G4NSJ - An end-fed wire aerial top band 160 metres amateur ham antenna
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- Опубліковано 22 лип 2024
- I this video, I chat about an end-fed wire aerial for top band, the 160 metre ham band. It's a great amateur band but not so good when it comes to aerials. A half wave antenna is 80 metres long!
IMPORTANT: Amateur radio licensees must comply with the ICNIRP general public limits of EMF. I will be taking this into account when completing the aerial installation.
www.radio-workshop.co.uk/g4ns... - Наука та технологія
Ray, after 58 years in radio, as an amateur and working tech, this is the clearist and easy to understand explanation I have seen.
Thanks, you've made my day!
That's the clearest explanation I've heard in my 46 years as an amateur. Thanks so much.
Thanks, I'm glad the video was useful. Cheers, Ray.
I love the rambling mate, don't change a thing about the way you make your vids! You're a great elmer and remind me of some of the guys that taught me back in the 80/90's :)
Thanks Mark, I shall continue to ramble! Cheers, Ray.
@@g4nsj Good good 😀 I always enjoy your vids!
Thank you so much for helping me begin to learn why a half-wave length of wire (on a transmitter) can be set up so much more efficiently. Like other people who have already posted, I never understood this concept until you drew it on the blackboard! Thanks so much for this!
I'm pleased that you found the video useful. All the best, Ray.
This is the best explanation of 1/4 vs 1/2 wave I have seen. Thank You!
Thanks John, that's nice of you.
Basic stuff, well and interestingly explained. I'll get people I know new to the hobby to watch this. Thanks Ray. 73 G4VZZ
Thanks, I hope the video will be useful to newcomers. 73. Ray. G4NSJ.
Thank You Ray,---Good old school chalkboard and clear easy to understand Teacher. Cheers, Ron.😁
Thanks Ron, glad you liked it.
The trouble is some hams don’t “heat the worms” (i.e don’t earth) and because it “works” it confirms their confirmation bias (never mind the fact that their equipment earth is at play!! Great video.
Too true. Glad you liked the video. Cheers, Ray.
In all my years in radio, this the absolute best explanation of how an antenna works. Bravo!
Thank you! It's appreciation like this that makes it all worth while. All the best, Ray.
I loved this video and how it explains everything. The explanation was the best part and I wasnt even expecting it. thanks for the all the info and details, it helped my brain understand!
Thanks. I'm glad the video was useful. Cheers, Ray.
Ray, what a cracking video! I don’t know if you realise how good it is, this video should be used in the uk foundation course. Please keep up the videos really appreciate it, thank you for passing on the knowledge. ps all your videos are great and your a natural at them and funny 12.10 the neighbours house gag brilliant
Hi Jim, it's great to hear from you. Thanks so much for your kind words. It's people like you who make all my efforts worthwhile. Cheers, Ray.
It's not boring, in fact your style is entertaining and pleasing. I'm sure most would agree. Keep up the great work. 73
Thanks, Steve. That’s very nice of you. Cheers, Ray.
Not sure of half of what Rays talking about but I could listen forever.
Thanks!
Excellent presentation you have here. This made more sense and clearly explained a ton of antenna theory and behavior. I struggled to understand radiation behavior of the antenna and you have filled in all the holes. Many thanks!
Hi Doug, thanks for contacting me. I'm pleased that you found the video useful. It's comments like yours that make it all worthwhile. Cheers, Ray.
Great video. I love all your videos and so does my wife. Can you do more of these instruction videos, would love to hear all your experiences.
Thanks William, more videos on the way. Cheers, Ray.
I do precisely that using a 49:1 transformer using two 240-43 ferrite toroids. At the moment it's for 40, 20, 15 and 10metres however I'm going to put a separate one up for top band and 80metres. Excellent briefing by the way! 73 de GØUSL
Thanks Mark, it’s nice to hear from you. Cheers, Ray.
Ray thank you for this video. This explained to me in under 20 minutes what I'm sure I've wasted years on trying to figure out myself. You're a true gent.
Excellent, thanks!
Put youtube on double speed and you can finish the video in 10 minutes! 73, de k2xt
YOU have finally broke through my brain blockage and showed a end fed working in a way I can understand! THANK YOU!
Excellent. Thanks!
This may be the best explanation of antennas I have seen. Finally it makes sense. Thankyou!
Thanks, Ray for your insight on this topic of EFHW antenna theory and practice. I thoroughly appreciate learning from you. WY8G- BRUCE 73 and I await your ongoing instructions. A lot of ideas for 160m antennas are intended for small areas. My 13 acres and 190 ft tower allow me to dream of larger antenna ideas.
Hi Bruce, great to hear from you. I wish I had 13 acres! Excellent! Cheers, Ray.
Wow. I'm sharing this video! Great explanation!!!!!
Thanks!
Another amazing video. Looking forward to the next one. I really like how you explain stuff.
Thanks, it's nice to hear from you. Cheers, Ray.
Always a pleasure to watch! Interesting videos, keep up the good work Ray.
Thanks!
Enjoyed your presentation this time - thanks, Ray.
Thanks Cliff.
Hello Ray, you do realise that those of us licenced in the 1980s are the "Old boys" now! We have stolen the G3 crown. Your videos are superb, thanks. 73 Ron.
Hi Ron, you’re right! The G4s have stolen the crown. It’s nice to hear from you. Cheers, Ray.
I love your thorough explanation of this, and I LIKE YOUR STYLE!
Thank you! 👍
Wow, this blackboard discussion is simply fantastic! It beautifully relates antenna function to analog circuit theory, making the fundamentals of end-fed and other HF antennas much easier to understand. I've struggled to grasp these concepts, but this explanation clarified everything for me. Thank you for sharing this insightful video! 73s K9OS
Thanks for your kind comments, they make it all worthwhile. 73 G4NSJ Ray.
Your videos are amazing! I get so much out of them! I'm a novice ham so it means a lot that you take the time out of your day to explain things.
Thanks for the feedback. I'm glad you find the videos useful. More coming soon! Cheers, Ra6y.
Thank you Ray for such a clear and concise explanation of antenna theory ! Very Good !
SBF
Thanks!
Great Video Ray. My neighbors know im touched in the head when they see me out shooting antenna lines into the trees. lol. They nick named me "Radio". Yea be careful with the torch in the alley at night. They might think your a cat burglar. lol
Thanks! It’s nice to hear from you. I’ll be careful in the alley! Cheers, Ray.
Ray keep up the good work,really enjoy your very interesting productions!!
Thanks!
Great presentation, as usual...
Love your “rambling”!
Well done Sir, you have presented the current and voltage behavior on a antenna better than I have ever seen before .
Thank you for making these videos.
Hi Keith, it's nice to hear from you. Thanks for your kind comments. All the best, Ray.
This is the best top band information to date. Cheers, Ray.
Thanks, I’m pleased that you found it useful.
See you at the pub, Ray.
Thank you for taking the time to explain this.
🍺 Cheers!
This was interesting. I do not know enough to say if it is all accurate, but it is interesting. However, I disagree with the bit at the end where Ray said you can only sue a dipole on the band it is cut for. That statement leaves out the beauty of harmonics and how you can use a dipole as a multiband antenna, especially fed with a tuner like an end fed has to be.
I had a friend who used to go deer hunting in Montanna, (I live in Minnesota) and he would take an 80 meter dipole, thirty feet of telescoping pipe, and set us an inverted V with the ends near the ground. With his tuner, we would communicate on a number of bands, and he got great reports from DX stations on 10 meter because of the multiple wavelength. You are not going to use an 40M dipole on 160, but you sure as heck can use it on part of 40M without a tuner.
I've been enjoying a lot of your videos recently. I'm an old pirate who's recently got my foundation licence and enjoying the hobby. Keep 'em coming!
Excellent! More videos coming soon! Cheers, Ray.
There’s a lot of people popped up on uTube over the last few years trying to tell us similar things that you do. But the difference I find is you know what your on about 🤔 Keep the vids coming ray, it’s good you share the knowledge and experience you have.
Thanks, it’s great to hear from you. I hope to make more videos soon. Cheers, Ray.
I enjoyed this one, it wasn't too long and you explained it well. There will be some that will guess and happily use something that resembles an aerial. Always best to get maximum efficiency from what you are using by knowing how it's working and minimising your losses and interference.
Yes, it is best to try and get max efficiency. No good having a posh radio and a naff aerial. Cheers, Ray.
Brilliant! Good show mate.
Thanks!
Learned a lot here Ray; all useful info for me (M7). Looking forward to seeing it in operation!
Thanks, James. I'll keep you posted.
Thank you great information on end-feed antennas.
Thanks!
Hi Ray, an interesting subject for top band. Its the same situation here with a postage size back garden and of course all the man made interference to go with it in built up areas now. Many stations have used their main transmitting antennas in combination with a low noise receiving loop to get the best of both worlds. Will be interesting to find out how you get on with the EFHW. Never spoke for a while so hope you are keeping well. Good video...M0DAD
All is good here, thanks. OK on your small garden, it certainly is a pain. A low noise receiving loop is a great idea. I’ll keep you posted on the EFHW. Cheers, Ray.
Thanks Ray, great explanation. Must join you at the pub sometime for the full story; 20 minutes is only really enough to set the scene. Occurs to me that the decline over time in deep technical thinking is directly proportional to the rising cost of beer!
...directly proportional to the rising cost of beer! I think you might be right! Cheers!
Thanks ray, very good info.
Really well explained, thanks mate.
Thanks!
I found this quite fascinating. Thank you.
Excellent!
@@g4nsj I think I will be making this antenna. Can you clarify for me the grounding? I understand I need an earth, but do I need just one ground stake? Or radials or something also? Would I need an Unun?
I have room to make a half wave or a quarter wave either one but they won't be very high. Maybe 10-15 feet off the ground.
@@daveengstrom9250 Hi, a single ground rod will work but the more wire beneath the ground the better. You shouldn't need an unun, just use a decent ATU. A half wave would be amazing, even if it is fairly low down. I hope this helps.
Great to see you ray Gary
Thanks, Gary!
@@g4nsj all the best wishes for you keep up the very informative and friendly video s especially about antennas God bless you and family
At our age we're entitled to repeat ourselves. I say we're ENTITLED to repeat ourselves. Or ramble a bit. But we can't all be video producers so take no notice of the miseryguts. There's a light goes on my in head when I watch your videos and suddenly I know a bit more about my hobby. Good luck to you sir!
Thanks for your lovely comments! You've made my day. Cheers, Ray.
Ok Ray, you got a new subscriber. Good stuff
Thanks!
Very helpful. I am very non-tecki but am beginning to understand antennas. Phil Suffolk
Thanks, Phil. I'm glad it was useful. Cheers, Ray.
Another great lesson. I have a "nightmare" radio earth /. ground here, very shallow sandy soil onto the bedrock which is very fine grained and thus low porosity. I also live at the top of a slope so that rain just runs off rapidly. My "earth" proves your point about the return current circuit from aerial to ground and back to the "generator", my return is very high resistance indeed.
I have bodged a a dipole and doublet for 160M however, my signals are useless on 160M even for nets around the UK. For many years I had a great damp and loamy earth, great results with voltage aerials and various verticals. Take care, 73 Tony G3ZRJ
You could try an endfed aerial with a counterpoise.
Graet video as all ways MR RAY
Thank you sir for YOUR time
Ps still hope a radio work shop cup😁
Thanks Joe, it's great to hear from you. I've not forgotten about the cup. Cheers, Ray.
Afternoon Ray,
I've just replaced a 40metre run of long wire for SWL into a kenwood R-5000.
A good friend of mine built and flew light aircraft (PPA/VFR) he sadly passed away a few years ago... I found a coil of wire, insulated, very very thin, ran it over a 40 metre run and the sensitivity has increased and the noise floor vanished!! Looks like stainless steel to me, it's not magnetic and incredibly tough... no way you'll "pull-snap" it.
Not sure of its resistance but I'll have a check.
There used to be a wire, "constantin"??? Virtually zero resistance??
Who knows?
But I've got miles of the stuff!!
That's interesting, thanks for the info. As you say, who knows! Cheers, Ray.
Very good show
Thanks!
As an M7 I've learnt a lot. Thank you.
Excellent! 👍
I came for the antenna, but once that chalkboard came out I would have stayed for just about anything. I can smell that chalk! 73 DE NØIP
Hah! Thanks!
Brilliant Sir
Thanks!
Ray, if you feed it with a 49 or 60:1 transformer you’ll get 160 plus all other harmonics up to 10m. BUT this then changes the radiation patterns so that you will get current max areas between the houses on the higher bands. 73
Thanks Tim.
Nice experience, thanks
Thanks!
Wow, I am not good at math, but what you are saying makes sense. At least I have a better idea of what's going on. I will have to watch this at least few more times, to get it to sink in better, but I have an outline, or at least some anchor points in the mind, if tht makes sense. Thanks for having the patience to cover this, for us 🔥
Thanks for commenting. Good luck with the antenna. Cheers, Ray.
@@g4nsj right on Ray. Hahaha, that's funny. Good luck. You KNOW something 🔥 lol.
That "luck" thing, that without it, at the very least probably involves mourning and using cuss words, due to factors out of my control. Oh yeh, I've heard that before. I am not into really cuss or cry, but frustration can be some huge influencers. Okay, I'll shut-up now. Don't want to waste anybody's time. Points made lol
You know Ray. I am starting to wonder, if I could invest in, something like a weather balloon, and go up, maybe 100 feet, during the day and 1K at night. Drift should not really affect it, if the proper wave length is employed. Ray, I am gonna hush now! Thanks for getting my gears turning 🔥
That’s a good idea. I knew a chap who flew a kite and used the thin wire as an antenna!
@@g4nsj sweet 🔥
Great stuff. I'm going to have to figure out the various voltage/current patterns for my existing 105' random wire with 9:1 unun 17' counterpoise and 35' of coax to an automatic match unit by the xmitter on various bands. Seems like it will be more complicated.
Sounds good to me.
Hi Ray, thanks for sharing yet another most interesting and informative video. are the houses fairly close together there? We are fortunate here in Melbourne Australia with space both sides of the house, as the house is on an angle. We then have a reasonably good size back yard. I have a longwire antenna from my den, going under the house and then along the back fence. It seems to work quite well for receiving medium wave. Anyway, wishing you the very best. Rob.
I've just had my very first contacts on 160m with a doublet 52m long. I live near Kings Standing in Crowborough. Ray M7AOE
Excellent!
Nice presentation. Thank you. Some random top band comments: A half wavelength on 160 is 260' +/-.. Good luck if you have that available.. If I had that available, I'd choose an off center fed dipole because I'd get multiband performance out of the antenna. Feeding at a high voltage point may or may not be good for the longevity of your transmitter. The most efficient return path does not go through a ground rod.. A small number of short counterpoises works better. Top band antennas, unless they are raised to an ungodly height are not directional. My optimal 160 antenna is a 130' wire with four 20' counterpoises. with a 9:1 UNUN at the feed point. Coax going to a tuner and then to transceiver. W9ZD.
It's great to hear from you. All your comments are very interesting, thanks. Cheers from the UK, Ray.
I suppose I’m lucky I just put up a 40m longwire connected to a SGC230 and the ground side is connected to our metal barn
I could get a full wave dipole up might take some doing with wire and supports though!
Good to see the principals put on view well explained thanks for that
I wish I had some land… like a few acres! Cheers, Ray.
@@g4nsj bonus of living on a farm 👍
Nice presentation Ray, theres a nice informative video on uTube form Palomar Engineering. I,m playing with a 9;1 unun which require non resonant lengths but i think the current is high at the feed point. i think this only applies to non resonance lengths but true with resonant half ways like you say. Another interesting video Ray and appretiate you understand that not everyone understand some of the things you mention.
Thanks Steve, I'll check the Palomar Engineering videos. Cheers, Ray.
ua-cam.com/video/4lzlZxxUzM0/v-deo.html
Nice to see SPRAT in image 🙂
Indeed!
Very good! I only have one comment and you probably already considered it. The max radiation comes from about the center third of the halfwave wire. If you can center that part over your garden you will have exactly what you want. In some situations you could make the wire a bit longer than a half wave if necessary. All that would do is move the current minimum away from your window. It would increase the current right at the window but a 10 or 15 feet would not be much.Going a bit longer than a half-wave usually makes it easier to match. The Z starts coming down again. I find exact half-wave is a problem sometimes. The so called “random end fed wires” ( they are not really random) avoid exact half-wave resonant points for that reason. In your case going maybe 10 or 15 feet over a half wave might be worth considering for both reasons. I used to use a simple L network for my antenna that was about 300 feet long. Don’t remember the exact length but it was just over half-wave on 160. I used it on all bands 160 through 10 with the L network tuner just inside my shack window. I had two galvanized pipes as ground rods at first. Good enough to work KH6IJ on 160 SSB and CW from Virginia. On 10 meters (the wire was pointed NE/SW toward Europe and South West USA) it rivaled my 3 element 10 meter Yagi in those two directions only.
I currently use an Inverted L for 160. It is longer than a Quarter wave to get the high current up on the vertical wire instead of at the ground. That makes it inductive (since it is long) and raises the real resistance to about 50 ohms or so. I simply cancel the inductive reactance with a large variable capacitor to obtain a great match on 160.
73,
N4DJ
Excellent info, thanks! Cheers, Ray.
Thanks Ray for the Video. Did the XYL say all that's going down to the workshop Hi. I eventually got the DATONG D70 Morse TUTOR and Working in mint condition It has memory's the good old days and top band 160 mere Thanks again Ray 73 de G6JMX
Hi Barry, good news about the D70. I often use mine to brush up on speed. The XYL is quite understanding... just as well! Cheers, Ray.
I just checked out your website and confirmed what I thought I saw. That CR100 was my first receiver. I bought it at the grand age of fourteen (I am now seventy three) and transported it home in a wheelbarrow. I was a member of the local radio club so the next issue of the club news mentioned that young Dave had been seen going mobile in. a wheelbarrow. I moved from Ashford Middlesex (now Surrey) to the US where I now hold the callsign N2SN. How's that for a CW callsign? I got to choose it after I upgraded my license after passing my extra class theory and 20WPM morse code test. I now live in sunny Florida USA. Hopefully we will meet on the air one day,. All the very best, Dave, N2SN.
PS: Do you remember the old Sunday morning top band nets where everyone was using a 10 Watt Codar AT5? Do you remember that awful beacon - HF radar in the middle of the band?
Hi Dave, mobile in a wheelbarrow! Love it! Great CW callsign, haha! The CR100 is a lovely old receiver. I got my first one in the early 60s. We might well meet on the air, I hope so! Cheers, Ray.
Brilliant Ray - you have inspired me to try something similar :-) I wonder if the far end of the aerial was arranged to be sort of vertical or elevated ( maybe up the top section of a tree) whether this would make the arrangement better for local contacts?
It might improve local contacts. Certainly worth trying. Cheers, Ray.
Awesome awesome awesome
Thanks, I'm glad you found the video useful. Cheers, Ray.
Thanks Ray, for very good explanation of this antenna-topic. With your antenna-basics it is not difficult to built your own wire-antennas for top-band. At the moment I use a dipole for 80M with 450 ohm ladderline and the famous S-match, and giving me also a good match on 160M. Did you also experience with dipole with 450 Ohm line Ray? I just get a remote antenna-tuner and will try a wire of almost 80M long for topband and the higher bands. 73 Jan PA2JJB Texel-Island
Hi Jan, it's nice to hear from you. Good luck with the 80m long wire. I've not tried 450 ohm feeder. Maybe I will one day. 73 Ray.
Wish you'd been around when I was trying to understand aerials from dull as ditch water text books! Aerial v Earth, best description I heard was that the aerial has to have something to push against. Magnus Magnusson? Nah, you mean Magnus Pyke. Suddenly, I feel old. : (
Magnus Pyke… yes, of course! It’s great to hear from you. Cheers, Ray.
Glad to see that you still call it a blackboard! Don't irradiate the neighbours! LOL
The neighbours love me… I think!
I’ll keep them safe.
Hi Ray, I watched it to the end! Why? Because it was interesting! Thank you. 73 Alex M0KVA
Thanks, Alex. That's nice of you. Cheers, Ray.
Hi Ray, I love your videos mate, I have a question for you about the 160m half wave aerial, I have around 130’ of garden so I can’t get 200’ of wire in! Can you form a coil to add the length I need? What size former and how many coils? Cheers Ray thanks John M0CDL
Try adding a coil at the radio end if the antenna. Experiment with the amount of turns on a 2 inch plastic pipe.
I've got an EFHW for 160 m useable on 80/40/20 (I've got the realestate). I also have an 80/40/20 etc... OCF. Both antennas are at the same height and close to same orientation. Comparing the two antennas, the OCF "hears" better 1 to 2 S units than the EFHW. Not sure why. I don't have any counterpoise on the EFHW besides the 50 ft. coax running to the shack but I did ground it out at the 49:1 transformer. Would a counterpoise help on the receiving end of the EFHW? 73 de KQ2N
Hi, great to hear from you. The only thing to do is try it and see. I think it might help. Cheers, Ray.
Couple of things Ray, I've recently put up an end fed 5/8 wave vertical "silver rod" for my unlicensed use on 27mhz and I've got into north America, Europe and even Russia on USB. Based on your antenna description is there any advantage on 5/8 over 1/2 wave on 11 metres?
Also, would it not have been a wiser idea to take your top band wire over the roof verses the alley?
Cheers
Hi Richard, I think the 5/8 wave is better than a half wave because the RF current is higher up the the aerial. I can't take the 160m aerial over the house as there are already too many wires there. I will be raising it at some stage... and lengthening it. Cheers, Ray.
Hi Ray..Excellent video..Thank you. Can I ask your opinion on gauge of wire for an efhw.. Does the wire gauge (within reason) make any noticeable difference.. Thank you.. John
Hi John, the gauge doesn’t matter. Obviously too thin will break and too thick will sag.
@@g4nsj …thanks Ray…John..G4EIJ
Ray what kind of counterpoise are you using for the 160 meter band? Since your shack is not on the ground floor and the antenna starts on the street side instead of your garden side I am curious. I am in a similar situation, I already have good results with an EFHW for the 80 meter band, but it starts from the garden. For the 160 meters I can make a 2nd EFHW and I could use a similar trick as you, but that makes it harder to have a good counterpoise.
I have an extensive earth system under the lawn at the back. There's a copper pipe that runs underground to the front of the house and connects to the ATU.
Hi ray good to see you I’ve been watching your video about the noise on 5mhz I suppose you.know of the Mfj noise cancelling unit just a thought.the other thing is maybe the 160 antenna is causing the noise hope you get rid of it .Gary
Hi Gary, I have tried grounding all other aerials but it makes no difference. I hope all is well with you. Cheers, Ray.
Ray, THANK YOU. I really enjoyed this presentation. You are down to Earth (no pun intended 🤣) and you explain clearly to us "non-tech" types, but we still make great operators hi hi. Ray, one thing, please excuse me. A 160m wire - half wave - say approx 80m long (will cut for centre of the 75Khz we have on the 160m Band here in Australia) What ratio Unun would I use? I have a 9:1 ... would that suffice, or are we looking more to a 49:1 etc ?? My feedline is LMR400 Coax. Cheers Ray, Mark VK2MRF.
Hi Mark, I think the 9:1 balun will be fine. Give it a try and see how you get on. Cheers, Ray.
How's the antenna look on the emf calculator ray
Don’t know, I won’t be running tests until it’s up and running.
Ray, it will be very interesting to know how you get on with this 'stealth' EFHW for 160m.
I will keep you posted.
Thanks Ray your really helping me here, my question if you have time to answer, if my end fed half wave is 160 meters can i then use it as a full wave on 80 meters
Hi Paul, a full wave end fed on 80 metres will be 80 metres long. A half wave is 40 metres. Yours will be two full wavelengths long. You can use an end fed wire of any length on any HF band but it will be better on some bands then others. The best thing is, try it and see. Cheers, Ray.
Thank you sir Cheers to you have a great day @@g4nsj
Hi Ray, thanks for the video and how did it turn out when finished? I'm just about to do a similar exercise. Out of my front room window (I have a bungalow) up to the roof ridge and down the garden 80 metres. I could go longer like 120 metres... would there be a benefit please?
It turned out well. I think 120 metres would be worth trying. Let me know how you get on.
@@g4nsj Thanks for your reply Ray. For a quicker set up, I'll try 80m first and when time permits, go longer. I'll let you know how it turns out. Best 73.
@@acestudioscouk-Ace-G0ACE OK, good luck with that.
Dont change, I love your videos as they are.
What kind of tuner is used for a halfwave antenna ?
Any decent tuner that has an end fed wire antenna terminal.
@@g4nsj Ok,thanks.
Hi Ray. Any report on progress, or were you wiped out by QRM on Top Band? The idea is a great one (but my neighbours would never let me get away with it. They go nuts if they can see a thin wire in "their" sky). 73 de M1GWZ
Lengthening the wire just made the interference worse. I think I might give up on top band.
Or you could make the wire even longer and terminate it with a resistor to ground and there would be no standing wave (beverage antenna)
Good idea but I don’t have the space.
Top Band is not easy in small gardens, I will have to stick with a quarterwave and attendant huge ground losses. The half wave end fed would be far more efficient. Being a pedantic sod though the current minima in your system will be about 10 times lower than in a 50 ohm system. (if you take it to be about 5000 ohms at the feedpoint). 73, good to see another video.
Excellent, thanks.
EMC regs Ray. The wire down the alley shouldn’t be close to people and animals etc.
I’ve filled out all the paperwork for my other aerials. You’re right, I’m going to have to get some height or move it away from gardens.
end fed with a ground rod is jsut a big dipole
the groudn is jsut the other leg of the dipole
nto quite but kinda XDD
Physics moment.
an end fed is an " aerial" for its " up there in the air..." but its NOT an antenna.
Neither is a loop.
Both are electro- static couplings, not antennas. They work very poorly compared to a structure with proper " antenna function."
A loop is a one- turn Inductor. A end fed wire is approximately one plate of a capacitor exuding field lines.
Those functions are not " antenna."
Yes according to a certain PHd text (Electric Waves, Skilling, 1948) these will emit a little energy at a distance due to energy wandering off like so many lost sheep, but they are extremely inefficient as being inductors or capacitors, they conserve most of their field energe locally to the structure, not emitting it. Most of thats wasted. This is why loops are plagued with high currents and end feds by high voltages- trying to load either a short or open circuit.
Neither is proper or conducive to operating with a modern 50 ohm Transmitter- they are useless relics of the early 1900s when transmitters had high impedance outputs.
Note that universally, amplifiers must be used with these couplers...
Instead of wasting time and power with these buggered up failures, learn to optimise a simple dipole.
Im daily/ weekly working E EU and S.A with a 20m dipole and 1-10 WATTS. Serbia, SSB, TEN Watts 5-5.
Best explanation.Wonderful.
Thanks, glad you found the video useful.
No, one doesn't actually really need an "Earth" ground as such, as described in the middle of this video. The End Fed Half-Wave antenna was initially developed for air ships (Zeppelins) and is in fact sometimes called a Zepp antenna if fed with an open-line quarter wave transformer (taking the role of the modern 49:1 Un-Un). When a Zeppelin is 5000 feet in the air, there's obviously no connection to Earth. In fact, have a look at the Zepp design and you'll see an open circuit at the end of the transmission line transformer. The antenna concept would work just fine in deep space, a lightyear from any planet. Even a modern implementation of an EFHW can use only a small counterpoise, because the high impedance feed point is also high impedance on the "return" side, so the system isn't driving high currents into the return side.
Whenever someone makes a claim about antennas and Earth grounding and lightning, run their suggestion or concept past the known existence of aircraft and spacecraft that are equipped with radios and antennas and even lightning protection. At the very least, they may be forced to clarify what they really meant to say. They may have correct understanding, but just said it wrong. Or in some cases they may have incomplete understanding. The "What about aircraft and spacecraft?" rebuttal can be very effective in clarifying concepts.
Hi Ray, thanks for sharing yet another most interesting and informative video. are the houses fairly close together there? We are fortunate here in Melbourne Australia with space both sides of the house, as the house is on an angle. We then have a reasonably good size back yard. I have a long wire antenna from my den, going under the house and then along the back fence. It seems to work quite well for receiving medium wave. Anyway, wishing you the very best. Rob.
Hi Rob, yes the houses are very close together. Everything here is very close due to lack of space! It’s nice to hear from you. I hope all is well. Cheers, Ray.