DIY 9:1 Unun End Fed Random Wire Antenna for Ham Radio 

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I'm glad to know I'm not the only one to strip the plastic insulators off wire terminals.

Thanks Ape. I'm sitting down with this video this morning with a big cup of coffee and getting everything sorted out.

Building toys is the best part of this hobby!!! I've started playing with my radio gear recently and realized how many antennas and other "things" I've made..lol!! Good stuff Ape!

Excellent, I've been thinking of building one of these for quite some time.

The BEST DIY antenna video I have come across. Thanks for taking the time to explain what many just take for granted

I was using the 84 ft wire with a 16-17 ft counterpoise and a LDG auto tuner before I moved, worked great. I now have less space and must go to a shorter wire, maybe 41 ft. Great video with most everything you need to know about setting up one of these antennas.

Great explanation into the unit that is a 9:1. A good antenna for /p where there is a need to be wary of EMF to those members of the public that may not be aware. I use my own with wire, vertical on a 10m f/glass pole.

Crimping ain't easy! Thanks for the great information Ape 👍👍

I'm looking to do this project soon. Gonna have to watch this vid a few more times and read all the comments before I sit down to make it.

Good job on both construction and a clear and concise explanation. I always install a CMC in addition to the one 8K-ohm choke that's permanently attached to the output of the rig as well as randomly placed, cheap EMI split beads (barrels) clipped on the coax feedline. When using ferrite cores split or not, use the proper size 31 mix core and the "turns-squared" advantage of 3-4 turns over a larger core versus a long string of snap on ferrites. 2-turns equals 4 beads. 3-turns equals 9 beads, etc... The other thing that causes a rise in SWR as frequency increases is leakage inductance and distributed capacitance of the windings as the turns approach a 1/4 wavelength. 73's AD6AE

Yeah. I'm using one now and it lit up my random wire. 👏

Noticed 4,5,6 and 7 colors are reversed in the graphic, but then corrected in 8. 9 and 1 the critical ones. I'm using the 14 ga. enameled magnet wire so following the windings closely. Love the way you explain things, no hype and down to earth! Subscribed. 73

I'm impressed by how easily your're able to get the wing nuts on without them wanting to cross-thread like always happens to me.

Good video Ape and while I was re-watching this video my wife came in with my with my order of wire and Toroids from JPM SUPPLY. Time for me to ge busy going to wind (2) 49/1 and (1) 9/1. JPM SUPPLY is very FAST, I ordered this on SATURDAY and here on Tuesday, that’s fast and THANKS for recommending them❗️👍 73 KV5P

Very good explanation. I have had great luck with 49:1 EFHW antennas, both bought and built, but the 9:1 I built has given me all kinds of problems getting it to resonate. This weekend I'm going to tear it apart and rebuild it from this video. 👍

Very good ,well explained 😊

Nicely done.

I put up an EFRW with a 9:1 balun, and a ferrite chole on the shack end of the co-ax (13ft long). Works great on 40 & 20, first contact was 3,000+ miles with 3.5W SSB on 20! The antenna runs slightly down, with the end just 6ft from the ground. I use a usSDX+ and an ATU-100.

I Love The Experimental Mindset. Just LOVE IT !

Your soldering iron heats up the connection WAY faster than mine! lol (that same music plays while I solder, though)... Thanks for the lesson!

Excellent! Thank you!

I've run both the 9:1 and 49:1 and both antennas worked very well....the 9:1 was much shorter which helped in my installation - however, I was constantly fighting RFI both in the house and my IC7300. And yes, I tried all the recommended fixes for RFI and none worked to my satisfaction!! The 49:1 EFHW has never caused RFI so it's the wire antenna I use. 73/K6SDW

Excellent much appreciated

Awesome video

Great information. I saw what you did there at 10:40, LOL

With a 117 foot sloper and a 9:1 UNUN I get great performance on 160-6 meters! The wire goes from 10 feet at the edge of my roof to 50 feet in a tree. Using 125 feet of RG8X and a line isolator at the back of the transceiver; all bands are under 3:1, so the internal tuner gets me the entire HF spectrum! By the way; earth grounding on the antenna side of the line isolator produces a dramatic reduction in noise. W6PDL

Hi nice video, I built a similar set-up a while ago but with very thin SOTABEAMS Wire, at 52 feet, it's in a SLOPER setup, it works quite well but sometimes I struggle at my legal limit of 10 watts, but it's quite a stealth antenna,

good work

I would Never PUT A LINE ISOLATOR AT THE ANTENNA SIDE. 1. It will effect your SWR and 2. Any interference picked up on the co-ax will feed direct to the TX. After decades of trying various lengths and configurations I found that a 10.14 Meter wire and 9:1 using the co-ax as a counterpoise around 10m at least of RG213 will perform well from 40 to 6m (if ATU goes above 30Mhz) The Isolator should be before the ATU. Best configurations are horizontal or L config. A word on toroid rings, a 140 may be fine for 100w CW or SSB but is not suitable for say FT8 above 25w, many commercial antenna unun's state that these are not suitable for constant power data modes. In that case up to 100w a 240/43 9.1 with PTFE wire is required at least. On the home brew Line Isolator use the same 240/43 with RG214 Coax Cable Double Shielded.

Great video! I am planning one of these now after watching your build. By way of comparison, would you be able to also show the difference in changing the antenna side to one of the longer wires maybe a 107/119? Keep up the great vids!

Thanks! A great low cost multi-band stealth antenna! I have a 71' sloper with 9:1 unun, 50' RG8x, & common mode choke at my XPA125B amp. No tuner needed on 20, 17, 15, 12, 10. Can use the XPA125B's internal tuner for 160, 80/75, 60, 40, 30. I fortunately get SWR of 1:6 to 1 or less on all HF bands. Have made SSB DX contacts from California to Europe, Caribbean, Asia on 40, 20, 17 SSB, & get 5/9 reports on 80, 40 SSB nets. Nope, NOT a hex beam, Yagi or multi wavelength loop, but still gives lots of QRP & 100 watt thrills!

Thank You :)

I love the ptfe wire. I have a triple core I run 450 Watts no problem ssb

I built a couple of these a few years ago. They are my go to antenna for POTA. I use a random length counterpoise and no common mode choke. Btw, the choke IS an unun, but a different build for common mode. I do not understand how this antenna generates RFI tho. POTA on and thanks for the video. WB2SMK

Благодарю за подробную инструкцию. Ты единственный хорошо всё объяснил и показал. Другие не показывают как правильно соединить провода.

I seriously enjoyed this video and look forward to the test results and impedance measurements. I am seeing so many use small company commercial versions without a counterpoise and would like to see the performance differences as I am still confused on this, Dave- KU9L

Thanks, buddy. I did this with 14 gauge solid copper core. Bit of a job on my fingers to wind, especially since they are still healing from sharpening my axes. But anyway, I think it turned out real nice. Cheers.

Second time watching. I want to build more! I need to order toroids! Yall should sell em! Wrapped and unwrapped!

“Box of these nuts” got me.😂😂

Ape! You are tinkererier than me lol. I went to that torrid website, so cool! After building your cahrtenna I went back and checked my first two Amazon ballun kits and they weren't even soldered! I guess I thought the magwire would conduct just on contact! How wrong I was! Now I have a WORKING 9:1!

Hello ! Thanks for all - BUTT please tell us the TYPE from that FERRO AMIDON. Thank you so 👋👋💪💪🍀🍀

amazing clear detaled love it! only question is PTFE 16awg wire - is that soid core? or stranded? and does that matter?

Very informative, thanks.

Nice Job. looks good. I have been thinking of trying one in place of my 80m EFHW I have one built but can't remember if I tested it.

These are great, but when are you going to post part two set-up tune and test? been looking but haven't found it. :-)

Does the number of times you wrap the wires around to torad make a difference?

Awesome! New to Ham and I'm going to build this as my first antenna. I do have one question about the Remington wire. Is that a specific wire? I'm seeing all sorts of wire on the website and just wondering which one I need.

Using the red crimper dies on a blue terminal won't crimp it tight enough. Adding solder is compensation, but where the hot solder doesn't fill, it's too loose. You're also using the insulated crimper die on uninsulated terminals. There is a different die set for uninsulated terminals that you should be using.

Smoke - really good EFRW build presentation here. Thank you. I think that I am getting smarter (?) about understanding EFRW and EFHF wave antenna designs, but one question sticks out - why do we use a wound toroid with a capacitor (an LC?) for an EFHW, but only a wound toroid (no capacitor) for a EFRW?

I mount my pl-239 on the inside and make sure the big hole is bigger so the collar of coax connector will fit in the hole. I get better connections with the crimp on lugs.

Got my IC-718 yesterday. Got all the parts I need for this except the feed line choke. So close to getting on HF. Question, is there anything I can do to substitute for the choke you use at the feed point? Thanks Ape, I watch all your videos over most for info!

I've always been a metal ham. Yagi's, beams, etc.. I just put up a 9:1 EFNR approx 180 feet long and 70 ft. of coax to unun from where I have 3-240/31 chokes. Inside the shack I have a 1:1 isolator. Almost zero rf in shack except on 18 and 21 Mhz when amp is on at 450 watts (I get rasp in my computer speakers) End result:

Where did you obtain the wingnut and lugs from? I am having a heck of a time finding examples similar to what you used in the video.

"...we're just gonna white trash this...." LOL. Fun to watch Ape. I enjoy how you teach as you go.

Thank you I've been a Technician only for many years ever since the no code change. However recently I have found so much interest in the HF bands and QRP projects. I just picked up a used G90 and hope to take the GENERAL Lic very soon and open the door to HF. Your video was awesome and can't wait to build one myself. Does anyone here have the answer to this: LDG shows no counterpoise on the 9:1 unun I will be using a 100' RG8X to the unun. Planned on no counterpoise with Ferrite Beads at transceiver to avoid possible rf return. Transmit is at 20W max. Or do I need a 1:1 Balun choke? Any info would be great. THANKS again for this great video!!!

What kind of Toroid would I want for a 160M antenna? (you mentioned the numbers). Later in the video you mentioned wire lengths. So, if I understand correctly, for 1.9MHz I would want to stay in the middle between 246 ft and 493 ft which would give me something like 369.5 ft. Is that correct? (thats an awful long wire).

You mentioned the antenna wire length. Does that length include the strain relief at the start and the tuning length at the end or did you add extra for those lengths?

So when you say the wire is cut at 41', is that the distance from the strain relief to the isolator/dog bone? I'm assuming it doesn't include what you loop back, but figured I would ask.

Nice build. What is the maximum power handing capability?

Question: if you are using the coax shield as the counterpoise as many home stations might, is it counterproductive to install a choke at the antenna feed point? I currently am using a choke before the coax enters my shake and I seem to be having some good results with that. It seems like I have had some trouble tuning the random wire if there is a choke at the antenna feed point AND I am using the coax shield as the counterpoise.

So, I wasn't able to [easily] locate where you actually tested the end-fed as a follow up to this video at least not from the titles. Could you please provide either the link here or respond if you decided not to do a follow up video. I've very closely paralleled your steps in building end-fed antennas w/o being aware of your build! End-fed antennas are my favorite portable go to.

Does your element need to be bare wire that touches your eyelet on the unun? I see you clamped it with the protective covering still on

Do ypu have a follow up video showing this antenna working?

Wowsers

Another advantage of an EFRW antenna is that the torroid doesn't heat up like an EFHW.

A 9:1 or a 16:1 should both work really well, if using stranded wire stay away from 26.0-27Mhz as that is the resonant frequency of the Chlorine Atoms in PVC.

Totally unrelated to what you're talking about, I have an issue with an old ZS6BKW wire antenna that never really worked that well and the ladder- line broke away from the balun last year, after some seriously strong winds here. It is set up as an Inverted Vee and I want to remove the balun so that I can have RG-213 as the transmission line into my shack. Should I just dump the whole antenna or can I at least use the element wires as a dipole? Because of the size of my property, I can't fit anything larger than this antenna to get any decent directionality. I do however have an MFJ tuner, if that is any help at all. What are your thoughts on this?, I'd really like to get back on HF if I could. Sorry to lay a question like this on you with next to no information. 73, Mike, ZL3XD

great video where did you get the box from tsk

that is called tri feller wound . also for more power 2 cours needed and larger PTFE wire. it takes heat better than MAG wire. them dog bone insulators as also used in electric fence in farm use. so Tractor supply company has them. some times you get lucky on some bands and need no tuner. but multi band use keep a tuner on hand. 73's

As far as. Balun is concerned,its ok, but as you said "fake antenna" for 470 ohm resistance used in place of antenna, the result might be fake for fake antenna.actual part is antenna not balun,balun use just to unbalance antenna.so when you test ,test with antenna otherwise ,i think result may be differ from actual.But,the same time ,if this balun tuned with any unbalance/untuned antenna then it's ok.pls, correct me if I am wrong

Is there a. Book that you can recommend on antenna making ?

One more question, please? Can I use a FT140-43 toroid core instead of a ft240-43 core? Do I only sacrifice a bit of power handling capability, or is there another reason?

Next trick in the book to fit the very small eye crimp connector: drive the point of a scratch awl from the eye side through the crimp wings to separate them enough to insert the wire.

Hi, Ape! What type of solder did you use?

Would there be any advantage to using a 240 vs 140 Toroid?

How do you lay out the counterpoise? Opposite direction of the antenna wire? Directly under the antenna wire? And wouldn't work better with a series of radials?

9:1 is turns ratio, have you tried connecting a 450 ohm resistor to the antenna side and checking it with a spec an?

In my humble opinion, the better solution is to use a wire that you resonate on the lowest F band of interest and use it with a multi-tap UNUN for a multi-band, no tuner needed solution :)

Question - How many watts will this handle?

I made a EFHW for 40-10. Does a EFRW have anything better than my EFHW? I get 4 bands with out tuner, and can get others with my tuner. I can even tune 80 with an external tuner.

How many wraps did you do? Maybe I missed that but isn’t it important? 9 wraps. Got it. You showed it later in the video. So 9:1 requires 9 wraps? Does that always correlate? So 4:1 would require 4 wraps etc?

Stranded wire would have more aggregate surface area, and we all know about skin-effect, so I would suggest that stranded wire of the same gauge would be better.

Is there a follow up to this?

But i knew the technique how to make balun ,but same time i expect correct balun ,i mean usefull

When You Talked ABout amrking The Ends Of The Wires, You Don`t Actually Need To Do That If You Have Multimeter, But Its A Good Practice To Do So. Box With That Snorkle You mentioned, Its Easy, Just Drill Two Holes , Or Lets Say, Drill A Hole THRU The Whole Body Of The Box, Then Put A Plastyic Pipe In It And Seal It With Silicone And Just Glue Plastic Bits In The Middle, But Don`t Block The Hole, That Will Help With Cooling The Inside Box Like A Passive Refridgirator. When You Pulled Out All The Nutts ANd Bolts I Was Thinking, Will You Not Use A Copper Ones? I Always Try To Use Everything Copper In The Antenna Or Between It BECAUSE IF NOT, The Radio Waves And Lets Just Say ELECTRICITY Will Threat It As A resistor And There Will be Some Problems, Even Copper Electroplating Is SUPER Good Thing To Do For Your Bits And Bops AND Not Only For RF, Its Good For Rust prevention To, I Have All My Wires SOlid Copper Ones, I Mean, The Big Ones Who Are In The Sky Attached Tto House Or From House To Down To Earth, All Copper And All The Connections Are Solid Copper As Well, One Thing Is Not Solid Copper, But Copper plated. :) I Will Make A Video Someday On How I Copperplate Antenna Things For it :) All My Things , Elements Are From Onne Old KGB Agent Who Passed Away And My Best Friend Inherited The Property And I Got All The Old USSR Devices, Wires And All Electronics, EVEN Radios That He Was Listening Into Hotel Rooms As A KGB Aggent, A Lot of folks who saw the devices said i need to give them to the Rīgas Ocupation Museum And Im Thinking of Doing That

Oh, it need tuner too!?

2.4 inches is the outer diameter :)

I am surprised you say that you use a 1:1 Balun as your choke, not a 1:1 Unun. From instructions on the LDG site they recommend use of their 1:1 Unun as a choke with their 9:1 Unun on a EFRW. (I am a new Ham and using the already assembled LDG Ununs and Baluns for my experimenting, but I assume the theory of how things work is independent of the manufacturer of the transformer.) I'll attach a link to their doc below. Just look at the 3 page LDG doc. The picture on the first page shows what they recommend.

If something has a “propensity” to break, rest assured I will find a way to break it on the very LAST hole I will drill. Usually I buy 2 boxes because I am almost always certain to frack one up. 😂. Hahaha

good explanation 73 pd0osg

My wife hates that I EYEBALL a lot of things, close enough for government work

10:41 “Deez nuts.” 😅

"A box of deez nuts"

is that a Jeep ?

This video is impossible to follow for me if you don't have the same color wire

I'm gonna' GO AHEAD and give some advice here: This is an excellent technical video, the message is important, and you definitely do neat bench work. Your presentation style is however definitely weakened by the repetitive use of the verbal crutch "Go Ahead". I do not believe that you are aware of this and I wonder if you would Go Ahead and listen to this entire video, Go Ahead and count the number of times "Go Ahead" is used, and then Go Ahead and form a plan so that you can Go Ahead and eliminate this distracting utterance from your armamentarium. Great video otherwise, 73.

Lossy, inefficient, wouldn't waste my time. A 9:1 unun designed to feed a 450 ohm load only and a random wire is not going to be 450 ohms on all bands ! The unun is only efficient when feeding a 450 ohm load. Then you have to add a tuner which adds more loss ! Yes, it will make contacts. But if you have to use a tuner, at least skip the unun and connect the wire direct to it and eliminate a little bit of loss !

Great video... I noticed that you didn't anchor the toroid inside the box other than soldering the input, ground and antenna wire connections. What would you suggest? The way I feel is, the fewer holes, the less chance of moisture getting in the box. I've used double sided foam tape for other projects. de KE7LOY

Wish I had a Jeep on MY vise. 😄