that sounds interesting, where could I find details on that please?
@@TechMindsOfficial it's now sold by Vibroplex. www.vibroplex.com/contents/en-us/p3409.html
@@TechMindsOfficial I use it as a sloper, with the feedline end about 1 foot off the ground.
Do you find it’s directional as a sloped?
@@TechMindsOfficial As oriented, the high end is pointing towards Vancouver from Ottawa, and I have a hard time hitting western stations. Lots of signal down the eastern seaboard, east to Europe, one QSO to S. Africa, and one to Chile, some to Brazil. So it's got some effects how it's oriented. I haven't modeled it yet.
Nice Video very informative, i have 1 question, do you leave your pole up in strong winds? I am looking at this sort of configuration "inverted L" but i am dubious as to the strength of "fishing" Poles in say gusts of 60/80mph. cheers n 73's
Yep, mines been up for over a year now. I do have one support rope, that’s attached around 2.5 meters up and it pulls the opposite way to the horizontal part. It sway in the wind but it’s never broken or fell over. It’s a good pole.
is the horizontal part make it somewhat directional?
how's the performance compared to "end fed random wire" ?
how would this antenna perform if the vertical part is only 2m off the ground ?
does it need to go up the pole 8m first? I have a efhw 40m with ( 35uH ) sloping upward all the way and it works great. Thinking about setting up new 80-10 efhw with 110uH but in sloper configuration all the way from my shack in second floor and up to a tree. Would it be ok as well?
These are directional antennas with the radiation coming off like an exploding doughnut. So if I want to transmit coast to coast in the USA I need to aim it North South right?
I am very new to this topic and have what is probably a newbie question. All the literature that I have seen so far shows an end fed antenna as a slopper, inverted L, or some form of inverted V. Does an EFHW antenna have to be installed as a using some form of slope? Can it be strong out reasonably horizontal?
It can be horizontal or inverted L like my configuration, which I think works best.
What is the insertion-loss for the 49:1 match? 73 W6MGV
hi just wondering how critical are the winding on the 110 loading coil thanks chas
Well, I guess the goal is to create a 110uh coil. I didn’t measure the inductance when I made mine, I just followed the recommended coil windings and hardware and it appears to work well
Which SDR radio setup are you running?
RSPDX with SDRuno software, it’s awesome!
can tht matching unit lower like 3-5m?
Link to plans not working
Очень компромиссная антенна.
If you have large trees growing on your grounds then what having at(SK's) W5JGV website and copy his Treetenna which uses a HEMIC Toroid to match the tree to your transceiver it is for 630mtrs but should be possible to get onto other bands by changing the tapping point.
When I downloaded the Antenna deisgn plans it says that the wire from top of the mast and to the coil should be 20.5meters. But on this video it says 12m.
And both of the versions has 110uH coils.. Why is that?
If you look again at video diagram it shows 8M vertical and 12M horizontal, which is 20M (ish) obviously the 8M vertical part can be changed to how ever high you want, assuming you want to use inverted L like I did.
What is your issue with the letterl "T"?
will it make a differences if you use 19swg for the loading coil
@charles parks, Yes it will make a slight difference to the final inductance of the coil, there are heaps of calculators on the Net, that you can use to work out how many turns you'll need.
@ Tech minds great vid i am just about to try and build one of these for the bands in your vid so did you ever trim the antenna to be more resonant also is there a link to the other channel you mentioned for the 80m choke with the wire dimentions ect this is realy interensting stuff if i can get my head around it also think i need to invest in some sort of antenna analyzer haha more fun keep the vids coming there a wealth of information for newbies like me de 73s M7CHA
You're welcome Mark, glad I can help :-)
Can you tell me what SDR software you are using in this video?
Thanks Brother
George
Alberta, Canada
31 Jan, 2022
-12 snowing
SDRuno from SDRPlay
If you don't have a tree, what are folks doing for the 8 meter or approximately 26 ft high vertical pole?
Fibre glass fishing pole as I’ve used is probably the easiest way.
@@TechMindsOfficial Thanks! Do you have a link to any that may work please?
@@ErnestGWilsonII www.ebay.co.uk/itm/Telescopic-Windsock-Flag-Pole-Ground-Stake-3m-4m-5m-6m-7m-8m-9m-FESTIVAL-CAMPING/184203655449?hash=item2ae364b919:m:m35N_B8Uo46joVLqtO4DtuQ Just buy a 9m or 10m 1 and remove the thin top section to bring the height down to 8m. Search for flag pole and not fishing pole and you will see thousands for sale on Ebay.
Best place would be from Cal @ DX Commander. www.m0mcx.co.uk 👍
why is not good u still can transmit on 1:9 swr
Hello Sir- Can I use a solid 20 Gauge about .75mm wire?
I find stranded to be way more flexible. I just purchased 1000’ of 20ga stranded for $41 automationdirect_dot_com (replace the two underscores)
What's the difference between the 9:1 and this 49:1 which one would be better for an end feed antenna??
9:1 you would mostly need a tuner, either in the radio or external. With the 49:1, with 20 meters of wire you will get 40m to 10m without needing a tuner.
Interesting, I saw a test that showed 49:1 worked much better on multi band than a 9:1 or a 64:1 balum. Thank you@@TechMindsOfficial
Does the Verticle part have to be verticle?
I would need to put this in a loft if I build it, and I dont have 26.2 foot in my loft to get the verticle.
The best I could get for the verticle would be about 8 foot.
Nope, you can install this antenna horizontally too, or even sloped. Best thing to do it try it and see how well it performs. I’d be interested in hearing more about your results. 🤙
@@TechMindsOfficial No problem I am going to try a W3EDP first
Hi, great video. I am new very new.. dont have my radio yet, but looking at Yaesu FT-450D - I have a postage stamp of a garden and can only really mount a antenna to my chimmy pot. its a bunglaow so not so high. what would u recommend?anyone can come back to me.
Welcome to the world of Ham Radio! For small size gardens then an EFHW in an inverted L might be best, but if you don’t have the room for the horizontal section then you could slope it. Alternatively you could try something like a vertical antenna. Either build your own using a fibre glass pole or buy something like the DX Commander.
What would happend if the coil is not exactly 110uH? Would it still work?
I dont have stuff to measure the loading coil - but I did build the loading coil from a calculator.
PVC Pipe diameter = 40mm
Coil length = 32.7mm
Wire diameter = 0.5mm
Turns in total = 59
Thanks - 73 - LB6CI
Just make the 80m end wire section slightly longer and fold back the wire to tune. Obviously tune the 40m section first before adding the coil. 73
Just to point out openoffice is not being supported, you need to switch to libre
Thanks!
Nice video just what i wanted. I bought the 49:1 today from ML&S so will be building the aerial in the next few days. Do i need the 110uH for the 80m band as I can get 78+ meters of cable round the garden.
It seems the plan link goes to nowhere... shame
Thanks for letting me know, I will get that fixed. Although, I think I show the plans in the video.
@@TechMindsOfficial Thanks for the quick response. Unfortunately, I can't do videos in the shop. :)
Too bad I live in a flat :/
That sucks man! :-(
Try a magnetic loop antenna.
from your window to another building.. thin enough so no one will notice 😉
Well you probly have the best intentions
LA1IC has made an endfeed slooper antenna
www.hamuniverse.com/slopinginvl.html
I made such and found that around 38m wire did the thing for me from 80m to 10m.
lowsy on 160m but did do some countries in europe.
abt 8m up over a branch in a tree - slopering 30m alongside the hedge in my garden.
longest distance from my sa7ard cottage in Sweden to Christ Churh New Zeeland Rob ZL30MDG 18000+ kms
less than 20watts. 30m PSK31 august 2009.
I learned 3 things.
1. A friend made one on 19,7m and made similar contacts.
2. a 1:9 unun worked better than a 1:4 as surgested by LA1IC
3. If you hang up the long end horizontally you will only get sideways contacts , in my case up/down Europe, so hang it up inverted L.
You dont have to make coils for the 80band on either one of these !
easier to make and gives more bands than EFHW - forget EFHW
73s de oz1gai (1979) sa7ard (2006) SM7H (2010) Hans