Very well done design improvement, Adam. This will make the build a lot easier than the old kits. You're an excellent teacher, Adam. Your explanations are very clear. 73 de AG7TX
Just finished my EFHF Build. Total finished length 61.5'. Flat 1:1 SWR across 40, 20, 15 and a good chunk of 10. No Coax - direct to radio. My tip: I placed a loop of paracord thru the small loading coil and use that as my lash point on the radio end.... the 6' of wire between that and the BNC are then 'loose' for connection to the radio. Thanks Adam!
Hi Adam, great kit and great video. I recommend one additional step before soldering the BNC: Do a continuity test to check that the enamel has actually burned off. Desoldering and resoldering the toroid after the BNC is in place is a real bear-I learned the hard way, 😂
Yes, they do. If you damage more than one lug, let me know and I'll get you a new BNC and updated PCB that fits better. Or, if you just want the PCB before building the kit so you don't have to bend them, I'll be happy to send one. All future kits will have the updated PCB specifically designed to fit the female BNC rather than the generic male one.
I built the 9:1 version today. Messed up the toroid winding! But found 3 colors of same sized wire and wound 3 separate windings. Colors made connecting them easy. With 29 ft element and 17 ft counterpoise tuned nicely and had 3 POTA hunter QSOs on 40, 30 and 20 at 5 watts CW. Got good reports. Thanks for good kit!
I BUILT up mine this afternoon. Wonderful. It really works. Endx halfwave antennas are great. I have experiences with Fuchs antennas. You only need a short counter poise ore even none. That's the advantage of these kind of antennas. I like that antennas.
Awesome, Nick! Please feel free to reach out to me with questions or if you have any issues. I want to make sure everyone is successful in their builds.
Wire is not the limiting factor, the toroid is. You can add a FT82-43 toroid and nest the FT50-43 in the center, then wind it as if it is a single toroid. Works great for up to about 30-35 watts!
Hi There! Greetings from UK. Great video and really happy to learn you came up with a way to make your design available to purchase. First time I saw you build one I said to myself I will struggle with the tiny capacitor directly to the BNC. This KIT makes everything easier. Thanks.
Thank you for providing the kit! I just ordered one! I never got around to buying the components myself to try and build it back when you had your video of how to build them. So glad you put this kit together. Juddie - WD8WV
Nicely done Adam, IMHO this is one of your best build videos. I built a version of this antenna based on your previous vidios and couldn't be happier with it. It bagged me my first SOTA DX in to Guadalajara Mexico. Keep up the great work/content Adam. 73
Thank you, Chris, and thanks for the Christmas letter and bookmarks. What a brilliant idea. I love it. Sometimes life gets busy and it's hard to keep up on video production and editing, but I'm definitely still around and creating. That won't stop any time soon even if it is a bit less frequent.
@@K6ARK No problem! Thank you so much for putting these kits together. I can't imagine the work involved to get to this point. Hoping with this kit to 'lose the coax' in the future lol.
He’s alive! I had thought you’d fell off a mountain, or you were on an extended ‘on location’ action film shoot, doubling for Bruce Willis as a stunt double. Huh, I’m rarely wrong…. But hey, I did build your kit, and hey, I love it… a 9:1 Unun with linked 20-40m legs… Bravo Adam! Now I need to figure out how to install your cap key kit into my QCX Mini…. de W7UDT Rand (dit dit)
Thanks Rand! Yes, I get busy with life sometimes as well, but I do need to get back to making some more videos again. I also need to finish my reply to your email. I do have more cap touch key PCBs and can get another headed your way. Thanks and 73.
@@K6ARK Hey Adam! Here’s a heads up… I’m working on a protective laced Kydex S/POTA board for my KX2… (what the ‘he double toothpicks’ is that?) My KX2 has rails, so the top molded half of the shell will be clear, and act as a cover for the KX2, being laced together with paracord to the bottom half, a 8x12” flat clipboard… the sides of the top case will be open on both ends, extending an inch or so off each end. The top cover will accomodate the front paddle. It’ll all hang from a lanyard off my neck, so when seated, I can comfortably operate and log my contacts… whatcha think? The laced board will provide the weather and impact protection the KX2 lacks…. Being laced by paracord, it will hold the radio securely.
Wonderful little unit. I would suggest having a blank piece of round pcb same size as the main pcb with a notch for the wires and add it right at the end of the heat shrink process as a cap on the unit and maybe hot glue it to seal it.
@@K6ARK So fun to see such a light cool unit; a round piece of hard plastic would work too. I could build one for my QCX and it would make a really light small portable unit. I am curious if it was you that I saw tuning one of these types of units using a spool of wire to roll it out while it is connected to the VNA and watch the dips and find the best length. Was that You? they first strung it out and found out how many turns on the coil was best and then trimmed the length of the wire to the best swr. I couldn't remember what the procedure exactly was and have been looking for the video and can't find it.
@@K6ARK Thanks for the reply. If you get bored maybe do a video on tuning the core and then the antenna sometime. I am sure you get bored haha. Thanks. I am going to look up one of your units on Amazon. Looks like a great unit. I love building stuff and that includes kits. The tuning method could also be used on higher powered antenna's.
Look back on amazon USA and was going to buy a male bnc kit there. Looks like you are out of stock already. I will wait for the next batch. Great kit, excellent videos. I'm learning a ton and starting to build. Thanks
So hypothetically speaking if someone were building this matching unit and their three year old walked off with the magnet wire and that someone searched the entire house for it but couldn't find it, what would you recommend as a replacement, would any magnet wire work, specific gauge, enamel type, etc? Thanks for any info, it would be helpful if this hypothetical situation were to happen. You mentioned Remington industries in your live stream with HRCC, but they have quite the assortment.
@@K6ARK Awesome thanks! Will do I also noticed that the affiliate links in this video description show as unavailable but there is a kit with your name on it with the female connector available on amazon is that just a new link of your or a copy cat. I will send the links I have found in the email
@@nehem11e yeah, it's a long story, but basically Amazon let someone else hijack my original listings because I didn't have a registered "brand". I had to create new ones.
I screwed something up. I cant tell what. Maybe I'll start over with a new one. The only thing I noticed is that I bridged the CP to GND pad when soldering the coax connector on.
Charles, the most common failure is not removing enough enamel from the magnet wire. Check for continuity between the BNC center pin, the antenna wire, and the BNC ground. Three should be close to 0 Ohms Resistance between them. If that's not the issue, feel free to send me an email with some close up photos of your build. Remove the external heat shrink if you installed it already. Try to get a few different angles so I can see which windings are connected to which pads. I'm always happy to send some spare parts if you do end up needing to rebuild.
I see they are back in stock. I just bought two as a way of saying thanks for all your help. I going to build some from scratch as well. Were do you source your antenna winders? Appreciate your work.
As described in the build instructions, adding a 10-12 turn coil at 5-6 feet from the feed point helps bring the SWR dips for the resonant multiples of the half wave frequency into the desired spots. I really need to do an EFHW tuning video one of these days.
@@K6ARK Thanks! Kit's not here yet, so no build instructions, lol. I figured I was learning as much by video as I could prior to arrival. Looking forward to it!
Vitor, it has been challenging to keep up with demand, but I have more inbound to Amazon as of today, including male and female QRP kits, and new 20w kits with an additional, larger toroid, longer magnet wire, and larger heat shrink. They should be in stock again soon!
Hello Adam, quick question regarding the mini microphone kit for the truSDX. Are you still producing them? Can’t find them on Amazon. Thanks Roger W8RLP
I produce kits when I have time. I work a lot at a day job and volunteer for SAR among other things, so my free time is limited. I try to balance it across preparing antenna kits, mic kits, and winders, and then of course doing an occasional fun thing for myself like a SOTA activation or backpacking trip. You can always build your own from the files on Printables and the bill of materials posted there. Link to it from K6ARK.com
Yes! I have more kits inbound to Amazon tomorrow. Feel free to email me (QRZ address is good) and I can likely get what you need sent direct as I plan to make a post office visit tomorrow as well.
Hi Adam, impressed by the size and simplicity of the design. Even for me it seems to be feasible to build the kit. Unfortunately it seems to be sold out. Do you have an idea by when this will become available again (in Europe)? 73 ON3STG Gert
Hi Adam. Cool kit and nice video. Pleas make that tuning video. I have no problem building these things, but the tuning is always different than what I see on RUclips. #73 - OZ4HJ
Nice Kit. Looks like Type 43 toroid which worked well for me with 49:1 transformer EFHW. Type 2 (Red) toroid was better for me as I got better performance with 9:1 UnUn, specifically 10m and 6m on NET Nights which I do portable at times ; ) Anyway a must have in my portable setup . How much power will it handle? Thank You. . . Mostly I use T200 Type 2 (RED Toroid) 9:1 UnUn, Type 43 RF Choke, 29ft wire and 17ft counterpoise (EARCHI Antenna)
Yes, it's a -43 mix which works well in all 3 build options. I generally recommend a maximum of 10 watts for lighter duty-cycle modes and 5 watts for modes like FT8.
Yes. I am trying to resolve issues with Amazon right now. Another Amazon vendor hijacked some of my product listings by claiming them as their brand. I am trying to get Amazon to fix this, but their seller support is a joke.
@@rogue_5508 $36 for the 100w. Also have just been working and busy witt SAR a lot this year which has taken up my kit prep time. Hoping it slows down a bit soon, and that Amazon fixes these issues.
My favorite portable antenna wire is Poly Stealth. I like 26 ga for the smaller kits, and although 26 ga will also work with 100w, I like 22 ga for the nicer handling characteristics.
@K6ARK Portable Radio i bought a kit after watching the HRCC build stream, looking forward to putting it together. I was looking for any info on tuning for EFHW build, I don't see any specific titles, can you point me in the right direction?
Your best bet right now is to review the text instructions. It briefly describes multiple ways to finish the antenna. If you have specific questions after that, fire me an email at k6arkportableradio@gmail.com
Not at this point, but I will likely put together a ~35 w max version targeted at KX3 and G-90 users. I'll think about design options for a 100 w option, but it will require some significant design changes including a much larger toroid.
Hi Adam, Happy New Year. Excellent build video. Close-ups were perfect. I think the silicone should be the acetic acid free type to prevent corrosion. Would dribbling some hot glue affect the tuning? Stay safe. 73 WJ3U
Thanks Don, yes, non-acetoxy silicone would be best. Hot glue should work well too, but has a lower melting point that may be a problem in hotter climates.
Is it bad to run the ant wire through the middle of the torroid for the EFHW config? Also, is the other heat shrink that is included in this kit just for fun?
It's fine to send the wire out the center of the toroid. The extra heat shrink and plastic tube is to make a loading coil to help with tuning on the higher bands as explained in the instructions.
I did the 9:1 build but used some cheap 26awg it's a big difference compared to the polystealth that comes with the kit... My question is can just use 14awg stranded wire I have plenty of that
You can see if Amazon will allow you to order and ship to the UK. If not, you can contact me and I can ship direct, but a batch order is likely necessary to make it worth it. Shipping starts at around $18-20 US but is the same for up to 4 or 5 kits because they're relatively small and light.
Also I heard a lot of people are losing capacitors, would it be prohibitively expensive to include a strip of like 5 of them in each kit just in case? As I recall those caps are relatively inexpensive
Hi! I've been trying to figureout what's the specs of these thin wires you use for the antennas. I saw this in your amazon sotre: "YXQ Yellow PVC Coated Tin Plated Copper Wrapping Wire Wrap 305M 30AWG Cable Reel" Is that the wire you use for EFHW, etc?
That 30 ga wrapping wire is super cheap stuff that's nice to have around for experiments, and I've even used it for some UL portable antennas that I have used for years, but it's not what I'd recommend for a solid build. The BEST portable antenna wire, IMHO, is Poly Stealth 26 ga wire from Davis RF. It's copper clad steel with a nylon jacket. It's strong and small. But it's also not particularly cheap at 29 cents/foot, plus shipping. So I have been using a PTFE insulated stranded copper wire in 26 and 28 ga that I buy in bulk from China. It's cheap and works well, but it's still not poly stealth. If you want to try some out, email me (good on QRZ) and I'll get some sent your way for a reasonable price. Hope that helps!
Can this antenna be connected directly to a radio or do you recommend a small length of feedline? I'm trying to decide between the male or female kit. Thanks
Hi Adam, I have one of your early pcb kits and have noticed no continuity between counterpoise pad and coax sheild pads, is that because this is an isolated transformer design rather than autotransformer? Intentional? (Btw ,a really fun kit!! Thanks! )
Wayde, good find! That was an error with one of the earilier versions of the boards. Please send me an email and I'll be happy to get you one of the latest kits to build.
I generally recommend 10 watts Max for lower duty cycle modes, and 5 Watts Max for heavy duty cycle applications like ft8. I would expect typical CW operation at 10 watts to be just fine.
You clearly don't understand how dB measurements work. It's a relative measure, and therefore the same % loss for any power. 1.5 dB loss is pretty typical for an EFHW transformer, and is similar to what you experience in your run of coax to a dipole, particularly in a portable setup with smaller coax.
@@K6ARK Obviously you don't know anything about heat loss and how it increases the swr causing further loss as that tiny toroid heats up ! In a 49:1 transformer, you need mass for efficiency !
Any idea on power ratings in different modes and different wiring configs? Obviously QRP, but would it stand up to 5 Watts in a high duty cycle digimode? Just curious. I love the design.
These things will handle 5 watts with high duty cycle modes and 10 watts with a lower duty cycle. If you want up to 30 or so watts, get an FT82-43 toroid, nest the FT50-43 in the center, and wrap it as if it is a single toroid. Works great!
@@K6ARK Cool. I've built a few 100+ Watt EFHW's and I know the commentary is always about how big you have to go with the toroid to handle the power. This guys seems so small. But then again, it is for QRP. Thanks!
@@K6ARK I did the same thing but I stacked 3 and I could never get a wire tuned in on it for some reason. I broke down and just got the bigger size and use one toroid.
@@K6ARK It works. I scanned the transformer with a 2.5 kohm load that also acts as a voltage probe. Looks good out to 50 MHz. I emailed you the magnitude of the transfer function plot.
I've explored a LOT of EFHW antenna ideas, but this seems to be the lightest and easiest, with the fewest number of things I can do wrong! I noticed none available at your Amazon links though.... any plans to start cranking out more kits? Either way, this is mad genius!!! -- DeWayne (KO4VNX)
Thank you, and my apologies for the lack of stock on Amazon. I have simply been too busy lately, and demand for these antennas has been greater than I ever expected. I will have more sent out to Amazon as soon as I'm able, and I appreciate your patience with me.
End Fed Half Wave (EFHW) uses a 49:1 yo match a resonant end fed half-wave radiator with feed point impedance around 2k ohms. The 9:1 unun is most commonly used as an impedance transformer to make a random wire (non-resonant length) a lower impedance for an easier match with a tuner. A tuner is generally required with a 9:1 unun and random wire. The kit can be built either way to suit your needs.
@@K6ARK my bad, just ordered another kit. I’ll disassemble and correctly build the kit. Read the instructions instead of bulling ahead. Keep those great mountain videos coming, we east coast people don’t get to see that beautiful country. Thanks, Steve
@@1911bladeguy seriously, please send me an email. I'm more than happy to send a few spare parts your way. A PCB, magnet wire, and capacitor fit in a regular envelope. You can reuse the toroid and the BNC. Can include heat shrink if you need that too. No biggie! Drop me a line with your address and what you need. 👍
My SOTA activity (and video production) has taken a back seat to other projects including putting together antenna kits for all of you. I've also been more busy with SAR training lately. I'll get back to it all for sure. Got a couple of activations in last weekend. 🤘😁👍
@@K6ARK I'll have to checkout the antennas. Cool that you got some activations, I need to get out and do that also once I get radio issues resolved. Lots of respect on the SAR! Cheers KJ7SHW
@@K6ARK Adam, I ordered one of your kits, looking to make a segmented version covering 80/40/20. Could you let me know what extra parts I will need please, or if it's even doable, lol. Cheers, and thanks again for your videos. K1AMT (new vanity call sign approved :-))
Thank you for posting this video and sharing it with all of us! A few questions please: 1. Is there a place we can buy a fully assembled unit? 2. Do you have a variation where you have built SO239 instead of BNC? 3. Which specific wire would you use if you were building an 80 meter EFHW? That wire is long and I'm wondering if folks have a preferred wire that doesn't tangle and is easy to manage? 4. if you were going to have a multiband EFHW, would you use a 9:1 and a random wire? Or a 49:1 or 64:1 and a half wave wire? When going multiband with 80 m as the lowest band, which of those would be the better choice? Thanks in advance and I am of course subscribed with notifications turned on and thumbs up! 73 W3GUY
Everybody should buy and make one of these. Adam's channel has been a great inspiration to me. He is a great teacher and very innovative. I have made several items based on his videos and been very successful in the QRP arena. Amateur radio operators need to support people in our hobby like Adam. Thanks for this video and I just placed my order. Well done! KJ7PRS
HNY everyone. Thanks Adam for sharing and making your design available for everyone who wants to have a go at making an antenna. Hope to hear some dx cool waves from summits in 2022 as bands pick up. Regards Ian vk5cz ..
![DDG & G Herbo - Nosey [Official Video]](http://i.ytimg.com/vi/I9Ra0Zc2NlQ/mqdefault.jpg)
Very well done design improvement, Adam. This will make the build a lot easier than the old kits.
You're an excellent teacher, Adam. Your explanations are very clear.
73 de AG7TX
Very well done, Adam. What a beautiful DiY kit and project. Keep up the good work!
Just finished my EFHF Build. Total finished length 61.5'. Flat 1:1 SWR across 40, 20, 15 and a good chunk of 10. No Coax - direct to radio. My tip: I placed a loop of paracord thru the small loading coil and use that as my lash point on the radio end.... the 6' of wire between that and the BNC are then 'loose' for connection to the radio. Thanks Adam!
Hi Adam, great kit and great video. I recommend one additional step before soldering the BNC: Do a continuity test to check that the enamel has actually burned off. Desoldering and resoldering the toroid after the BNC is in place is a real bear-I learned the hard way, 😂
nice - like the use of the board mount connectors - I built the original version grinding away the connector :-)
Just got mine. Great kit. Be careful when bending the posts on the female connector. They snap if you fiddle with them too much.
Yes, they do. If you damage more than one lug, let me know and I'll get you a new BNC and updated PCB that fits better. Or, if you just want the PCB before building the kit so you don't have to bend them, I'll be happy to send one. All future kits will have the updated PCB specifically designed to fit the female BNC rather than the generic male one.
@@K6ARK thank you the offer. I am good - just wanted the first gen folks to know to go gently :)
I built the 9:1 version today. Messed up the toroid winding! But found 3 colors of same sized wire and wound 3 separate windings. Colors made connecting them easy. With 29 ft element and 17 ft counterpoise tuned nicely and had 3 POTA hunter QSOs on 40, 30 and 20 at 5 watts CW. Got good reports. Thanks for good kit!
I BUILT up mine this afternoon. Wonderful. It really works. Endx halfwave antennas are great. I have experiences with Fuchs antennas. You only need a short counter poise ore even none. That's the advantage of these kind of antennas. I like that antennas.
Thanks ! As soon as I seen this video I went straight to Amazon and ordered 2 of your kits.
Awesome, Nick! Please feel free to reach out to me with questions or if you have any issues. I want to make sure everyone is successful in their builds.
@@K6ARK would it be possible to make this be able to handle 20-25 watts by using a bit bigger wire ?
Wire is not the limiting factor, the toroid is. You can add a FT82-43 toroid and nest the FT50-43 in the center, then wind it as if it is a single toroid. Works great for up to about 30-35 watts!
@@K6ARK thank you!
@@nickrupp2336 built that way, it's a fantastic G90 antenna. I may make some G90 kits at some point... 🤔
Hi There! Greetings from UK.
Great video and really happy to learn you came up with a way to make your design available to purchase.
First time I saw you build one I said to myself I will struggle with the tiny capacitor directly to the BNC.
This KIT makes everything easier.
Thanks.
Thank you for providing the kit! I just ordered one! I never got around to buying the components myself to try and build it back when you had your video of how to build them. So glad you put this kit together. Juddie - WD8WV
Nicely done Adam,
IMHO this is one of your best build videos.
I built a version of this antenna based on your previous vidios and couldn't be happier with it. It bagged me my first SOTA DX in to Guadalajara Mexico.
Keep up the great work/content Adam. 73
He's Back! It's been too long Adam! I just placed my order. Been waiting for this or a long time. Instructions look great!
Thank you, Chris, and thanks for the Christmas letter and bookmarks. What a brilliant idea. I love it.
Sometimes life gets busy and it's hard to keep up on video production and editing, but I'm definitely still around and creating. That won't stop any time soon even if it is a bit less frequent.
@@K6ARK No problem! Thank you so much for putting these kits together. I can't imagine the work involved to get to this point. Hoping with this kit to 'lose the coax' in the future lol.
I can't wait to put mine together after work today! Funny I had most of the components except the board and the BNC Connector
He’s alive! I had thought you’d fell off a mountain, or you were on an extended ‘on location’ action film shoot, doubling for Bruce Willis as a stunt double. Huh, I’m rarely wrong…. But hey, I did build your kit, and hey, I love it… a 9:1 Unun with linked 20-40m legs… Bravo Adam! Now I need to figure out how to install your cap key kit into my QCX Mini…. de W7UDT Rand (dit dit)
Thanks Rand! Yes, I get busy with life sometimes as well, but I do need to get back to making some more videos again. I also need to finish my reply to your email. I do have more cap touch key PCBs and can get another headed your way. Thanks and 73.
@@K6ARK Hey Adam! Here’s a heads up… I’m working on a protective laced Kydex S/POTA board for my KX2… (what the ‘he double toothpicks’ is that?)
My KX2 has rails, so the top molded half of the shell will be clear, and act as a cover for the KX2, being laced together with paracord to the bottom half, a 8x12” flat clipboard… the sides of the top case will be open on both ends, extending an inch or so off each end. The top cover will accomodate the front paddle. It’ll all hang from a lanyard off my neck, so when seated, I can comfortably operate and log my contacts… whatcha think? The laced board will provide the weather and impact protection the KX2 lacks…. Being laced by paracord, it will hold the radio securely.
I've got my kit and I'm hoping to pair it with an FX4C sometime in the future for an ultra-portable rig.
I've got a couple on the way. Can't wait to have my own K6ARK antenna!
I just placed my order. I hope my fat fingers can get in there to build this antenna :)
Just ordered a kit, looks like a nice little winter project. Thanks for the video! 73, NJ0Q
An excellent video, lots to learn and good tips even if you don't buy the antenna, which you should.
My kits in the mail, can’t wait to get it
I have 2 that just arrived. Thanks for making these available. I can't want to build them.
Happy New Year into San Diego County... 💯🎸🙋♂
Just ordered. So excited
You have to sell your Pixy in an Altoid Mini. That thing was awesome.
Adam, any change you have a contact who buys your kits and assembles them and sells them assembled?
Wonderful little unit. I would suggest having a blank piece of round pcb same size as the main pcb with a notch for the wires and add it right at the end of the heat shrink process as a cap on the unit and maybe hot glue it to seal it.
Oh, good idea. I may have to test that out. Thanks for the idea.
@@K6ARK So fun to see such a light cool unit; a round piece of hard plastic would work too. I could build one for my QCX and it would make a really light small portable unit. I am curious if it was you that I saw tuning one of these types of units using a spool of wire to roll it out while it is connected to the VNA and watch the dips and find the best length. Was that You? they first strung it out and found out how many turns on the coil was best and then trimmed the length of the wire to the best swr. I couldn't remember what the procedure exactly was and have been looking for the video and can't find it.
Nice! Thanks. That is indeed my tuning strategy. I can't remember if it's in a video or if I just described it. Regardless, it works well!
@@K6ARK Thanks for the reply. If you get bored maybe do a video on tuning the core and then the antenna sometime. I am sure you get bored haha. Thanks. I am going to look up one of your units on Amazon. Looks like a great unit. I love building stuff and that includes kits. The tuning method could also be used on higher powered antenna's.
Look back on amazon USA and was going to buy a male bnc kit there. Looks like you are out of stock already.
I will wait for the next batch. Great kit, excellent videos. I'm learning a ton and starting to build. Thanks
Just sold out! Next batch is already en-route to Amazon. Soon!
Whoo just ordered one last night!
Awesome! I enjoy your videos very much, especially the antenna build ones. keep up the great work and more videos coming...73 de N6LPV
Ordered it yesterday.
Nicely done!
Unable to purchase this on UK Amazon
Looking forward to this build. Thanks Adam!
de W2MSA
Sweet! If you bought a kit recently, be sure to use the written instructions on www.k6ark.com. they are a little different now.
Will do. Should be a nice match with my KX2.
just built the EFRW now to test it! de ke4d your valley center acquaintance. back in the day before your time!
Now for that micro pixie. Or better, a micro cricket. It’s got side tone! No pressure hihi
Thanks Adam well done !
I'm going to need Professor Farnsworth's glasses to see that capacitor. 😀
Definitely will not need the finglonger to grab it though
So hypothetically speaking if someone were building this matching unit and their three year old walked off with the magnet wire and that someone searched the entire house for it but couldn't find it, what would you recommend as a replacement, would any magnet wire work, specific gauge, enamel type, etc? Thanks for any info, it would be helpful if this hypothetical situation were to happen. You mentioned Remington industries in your live stream with HRCC, but they have quite the assortment.
Send me an email, I'll get some sent to you on Monday. No biggie...
If you have some laying around the house, any 28 ga or 26 ga magnet wire will do.
@@K6ARK Awesome thanks! Will do I also noticed that the affiliate links in this video description show as unavailable but there is a kit with your name on it with the female connector available on amazon is that just a new link of your or a copy cat. I will send the links I have found in the email
@@nehem11e yeah, it's a long story, but basically Amazon let someone else hijack my original listings because I didn't have a registered "brand". I had to create new ones.
Received the magnet wire. Thank you!!
Is the low power rating the reason you can get away without a counterpoise?
Is there a calculator online for how many times you need to wrap the toroid with X-type of wire to get a X:1 unun for XXXw?
I only have one hand, any chance this will be available already completed?..
What size heat shrink for the 26 gauge poly stealth? I want an extra roll laying around for additional links and banana clips. Thanks!
Where can I getbthe Banana clips?
I screwed something up. I cant tell what. Maybe I'll start over with a new one. The only thing I noticed is that I bridged the CP to GND pad when soldering the coax connector on.
Charles, the most common failure is not removing enough enamel from the magnet wire. Check for continuity between the BNC center pin, the antenna wire, and the BNC ground. Three should be close to 0 Ohms Resistance between them.
If that's not the issue, feel free to send me an email with some close up photos of your build. Remove the external heat shrink if you installed it already. Try to get a few different angles so I can see which windings are connected to which pads. I'm always happy to send some spare parts if you do end up needing to rebuild.
I see they are back in stock. I just bought two as a way of saying thanks for all your help. I going to build some from scratch as well. Were do you source your antenna winders? Appreciate your work.
How about using a hot glue in the toroid
i world love to use that new winder you show last in that livestream, please share it whit us:)
Yes! I've been building up some stock and will have them available soon.
@@K6ARK please Share the .stl file i got myself a 3d Printer
Great video, kit ordered! I'll be building an efhw, any guidance on the loading coil? I looked for another video and didn't find one.
As described in the build instructions, adding a 10-12 turn coil at 5-6 feet from the feed point helps bring the SWR dips for the resonant multiples of the half wave frequency into the desired spots. I really need to do an EFHW tuning video one of these days.
@@K6ARK Thanks! Kit's not here yet, so no build instructions, lol. I figured I was learning as much by video as I could prior to arrival. Looking forward to it!
@@gregorybarra5376 no problem! Build instructions are at www.k6ark.com
@@K6ARK Got it, thank you! 👍👍👍😎
Hi, Your antenna kits have been unavailable on Amazon. Can I purchase them direct from you or is there another option? Thanks
Vitor, it has been challenging to keep up with demand, but I have more inbound to Amazon as of today, including male and female QRP kits, and new 20w kits with an additional, larger toroid, longer magnet wire, and larger heat shrink. They should be in stock again soon!
Hello Adam, quick question regarding the mini microphone kit for the truSDX. Are you still producing them? Can’t find them on Amazon. Thanks Roger W8RLP
I produce kits when I have time. I work a lot at a day job and volunteer for SAR among other things, so my free time is limited. I try to balance it across preparing antenna kits, mic kits, and winders, and then of course doing an occasional fun thing for myself like a SOTA activation or backpacking trip. You can always build your own from the files on Printables and the bill of materials posted there. Link to it from K6ARK.com
@@K6ARK Thanks Adam, I appreciate the info. 73
Will you be selling the BNC Female version? It says it's currently unavailable.
Yes! I have more kits inbound to Amazon tomorrow. Feel free to email me (QRZ address is good) and I can likely get what you need sent direct as I plan to make a post office visit tomorrow as well.
can somebody tell me where the capacitor is supposed to be in the circuit? it isnt shown in the instruction manual. i am confused as to its use.
Francois, the capacitor is in shunt across the input. It connects the BNC input pin/center conductor to ground.
@@K6ARK ohh thank you! i need to study this.
Great .. just ordered .. Tnx
Hi Adam, impressed by the size and simplicity of the design. Even for me it seems to be feasible to build the kit. Unfortunately it seems to be sold out. Do you have an idea by when this will become available again (in Europe)? 73 ON3STG Gert
Hi Adam.
Cool kit and nice video.
Pleas make that tuning video. I have no problem building these things, but the tuning is always different than what I see on RUclips.
#73 - OZ4HJ
Nice Kit. Looks like Type 43 toroid which worked well for me with 49:1 transformer EFHW. Type 2 (Red) toroid was better for me as I got better performance with 9:1 UnUn, specifically 10m and 6m on NET Nights which I do portable at times ; ) Anyway a must have in my portable setup . How much power will it handle? Thank You. . . Mostly I use T200 Type 2 (RED Toroid) 9:1 UnUn, Type 43 RF Choke, 29ft wire and 17ft counterpoise (EARCHI Antenna)
Yes, it's a -43 mix which works well in all 3 build options. I generally recommend a maximum of 10 watts for lighter duty-cycle modes and 5 watts for modes like FT8.
Fantastic job, it’s a sub from me. Happy to be aboard.
So it's unavailable everywhere I looked. What's the deal?
Too busy with my day job. Will prepare more kits when I'm able.
Are these kits going to be available again? I noticed it said they were unavailable on Amazon
Yes. I am trying to resolve issues with Amazon right now. Another Amazon vendor hijacked some of my product listings by claiming them as their brand. I am trying to get Amazon to fix this, but their seller support is a joke.
@K6ARK Gotcha! I'd love to purchase the 100w version for sure when things get sorted out, what is the price for the kit?
@@rogue_5508 $36 for the 100w. Also have just been working and busy witt SAR a lot this year which has taken up my kit prep time. Hoping it slows down a bit soon, and that Amazon fixes these issues.
Hi Adam!!! What antenna wire is recommended for the 5w, 20w and for the 100w kit?
My favorite portable antenna wire is Poly Stealth. I like 26 ga for the smaller kits, and although 26 ga will also work with 100w, I like 22 ga for the nicer handling characteristics.
Thanks for the info!! @K6ARK
@K6ARK Portable Radio i bought a kit after watching the HRCC build stream, looking forward to putting it together. I was looking for any info on tuning for EFHW build, I don't see any specific titles, can you point me in the right direction?
Your best bet right now is to review the text instructions. It briefly describes multiple ways to finish the antenna. If you have specific questions after that, fire me an email at k6arkportableradio@gmail.com
Is there any plan to make a kit that is capable of doing 100 watts?
Not at this point, but I will likely put together a ~35 w max version targeted at KX3 and G-90 users. I'll think about design options for a 100 w option, but it will require some significant design changes including a much larger toroid.
WOW!!!
Hi Adam,
Happy New Year. Excellent build video. Close-ups were perfect. I think the silicone should be the acetic acid free type to prevent corrosion. Would dribbling some hot glue affect the tuning? Stay safe. 73 WJ3U
Thanks Don, yes, non-acetoxy silicone would be best. Hot glue should work well too, but has a lower melting point that may be a problem in hotter climates.
Does it hurt to add the counter pose, even if you are not intending to use it?
Quick Question: what wattage are these rated for? 10W ???? VE6KBI
Yes, I generally recommend 10 w max.
Is it bad to run the ant wire through the middle of the torroid for the EFHW config? Also, is the other heat shrink that is included in this kit just for fun?
It's fine to send the wire out the center of the toroid.
The extra heat shrink and plastic tube is to make a loading coil to help with tuning on the higher bands as explained in the instructions.
@@K6ARK I should probably re-read those...
@@jampskan5690 and I should probably create a video for tuning as well. The loading coil is mentioned in the tuning section.
I did the 9:1 build but used some cheap 26awg it's a big difference compared to the polystealth that comes with the kit...
My question is can just use 14awg stranded wire I have plenty of that
Yes, it's just going to be a very large antenna. Kinda defeats the purpose of the tiny matching unit.
Just got one today, but won't come in until Feb - can't wait. Hey Adam, do you have an Instagram account?
I do, but I'm a slacker and haven't posted much. @tradmonkey
How do I get these in the UK please?
You can see if Amazon will allow you to order and ship to the UK. If not, you can contact me and I can ship direct, but a batch order is likely necessary to make it worth it. Shipping starts at around $18-20 US but is the same for up to 4 or 5 kits because they're relatively small and light.
Also I heard a lot of people are losing capacitors, would it be prohibitively expensive to include a strip of like 5 of them in each kit just in case? As I recall those caps are relatively inexpensive
Interesting, I haven't heard of anyone losing a cap yet. I'm happy to send a spare if needed. FWIW, the caps cost me about 11 cents each.
Hi! I've been trying to figureout what's the specs of these thin wires you use for the antennas. I saw this in your amazon sotre: "YXQ Yellow PVC Coated Tin Plated Copper Wrapping Wire Wrap 305M 30AWG Cable Reel"
Is that the wire you use for EFHW, etc?
That 30 ga wrapping wire is super cheap stuff that's nice to have around for experiments, and I've even used it for some UL portable antennas that I have used for years, but it's not what I'd recommend for a solid build. The BEST portable antenna wire, IMHO, is Poly Stealth 26 ga wire from Davis RF. It's copper clad steel with a nylon jacket. It's strong and small. But it's also not particularly cheap at 29 cents/foot, plus shipping. So I have been using a PTFE insulated stranded copper wire in 26 and 28 ga that I buy in bulk from China. It's cheap and works well, but it's still not poly stealth. If you want to try some out, email me (good on QRZ) and I'll get some sent your way for a reasonable price. Hope that helps!
Will hotglue affect the matching unit?
Can this antenna be connected directly to a radio or do you recommend a small length of feedline? I'm trying to decide between the male or female kit. Thanks
I prefer the male kit for direct connection to the radio as you see in many of my videos.
Hi Adam, I have one of your early pcb kits and have noticed no continuity between counterpoise pad and coax sheild pads, is that because this is an isolated transformer design rather than autotransformer? Intentional? (Btw ,a really fun kit!! Thanks! )
Wayde, good find! That was an error with one of the earilier versions of the boards. Please send me an email and I'll be happy to get you one of the latest kits to build.
Will these kits be available again soon?
Yes, more inbound to Amazon this week including 20w versions and winders.
@@K6ARK Ok cool! I'll probably purchase something! Thanks!
Thanks for the kit! Great little balun!!
Can I use that with 10 watts power ?
I generally recommend 10 watts Max for lower duty cycle modes, and 5 Watts Max for heavy duty cycle applications like ft8. I would expect typical CW operation at 10 watts to be just fine.
This thing might be very lightweight, but with such a small toroid, the efficiency will be very low too!
Measured at about 1.5 dB. Actually not bad.
@@K6ARK 1.5db loss ?
That would be a lot at QRP power levels !
You clearly don't understand how dB measurements work. It's a relative measure, and therefore the same % loss for any power. 1.5 dB loss is pretty typical for an EFHW transformer, and is similar to what you experience in your run of coax to a dipole, particularly in a portable setup with smaller coax.
@@K6ARK Obviously you don't know anything about heat loss and how it increases the swr causing further loss as that tiny toroid heats up ! In a 49:1 transformer, you need mass for efficiency !
Any idea on power ratings in different modes and different wiring configs? Obviously QRP, but would it stand up to 5 Watts in a high duty cycle digimode? Just curious. I love the design.
These things will handle 5 watts with high duty cycle modes and 10 watts with a lower duty cycle. If you want up to 30 or so watts, get an FT82-43 toroid, nest the FT50-43 in the center, and wrap it as if it is a single toroid. Works great!
@@K6ARK Cool. I've built a few 100+ Watt EFHW's and I know the commentary is always about how big you have to go with the toroid to handle the power. This guys seems so small. But then again, it is for QRP. Thanks!
Yeah, I've typically used a stack of two FT140-43 toroids for a 100 watt unit. A single is probably enough for some bands and modes.
@@K6ARK I did the same thing but I stacked 3 and I could never get a wire tuned in on it for some reason. I broke down and just got the bigger size and use one toroid.
Are you using a 50v or 500v capacitor in your kits?🤔👍
500 or 1kv for the QRP and 20w kits.
@@K6ARK When will your kits be available again on Amazon?
@@barneymerrill3188 there are a bunch more at their warehouse waiting to be accepted into inventory, so hopefully soon!
@@K6ARK Cool...I'll keep an eye out!🤠👍
Can this handle 10w QRP?
I recommend 5 w max for heavier duty cycle modes and up to 10 w for lower duty cycles.
how much power can the transformer handle? Looks great.
Andy, I recommend 10 watts max for lower duty cycle operation like SSB, and 5 watts for heavy duty cycle modes like FT8.
@@K6ARK Thanks.
@@K6ARK It works. I scanned the transformer with a 2.5 kohm load that also acts as a voltage probe. Looks good out to 50 MHz. I emailed you the magnitude of the transfer function plot.
What's the max transmit power for this?
I generally recommend 5 w for heavy duty cycle modes and 10 w for lower duty cycle.
I've explored a LOT of EFHW antenna ideas, but this seems to be the lightest and easiest, with the fewest number of things I can do wrong! I noticed none available at your Amazon links though.... any plans to start cranking out more kits? Either way, this is mad genius!!! -- DeWayne (KO4VNX)
Thank you, and my apologies for the lack of stock on Amazon. I have simply been too busy lately, and demand for these antennas has been greater than I ever expected. I will have more sent out to Amazon as soon as I'm able, and I appreciate your patience with me.
@@K6ARK no stress, in the meanwhile, I've learned a LOT from your videos! Hahahahha, the dreaded toroid winding!!!
Thought it was going to be a 9:1 UNUN that was going to be used as a EFHW match.
End Fed Half Wave (EFHW) uses a 49:1 yo match a resonant end fed half-wave radiator with feed point impedance around 2k ohms. The 9:1 unun is most commonly used as an impedance transformer to make a random wire (non-resonant length) a lower impedance for an easier match with a tuner. A tuner is generally required with a 9:1 unun and random wire. The kit can be built either way to suit your needs.
I mounted the PCB board upside down
Oh no! If you need spare parts, let me know.
@@K6ARK my bad, just ordered another kit. I’ll disassemble and correctly build the kit. Read the instructions instead of bulling ahead. Keep those great mountain videos coming, we east coast people don’t get to see that beautiful country. Thanks, Steve
@@1911bladeguy seriously, please send me an email. I'm more than happy to send a few spare parts your way. A PCB, magnet wire, and capacitor fit in a regular envelope. You can reuse the toroid and the BNC. Can include heat shrink if you need that too. No biggie! Drop me a line with your address and what you need. 👍
Somehow, I see lots of kits in your future! G7VFY
Just grabbed two kits, can’t wait to try and create one of your antennas for my SOTA outings. Don (N8FN)
Awesome, Don! Enjoy the build, and please feel free to reach out with any questions. The build Instructions at K6ARK.com are detailed and effective.
Nice instructional, thanks for the video. Haven't seen any SOTA's in a while, getting out again soon?
Tony
KJ7SHW
My SOTA activity (and video production) has taken a back seat to other projects including putting together antenna kits for all of you. I've also been more busy with SAR training lately. I'll get back to it all for sure. Got a couple of activations in last weekend. 🤘😁👍
@@K6ARK I'll have to checkout the antennas. Cool that you got some activations, I need to get out and do that also once I get radio issues resolved. Lots of respect on the SAR!
Cheers
KJ7SHW
@@K6ARK Adam, I ordered one of your kits, looking to make a segmented version covering 80/40/20. Could you let me know what extra parts I will need please, or if it's even doable, lol. Cheers, and thanks again for your videos.
K1AMT (new vanity call sign approved :-))
Are you planning another round of these? Or maybe the a PCB on OSHpark? I would really like to build one of these
What voltage is the capacitor rated at?
I believe the one in the kit is a 500v.
Built one and lost it somewhere..should have painted it flourescent!!
Thank you for posting this video and sharing it with all of us!
A few questions please:
1. Is there a place we can buy a fully assembled unit?
2. Do you have a variation where you have built SO239 instead of BNC?
3. Which specific wire would you use if you were building an 80 meter EFHW? That wire is long and I'm wondering if folks have a preferred wire that doesn't tangle and is easy to manage?
4. if you were going to have a multiband EFHW, would you use a 9:1 and a random wire? Or a 49:1 or 64:1 and a half wave wire? When going multiband with 80 m as the lowest band, which of those would be the better choice?
Thanks in advance and I am of course subscribed with notifications turned on and thumbs up! 73 W3GUY
Is the second video up?
Everybody should buy and make one of these. Adam's channel has been a great inspiration to me. He is a great teacher and very innovative. I have made several items based on his videos and been very successful in the QRP arena. Amateur radio operators need to support people in our hobby like Adam. Thanks for this video and I just placed my order. Well done! KJ7PRS
Wow Adam your engineering is showing, fantastic design. Nice idea using the PCB and BNC PCB mount. 73
Just built this version - sooooo much easier lol thanks - goes well with my qrp field kit
HNY everyone. Thanks Adam for sharing and making your design available for everyone who wants to have a go at making an antenna. Hope to hear some dx cool waves from summits in 2022 as bands pick up. Regards Ian vk5cz ..
Just found this video and I am a complete noob on antennae. Could something like this be built for 10m, 6m, and 2m use?