Clearing Up Some Confusion About End-Fed Wire Antennas.

Hoping to clear up some confusion on end-fed wires, half-wave or random and the impedance transformers used with them. You also get a free rant on contests and a quick glimpse of my new Elecraft K1. Check out the Half-Wave End-Fed antenna group on Facebook, by Steve Ellington. Formulas for half-wave wire calculations are 143/f in MHz for meters and 468/f for feet. Feedback would be appreciated especially to correct any mistakes I may have made in my analysis. Version Française en cours d'édition...
EARCHI 9:1 UNUN:
www.earchi.org/92011endfedfile...
Random Wire Antenna Lengths:
www.hamuniverse.com/randomwire...
udel.edu/~mm/ham/randomWire/
Please help this channel:
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[@jeff-73]

Every 5 seconds of this video you cleared something up that was confusing me and no one else could explain it for my grey matter to digest. You are an amazing teacher and your presentation and instructional aids were amazing. Thank you so so much for this.

[@RadioPrepper]

Thank you :-)

[@cw2gtc]

Agreed. Very professional, yet personable to listen to. (😉disclaimer… My mom was a US military wife, originally from Luxembourg. So, the dialect is most pleasing to my ear).

[@Justin-bd2dg]

I built a 3 core version 64:1 and then I tapped the coils at the 49:1 point and ran a seperate wing nut. So now I have 2 transformers in one, a 64:1 and and 49:1, it works great! Thanks for the video!

[@RadioPrepper]

Good idea!

[@AllFouRoux]

This should be mandatory viewing for Hams; so much great information packed in this video.

[@dougtaylor7724]

Something about the presentation helped me to finally understand 1/2 waves and their transformers. Many thanks, enjoyed your video.

[@TheHarpanOnly]

Yep, I feel same.

[@davidwilcox9110]

The last half of this video is the most important and a very good explanation. I have been a ham for 62 years and this is the best explanation I have seen. Dave K8WPE

[@Steve_Wardley_G6JEF]

Gil, what a brilliant explanation of wire antennas and UnUn's. You've cleared up a lot of confusion for me on this subject. Thank you.

[@spudmurf9323]

For me also A1!

[@adriansalt4521]

I just had to say thank you so so much for what I've found to be the best explanation to End Feds, Random Wires and Dipoles on the internet. You have allowed me to understand such fundamental principles of resonance in a wire, why feedlines don't radiate EM energy and allowed me such a fantastic and solid grasp on the basics of EM radiation in a wire. I also have to thank you for your superb explanation on UNUNs and why and in what cases they would be needed. I really cannot thank you enough. Just had to tell you! Adrian, M0AAG.

[@RadioPrepper]

Glad it helped :-)

[@Dennis-sb7gp]

Great job at explaining everything on end-fed, random wire, and un un, I got a lot out of this thanks Gil.

[@frastephen]

This is the best explanation of the theory behind an EFHW antenna that I have seen ... Well done! And, very helpful!

[@Aussat]

Great video, I have been wanting to make my own for some time now but was confusing, your presentation has made it crystal clear. Thank you very much. 73 Glenn ZL1MY

[@joselima9398]

thanks for the great explanation, probably the most clear explantion i've come across and i defintely learned so much about how end fed antennas work.

[@JulietNovember9]

I scoured youtube and google to understand transformers and this is THE best explanation ever. Very clearly done. Thank you!

[@larrywieberdink8379]

This is the Best!! explanation I have ever heard comparing 1/2 wave and random length antennas and the need for size appropriate transformers. Excellent job!!

[@kelpfl]

Nice video! Thanks for covering this stuff. I can't tell you how many concepts you covered in this video that I have heard people discuss and never understood.

[@metalfabman5477]

This is the best video I have ever seen that really explains in layman's terms the whole end fed, half wave antenna thing using ununs or baluns. You have finally explained all of this so that even an old retired welder like myself who just enjoys making antennas and trying different things to get on the air can understand how it all works, even without an electrical engineering degree!! Thanks so much for taking the time to make this wonderful video!😃

[@RadioPrepper]

Glad it was helpful!

[@StevePotter-G6HOQ]

Whenever I see any hams asking about end fed antennas and how to go about making one I always point them to this video, so easy to understand, and even if licenced 30+ years you can always learn something new.

[@RadioPrepper]

Great thanks!

[@mhinnebraska]

Thank you for the clear details. This helped me to understand concepts that were very murky before.

[@Wyowanderer]

GREAT video, Gil. There's more information in this ONE video than I've been able to glean in the last couple years. Thanks again, friend.

[@dancingbear6239]

Thank you! Your explanation of current flow in a HW was excellent. I now understand why radials are not needed for a HW but are needed for 1/4 wave. Non technical but spot on.

[@eddy2561]

Absolutely the best explanation 49:1 vs 9:1 out there! Merci beaucoup. ~ k6sdw

[@JDS11ify]

Very clear explanation of ununs and the cause and effect of the windings. Will listen in more!!

[@AdamosDad]

I hate contesting, its so rude for a guy that wants to rag chew to get pushed out by the "all important contest" Great informative how to video, thanks Gill 🎙73's kd9oam

[@Pelnied]

I hate rag chewers, it's so rude for a guy that wants to contest to have a frequency taken up because it's the rag chewer's special frequency that he uses every day to listen to himself talk for hours on end. He's already talked enough, let someone else talk! Share the band and don't hog frequencies, whatever you are doing!

[@georgebodley8068]

@@brad1367 try giving other operators some room on the bands instead of hogging the whole band width be like the RSGB contesters operate within a certain band width which gives other users the opportunity to use the bands don't be selfish.

[@georgebodley8068]

@@Pelnied you might hate rag chewers but dont be selfish and hog the whole bandwidth make room for all users Remember Amateur Radio is a broad church .

[@99jcarter]

​@@Pelnied9o

[@noimnotarobotcanubeleiveit7024]

Im no rag chewer but i like to have a chat for up to t minutes before moving on. Shouting numbers is boring. I often end up pushed on the warc bands when propagation is poor over 20m. All bands should have a warc section where contests are invalid for points. And we dont need 4 channels for ft8 warbles.

[@rjinnh3933]

Very good compitition of Half vs Random length antennae. Thanks. And 30+ minutes is not too long on a technical subject like this. Keep up your good work. We appreciate what you do......

[@RadioPrepper]

Thank you!

[@markcarleton6647]

Thanks for the fantastic explanation of the difference between 1/2 wave and “random” wire antennas!

[@nochems]

Great video. Easy to understand information for someone beginning to learn about HF antenna building.

[@henbentoify]

Thank you for your time. Best presentation I’ve ever seen on aerial transformers. 73

[@MoTown44240]

Thanks Gil. I watched this several times and got more from each viewing. :)

[@tonypoloney8721]

Wow! what a great presentation. I will have to watch several times for this very interesting information to sink in. Really enjoy your videos. Thank you so much.

[@simonbates8735]

I go to the 30M band. Regarding end-fed antenna I use a W3EDP (25.6M) which seems effective across all amateur bands. Love your regular KZbin videos. Thank you.

[@kengerace]

I just happened to stumble on your video through a suggestion from you tube. Well done sir. Very well presented. Thank you. I’m going to checkout more of your work.

[@thirtycrows]

Brilliant. Can't tell you how often I've watched this video. Built one for 30m yesterday and it worked extremely well.

[@RadioPrepper]

Glad it helped 😀

[@stevenharris4151]

What an excellent clearly delivered video. Thanks for clearing up some of the issues I've come across. :-)

[@Mil1806]

So well explained! EFHW seems so easy but they have their peculiarities. I have a core ready for making one for my qth, this video will help me a lot! Thanks for your videos!

[@binder098]

Thank you, when I watch enough of these videos and especially with concise hands on experienced operators like yourself, it all slowly sinks in. Actually, I feel your misfortune with the contest turned out to be quite fortunate for this viewer and like a cat, you anded on your feet with this content substitution.

[@sircompo]

I'm just starting out and this video has been more enlightening than anything else I've found so far. Thanks Gil 👍

[@RadioPrepper]

Glad it helped!

[@ernestb.2377]

Well Sir you did a very good job explaining some important basic working principles. Very glad I have watched it. Thank you!

[@chrislewis954]

I agree with others here that you do a very clear and helpful description of the basics. A valuable resource - Thanks Gill

[@jackernissee2372]

Thanks for this great video - Explains a lot. The best I’ve seen so far.

[@DucatiMTS1200]

Thank you for explaining the workings so clearly. Now I understand a lot more. You are an excellent teacher.

[@RadioPrepper]

Thanks, glad it helped!

[@trbowlin]

Great video. I learned more in this video than in the last 5 or 6 I've watched. Thanks!

[@acestudioscouk-Ace-G0ACE]

Thanks so much for this. I'm returning to amateur radio after a 31 year break. The information you give here and in your other videos is really useful. Thank-you.

[@RadioPrepper]

Glad it helps :-)

[@peterfitzpatrick7032]

I imagine you are well rested... 🙄😂 😎👍☘🍺

[@PatFortino]

Thanks for the detailed explanation of 1/2 wave wires and end feed antennas.

[@hobbiehobbs]

I always learn more when I view your videos. Thank you.

[@DennisMathias]

This was quite entertaining! I agree. Contests are agrivating.

[@briantheminer]

I’ve learnt more from this video than any other antenna learning method!!! Great 👌

[@RadioPrepper]

Glad it was helpful!

[@robertlundstrom8061]

I also have a K1 that I built. This video is terrific! One of the very best antenna instructional videos. I can't wait to build my 64:1 unun! Thanks for the info. - W9PZ

[@RadioPrepper]

Let me know how it works for you!

[@Rockeyes]

What a brilliant KZbin video. Very helpful. Subscribed 😃

[@G4KDXlive]

Agree with your comments on contests. I've heard them say " everybody enjoys contests " - inability to see the hobby from anyone else's perspective.

[@theunconventionaldeal3879]

Contests are a big spam challenge, what's worse is they will spam right on top of you after asking "is any station on this freq" instead of waiting for a response they crap all over your qso.

[@jamesk0ua]

Contest's are a great way to work DX entities that you need and If working for WAS, I can think of no better way to quickly work many states.

[@ReverendBow]

Couldn't agree more... contests are a waste of frequency spectrum... I love it when you hear someone have to repeat his callsulign 5 times, then the get a "5-9" report...

[@StreakyP]

three simple rules to add to all contests to make them more acceptable to all (whilst not detracting from the contest);- a) only use "even 10's of freq" for the contest... ie 0-10 yes, 10-20 no, 20-30 yes, 30-40 no... 200-210 yes etc etc. b) if you have "big boots" you cannot monopolise a single freq and just "claim it" to the detriment of all others (including other contesters)... implemented by you cannot be on any one frequency for more than 10 minutes... you must move after that time and find a free space yourself. If your log times show excessive single freq use then points after 10 mins will not count. If you repeatedly stomp on smaller stations to make your space you will be deducted points. c) With the easy availability of waterfall displays these days, Splattering "wide boy" contestants will simply be disqualified.

[@KjartanAndersen]

Totally agree. I do not like contests. I like experimenting with antennas and get feedback on different setups on air. Contests are only hello-goodbye-next. Never understood the appeal of it my self. Leave some of the bands off limit for contests.

[@PeteSnipe]

Top info. A very good video. Took me over two days to watch all of it. Practical and informed. I liked the 'don't ask me how it works' statement. Have subscribed.

[@RadioPrepper]

Antenna theory can get very complicated, and I'd rather play with radios ;-)

[@darrinpearce9780]

I've always run 0.05WL and never had RF coming back at me. Great antenna for portable/QRP. Thanks for the excellent information and explanation. Toroid material is always a mystery ;) 73's and fair winds.

[@gettingpast4391]

Best video ive ever seen regarding end fed wires and impedance match transformers... built a 49:1 for QRP immediately after watching this video and realizing i had some small type 43 cores in my box. works great.

[@RadioPrepper]

Awesome!

[@dogtowndrums]

Thanks for this video. This is the first time that I feel that I've actually understood this subject. 73

[@alexeizhiltsov6797]

Gil, this is an amazing and very helpful video. Thank you so much. And it does not matter whether your explanations are correct from the point of view of high physics, with all those formulas and reactivities, as some people tend to say in the comments: the important thing is your advice works in practice and helps those who do not have time to read specialized books on how to engineer Space Shuttle antennas - we want something simply in our backyards. To me the simplicity of your explanation is the primary advantage - it is easy to remember what to do and how to do, and results are effective in real life. Also thanks for the links to those antenna shops - I never knew they even existed, being limited to MFJ, Diamond and similar huge companies. Do make more of your wonderful films if you can - this is very helpful for the HAM Radio community. They inspire to experiment, to fo to the fields and develop the hobby skills, thus developing the whole hobby. Everyone can go and pick those professional books on antennas - I have dozens of them, but get lost after 10 minutes. So, I prefer your films than professional books, mostly meant for professionals in celular and commercial communications. 73 de R2ARM!

[@RadioPrepper]

Thank you. My goal was primarily to make it understandable...

[@chipandrews2892]

Awesome video Gil....I know this is an older video, but I just ran across it....your style and delivery sure made it very easy to understand the advantage of using a 1/2 wave end fed antenna with a UNUN. Thank you for sharing! 73, KL7CA

[@RadioPrepper]

Glad it helped!

[@mdouble100]

Excellent video. Thanks for offering this information.

[@Fishermanfred1]

Really enjoyed this video Gil. Thanks 😀👍

[@jay-rus4437]

Agree with you on contesting. Glad that there are so many options and variations of amateur radio. However, we are taught as a general rule to show curtesy to others, but this seems to be put aside during contesting. There should honestly be some band plans put together for temporary areas to be used for contesting. 73 K5JRX

[@rl4795]

THIS WAS....BY FAR.... the best visual explanation of this topic. THANK YOU so much, Sir. KF4UTF/HZ1 - Robert

[@RadioPrepper]

Thanks!

[@2000alexgrim]

Gil, thank you very much for this clear and didactic video. PY1AHD ALEX - Alexandre Grimberg

[@kiweekeith]

Thanks a Stack.... Greetings from New Zealand ..... What an Absolutely Brilliant vidclip .... So 'Simply' and well explained vidclip ....Very best to All from ChCh, NZ

[@nathanhouck2403]

I genrally agree with your comments about contests, but without seeing if anyone else has mentioned it, we do have 30m (at least stateside) as a playground during contests. Thank you for info on end fed antennas. Good info.

[@dr.tomgio6694]

Gil, this is an excellent instruction video! Thank you for your efforts. Tom IK7YCJ

[@videog7747]

New ham here. Thank you for this. You are really great at explaining things!

[@rodchisholm4790]

Thanks Mr Radio Prepper. Very useful information & education. Comprehensive, comprehensible and entertaining. I am learing so much from you. Merci Beaucoup vraiment!

[@RadioPrepper]

Glad it helped:-)

[@LarryAnnen]

I can’t thank you enough for your detailed explanation on how to make an un un.

[@RadioPrepper]

Glad it helped :-)

[@dennisbauer3315]

Wonderful video, thank you for all you efforts, good instructions.

[@AndrewBryantPianoTuner]

Please keep making these videos you are an excellent teacher my friend and people love you..

[@RadioPrepper]

Thanks, will do :-)

[@cthoadmin7458]

Excellent info! Thanks Gil. Tried the 0.05 wavelength, as you said it had no effect. Stacked 3 ft240 -43 together for a high power efhw and it handles 400w with no problem. Steve Ellington’s channel is good for this.

[@RadioPrepper]

Great, thanks for reporting :-)

[@noelbulls8628]

To calculate the 1/8th wavelength do this example: 468/frequency =1/2 wavelength x2 then multiply it by 0.05 this will give you the length of counterpoise. Cheers

[@pincus321]

Thank you for explaining this. I now understand more.

[@BarefootBeekeeper]

You cleared up some confusion for me - thanks!

[@terryd2634]

Very well done presentation, I learned alot. Thank you.

[@MrHowieGee]

Thanks Gil. Great video and great information. i am looking at end fed antenna for SWL at the moment. This video has helped a LOT Now I need to create a multi half wave antenna and start winding my Txfmr

[@RadioPrepper]

Great, good luck with it :-)

[@colpar]

Very well explained and easy to understand. Thank you.

[@dangruner5926]

I like this guy. Feels exactly the same way about "contests" as I do! ;)

[@Roger_Stenning]

Well said, indeed :D 73 de G1LIW

[@RadioPrepper]

That's because they only know how to sent five numbers: 599 73.

[@TXLorenzo]

Contests are another form of radio jamming. They are my que to play on FT8.

[@brianshanahan3878]

Another excellent video sir!

[@davidcarroll6020]

Excellent training and information that is very usable, thank you

[@peterdekeles.]

Thank you. I now understand unun and 49:1 vs 9:1. great information

[@RadioPrepper]

Super!

[@ronmorella6541]

Great video Gil, I learned a lot. Thanks for taking the time to do this. 73 - n2imb

[@RadioPrepper]

Thanks.

[@AzPauly]

best antenna lecture I have ever seen, thank you.

[@RadioPrepper]

Thank you 😊

[@billhartig4805]

Extremely well explained. Thanks.

[@vb7913]

Excellent and informative video!!!

[@GeezerDust]

Excellent explanation of feed systems. It broadened my understanding of antennas. Also, I have the same thoughts about contesting.

[@RadioPrepper]

Glad it helped!

[@AlvinMcManus]

Great talk. Very TED like. I enjoyed it and learned something new. Thank you.

[@MrAnviljenkins]

Lots of good info :-). I ordered the EARCHI UNUN.

[@peterb9580]

Gil good video, the distinction between unun 9:1 49:1 and the different ferrite efficiency was helpful thanks !

[@RadioPrepper]

Great!

[@mikekrieger8171]

Nice, this was very educa tional. You do a fantastic job.

[@michaelclutton8446]

Have just subscribed, agree with you totally about contests after 50 years in the hobby still think it’s just an ego trip for a lot of people

[@garrykraemer8993]

Very good presentation of material! Outstanding! WD0DUD, Thanks!

[@LarryMassey]

Excellent presentation, thank you.

[@noelstephenryan4837]

Excellent simple explanation.

[@davidportch8837]

excellent video Gil - really useful...many thanks.

[@joecraft4409]

Explained so well even this boy from Texas USA can understand. Fantastic job Gil!

[@RadioPrepper]

Glad it helped!

[@captainwyattoutdoors1636]

Excellent explanation, thank you!

[@haggar11]

Informative video, I enjoy watching your video. Thank you!

[@stuarthall3874]

That was an extremely helpful video Gil. Thank you. You have a great presence that makes the material approachable rather than intimidating.

[@wayneskiba1237]

Very interesting and informative, thank you for doing this video.

[@daveryan2148]

Great video! Wish this straight forward information was around when I was first learning this... I had to descramble wives tales from old guys and experiment.

[@Cardassiaprime]

Great informative video, very well explained- esp winding the toroid 👍🏼

[@RadioPrepper]

Thanks!

[@DrHWO]

Fantastic presentation Gil ! This has provided the clarity I needed to grasp the general principles of feeding random vs half wavelength antennae and the benefits and disadvantages of each. A whole new world of experimentation has opened up! Thank you. 73, 2E0HWO

[@joczo97]

Nice video,i've learned a lot! Yeah those nice currents with a random wire,had so many surprises with 300W :D