EFHW End Fed Half Wave Antenna Higher Power Using 52 Mix Ferrite
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- Опубликовано: 27 авг 2024
- This is for 80 - 10 only. 160 requires a 3:21 ratio, 43 mix and 200 pf capacitor.
After months of research I found a way to make the transformer handle high power. I can now run 500 watts + on 80 meters using CW. CW has a much higher duty cycle than SSB. 40% vs 25%. I am using 2 primary turns and 13 secondary turns for 80-10 coverage.
Update: 10/12/2019
We now use 14 turns total.
We are also using 12 AWG enameled wire for this 3 core transformer. It's harder to work with but results in better SWR and power handling especially on 80 meters when running high duty cycle mode.
Rather than starting with 2 pieces of wire fold back with a single length and use a hook in the drill. Makes a neater wind and no damage to the wire
A rubber band wrapped around the wire would help the drill chuck grip the two wire and prevent damaging the enamel coating. As always, nice video for a newbie and very informative.
You're going to be removing that enamel anyway to solder it.
I built one per your instructions. tonight I worked a station 4900 miles from me on 85 watts thanks Steve works great. Ron C KG5GFV
I couldn't wait to build mine after watching your video... I dropped one of my Toroid on the kitchen floor, it shattered like a glass being dropped. I just ordered another one!
I'm counting 2 passes of the twisted wire through the core center then 4 single wire passes then 7 when cross over then 8-12 (5 more) at the end to the antenna output. Total 12, not 13. Am I wrong? Thanks.
TEMCo makes good stuff! I've used their magnet wire and resistance wire for years with no issues. Even experimented with their NI200 wire for electroplating experiments and have always had good luck with anything they make.
Thanks for you video. I just finished winding my first 52 mix transformer. Haven't mounted it in an enclosure yet. But first test of SWR are very impressive.
All bands testing out at round 1.5 to 1.7 SWR except 160M which is 1.9 to 2.4 and 10M is 1.6 to 2.1
I believe once I get it trimmed up and installed in an enclosure it may be even lower.
Thanks again for your video.
This is for 80 - 10 only. 160 requires a 3:21 ratio, 43 mix and 200 pf capacitor.
I just discovered Arrow myself a couple weeks ago. Hands down best pricing and service.
Hello David, I am having a hard time finding this Arrow Electronics. Could you send me their URL? Thanks
arrow.com
Thanks for your videos
Just ordered 3 each ft240-52 from digikey for $10.89 each.
Arrow was charging a tariff, sales tax and shipping fee
Going to give this a try
12 turns in the box at the end Steve. What gives?
You still active much on Cw Steve? Haven’t heard you in a blue moon. I think you’re running a loop now ? 73 from Ky
Hi Steve - Got 3 of the 52 mix being delivered tomorrow and have already twisted the 14ga (as per your video). Are you now recommending 13 secondary turns versus 14? I see both in the comments. BTY Tks for the videos. Persuaded me to wind my own. Already got 130+ 14 ga stranded hung sloping up to 40' from a previous 9:1 Unun that baked the cores on 80M after more extensive CW due to band condx.
Use 14 turns Allan.
Yep watched this several times. Found sized lugs but had to look around a bit. I have two xformers done. One has 3 43's (because they sent me the wrong ones) and was has 3 52's (they finally sent me the right ones!) So at 100w, I'll get to see the difference if any between the two. Thanks again N9DMS Dave
What did the verdict end up on the difference
Steve thank you for making these videos and sharing them with all of us. I continue to watch your videos and read articles and do as much research as possible, but I am still confounded by some basic questions. Can you please help shed some light on this one item that I still struggle to understand:
What was the purpose of using three cores? Was it to increase the total power handling? What if we used four cores? Or five cores?
Put simply, what does adding each additional core add to the solution?
Is there a simple rule of thumb?
One core 500 w, two cores 1,000 w, three cores 1500 watts?
Thanks again and 73 W3GUY Ernie
The core of a transformer affects the inductance of the winding. Too many cores and you would have too high of an inductance. Note also that it takes more wire to go around more cores which also increases inductance. Your high frequency limit comes down as inductance increases. 3 cores is about the limit for good coverage up to 10 meters. You might get by with 4 cores but keep an eye on the swr for 10m. More cores takes longer to heat up so yes, the power handling increases with more of them. It's a juggling act!
@@n4lq thank you very much, that clears it up! That one paragraph that you just wrote makes it so simple, hours of reading and I couldn't figure that on my own, sorry and thank you again! 73 W3GUY Ernie
Hi Steve. I just watched your video and had two questions. First, it's been a year since you posted this video so I'm curious how your antenna has held up. Second, do you have a diagram of the transformer circuit? I'm getting the general idea but a diagram for reference would be helpful. Can you point me to one? Thanks!
Steve has a FB group now and it's a madhouse, but that's where the "current traffic" is. These antennas are the bomb.
What is the FB group called?
Steve, thank you for the video....I followed your instructions in the construction. I work it in λ/2 for top band. Swr 1,1 at 1.9mhz,,,,1,1 3.700,,,...1,2 7,150...,,,1,3 14,200...,,1,3 18.120,,,,1,2 21,200.,,,,1,3 24,940..,,,.1,2 28500,, ,,1.4 50.200. The results, fantastic. Big difference with 14 and 18 awg wire......tnx SV2FNN
This is for 80 - 10 only. 160 requires a 3:21 ratio, 43 mix and 200 pf capacitor.
@@n4lq my wire is 79.5 m long ,,,about 6m...to 8m above ground,,,,,...i run 100w icom 756 pro,,,,,,,I start with 23m rg213,,,,,,,,i got swr 3,1. ON 1.935 MHZ..( the other bands let s say ok)......Αnd then i add 15m more,rg213,, so 38m,,,,, rg 213,,,,and of course 8m counterpoise,,,,,and WOWWWW,,,,!!!!...ALLLLL...OUR BAND,,,,FIX...THE SWR....160M----6M....!!!!!!!!!!!.....on 17 jul 2022 14.213 MHZ== PY7ZC.....5/9...............5 June 2022 14.214==JG2MQM.....5/7.....................I USE 100 pf,,,,,in the unun......TNX
What caused you to move from the 43 mix cores you started with to the 52 mix? W7DCF
The maximum Curie temperature of the 52 mix is double the 43 allowing much higher power especially on 80m CW where the 43 would over heat. Also per Fair-Rite corp, there is less power loss in 52 over the HF spectrum.
I am going to give a 3" T2 (red core) powdered toroid a try. I've built a 1: 1 transformer using it on a 80M folded counterpoise antenna full legal limit with no problems. I'm hoping the coupling would be adequate for the impedance transformation.
@@n4lq Is there an advantage or disadvantage for using 52 mix instead of 43 when using only 1 toroid for say 100w? I ask because I only have 100w and I hastily bought 3 of the 52 mix per your suggestion before I read WHY you were using it (for higher temperatures associated with higher power). Or put another way -- Is there a disadvantage of using 52 mix when using only 100w wound at 49:1?
@@JoeBurden 52 mix has less power loss than 43 however permeability is lower with 52. With only one core of 52 mix folks are using 3:21 ratio instead of 2:14. The extra primary turn compensates for the lower permeability. I have not tried this however.
@@n4lq Being that the gauge of wire would make a difference on the number of turns as well I am still puzzled about solving the problem. I have some 18awg solid copper wire I plan to use. I guess the only way to know is test it but unfortunately my knowledge and toolkit have not progressed to that level. I certainly don't want to burn up any radios over a couple of dollars. I appreciate your time and quick response. KO4DEF
How long is the enamelled wire to go around the 3 cores? I'm guessing around 4 foot.....any info please? 73 Des
Question: why twist the enamelled wire for the first few turns? Is it for cosmetic reason or does it serve a purpose? thanks
The wires are twisted for better coupling between the two wires.
@@renaat9829 thank you! 😉
That is massive! Nice video...
Great video Steve. I've watched your "test" of the EFHW strung out over the yard, and your video with the 160M "add on" with the relay. That was really slick!
I've been out of Ham radio for at least 20 years and poplar trees have grown up ( and out) in all the wrong places ( and my house is right on the property line NE corner with 4 acres due south and west. ) Running a Delta Loop was my original intention, but nothing fits. Getting a straight shot either south or west would work better with a single wire and only a few trees to get out of the way.
Which RF suppression beads would you recommend and where's the best place to put them? I'm going to need close to 75 feet of coax to get to my transformer location ( the run is not parallel to the antenna ). I'm only running 100 Watts so I'll save some money on the Toroids. Kitsandparts has the snap on beads. How many of them would do the job, or would some turns of coax near the transformers cut it? Or, should I make a 1:1 unun. ( which I'll have to research). I'd rather try to build it vs buy it.
I made the comment hear so others could chime in on my question(s).
Many Thanks Wayne / N3TNS
Be sure to watch my video on EFHW Grounding Compared first. You should not need any beads or chokes and never put one at the transformer. Only use them in the shack if needed. Ground your transformer to a 8' gnd. rod.
@@n4lq Steve, Roger that! I'll go over them again.
To make this work with your 160M relay mod, is the inverted L required, or will a straight run work. I was thinking of mounting a 6 ft grey pvc mast right where the coax leaves the house The studio side is about 2 feet higher than the rest of the house. I have a pvc conduit to run coax thru. It daylights to the ridge of a "Shed Roof" on the other side. All of the trees are up and out from there.
If I need the inverted "L" I have a 60 foot Pine right near my studio that I could use for that configuration.
I was looking at the notes from the slide show you have posted. Running a 100 watt rig, would I gain any efficiency using 3: 240-52's vs 2 ... or 3: FT240-43's.
Kits and Parts Dot Com has the 18AWG magnet wire. I noticed you were using 14AWG.
Is there a gain in using 14 over the 18?
Thanks for getting back to me.
Wayne
@@waynegrauel1031 The L will have lower angles for dx. Sloping will be fine for regional work. 52 mix is best but expensive. doubt if anyone can hear the difference. I get toroids from Arrow Electronics... Kits and parts is very expensive... 16 or 14 wire is ok.. 18 is questionable
@@n4lq Steve, you're very gracious your time and the help you provide. Eliminates stepping on a lot of land mines!
You're spot on about Arrow... Big difference!
Have you seen any sources for the nice stainless wire clamps like the Dutch use (Hyendfed)?
73's! and Thank you.
Wayne
@@n4lq Steve, I'm good on the parts. Arrow had the Toroids, Cap, and Vents!
Many Thanks for getting me interested in building my own antenna!
Wayne
Steve, where did you find the vents you added to the box?
They are just little vents made for siding. I got mine at Lowes but here's some on Amazon
www.amazon.com/Maurice-Franklin-Polypropylene-Louver-PLW-100/dp/B00AFESGPC/ref=psdc_2231044011_t1_B000BQQVYM
Nice video Steve, thanks.
Steve,
What length of wire are you using for the antenna for 80 - 10 coverage? 73 WB3BJU
Start with 134', lengthen/shorten to set your primary harmonic when the wire is installed, never before.
How much power will this handle?
Thx for sharing!
I wonder what mix 51 would do?
Hi Steve, you say the ratio is 2 primary and 13 secondary?
I see 2 and 10.
It is true ?
Count every wire. Yes every time a wire passes through the secondary it counts as a turn. I recommend 14 total. Count the twisted wires too
May I ask why your antennas are end feed instead of a traditional dipole or inverted vee? Is there a reason that I have not read or have been told.
An 80 meter dipole has an impedance of around 50 ohm. That same antenna on 40 meters has a center impedance of about 3,000 ohms. The only way to match it is to use ladder line and a wide range tuner along with a balun. Things can be complicated. Now with end feeding a half wave antenna your impedance is ALWAYS high and the method of matching stays about the same for every band. No more tuning when changing bands. It's a huge advantage for someone what want's efficient multiband coverage.
Thank you for the explanation. I will have to give it a try. I do not have a bunch of height but I do have plenty of real-estate.
Your transformer is 36:1 since you wound 12 turns thru the center and have two on the primary. 6 squared is 36 times primary impedance. Danny E73M
That what I was thinking. He says it should be 13 turns over 14, but here this one is 12. 73 kd2nfc
@@directedbypuma in earlier parts of the video Steve id have 13 turns but when viewed in the box, it only had 12 turns.
What are the "copper tab things you found in your junk box?" Lugs? And what are they attached to and where do they go? Besides the ground, what else do you solder to the CAP? Really tough to see on the video. Thanks for doing all this! Dave N9DMS
The copper lugs are something I found in the junk box. Any lug will do fine. The capacitor goes between the so-239 center and ground. So does the transformer. You should watch this one. ruclips.net/video/BpdpkUEW39o/видео.html&ab_channel=SteveEllington
@@n4lq Thanks. Watched this video. Will watch it again. '73 Dave N9DMS
I believe the mystery is the tail end of the primary appears in two stills in the video you refer me to get into the center of the SO239 but it is not discussed or labeled in the video. If I am assuming that correctly, would it work OK to stick that bottom of the primary into the center of the S0-239 along with the CAP and solder them both at the same time?
@@davidsapadin Maybe this helps.... static1.squarespace.com/static/5b1576d036099b603985500c/t/5c5236b57924e85a9a1ccd62/1548891830343/19-End+Fed+Half+Wave.pdf
How much power can you use .?
What happens if you mix ferrite's with 31,43 and 52?
Don't. 31 especially has too high of a permeability. 43 and 52 will work together however the 43 would get hot and reach the Currie point before the 52 mix.
I'm new to the hobby, I have 240-31 can they be used to make a 49-1 transformer?
You should do some more research to confirm, but my understanding is that 31 mix would less suitable for use as a broad multi-band transformer. Might possibly work for 160-80m.
Steve's original recommendation was to always use 43 mix but he revised that to 52 mix for the 80-10m designs. I think you can move up to 61 mix for 6m, but it may be less suitable for the lower bands.
Mix 31 will just work for 160m and below, but is very suitable for common mode chokes up to 30MHz.
ahh I see. for 3 cores you did 13 turns. Does it really provide low swr?
are you just doing 13 turns, actually I see 12 on this one lol...because you are using 53 material?
STARTING WITH SCHAMATIC DIAGRAM BY MENTIONING ALL COMPONENTS VALUES, Etc IS GOOD.
For 100 watts can I still use the 43 mix? I already have three of these here. Sergio PY1BEK
Yes. Three 43 cores are good up to 300 watts cw on 80 meters and much higher on the higher bands.
Somebody please help me on this, I just don't get It , will.trade for woodland space
At $14 per core from DIZ, I 'm waiting for a next video on how it worked out....hi....hi.
Lee, WA8QFE
Steve has been working with this sort of antenna for a good while. This isn't his first build. Check his other videos or goto FB page for End Fed HALF WAVE
Would 1 torroid be enough for 100 watts?
Power isn't the main concern in this case. When using 52 mix you need 3 cores to produce enough inductance down to 80 meters. You can get by with one core of 43 mix but at greatly reduced efficiency.
@@n4lq ok. Thanks. 👍
@@n4lq Steve... Couldn't you increase the turns on a single core of 52 to get more inductance?
@@rickkeniuk5053 Yes, but then you have more capacitance between the wires, which affects the higher bands.
Where should I order the torrid’s from?
Take care 73 de ve3hip in welland Ontario Canada 🇨🇦
Try DigiKey. Stock is low or zero at other places.
@@cbjackson4310 www.mouser.com/ProductDetail/623-5943003801
FT240-43 cores $5.95
Is it better to use ft240-43 or 240-52?
52 mix is best but expensive. It has much less power loss.
For 40/20/10m bands, what is better?
@@bertolo75 As far as I know, you can go with 43 mix for these bands.
Hallo, how big capacitor I need?
At least 3kv or higher
@@n4lq and 100pF right?
What are your wire lengths?
About 6' and 1'
I have been watching lot video's on
Efhw antnna n I think your are the best for whut for my needs
I'm have put all new antnna up
Had tornado last year
I mostly do 20m n 40m ssb I want b abull use my amps so up 1.5 kw
If need b n git on 75m ssb some
The fare end b straight 35 up above my cattle electrified fencing
Do you have eney advice or thing Chang on your design
73 n9prf Joe n good dx
How do we determine the power handling capabilities of the torioid mixes? I have some 43's and 31's. Acutally 3 each.
43 or 52 is all you want for our purposes. You can use other stuff, but don't expect any sort of performance or efficiency---IOW make a wet noodle.
WAS SHARED TO ME, THAT 31 MIX IS FOR THE LOW BANDS - 80 & 160 ,I BUILT AN UNUN FOR A FRIEND WITH 43' FT VERT. WITH 2 52sMIX, FOR HIS 100 WATTS , HE GETS 10-160 W / TUNER AND IS VERY HAPPY WITH THE RESULTS . THINKING ABOUT HAVING A SWITCH OR RELAY TO PLACE 2 UNUNs SO I CAN CHOOSE LOW OR HIGHER BANDS . PS , THE 1ST ONE I WOUND FOR MY BUDDY WAS 43MIX 4-1 BALUN DID NOT WORK WELL AT ALL , HOPE THIS HELPS SOME , 73s
This 49:1 unun?
yes. transformer
What is a maximaal power?
Until the case melts then add a fan
@@n4lq of one more ferrite ring pfff🤣🤣🤣
swr????
1:1
Like so many videos of this sort, this one falls short. Nice to see all the techniques involved, but without empirical data, it's just a guess whether or not this thing will work. Put it up, show us the configuration of the wire (sloper, inverted V, etc.) and show us the SWR curves for all the bands. It will then be more meaningful.
Put it up yourself. There are plenty of other sources for SWR curves. You will never build one anyway. Go buy it from MyAntennas.com.
this thread is 5 years old. Why not read thru the comments?? Folks have been following these instructions and successfully building a great antenna for years now....