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.
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).
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!
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
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.
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.
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...
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.
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.
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.
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
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!
@@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.
@@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 .
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.
Holy moly this video is gold. Thanks mate! There is a gap of knowledge in the radio side of youtube. I feel like we have the option of watching people who have been doing it for 50 years and dont remember the little things beginners need to learn. Or you find the goon who knows nothing and is just regurgitating what he has heard. Thanks again. I look forward to the rest of your videos.
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.
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
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 TH-cam videos. Thank you.
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!😃
What an excellent video, very well presented. You go into just enough details for us to understand the purpose without going down the rabbit hole! 7:1 ratio, 7 square... Just enough to clear the mystery. I am hoping that goes further into all of this so we can geak-out even more! I like the view from your balcony and the top of that mountain! Merci!
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.
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
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!!
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......
Great video. Regarding the 100pf capacitor on the RF Transformer there isn't 3kv on the RF input, if there was your radio's final world be toast. Yes there will be 3kv on the high impedance output to the wire antenna. I only use a capacitor rated at 400v with no issues.
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.
I am a swl and I know what you are saying the power output from some stations obliterate a wide bandwidth and only they ask for certain contacts which defeats the object of collecting contact from anywhere and dx and ruins the ham radio for new licenced hams.
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.
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.
Excellent, Gil, thanks! I heartily agree that the contesters shouldn't completely take over the bands. It's kind of ridiculous. Supposedly no radio amateur has priority over anyone else. However, that seems to go out the window during a contest. Anyway, very interesting information about end-fed antennas. I learned quite a bit!
There are the so called “contest preferred” band segments which are an attempt to give everyone a bit of breathing space. However it is up to the contest organisers to make these segments an important part of the rules. 73
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
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.
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.
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.
I agree 100% with you my friend. I was a QRP for years in India and then in US about 40 years ago. Well, NOW i am back after other life things! And very surprised - shockingly to what you said is so true. Oh well I still plan to get back in 4-5 months.. 73 ...ex vu2du/w3
You make a good point. Sometimes the WARC bands, 30, 17, and 12 meter bands, are not open. Contest organizers could set aside 50 KHz of the CW and voice bands they use and make them off-limits to contest activity. That would leave a little space for everyone else.
WOW! What a fantastic teacher! Just one little thing - "Impedance" is pronounced "Im-PEE-dance". Many thanks for such a clear and informative explanation.
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.
A full wave length wire also wastes a lot of power from what I understand. I think it had something to do with cancellation but I don’t remember specifically what the issue was.
There is one thing I don't quite agree with in your 1st schematic. At the end of the antenna by definition the current should be zero, the missing current should be graphed at the other end (near the feed input).
Excellente explication Gil sur le sujet. Some explanations in English now for the non French speaking amateurs to understand: Cap is supposed to help on higher bands and raise resonance frequency as far as I remember well :) Also as far as I remember well, material #52 is good for the lower bands and higher power (ex. 3 stacked 240-52 for 1/2 kW with still good efficiency ratio) and 43 will go up to 10m but with the cap to have a more centered resonance frequency. Also, on 6m, I would advise either use a 2 meter 5/8 antenna which happens to be electrically 1/4 wave on 6m or a telescopic antenna with some counterpoise, so depending on the available supports.
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.
Ferrite core transformers work well at low impedances - above about 9:1 losses get really high. To check losses, run 100 watts through the matching network / wire for 30 seconds or so and then, with RF off, feel the cores' temperatures. If the network is efficient, they will be cold to lukewarm. The other issue is that an end-fed wire is a single ended load fed against a ground connection or counterpoise - this often introduces significant losses. Some time spent modelling antennas with EZNEC will show what impedance various wavelength antennas present.
True, but often dipoles aren't mounted high enough and suffer ground losses. I think the difference if the lower angle of radiation of the vertical end-fed, even if the transformer is a bit lossy...
Well said sir. I have nothing against the idea of contests but I hate how the contesters just take over all the frequencies with no thought to sharing the spectrum with other hams.
This bloke and TRX Bench are top blokes, I love the way they pronounce balun, love it. and yes contest, what is it that makes them the Lords of Amateur Radio, is it a power trip, some times I think so.
Contests are awful. If you only have time to play radio on weekends like I do it really puts a dampener on the hobby. I get pretty sick of it. This was a super helpful video and clearly explained the diffrerences between randoms and half waves. I'll watch it again I imagine! Thanks.
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
I'd love to know how/why each of the turns do what they do, what the cap does and how etc. I've built a few successful to plan baluns for different antennas that have tuned well but I still don't get the science behind it. My next project for my next house (this one is a lost cause as there is a MASSIVE noise issue 15m and south all the way) will be a multiwire instead of just an OCF dipole.
I hv an 80-10 efhw with a 49/1, 130 feet long. My antennas brand. Very good on all bands. Adding a counterpoise off of the ground rod, I am able to work 160 decently! If I put up a 173 or 202 foot 9-1, wld it gv me better results on the bands, especially 80 n 160?? Ps…I am running an Mfj 998 tuner. Thanku. William
When you working QRP, common mode current is not a big problem. Even if antenna is resonant, length is about half wave and you are using more power (for instance 60W) counterpoise is good idea.
End fed QRP antennas are fun to build. Buy them if you have the $$$$ but building and experimenting with them is A LOT OF FUN!!!!! The comps are keeping CW alive and making the bands busy.....but I do concur on better organising of the bands as "the bands are there to share!" :)
So today, learned, type 2 material for 9-1 and ft-243 for higher impedance ratios. And others mentioned. VERY helpful, but, I'm going for super long wires, so not sure what I'm getting into. 1000ft . With my full wave loop 80 m I have had rf in the shack. It is fed with open wire line, and have had problems ever since I used it, but also DX like D4C (6000 miles Off coast from Dakar) with 5w usb 15m makes it worthwhile to put up with problems. I just updated a measurement, about 200 long wire antenna South east/North west direction. 75 to 100 feet high. Yes, FT-240-43
FT-240-43, not FT-243. The length itself is not the issue. If your very long wire is a multiple of half-wave for the band you use, use a 49:1. If it is not a half-wave multiple, use a 9:1.
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!
Big fan of you and the work that you do... your videos are excellent. You are to amateur radio what Milton Friedman was to economics... having a solid foundation of knowledge, you're able to communicate that knowledge in a very easy to understand method.
Great explanation. Thank you. Quick question if you have time. What constitutes the primary winding and he secondary? For example, is the primary always the input? Is the secondary always the output or ground? Thanks again for all the great work you do to help Hams. 73
Thanks Mr Radio Prepper. Very useful information & education. Comprehensive, comprehensible and entertaining. I am learing so much from you. Merci Beaucoup vraiment!
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.
Thank you :-)
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).
This should be mandatory viewing for Hams; so much great information packed in this video.
You can also tap a 9:1 midpoint at the junction, and have a 4:1 ratio, which may be a closers match on some bands....almost free.
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!
Good idea!
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
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.
Glad it helped :-)
Something about the presentation helped me to finally understand 1/2 waves and their transformers. Many thanks, enjoyed your video.
Yep, I feel same.
Agree with your comments on contests. I've heard them say " everybody enjoys contests " - inability to see the hobby from anyone else's perspective.
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.
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.
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...
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.
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.
I scoured youtube and google to understand transformers and this is THE best explanation ever. Very clearly done. Thank you!
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.
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
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!
@@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.
@@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 .
@@Pelnied9o
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.
Holy moly this video is gold. Thanks mate!
There is a gap of knowledge in the radio side of youtube. I feel like we have the option of watching people who have been doing it for 50 years and dont remember the little things beginners need to learn. Or you find the goon who knows nothing and is just regurgitating what he has heard.
Thanks again. I look forward to the rest of your videos.
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.
Great thanks!
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
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 TH-cam videos. Thank you.
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!😃
Glad it was helpful!
Very clear explanation of ununs and the cause and effect of the windings. Will listen in more!!
Absolutely the best explanation 49:1 vs 9:1 out there! Merci beaucoup. ~ k6sdw
What an excellent video, very well presented. You go into just enough details for us to understand the purpose without going down the rabbit hole!
7:1 ratio, 7 square... Just enough to clear the mystery.
I am hoping that goes further into all of this so we can geak-out even more!
I like the view from your balcony and the top of that mountain!
Merci!
Brilliant. Can't tell you how often I've watched this video. Built one for 30m yesterday and it worked extremely well.
Glad it helped 😀
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.
Great, thanks for reporting :-)
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
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!!
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.
For me also A1!
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......
Thank you!
This is the best explanation of the theory behind an EFHW antenna that I have seen ... Well done! And, very helpful!
This was quite entertaining! I agree. Contests are agrivating.
Great video. Regarding the 100pf capacitor on the RF Transformer there isn't 3kv on the RF input, if there was your radio's final world be toast. Yes there will be 3kv on the high impedance output to the wire antenna. I only use a capacitor rated at 400v with no issues.
Great video. Easy to understand information for someone beginning to learn about HF antenna building.
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.
I am a swl and I know what you are saying the power output from some stations obliterate a wide bandwidth and only they ask for certain contacts which defeats the object of collecting contact from anywhere and dx and ruins the ham radio for new licenced hams.
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.
Great job at explaining everything on end-fed, random wire, and un un, I got a lot out of this thanks Gil.
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.
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.
Excellent, Gil, thanks! I heartily agree that the contesters shouldn't completely take over the bands. It's kind of ridiculous. Supposedly no radio amateur has priority over anyone else. However, that seems to go out the window during a contest.
Anyway, very interesting information about end-fed antennas. I learned quite a bit!
A lot of contesters are a damn nuisance-a law unto themselves even swamping all the QRP HF freqencies!! this worlds gone mad
There are the so called “contest preferred” band segments which are an attempt to give everyone a bit of breathing space. However it is up to the contest organisers to make these segments an important part of the rules. 73
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
Thanks for the fantastic explanation of the difference between 1/2 wave and “random” wire antennas!
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.
Glad it helps :-)
I imagine you are well rested... 🙄😂
😎👍☘🍺
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.
Thanks for explaining. I have a 42 metre wire and a 9:1 unun. I have had no surprises yet but perhaps I should add (some) radials or an earth spike.
Hard to predict with a 9:1...
What's hard to predict?
SWR and common mode current issues given different counterpoise and ground configurations using a 9:1 with a non-resonant wire...
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.
Awesome!
I agree 100% with you my friend. I was a QRP for years in India and then in US about 40 years ago. Well, NOW i am back after other life things! And very surprised - shockingly to what you said is so true. Oh well I still plan to get back in 4-5 months.. 73 ...ex vu2du/w3
You make a good point. Sometimes the WARC bands, 30, 17, and 12 meter bands, are not open. Contest organizers could set aside 50 KHz of the CW and voice bands they use and make them off-limits to contest activity. That would leave a little space for everyone else.
I agree about the contest freq range.
I thing that CW is allowed on the whole band. So in the time of contest one can morse CQ SOTA at SSB part of the band.
Maybe they could put the contest there..
I agree with others here that you do a very clear and helpful description of the basics. A valuable resource - Thanks Gill
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.
one of the best explenation ı have ever seen...perfect....super...thank you Gil...
They also use frequencies that have agreed uses, like QRP, RTTY, SSTV etc.....
I hear ya. I'm into emcomm, nets and talking about radio, not contests.
WOW! What a fantastic teacher!
Just one little thing - "Impedance" is pronounced "Im-PEE-dance".
Many thanks for such a clear and informative explanation.
Noted thanks!
Thank you for explaining the workings so clearly. Now I understand a lot more. You are an excellent teacher.
Thanks, glad it helped!
I’ve learnt more from this video than any other antenna learning method!!!
Great 👌
Glad it was helpful!
I always learn more when I view your videos. Thank you.
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.
I can’t thank you enough for your detailed explanation on how to make an un un.
Glad it helped :-)
A full wave length wire also wastes a lot of power from what I understand. I think it had something to do with cancellation but I don’t remember specifically what the issue was.
I'll look that up thanks!
Great video. I learned more in this video than in the last 5 or 6 I've watched. Thanks!
Thank you for the clear details. This helped me to understand concepts that were very murky before.
There is one thing I don't quite agree with in your 1st schematic. At the end of the antenna by definition the current should be zero, the missing current should be graphed at the other end (near the feed input).
I agree on the contesting...that's why I prefer to stick to 17 meters when the contests are going on
I believe the capacitor is to cancel out stray inductance for better matching on the high bands.
Well Sir you did a very good job explaining some important basic working principles. Very glad I have watched it. Thank you!
Excellente explication Gil sur le sujet.
Some explanations in English now for the non French speaking amateurs to understand:
Cap is supposed to help on higher bands and raise resonance frequency as far as I remember well :)
Also as far as I remember well, material #52 is good for the lower bands and higher power (ex. 3 stacked 240-52 for 1/2 kW with still good efficiency ratio) and 43 will go up to 10m but with the cap to have a more centered resonance frequency.
Also, on 6m, I would advise either use a 2 meter 5/8 antenna which happens to be electrically 1/4 wave on 6m or a telescopic antenna with some counterpoise, so depending on the available supports.
Thanks. I do have the same video in English..
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.
You're explaining the exact way the American Field Days is each year, don't want to not "play", then suck it up and come back later. I feel your pain.
Please keep making these videos you are an excellent teacher my friend and people love you..
Thanks, will do :-)
Ferrite core transformers work well at low impedances - above about 9:1 losses get really high. To check losses, run 100 watts through the matching network / wire for 30 seconds or so and then, with RF off, feel the cores' temperatures. If the network is efficient, they will be cold to lukewarm. The other issue is that an end-fed wire is a single ended load fed against a ground connection or counterpoise - this often introduces significant losses. Some time spent modelling antennas with EZNEC will show what impedance various wavelength antennas present.
True, but often dipoles aren't mounted high enough and suffer ground losses. I think the difference if the lower angle of radiation of the vertical end-fed, even if the transformer is a bit lossy...
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
Well said sir. I have nothing against the idea of contests but I hate how the contesters just take over all the frequencies with no thought to sharing the spectrum with other hams.
Agreed, contesting is waste of time in my opinion.
Thank you for your time. Best presentation I’ve ever seen on aerial transformers. 73
Totally agree with you about contests.
This bloke and TRX Bench are top blokes, I love the way they pronounce balun, love it. and yes contest, what is it that makes them the Lords of Amateur Radio, is it a power trip, some times I think so.
49:1 and 64:1 is the turn ratio of the transformer. The impedance ratio is the square root. The former is 7:1 and the latter is 8:1.
49:1 & 64:1 are the impedance ratio. 7:1 & 8:1 are the turn ratios. The impedance ratio is the square of the turn ratio.
@@RadioPrepper Sorry, I get it wrong. Ohm's law.
Contests are awful. If you only have time to play radio on weekends like I do it really puts a dampener on the hobby. I get pretty sick of it. This was a super helpful video and clearly explained the diffrerences between randoms and half waves. I'll watch it again I imagine! Thanks.
Thank you :-)
Thank you. I now understand unun and 49:1 vs 9:1. great information
Super!
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
Let me know how it works for you!
Contests are a pain & your point about them taking up the whole band is exactly right... 🙄
I'd love to know how/why each of the turns do what they do, what the cap does and how etc. I've built a few successful to plan baluns for different antennas that have tuned well but I still don't get the science behind it. My next project for my next house (this one is a lost cause as there is a MASSIVE noise issue 15m and south all the way) will be a multiwire instead of just an OCF dipole.
I hv an 80-10 efhw with a 49/1, 130 feet long. My antennas brand.
Very good on all bands. Adding a counterpoise off of the ground rod, I am able to work 160 decently!
If I put up a 173 or 202 foot 9-1, wld it gv me better results on the bands, especially 80 n 160??
Ps…I am running an Mfj 998 tuner.
Thanku.
William
I have that antenna. When you use a counterpoise, you create an off-center-fed dipole..
@ Thanks!! Didn’t know
Any input to the question of a 9/1 with longer wire?
@@WILLIAMPERRELLI you can use a very long wire with a 9:1, as long as it isn't a half-wave or a multiple of a half-wave...
Thanks for the detailed explanation of 1/2 wave wires and end feed antennas.
When you working QRP, common mode current is not a big problem. Even if antenna is resonant, length is about half wave and you are using more power (for instance 60W) counterpoise is good idea.
Sometimes it does mess up keyer chips...
@@RadioPrepper It absolutely can happen especially when cable between manipulator and TRX is not shielded (which is not in most cases)
Thank you for explaining this. I now understand more.
Not a single frequency free for CW? This was very usual 25 years ago ...
End fed QRP antennas are fun to build. Buy them if you have the $$$$ but building and experimenting with them is A LOT OF FUN!!!!! The comps are keeping CW alive and making the bands busy.....but I do concur on better organising of the bands as "the bands are there to share!" :)
Excellent teaching Thankyou
Awesome
So today, learned, type 2 material for 9-1 and ft-243 for higher impedance ratios. And others mentioned. VERY helpful, but, I'm going for super long wires, so not sure what I'm getting into. 1000ft . With my full wave loop 80 m I have had rf in the shack. It is fed with open wire line, and have had problems ever since I used it, but also DX like D4C (6000 miles Off coast from Dakar) with 5w usb 15m makes it worthwhile to put up with problems. I just updated a measurement, about 200 long wire antenna South east/North west direction. 75 to 100 feet high. Yes, FT-240-43
FT-240-43, not FT-243. The length itself is not the issue. If your very long wire is a multiple of half-wave for the band you use, use a 49:1. If it is not a half-wave multiple, use a 9:1.
New ham here. Thank you for this. You are really great at explaining things!
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!
Big fan of you and the work that you do... your videos are excellent. You are to amateur radio what Milton Friedman was to economics... having a solid foundation of knowledge, you're able to communicate that knowledge in a very easy to understand method.
Thank you!
Great explanation. Thank you. Quick question if you have time. What constitutes the primary winding and he secondary? For example, is the primary always the input? Is the secondary always the output or ground? Thanks again for all the great work you do to help Hams. 73
Thanks for this great video - Explains a lot. The best I’ve seen so far.
Explained so well even this boy from Texas USA can understand. Fantastic job Gil!
Glad it helped!
Thanks Gil. I watched this several times and got more from each viewing. :)
Very clear explanations. Thank you. Curious about your sketch diagram with inverted V antenna.
Thanks for this video. This is the first time that I feel that I've actually understood this subject. 73
I like this guy. Feels exactly the same way about "contests" as I do! ;)
Well said, indeed :D
73
de
G1LIW
That's because they only know how to sent five numbers: 599 73.
Contests are another form of radio jamming. They are my que to play on FT8.
Excellent training and information that is very usable, thank you
Thanks Mr Radio Prepper. Very useful information & education. Comprehensive, comprehensible and entertaining. I am learing so much from you. Merci Beaucoup vraiment!
Glad it helped:-)
Hello! I want to build unun 49:1 for my antenna End Fed. I like QRP and max 20W in SSB, CW. What do you think about ferrite? Amidon Ft140-43 is ok?
That's perfect.
@@RadioPrepper Ok, so I will use Ft140-43 for this project. 73!