How To Build The K6ARK 100w End Fed Antenna - Instructions 49:1
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- เผยแพร่เมื่อ 27 ธ.ค. 2022
- K6ARK EFHW Kit is available here (at the time of recording, sold out) - amzn.to/3veA5tA - That is an affiliate link, which means I may make money off the purchase of this item. Listen, I know the audio is cutting out/fading out. This is a noise gate thing. I don't have the time to go back and re record this, unfortunately.
K6ARK EFHW Instructions here -
docs.google.com/document/d/1G...
Link to a diagram on how I wrapped my 49:1 (Minus the cross over at turn 8, DO NOT DO THAT) elginradio.wordpress.com/2017...
Note: I did the 49:1 with no crossover as well as a 56:1 (2 primaries 15 secondaries) as tested by @MM0OPXFieldRadio (check out his channel on youtube where he tests a LARGE variety of antennas)
Original twitter post for the 56:1 - / 1554076131220983808 .
Finally, you can always link the EFHW (a linked efhw, imagine that). Before making a 40m EFHW, Choose a band, for example, 17m. 17m/2 = 8.5m (27.89 ft) take 27.89 feet, put it on the Antenna out, cut until it is resonate on 17m (you may find it resonate else where, happy coincidence.
After you have 17m cut (again for example), install a banana connector on that and use some sort of strain relief. Then cut 37.71 ft of wire for a 40M EFHW. connect the 17m link and the freshly cut 40m link then check the SWR, it will probably be high at 40 20 15 and 10. Cut the END of the 40m link until 40, 20 15, 10 are good for you. then any time in the future you wished to use 17m, just disconnect the banana connector, while keeping both wires within the strain relief.
This allows for a rapid band change without having to reconfigure the antenna. Will it work on 6m? Probably not.
However, you can continue this process throughout the band. so for example: 12m, 17m, 30m then of course your 40m length which gives you 40, 20, 15, and 10.
All my testing and was tested in the sloper configuration from 25 feet, sloping down to about 3-4 feet.
BNTECHGO Silicone wire - amzn.to/3hM3poh (Again, this is an affiliate link)
Good luck with the build, you got this.
Videos to help you:
• EFHW Playlist - บันเทิง
Thanks Dude!
Appreciate everyone's patience with me. I'm working on more kits to be ready early in the new year. Sorry for not being able to keep up with demand.
You mean, you aren't a robot?!
@@HAMRADIODUDE 😆
Alas, I am human.
That's a good problem to have.
Worst problem is you build a thousand kits and don't sell one.
😂
Appreciate your videos... Great job
Hello Adam, are any avail yet?
Built mine this last weekend and tuned a wire on it. The part prep was excellent. It’s working great. I also added cords to give it attachment options.
I believe Adam is doing a great job in getting these kits built and out the door. I received mine a couple of days ago; although it was scheduled to ship early in the new year. Thanks Adam. Hey Dude, nice job with the video!
Glad you hear you got it. I do hope the build goes well, enjoy!
You are great at giving me ideas to do things on my own. Thanks!
It's here! I'm so excited!
Absolutely man. I'm excited it could be there for you
I've been sitting around fixing stuff waiting lol
So it's good. I GOT MY trusdx and qcx mini working lol
G'day I was very taken by you checking each part you soldered in the circuit. Normally this is not shown, this is saving you going back fault finding later. Thanks for the build and your sharing your ideas. cheers 73.
Thanks. I'm very bad at soldering (Can only get better :D ) so I figured, I better check my work to know where the fault is.
Thanks for the info on EFHW.
I have built a couple with 240-43 toroids. To fine tune it on 20-10 meter you could make a little coil about 2 meters from the connection point of the antenns wire, use a smal piece of plastic pipe 25mm and do 6 turns of the antenna wire. You get the peek of the swr a bit lower in freq on 20-10 meter.
Best regsrds
de SM3TEK
Very good. Thanks for the information, it's definitely something I'll try! Best wishes to you!
Adam this was a great video. I am going to build this antenna. Thanks for the advice on the how-tos. I will be putting a coil on it to reach 80 meter as well. Going to be fun! 📡
I'll let Adam know! Good luck with the build!
1:55 Good job. It is worth mentioning on every occasion - no flux, no go.
Absolutely, it was so rough on this build without flux. Running out of it was not good. I will say, I'm excited to go to the store on Friday and get some more 😎. Thank you my friend, happy new year and nice to see you!
@@HAMRADIODUDE, try to search for "no clean" flux. No more IPA after soldering.
I have built about 12 49-1 auto transformers. Pretty much the same as you have minus the circuit board. I use 26awg wire for them. All of them are 67 feet long to get resonant at 7 MHz. I always use sloper from 10ft to 25 ft. I am surprised that you are resonant at 65. I know it depends on velocity factor of wire material. I am using stranded copper clad wire. I wouldn’t think there would be a 2ft difference. I don’t use a counterpoise other than connecting ground to coax shield.
Great video Sean, nice build and good instructions on how to do this build. Happy New Year my friend. 73
Thank you. I wrote instructions on trimming the wire. However, I think after the new year I'll just go ahead and make that video as well.. unfortunately I'm a little short on time. Happy New Year Steve! I'll be in fort Lauderdale in April
The only thing i can advice is to read "The Art of Soldering ARRL". It describes on one page how solder works. Get an a soldering iron that is big enough for the job. A hot soldering iron will get the job done without frying the components. Sometimes a heatsink should be made so the heat can dissipate and not go into electrical components that can be damaged.
If the solder joint is convex you know its a cold joint. A concave solder joint usually is a good solder joint. You can use flux to make the solder go in better.
Good luck!
Greetings,
Jeff
Thanks! I'll try to find that book!
Super job Dude. Great information on building the EFHW, some of tips will go to other projects. Thanks N9TDE
Heck yeah. Glad it was a help, Marvin. Happy New Year!
I used to solder capacitors 1/4 that physical size with the aid of a microscope, but having cataracts 14 years later does not do well toward visual acuity, lol. I could probably do most of it, but I think the "Old Fart" click button is missing from Adam's order form to have the cap come already soldered, LOL. That said, the SO-239 version seems easier to build than the BNC version the way you have to solder the BNC socket after you already have the toroid soldered on that QRP build. I am waiting for my TR-35 to be built so I can get my antenna built in the meantime, My Wellington solder station is in storage in IL right now, 1300 miles NW of me, I am limited to soldering on a picnic table since this 23' RV is controlled by my XYL who is also a ham but won't tolerate a messy ham shack, LOL. 72, Dave - KU9L
Thanks for your help
Happy to help
First my smart ass side said: EX=used to be! Spert=A drip under pressure! Sorry I just had to say that. Thank you for the information. I will NEVER do SOTA as most think of it. I have too many screws in my back. But small lightweight is always good as long as it will do the job. Most of the radios do not go over 100 watts. So this should do good! This will not do 100 watts on digital, but most radios will not do it also. I have watched many but not all your videos. You do a very good job of explaining things. Checking things as you go is a very good idea. I would have put it all together then try to find out where I screwed up. That would not be fun! 73 W4DES
Hi Sean,
To help soldering those small barrel connectors, take a scrap piece of wood and drill some holes sized to hold the connector but don't drill all the way through. You can now put the connector in the hole and it will be held vertically while being soldered. Have a Happy New Year and stay safe. 73 WJ3U
Pro tip right there. Thanks so much!
Also happy new year
Yes! I did the same 😆
Good video👍❗️
Thank you!!!
#TeamReplay This kit is great.
Yes sir !
Love your videos. Hope you have a good and prosperous new year, 73. N2SCD
Thank you, I appreciate it! Happy new year!
I like the way this was wound
Thanks
Thank you so much. I tried to make it, but it worked not on all planned bands
Which bands did it not work on? How high was the swr? Thanks
@@HAMRADIODUDE it worked on 40, 20, 10 meters, but 80 meters was out of band close to 2600KHz. On 80 meters VSWR around 4.
@@okhamradio Do you have a coil installed?
@@HAMRADIODUDE yes
@@HAMRADIODUDE finally I have done it th-cam.com/video/3ARO00ExuAo/w-d-xo.html
Thanks for the video. You referred to a previous video that we should watch for more detailed information. Could you provide a link to the specific one you were talking about? Keep up the good work.
This may be it: th-cam.com/video/tQs0Pv_RrrE/w-d-xo.html. Also at the bottom of the description, there is a playlist with other efhw videos. Good luck!
Actually I think I was traveling to this video th-cam.com/video/eqNZ_G4XWd4/w-d-xo.html
@@HAMRADIODUDE Thanks, that really clears up some points and I encourage others to view it if they have questions.
I don't know what efficiency tests have been done on these transformers, but I don't like the idea of the proximity of the conductive PCB plate and so239 to the transformer. I think they would affect the efficiency. Has someone done efficiency tests on this transformer design? As I understand it, K6ARK has been designing ultra-compact, ultra-lightweight setups for backpacking up mountains. But 100 Watt rigs aren't commonly used for SOTA applications due to their weight, and using the same design techniques for 100 Watt transformers may not be optimal.
tin both ends with solder before you join them and heat with soldering iron
Thank you
If i wanted to locally source the toroid, what would I search for? The 140-43 looks to short in my search
You'd probably be better off asking K6ARK, He is the one who built the kits and has the parts list and would be your best bet.
Thanks!
Hes out of stock. Just asking if you had the numbers to search the toroid online or locally
Thanks for the shout out Sean 👍. My channel doesnt have a great reach and I'm more than happy for you to share my research on my back to back tests showing how much more efficient this core is over the 240-43 or to join you on a video to explain if that helps. No pressure. It can only help @K6ARK with his kits (not that he needs it).
I would have mentioned you in the video, but I already recorded it and then discovered that Twitter post this morning. I went out and tested a 56:1 , 49:1, and 64:1 this morning. I do need to test more, however. Have a good one!
@@HAMRADIODUDE Just realised my previous comment could have come across wrong. No need for any mention in the video. On your field testing you will notice differing SWR's on configurations. The inv v is easiest to achieve but I prefer the inv L as it has lower angle radiation and only the 56:1 suited that.
@@MM0OPXFieldRadio no offense taken at all! 😎. There's so much good info out there! I'll have to try out the inverted L.(when it's not so cold)
guys I need to get my standard australia radio license and I,m hopeless at calculous and I,m an older person...I just want to listen to others and occasionaly talk to them...I have my foundation license however,10 watts pep isnt enough I feel.....I dont want to build or repair radios etc..Any constructive advice is welcome...
Hello there, I am not great with the questions on the Australian test. HOWEVER, I do know @ham radio dx - th-cam.com/channels/o_jX41l6nYfnrQuk0qsZFw.html is from the area and may be able to assist.
If you have specific questions, I can try to answer, but I may not be the best resource.
cheers
You're my favorite. Just saying. Lol.
Hey man thanks.. captain happy and lt dude
GREAT ARTICLE , DUDE!! However,...using the same toroid core that you show, there is an alternate way that might be considered, and is a good-bit more efficient way of winding your 49:1 transformer, than the way you did, with MM0OPX providing the specifications to prove it :
th-cam.com/video/nZ-G4hJCTSM/w-d-xo.html (It is an unusual 56:1 ratio, WITH a crossover, that sports more efficiency than a continuous, linear-winding, that what you showed. I wound mine to his specs and WOW!! Compared to my commercial 'Cobweb', my newly wound core completely blows my Cobweb out-of-the-water (compared ONLY on 20 meters), with a 40 meter EFHW, that gives me 1 to 1 SWR on 40, and about 1.2, on 20 meters. (I only work those 2 bands) Ron...K6PAM...... I hope this will help you!! Good Luck, Dude!....Love your informative videos!!
Great information! Thank You! MM0OPX has great videos too! I appreciate it. I am going to do something good with this information, someday (I have an idea brewing). Thanks and have a great one!
Oh Oh... you said the "F" word. FLUX