The 49:1 Half-Wave End-Fed Antenna Transformer, Part 2.
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- เผยแพร่เมื่อ 11 ก.ค. 2024
- Good results with 6m and 30m half-wave wires. At last I made a contact with my PRC-352 but I cheated a bit... Operated from the Escarpelle terril near Douai. You can get one here: igg.me/at/radioprepper DISCLAIMER: The Radio Prepper logo (depicting a microphone) is indeed inspired from a famous flag created in 1775. It is NOTHING BUT a symbol of freedom and independence. It does NOT imply support to any political group. It does NOT imply, represent nor support any ideology with an intent on harming anyone. Freedom means freedom from persecution based on any human trait or belief such as, non exhaustively, race, gender, religion, sexual orientation or nationality. The Radio Prepper channel is a technology and science channel with a focus on preparedness and use of radio technology for disaster relief and small group communications in times of need. It is apolitical and open to anyone sharing the same interests. .
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Thank you Radio Prepper you are a wealth of information for a newbe like my self.
Gil, your absolute courtesy in translating for us makes the French so enjoyable! Merci!
You're welcome :-)
Really good series of videos. Thanks for the care you take in making everything clear and detailed.
Thanks!
Another useful video and it's so good that your explain and translate in a ribbon line at the bottom.
Just putting a 9:1 in an old CB 5/8th wave myself. I can only hope it comes close to the results you obtained. It is a joy to watch as you work, thank you.
Thank. No harm in trying!
Another great informative video on end fed half wave antenna, I use end fed wire antennas for my home qth station, I like you think that these antennas are them greatest! Thank you for all the information that you provide in your videos!
Congratulations on finally getting a 6 metre contact on the PRC Gil, well done! I'm a big fan of halfwave end-feds too, I used to have a 'fan dipole' up for 40-20-17&10m, I was able to switch between it and my 20m long end-fed to enable back to back testing, after a couple of months the dipole came down, the end-fed was always as good, and in some cases 1-2 s-points better! 73, M0KED.
Thanks, not surprised..
Excellent video Gil. Very informative as always.
Thank you.
Thank you 4 ur blessing
Thanks for the video !
Gil ..Your tech knowledge is par excellence.. I don't know if you are aware of it but your English is better than many, (MANY) English men. I realise just how much effort you have put into learning our bastard language so I know how you will welcome a little, one-word adjustment.
You say "impedance" with the E sounding like "Head or Bread."
It is actually much closer to your "vite"...or our "street..treat..sleep, sheep." Comme l'Impeedance
Je vous remercie bien pour toute.
Vive La Belle France et peut-etre Gen. De Gaulle.
A bientot! Mon Cher..
Vive L'hot club, Le Django Rheinhart Merveilleux et le Grapelli encroyable!
G3NBY
Thank you! 22 years in Florida ;-)
Also very nice scenery!
Looks like you are having fun making contacts on DMR and your PRC-352 =) Great job Gil on the radio outing =) Nice "49:1 Half-Wave End-Fed Antenna Balun" build =) Great contacts using the KX and 49:1 end-fed antenna well almost "Stealth" mode :-)))
Yep, more fun with the PRC-352, but carrying it sucks..
Usually when using the PRC-325 was pressed into service you where being hunted and shot at /-) Still all in fun Gil good job =)
I look at HAM Radio like fishing. You're not sure what you're gonna "catch," but stay at it long enough, and you will catch something. Gil just proved my point. Glad you got your 6-meter contact, congratulations! *"Welcome to France, where everything is prohibited."* lol
I like the spoon throwing!
Excellent video, thanks Gil. I've made and had success with a 9:1 unun and radom wires but not made the 49:1 yet for efhw. I think I will now.
It's definitely more efficient, and no stray currents problems.
@@RadioPrepper
Ah..THAT answers one of my queries
This is such a great video, I'm just about to start using a 49:1 half wave antenna. I missed your crowd funder appeal, I was new to the hobby back then and new to TH-cam too :-)
I am testing different transformers for 6m right now...
th-cam.com/video/HzUlyPv6DPA/w-d-xo.html
Good job Gil
FB Gill. Keep up the good work. I enjoyed your video. Not much doing on the bands due to the conditions but you seem to enjoy getting out and about. Keeps you fit. 73 de John-G0WXU
Thanks, will do!
Good video.
Good job Gil!
Thanks!
Everything is banned here in England as well. I agree with 'peace & quiet' but sometimes too many regulations! (I blame William of Normandy for this problem!). Excellent and informative videos - encouraging me to take up SOTA; Yes, even in South East England - and on frequent trips to North West Wales to see friends! My wife's church is twinned with a church in Douai and they visit each other _ I must go with her sometime and follow in your footsteps; literally! Keep those videos coming - please! de Richard G8ITB - originally from SP/land.
Will do! Let me know when you visit :-)
good video Gil i did some testing with the 49t1 I made but have not made any qso yet. Away on SOTA this week but using link dipole. Seeing you are not into shaving you could use your old shaving brush to clean your keys and rig face, I use one all the time saves sticky finger marks or scratches from rubbing the dust into shiny surfaces. vk5cz ..
LOL, I'm not into brushing either ;-)
Du moins la chasse n'est que reglée. (Reste à voir combien ça coûte la permission...) Pis c'est pas ce qu'on entend par « la pêche à la cuillère », le França! Super vidéo comme toujours Gil!
Merci!
Amen ! LOOOOL !
EFHW used to be fed with a 1/4 wave open wire feeder to shift from low Z Tx o/p to high Z on a trailing HW antenna on the Zeppelin Dirigibles.
This kept the Hi Z feed point which might arc, well away from any stray H2 which drifts upwards and away by slipstream. You don't want sparky bits near Hydrogen leaky bits.
Hams then used it at ground level and tucked a second HW on the unused leg of the open wire feeder...Hence vee haf zer dooble Zepp! Vee haf vays of making you QSO!
Ich entschuldige mich für meinen groben deutschen Akzent auf Englisch. Es macht die Eingeborenen glücklich.
Good evening! I have a doubt about the use of the lenght wire of the EFHW. I've been seeing some videos that shows a lot of EFHW antennas and I dont know excatly wich band covers using just one 49:1 balun. my question is: Is it possible to cover the entire HF band (80 to 10 m) with just one wire of 134' long, or 67' long (for 40 to 10m band). This antenna is ressonable on those frequencies or not? I wonder all of these things because I want to make just one of it, but I have a single doubt if is better to make a 9:1 balun (using, of course, a counterpoise and a wire with 63 feet long), or make a 49:1 balun (without counterpoise), with near the same lenght and get some more ressonable frequencies on my RIG. Just because I do not like to use external/internal ATU.. Thanks for sharing, I watched all of your videos and liked all. 73 ES PR7RC.
very good very good 73
What are you using for the ground side? Ground or a counterpoise? 73
Gil,
Okay I'm going to abandon the full wave antenna on my 49:1 EFHW TRANSFORMER and take you're advise and go with the half wave antenna at 17'. That's probably why I don't hardly hear anything because of my 29' sloper not tuned to 11meters. Thank you for you're extensive knowledge/experience on this.
Thanks. Remember, longer isn't always better. The correct length for the frequency is the most important, and half wave is usually the best.
You're videos are very informative what formula did you use for the wire to get a low swr reading 468/f. Any help would be greatly appreciated.
73
Thank you. Yes, 468/f or 143/f (metric).
Terril sounds so much nicer than slag heap...
LOL, it does.
Radio Prepper I propose the welsh officially adopt the French word! Terrils has a nice ring to it.
Hi Gil, How are you connecting your End Fed Half Wave antenna to the Clansman PRC 320?
Is it via the gooseneck and earth tag on the side of the manpack or do you disconnect the dog-bone arrangement at the back of the rig and hook to the BNC connector. I am thinking I would prefer to set up to the gooseneck and earth tag so that i can use the internal ATU.
I have made the EFHW antenna and work very well on other Hf rigs . 73 Colin vk2jcc
Oh yes, directly to the BNC connector, no need for a tuner.
The Computer Morse was 75Baud RTTY well that's what it sounded like to me..I remember using 2 relays to key the Mark and Space rtty tones using a Commodore 64 on 20Mtrs had a great qso with a Ham who was in a beach house in Taihiti back in the 80s...Well done on the 6Mtr Contact👍I still have not had any 😢.
Yep, my friend Ray told me. Presumably a 10KW German station...
Radio Prepper Hahaha Yes most likely German's or may be the Italian Mafia 😊. Look out for a Visit from the Pope Complaining about you Blessing your Viewer's on TH-cam 😆.
Church of the holy frequency ;-)
I use a 49:1 matching transformer and I'm about to replace a 10m pole that broke with a 12m spiderpole . It was suggested to me to coil the antenna wire 4-6 times at the base of the pole . Would it make any difference? .
Don't do it. It changes the apparent length of the wire. You can use coils if needed but that's another story...
I have never known the HF bands as bad as they are this summer, hopefully things will start to improve soon!
No solar spots... It's 80m NVIS year... Let's hope so...
Greetings could you tell me what gain have the EFHW antenna. Excellent your video
W4EDY
Hi, slightly less than a dipole.
Thanks so much 73
W4EDY
Welcome to France were the most is done to 1) preserve nature 2) preserve hikers tranquility... I'm sure you prefer calling CQ without engines mess and fumes in the background ;)
Oui, mais il y a quand même beaucoup trop de règlementations inutiles et stupides.
👍
What will work for a step down transformer for 700-800 mhz with a 1/2 wave 50 ohm antenna?
I do not know. I never heard of an end-fed for such a high frequency. Not much of a benefit, the antenna being so short. It might be possible, but I don't know how...
hi gil..for the little capacity in blue, always about 100pf 3kv, or another value ??? thanks for the fantastic video as ever, and as i have enough place to put some easy antenna at home, i would try to put an antenna for the 6m band !!, and would have a try sometimes on ... 51.7mhz you said ?? why not !! we just have to make some publicity before to encourage users on this band !! why not using for example, dmr band on TG208 french national, to make rendez vous before climbing the mountains ?? ;+)) would be a good idea to make pub and find someone ready on the band, instead having no one ready, because they don t monitor the 51.7 mhz FM portion !! ha ha ha !! si tu utilises le dmr dans ton coin, on pourrait se faire un chti qso sur tg208 un de ces jours avec plaisir !! 73 s pascal f5pnp
Bonjour Pascal et merci. 100pf oui, au moins 3KV ou plus pour QRO. Pad de relais DMR dans ma région, à ma connaissance. :-( Je m'annonce sur les relais de la région..
Hello Gil, F4WBY,There is an interesting, much better way to construct antenna transformers, using a number of equal-length pièces of 2-wire cable (e.g. indoor phone cable), wound onto antiparasiting ferrite toroids ("blue" ferrites). On these windings, the symmetric mode is suppressed by the core's inductance, whereas the antisymmetric mode can propagate through the core without hindrance.Now, for making a 1 to 9 transformer, just take three of these wound cores and connect the one ends of the bifilar windings in parallel, and the other ends of the bifilar windings in series. Take care of the correct polarity of the wire (phone cable has a black and a white marked wire, which helps to respect polarity). At the entry, the current divides by three, and at the exit, the three voltages add up together. The transformer ration Zin to Zout is thus 1 to 9. All signals propagate exactly the same length from the entry to the exit, which makes this antenna transformer extremely broad-band. If the wire length on the cores is smaller than 1/10 of the wavelength, there is no problem with impedance matching.To make your 1 to 49 transformer, just use seven of these wound cores and connect them in parallel at one side and in series at the other! I published this in HBradio.73, Edgar, HB9TRU
Yes, I have made a couple 9:1 that way, but this one is a 49:1. I have a video about the subject, check it out.
People think it's odd that I laugh at my own jokes.....haw haw hawww. I mean , seriously why wouldn't I?
Sure, avoids the awkwardness!
@@RadioPrepper Good job. ;)
“Welcome to France....where everything is prohibited.” LoL
It's even getting worse!
Radio Prepper Sad to hear it. Seems to be a fair bit of that around these days.
It is a global push in that direction; no coincidence...
Not yet but being on lockdown doesn't help!
where can i get a hand set like that?
clansman-radio.co.uk
I wouldn't call that cheating. You're testing/experimenting and what better way to validate an antenna build. I've noticed that the bands have been bad as well. Somedays/evenings, I'll turn the rig on and spin the dial and I don't hear much activity. I've had good results with endfed antennas and the 49:1 transformer is a must have, in my opinion.
Definitely. I want to make smaller ones, using the same core.
I've thought about building one and taking it to my job. We have some plastic dip that I would use, completely coat it with 3, or so coats and it will have a rubberized exterior without the need for a box. Hmmm, sounds like a video!
That was sort of my plan. Sotabeams has some goop like that...
I'll definitely make a video if I can get it done that way!
Ron C looking forward to the video
Gil,
Could you help me I'm want to make a fullwave antenna using a 49:1 transformer. What would be the correct length of the for 27.385 mhz (11m) Any help would be greatly appreciated.
Sure, but you want a half-wave, not a full-wave. 468/27.385=17ft.
Gil,
Wouldn't a 34' wire work with the 49:1 transformer. I understand nobody wants to do it but it's worth a try to see how a fullwave wire would perform on it. That's what amateur radio is all about experimenting right?
Try it, but longer isn't better. You will increase the angle of attack, which for such a high frequency will send most of your signal into space. It won't refract. If you absolutely want to use a full wave wire, use it horizontally then, as high as you can.
Gil,
So building a 49:1 EFHW TRANSFORMER half wave antenna will basically work better than the full wave? If that's the case will my 17' sloper antenna up 35' in a 50' tree be better. I live in a hoa development facility and can't put up any on the roof.
It depends on the wire angle. I would definitely recommend a 17ft vertical wire. A sloper, hard to say. Let me find a link, hold on...
Salut Gil, a verifier mais il me semble que la prononciation de Fuchs = "foux" en prononcant le "x" ;)
Ok merci.
Any of these still available to purchase? thanks
what was that?
@@RadioPrepper Hi Gil, I was referring to the 49:1 transformers, do you have any for sale? thanks
@4:20 In nomine patris et filii et spiritus sancti
Thank you Reverend Gil!
Father Gil did you ever try to improve the swr with holy water?
And can you bless my antenna via Twitter?
Amen Tim
Maybe there is a market there ;-)
nice video. Simple. Thanks, de WD8LIC
Thanks.
where do i get the capacitor
Ebay.
I have a question: Is this terrril ground conductive? Pls measure it next time
Ty
Hi, I am not quite sure. They are made of schist, but there are different kinds of schists, some containing graphite. In this region I think it is silicium, alumina and iron oxyde mixed with rocks. There can be residual carbon in there, and some actually enter a slow combustion...
@@RadioPrepper
Please explain Terril?
Can't find it in the dictoire
Thank you.
Left over from coal mining.
@@RadioPrepper
Wow! Never heard that expression before. You improve MY English!
Je vous remercie bien..
Will this work at 700-800mhz?
No.
What would happen if you use two bananna plugs inplace of the bnc, and feed it with latter line? KG7CQG
Ladder line is 450 Ohm... It would make no sense to use that...
@@RadioPrepper
He would set up an SWR on the line and obtain uncertain Z and reactance at the rig end with which would need a A1 ATU to handle. Radiation off the feeder would distort the pattern of the radiating element.
Why do it? D'accord...Cela n'aurait aucun sens!
Many tricks of the trade when it comes too s.w.r.regulations.usually in dependence of wire length or even wire triangulation.power adjustments has little diverse effect and all these little adjustments add up.pioneering with amture radio isn't an easy task because the calculas canbe complicated upon measuring the electrical field.thou there is many trade secrets when it comes too antenna innovations too signal amplifiers such as preamp power sources and leanors.we allways consider the ground for signal clarity but among some special cases too where the user is in a mobile situation unable too find a proper ground,I've discovered from an a.f.pilot that a common soda can can confinsate.😊
Hi Gil. Have you heard of the Wolf River TIA coil? May be a very good prepping antenna. I just picked one up and did a brief setup video on my TH-cam channel. It works very well so far!! Here is their website: www.wolfrivercoils.com/TIA.html
I'll check it out thanks!
I thought you were going to show how to build the unun. You did not show Crap!
I did more than once in other videos on this channel.