The 49:1 Half-Wave End-Fed Antenna Transformer, Part 1.
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- Опубліковано 15 лип 2024
- Building 49:1 impedance transformers for half-wave end-fed antennas, single or even multi-band with certain wire lengths, 134 or 67ft. The first one, wound for the lower bands turns out to be a real winner. I am even thinking about building a bunch of them, would you be interested? / 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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I used a 240-31 toroid for a 49:1 transformer on an inverted L. The antenna was resonate on 5 bands!
Great informative video, I enjoyed it very much, a lot of good information, and I finally understand the difference between random and half wave end fed antennas, thanks to you!
Great video!
Glad to find OMs sharing experiences and nice projects!
Keep on the good work!
:-)
Brilliant, I have been thinking of a use for all that enameled wire, I just ordered a 240/43 Toroid and I now feel happy to make a 49:1 UnUn. Thanks 73 Mike M0XMX
Absolutely brilliant project Gill👍 I'll be interested in learning more about this. Looking forward to part 2 have a good one my good friend 😃👍
Thanks, yes, something I will use quite often.
I enjoyed your video. It was very informative.....easy to follow instructions. Well done!
I made a 64 to 1 UnUn, shunted on the 50 ohm connection with a 150 pf cap. I use 65 feet of wire and get below 1.5 to 1 on 6, 10, 15, 20 and 40 meters. I use to use an OCF40 but now my go to portable antenna is the end fed. I also use a KX2.
KU3X
Most efficient, my favorite too!
Thanks for this Gill, I'm just about to build a long wire antenna, so this has been very useful.
Great, post your results!
Amazing video Prepper! I watched the whole lot. Excellent construction and amazing results. The fact that you were so close with the tuning without doing anything was amazing :) Loving your videos. I've subscribed. 73 from Andrew, VK2XXL
Thanks Andrew. On 80m the tuning was good down to 3.3mHz, so my wire is too long... A few inches less and it will be perfect! I should measure it... I know it's close to 134ft, but I forgot...
Always easier to trim (or fold) rather than lengthen, but as you say in the video we've all been there. I feel as though the end fed half wave deserves the same reputation as the G5RV and unlike the G5RV, it actually is meant to be a multiband antenna and works like one as you've shown above. That performance on 30m especially was amazing :)
Thanks for providing this very nice video. From the contacts made it appears to work quite well. I will be trying this on my KX3.
Thanks.
Thanks for the video!
Oh, great video Gil.
Going to find your #2
73
wow first 2 min of this video taught me everything i was researching for days.....coax.... dipole.... these are the nuances i didnt know!
Imagine if you watched all my videos ;-)
It is wonderful that you make your own parts.
Thanks, best way to learn something new!
Thanks, great video. You got my subscription.
Very interesting and useful video.
Thanks!
thank you for sharing your experiences... i am learning so much. Stay well 73 KC3RRW
I would love to have one of those efhw antennas great descriptions 👍
Thanks! You’re my first Patreon-Supported channel!
Just saw it, thanks! It does help a great deal believe me :-)
There's always the 44 foot doublet fed with ladderline for a multiband antenna too. Great vid. 73
Yep, I like this one because it doesn't need a tuner, less losses...
I've made this transformer using the same design document! It's fairly easy and so far has worked great.
Indeed, it was a quick build, no difficulty really..
Granted...I did not put mine into an enclosure...but now I want to. I used the part numbers on those instructions, so I had the larger toroids and magnet wire. It's a big transformer...61mm outside diameter and 12.7mm height
Presumably, the enclosure really doesn't make any difference and rain does not affect performances...
Presumably, the enclosure really doesn't make any difference and rain does not affect performances...
True, but it sure looks a lot better and more professional. I'd rather have it in an enclosure.
photos.app.goo.gl/FL7c4pamYAqWxbJB2
Ugghhhh.
Drilling a hole with such a powerful drill and holding the job by hand is a good way to stop you from playing the violin for the rest of your life and make you scratch your bum with the other hand!
Yep, definitely...
Yup. I was building a speaker cabinet and putting a screw in and the wood broke. Well, the screw went into my hand while my finger was on the trigger of the drill. Lucky for me when it hit bone it deflected and didn't do anything other than tissue damage. I still have that screw and it still has some dried out flesh and muscle attached to it. This was like 25 years ago.
Soon or later luck runs out. Better be later...
I use step bits in plastic and metal. You won't crack the plastic box.
Great video. I enjoyed it.
I use my own 40 meter HWEF. I use a 64 to 1 and get great results on 10, 15, 20 and 40 meters. I don't need a tuner at all. The core is an FT 140-43.
For my 150 watt model I also use a 47 to 1 and a longer wire to cover 80 meters. I get close to the same results as you do.
Great little antenna and easy to erect portable.
Barry, KU3X
Excellent!
Thanks !
Good job Gill
Thanks!
I use pill bottles from empty Rx drugs is get prescribed for waterproof conections and small circuits. Line inside with sticky metal foil for shielding.
Nice but a bit small for a 1500 watt transformer.
yesss Gill verry nice video, i am a big fan of your work, i have a ubitx and i have made houndreds contacts in cw with a 40m dipole, i go a lot on camping and fishing and it will be nice to have such an antenna. All the best i appreciate all your work. i am a cw-qrp person for 15 years and with your videos you are answering to a lot of my questions.
tnx Gill 73 all the best from yo4huj Ady.
Thank you. I still have a BitX40 to wire up. The uBitx is tempting!
i also have the bitx40 homemade i have modified it to work on cw added smeter and swr meter is doing a great job, but now i ordered the ubitx and it is waaay better i have mounted it in a car stereo case and now i am working at the swr bridge and litrium batery pack. with the dipole antenna for 40m i have nice contacts in all the band except 160 and 80.
It does 160? I thought the limit was 3mhz?
yes you are right with the original firmware does not goes lower but i have changed to CEC version wich is more stable the rotary encoder works much better, it has s meter on display wspr , cat , etc and a lot of usefull function.
Good to know, thanks.
I would buy one. My favourite channel. Bon!.
Merci!
Polyurethane is what you use for potting,it's non corrosive to parts and offers high insulation to RF,plus moisture resistive properties.Great video!
73's Rob
Good to know thanks!
Hi PREPPER,
I was going to try to build one but had no luck finding the right core.
Anyway i won the Chameleon E comm 3.
Had one in the past and now for the last 7 years i;m hooked on wire antennas.
Thanks for the fine video
BOB AF2DX
I found my cores on Ebay, but you can find them anywhere, they are very common and all electronic component stores will have them. Skywave DXer just posted a link for Mouser...
Thanks!
I always fed vertical dipoles in the center of the antenna. I guess there is a way to feed a vertical dipole from the end as well. I knew there was a way to do it. I just did not know how to do it.
Gil, thanks for the great videos... you should be a teacher. 😊 My French is poor but I used to live in Trier so my German is ok. However I do enjoy your French videos. I am retired now so I must build most of my gear like I did as a kid due to budget limitations. Therefore your videos are very interesting and helpful. Not many young hams these days and even fewer who build their own rigs. Things are very different these days than back in the 60's. Thanks for the great videos and promoting Morse code. I had to learn Morse code as a Cub Scout... now most kids do not even know what it is... Thanks again.... later...
K8LMC / WQZW847
Thank you. I have always enjoyed teaching, and am looking for a job, lol.
Yup I'll buy one. :)
Ok, one, LOL, thanks.
I'd buy one Gil!
Thanks!
Good job Gil on the UN - UN =) Yep sometimes the "CONTESTER" are a bit rude when they are chasing contacts and "NUMBER of CONTACTS" .... sometimes you can see if anyone can hear you off to the side of them :-))) Always say you are running 1000 Watts if they ask and never running QRP during HOT Contestors spawning =)
LOL yes. I have made up numbers sometimes, but now I just say no-test.
Great video Gil! Nice build. Charlie KM4ZZ
Thank You!
I built one with 100 feet of wire. Used a 9:1 transformer and have great results on ALL bands from 160m through 10m. I imagine the 49:1 transformer would be even better. Not all of us have room for a 134 foot wire. And I think 67 feet may be too short to work well on 160m. Always interesting to improvoise and experiment with antennas. Use whatever works well for you!
Hi, the 49:1 is for a half-wave wire only. 9:1 is for anything other than a half-wave...
Impedance is related to voltage ratio squared (ie. turns ratio squared) because resistance is related to square of voltage R = U^2/P (derived from ohms law and knowing power P = v oltage * current)
Materials required for one F4WBY auto-transformer:
1 FT-140-43 toroid
14 gauge enameled magnet wire
1 100pf 30kv capacitor (3kv OK for QRP.)
1 BNC bulkhead connector
Hammond enclosure of unspecified size.
(Thanks, Gil!)
Excellent Gil, 73 de VE2AW
Thanks!
Hi Gil, very nice videos and thanks for the effort.
If you do make a hand full of 49:1 transformers I'd be interested in having one. I too strictly use QRP and at the moment I am using a random wire endfed with a mfj16010 L tuner. I built a 9:1 for the 58 foot random wire I am using and it was better off with just a direct connection to the tuner minus the transformer for some reason. I like the idea of the half wave ended and really would like to make the change.
Thanks
R Mike Boyer aka KC2WVB
Thanks, I might.
please post part numbers on the pars to make it easy to people to fined them..
Yes, I would enjoy a 49-1
Transformer. Count me in.
73 de Mike w9mvm
I noticed some arching on the points. Tiny, but it there.
That Elecraft cleaned you out I bet. Those are nice radios. First world poverty, I know the feeling.
Yes, I ended up selling it and got a K1..
@@RadioPrepper Very cute little radio nice
Thank you Gill I enjoy your channel, I was wondering , about the projects that you made if you might place them up as a link on your channel , as in, diagrams .
Sometimes I post them on radiopreppers.com...
ty , I am a new subscriber just starting in the ham radio thank you Gill.
Can you tell me can this 49:1 unun used as a Shortwave listener coax to telescoping whip antenna coupler.
Absolutely.
Hi. I want to make an endfed antenna. I have a 20m long garden, so max 20m long antenna. I want to work 40m/20m and any other bands will be a bonus. should I use a 49/1 with 20m antenna or random length with 9/1? thanks
I would definitely use a 49:1 with a 20m wire.
LID !
I am currently building a random wire end fed for my home antenna because of support limitations, i only have trees far out in my backyard, and dont want to run coax 250 ft to use a dipole. So my plan is end feeding it at the house ( about 12 ft in the air) then running a support rope to the highest point i can get it into the trees in the back to make a sloper.
Im still not sure on what i want to do for my portable antenna though, maybe another smaller random end fed, a dipole, or an antenna like you built in this video.
Make the two versions like I did!
connly33
Don't get the feed-end TOO close to the house on the half-waver. It's got lots of HV RF floating around which just loves to get into your rig with all sorts of probs. including burning your lips with a metal mic!
It can still happen with the random wire if you hit freqs which present a high impedance at the 9:1 UnUn
That's why Radio Prepper gave you that list of wire lengths.
Better to run the coax to the bottom of your garden and feed it there, and then let the antenna come back up and over the house.
I need a broadband antenna for ALE experimenting but l think the wire with a 40:1 Balun would be too long. Have you ever used T2FD classic or a butterfly folded dipole antenna?. Seems good if you have limited space like a attic....
Hi, no, but I will look into those...
Ham radio construction video as it should be: clear and no machoism!
I’m just beginning in building or thinking about building antennas the trouble I have is deciding when to use a Balun and deciding which Balun and Why. I would need a 49;1 9;1 4;1 1;1 ? Can you help?
ua-cam.com/video/0zF7bDoqkG4/v-deo.html
And what about the longwires? :D
Is it normal then at the impedance transformer, to get a continuity reading with a multimeter (audible buzz) between the antenna wire terminal wing nut and the ground side of the PL 259 plug coming from the transceiver as I do . I thought it was a fault, but seeing this it looks like I would get a buzz - according to the wiring.
With some transformers yes. While it is a DC short, it isn't a short for AC current.
@@RadioPrepper Oh Many Thanks for the quick reply Gill. I understand now. I am a retired electrician in England and Have the Ham Radio Call Sign M3 FEC. Only the Foundation license at the moment. I subscribed to your channel yesterday - Your videos are very helpful - 73 from Frank.
Nice! How is it for receiving, better than a vertical or dipole, etc? Noise?
I'd say similar, but you will generally get more noise on a vertical.
Hi Gil, great video. Im new to ham radio and trying to set up HWEF. I have a 49:1 UNUN and enough room for the 40m of wire. Im ok with the coax connection but the UNUN has an earth connection. Now some say put a counterpoise on it some say earth it with short wire to my copper pipe in the ground. Also how high should the UNUN be off the ground. I would prefer the UNUN close to the bungalow so I keep the feeder line shorter??
Any help please. Regards Ian
If it's a permanent installation I'd say earth. See if it works better that way. The transformer can be low but try to avoid the proximity of metal for it and the wire...
@@RadioPrepper Thanks for the reply. I thinking, do I need an RF Isolator at the radio end of the feed line?
Hi, no.
How do you like the Kent paddle in comparison to the palm?
Two very different things. Both work great. The Kent is a desk paddle while the Palm is small/light for hiking.
Salü Gill, this is realy nice antenna. if you build some of them, i think someone want own one of them. i hear sometimes on websrd. and there are so many morse-guys at the same frequencys, i think thats ugly. isnt it?
best greets to you, and thanks for share this video to your fans/friends/interested peoples.
73+55, Jan
Thank you Jan. It does get ugly sometimes with the contests!
Good video, good communication. Did you end up filling the box with resin?
No, I tried Epoxy before, it no longer worked..
@@RadioPrepper ah ok, good to know, thanks. :)
Hello. Is it possible to build both and use a switch, depending on which bands your on?
Probably, using two cores. I wonder though if there is much of a difference between those two windings....
Yes i buy some off you I’m amateur radio operator my self
Thanks, it might just happen...
can you do a shorter wire if you dont want to go all the way down to 80m?
Certainly.
If you were to make some I would be interested in buying one. I have a long wire in my backyard attached to a CWS Byte Mark W2FMI 12:1 balun, it works well. Keep your vids coming, 73 de Paul VO2PRS
Thanks, thinking about it...
Hi Gil! Thanks for the video. I built one of these but never actually started using it! Question: when you were testing each of the bands' SWR on the KX2, was that going through the tuner? Or did you have the tuner bypassed? I didn't hear any relays clicking, but it's always hard to tell with those super-fast Elecraft tuners! 73, Rex KE6MT
Hi, no tuner, my KX2 doesn't have one..
Ah! That makes a whole lot of sense!
Yes, yes, and a little bit more yes! I'm just now getting around to finding this video but if you did decide to make some I would certainly buy some.
I did have a crowd funding campaign a while ago... Only got one order... Canceled it.
Hello Gil. I was wondering if you still use your end fed chameleon antenna ? I was going to buy one myself. Thanks Fred.
Hi, I sure do, very convenient...
I have access to a FT140-43 toroid only...what are the chances I could make it work with this design ? Perhaps for 40m and higher only ? Only operating on 5W QRP if that makes a difference. Thanks for the video, 73 de ZS2OE
That's what I use, works great on all bands. No difference with QRP.
Excellent video! Question how the other end of the antenna was secured? and to where? I'm wondering if it was anchored to the ground. 73'
To the ground with a tent stake but insulated from it.
Have you tried the 67' version ? The 134' one is probably too long for the type of deployments I do.
I don't need 80m so was wondering how the 67' version (40m-10m) performs. 73'
Not yet. From reports from the HWEF group on Facebook, it works very well.
That table of random wire recommended lengths, does it expand out to the 1000/1500ft area ? Wow, very good, 49to ONE !
I don't know but as long as you avoid half-wave with a 9:1 you'll be fine.
49:1 is for half-waves; 9:1 for anything else
..
@@RadioPrepper Well, thought you had chosen a "random" length.
And, I do have a 9/1 I could use for the really long wire.
Very nicely done Gil. Any luck on 160?
Thanks. I don't have a radio that can do 160 yet!
Radio Prepper I am going to follow your lead and try it on 160. I will let you know here.
Please do! Post it on radiopreppers.com!
Gill
If you make a half wave for 80m then it will be resonant for the higher bands also. I think 60 and 30 are not resonant but don’t quote me.
Correct.
Did you tune the antenna, or did you just show the swr meter?
No tuning.
I believe if you use the inverted v you can use the 468 / by frequency in mhz but if horizontal flat up high it is a different number. I found the calculator on the internet and it is different and i used it and put up a home made antenna using the length from that calculator and a 49:1 unan and then checked with my antenna analyzer and it was perfect smack on and if i had used the 468 for my horizontal flat end fed half wave i would have been off.
Yes I would be one of the first to purchase one of your 49:1 transformer if you decide to build a few to sell. It would be awesome if they came with the wire also. Thanks for the video on the 4S Antenna Tuner, I knew you cold assemble them no problem. Enjoy. Joe KG7CQG
Thank you Joe! One has an issue I need to fix, but I should send it to you then. Email me at gil@radiopreppers.com
Great, we'll see if there is enough interest...
Another comment I would like to make (if you can help me) is on the ferrite or toroid that you are using how do you decide which one or size! And what values?
Watch the video I posted on your previous comment, it answers all your questions :-)
Gil, what size magnet wire is depicted here? I built a 49-1 Transformer on a 250-43 toroid using 14ga. Magnet wire and it looked a lot bigger than this. The wire here looks more like 16 or 18ga. I'd like to build one on a 140-43 Toroid but I think 14ga. wire is to thick to do 14 turns.
1mm, not sure what guage that is...
@@RadioPrepper 1mm is 18ga wire. Thanks for the quick response. I watch you videos often. Appreciate the help. 73 - WB2TQC
Gil -- Took me three tries but I got one done today. 140-43 with 2 primary and 12 secondary turns using 18ga (1mm) enameled wire. Now to test it and hope it works well.
Don't forget the capacitor..
Hello Gil, ou trouver des jolies boîtes noires comme celle ci ?
Je cherche sur Amazon et Ebay...
Hi Gil,
Great videos, do you prefer the Elecraft KX2 or the KX3?
Just passed my morse 12wpm and 15wpm over the last two weekends and hope to do 18-20wpm soon so I hope I get to QSO with you on air!
Kind regards,
Simon
M0SYS
Performance is similar. Of course the KX2 is smaller... It all comes down to wanting 160/6m, or not...
@@RadioPrepper Good point. I was thinking more about having that bit extra power/having internal batteries in KX3 AA cells vs the lithium ones in the KX2 - I heard the KX2 only runs 5W mostly since the voltage of its internal batteries decreases and drops the power quickly. Is one easier to use than the other?
Don't worry about power. The kX3 also accepts a 2m module... Only choose based on size and bands...
@@RadioPrepper OK, How important is 160 or 6m? I suspect they aren't normally used portable, other than the weather proofing you mentioned in another video, are there any other down sides to the KX2?
No other downsides. 160 and 6m are probably not starter bands, especially 160m. 6m is used portable. You will probably want those bands later... The question is... How much later..? If the bigger size isn't a problem, go KX3...
hi Gil nice video! i have one question the wire needs a coil or not after the box of 49:1 i mean tnx..
No. The coil is for 10m.
@@RadioPrepper need to use it for 80 40 until 20m for Sota i think is good and cheap choice .
Definitely, and I don't use a coil.
@@RadioPrepper no coil for both construction lower bands and higher bands?
Well, I don't usually use bands above 20m... It works well without a coil from 20 to 80m.
Great Results Gill Well done..I didn't like the twisted primary winding and would just use a slightly thicker size single wire, although at QRP levels the thickness would not be a big issue.
One think that really annoys me is the Hams who use computer's to reply to you in CW insist on sending at high speed 😢😢😩😩why can't they have the decency to slow down a bit to match your hand sent speed 👍. .which by the way I could listen to your Hand Sent CW all day because it sounds so much better than Computer generated cw. .73 de Steve
Thanks Steve. They probably think everyone uses a decoder..
Radio Prepper I also noticed your KX2 was decoding your hand sent CW 100% and yet the contesters computer generated was not decoded properly 😂so if they reduced the sending speed they may even get a higher score in there contest. But just don't realise it..good luck with the 30mtr version.
Thanks!
It is 1:49 because it transforms the voltage factor 7 Up and the current factor 7 down this means for the Impedance transformation: R = U / I means R= (7U) / (1/7 * I) = 49*U/I That is all the magic. And, why did you not middle turn your 80m winding? And as far as I could see, you are using 3 turns primary instead of 2 right?
Yes, definitely 3KV!
Hi Gil, my KX2 arrived :-) Which Peli Case are you using? I am in doubt which one to get... 73s Stephan. DF6PA
Will let you know tonight..
1120
Salut Gilles,
What happened to the mix 31 torroides?
Bonjour, je n'aI pas encore essayé.. On me dit que ça ne marcherait pas très bien. Un détail, c'est Gil, pas Gilles :-)
J’ai essayé, sans trop de succès, avec un balun 4 pour 1. J’ai trouvé une référence sur palomar engineers qui dit que le mix 31 est surtout utilisé pou4 atténuer les interférences radio.
Effectivement. Le 43 est le meilleur jusque 20m. Au dessus, 53. Le transformateur 49:1 marche super bien!
L’as-tu comparé à celui des Hollandais?
C'est à dire?
would this work on 145mhz?
I will not... Not that way at least. I suspect the maximum might be 50mhz, using 61 material.
that KENT TP1 key is a pain, still have mine but needs a good polish, but don't use it, BEGALI is the way to go
I'd love the travelers light...
Nice video again Gil. Do you know Yann F5LAW who lives in Lille?
Sandy g0vqw
Hi, I may have heard him but I can't remember... I am in the neighborhood until the 8th and will listen to the Lille repeater..
He's a white stick operator and I think only uses CW. Quite often qrv on 80 meters around the qrp frequencies.
I'll check in my log when I get back home next week!
La compagnie hyend de Hollande, un de mes amis vient d’acheter un de leurs systèmes compacts
Ah, il faudra que je teste ça!
Hi Gill. Great tutorial! You used a smaller toroid than the diagram, but did you still use 14 gauge enamelled wire?
Hi, I use the FT-140-43 with 1mm wire or the FT-82-43 with 0.7mm wire..
"Why is it calculated like this? I don't know."
It's calculated like this because you want to match an impedance of between 2400 ohms and 5000 ohms, and 2400 / 50 = 48 and 5000 / 50 = 100. That brings your SWR down to between 50 / 48 = 1.04:1 and 100 / 50 = 2.0:1. The closest *convenient* perfect square to 50 is 49, so, recalculating, 2400 / 49 = 49 and 5000 / 49 = 102, bringing your SWR to between 50 / 49 = 1.02:1 and 102 / 50 = 2.04:1, an easily tunable range. To create an appropriate 49:1 transformer, therefore, we go back to the definition of mutual inductance between two coils with ideal coupling (k = 1), which makes Vs = Vp(Ns/Np), where N is the number of winding turns. Remembering that P = (V^2)/R, (Vs^2)/Rs = (Vp^2)/Rp, and substituting Vs from above, we have Rs = Rp(Ns^2)/(Np^2), or Rs/Rp = (Ns^2)/(Np^2) = (Ns/Np)^2. So, 2400 / 49 = (Ns/Np)^2 = 49, or Ns/Np = 7. If we wind one side with two turns, we must wind the other side with 7 x 2 = 14 turns.
Great thanks!
@@nojiratzlaff4388 thank you.
I would be interested but I am poor right now.
HAM radio operators are always poor ;-)
Hi Gil ! J'ai construit un "transfo" 49/1 avec un tore 240-43,j'ai donc bobiné le fil comme indiqué ,mis 2 capas en série afin d'avoir les 110 pF ,ok jusque là,mais catastrophe en réception ! L'antenne semble en court circuit. Dès que je retire la masse du cäble c'est bon ,j'ai de la réception et en émission je peux voir mon signal sur le webSDR de Hack Green en Angleterre avec la prise vissée rien ! Je comprends plus la... Les mesures de SWR sans tuner : 40 m = 1.8/1; 30 m = 1.8/1; 20 m= 1.9/1; 17 m = 2.4/1; 15 m = 2/1; 12 m = 2.5/1; le 10 m bas = 1.9/1 et le haut de bande 2.0/1. Le fil d'antenne fait 20,40 mètres environ,j'ai essayé un contrepoids de 5 m et quelques nada ! Toujours le même soucis. Mystère... 73 de F4DNP.
Bizarre. Il est normal que l'antenne soit en cours circuit en courant continu, mais 50 ohms en alternatif à la bonne fréquence. Combien de volts tes capas?
@@RadioPrepper Hi Gil merci pour la réponse. En fait j'ai tout repris de A à Z je m'étais lamentablement planté dans les tours ,il en manquait un sur le secondaire...) ! La j'ai reconstruit le transfo comme il se doit et c'est nickel ! A part le 17 et le 30 m où j'ai un SWR > 2 tout le reste oscille entre 1.1/1 et 1.2/1 A l'analyseur j'ai de bons résultats également,il me donne par exemple 1.24/1 pour R=52 Ohm sur 20 m . Merci et 73 au plaisir d'un éventuel contact e PRC 320 à PRC 320 avec EndFed ! ;)
Super, oui! Il y a pas mal de 320s sur 14320..
A 13:20 , 10pF 3Kv pour le qrp ... je ne suis pas trop pour ceux qui montent sur un point haut , déplient un mat de 12/15 m de haut ,
et qui balancent 3Kwatts...( je ne citerais pas de qrz ... hi ) ... je serai plus pour les " SOTA " , se faire un point haut avec une antenne fabrication Om
Batterie/panneaux solaires .. 5/10/20 W maxi ... 73 Merci pour cette video ... Bon Dx ....................... Dominique - Besançon
Merci!
very good resolts like to bild one can you live the mageur in meters pls tks for atention 73 dx py1ax tony
Thank you! I'll always use both units of measurement.
Do NOT use epoxy resin! use meltglue ;-) epoxy will throw things off....
Indeed. I wasted two toroids trying.
whats the morse code in the begining haha
VVV DE GIL
V in Morse basically means "attention!"
Glad you tried the 7 metre band! Also, you were out of band on 10 metres my friend! 29.79 MHz. C'n-est pas pour les radio emmeteurs!
29.79 FM?
Radio Prepper The upper limit for FM or any other mode is 29.700 MHz. You should know that, cher ami!
I never use 10m!
I'm
Bonjour Si vous pouvez faire votre vidéo en français !
Il y en aura d'autres!
and this one is how to make the coil and antenna ua-cam.com/video/kSQzUETRMlk/v-deo.html worth a watch
A European - a French man no less using feet and inches ??? Progress at last
LOL, metric is much simpler!
@@RadioPrepper not if you are un Americain!
@@af4k LOL! Yep using Metric is definitely very "un-American" And even the British, who invented "Imperial" measurements, have more or less officially abandoned them.
For the record (and at the risk of touching off a flame war...) there's nothing simple about the metric system. It's more consistent than the English system, but what isn't?
If the French revolutionaries had been thinking clearly, they'd have based their new system on 12, not 10. Much more useful. As a Canadian I'm "bilingual" (pour ainsi dire), but find myself defaulting to English measures most of the time just because jumping into fractions only two stages in (10 halved is 5; 5 halved is 2 1/2, 2 1/2 halved is...uh...), and dealing with a base that's not divisible by anything but a prime number and 2, is needlessly complex.
The conclusive argument for the Yanks converting to metric is simply because everybody else uses it. 'Course the Yanks aren't always the most practical lot...
Why not build one, put it on ebay, and see how fast it sells. I'll be your U.S. distributor. Need a catchy name, "Antennas by Gill, Old world craftmanship with cutting edge technology". Have a great day. JJK
Not a bad idea...