Thank you, first time I think I understand the difference between UNUN and BALUN. I get lost quickly when David Cassler starts drawing on the whiteboard giving likely correct but very complicated answers to simple questions 😅
Different learning styles. I need to have the “why” stuff to internalize information. But I understand that most people learn better with technique vs theory. So this video left me unsatisfied. But it works for many (most) people. Awesome that we have so many Elmers right here in one place (UA-cam)!
@@Frisky0563 I like Dave. He's like a gnome in his workshop trying to explain the hardships of Santa to the elves. Honestly, I mean that in a good way. But yeah, he talks in his language from his perspective. I have noticed that sometimes even he isn't technically correct even if in a practical sense he is. I think it comes down to what people are familiar and comfortable with. I like gnomes. ☺Cheers.
@@mewintle I'm the same way in needing to know the why and how of things for them to fit and stick into their place in my understanding of things to see and figure out how things work in relationship with each other and what needs to be done when. While it isn't perfect of course, things such as the water analogy for electrical circuits have gone a very long way for me. Taking that further, RF is perhaps a bit like sonar... 🙊Cheers.
This is the stuff every other Armature Radio UA-cam channel just glosses over because they think it's common knowledge without thinking of the newbies trying to get into the hobby. Thank you for explaining things in simple terms beginners can understand. This is also the best video I've watched on the subject! I didn't get into armature radio to nerd flex on other nerds. I'm into armature radio because I'm legitimately excited on how it all works. We all want more people to play radio with. Thank you again for helping more people get into the hobby.
We live on the far eastern fringe of the Los Angeles area, in San Bernardino County, and my stereo systems AM/FM receiver struggles to pull in even the mighty KFI 640kz signal with their tower located not that far away. Everything else is just noise. So far, I'm just using the wimpy post-card sized wound wire antenna that came with my receiver, which only excels at bringing in noise from our lights and other electronics. Now I'm no ham operator. I was an avionics tech and airborne radio operator on USCG aircraft in the distant 70's, and I've been a fan of the AM band, static and all, since I was a kid. I recently found a Radio Shack longwire antenna kit amid my garage debris, and thought I might string it up on the roof, going from one chimneys the other and then across the roof a bit more. The twisted copper antenna wire in the kit is about 75-80 feet long. Way short for full wave or even half wave So I'm not TXing here, just RX. Should I go with the full 80 feet or trim it down? To use the full length, I'd have to dog-leg it, up to 90 degrees or so. Would this degrade my reception, or possibly improve off axis reception? I'll be using maybe 20 feet of 50 ohm coax for a lead-in. Would I benefit from a unrun? (Something I never even heard of before). Anyway, any help is greatly appreciated. Great and Informative video. George Rancho Cucamonga, CA
Good explanation. Many former Elmer's are smiling down on you from the great beyond. I agree that the KISS way of explaining things is the best approach.
Many years ago (during my CB days) I learned a balun can be a really neat thing. But you have to be willing to experiment a little. Someone gave me a 4-element beam which had an insulated dipole driven element with a hairpin match (He did not know how to feed it). Not wanting to try and feed it directly with coax (did that with another similar beam one time with poor results), I decided to try and feed it with a 1:1 balun. Since the dipole driver would have a 75-ohm feed point impedance, I connected the balanced side to the hairpin, and used 75-ohm coax to feed it (not CATV coax). All I can say is 'wow'! Not only did the antenna work very well, it was also the quietest antenna I have ever had. The SWR measured at 1.3:1, and I could hear signals others could not, especially in dry-air Santa Ana conditions when the air becomes 'charged' and a lot of static is present. The hairpin match provided an awesome DC ground which, in combination with the balun, provided a virtually noise-free beam. I used it for many years before a wind finally blew it down. Wish I still had it!
Thank you… my confusion is no longer there. Your explanation is simple and correct. Your material (IMO) should be thought and provided in our question pools. So many ridiculous questions that are not relevant. 🎙️W1FYG
Great explanation on baluns/ununs.....thanks!! For wire antennas though, are baluns and ununs primarily just a tool for connecting the wire to the coax....and doing that in a way that will closely match up the two with a transformer, (as well as to keep RF from making its way back to the radio)? I have my first HF radio on the way, and I ordered a manual tuner as well, since I thought it was a good idea to always use one. If I'm understanding correctly, the two options are....1) to use a balun/unun so you don't need a tuner and 2) to use a tuner with a choke so you don't need a balun/unun and just connect with a banana clip? In other words....using balun/ununs keeps the equipment to a minimum and gets you on the air quicker? Seems obvious now that I think about it.....but confirmation that I'm thinking correctly is appreciated.
And here I was scared you were going to pull up a Smith chart(kidding!). Thanks for the simplified approach of impedance matching coax/feed line to the antenna.
The Delta Loop raw impedance is closer to 100 ohm than 200 ohm. I've had better luck with a 2:1 balun and no tuner. Nevertheless a 4:1 balun will work... Txs for the video, very useful and well made. Keep on the great work!
Thanks for another really informative video. Where did you find that chart of the wire lengths and corresponding transformer? Also do you have a video showing when you might need a counterpoise, vs radials? Now that the weather is a little nicer I’m going to actually start building these antennas.
Great question, you can use a VNA, antenna analyzer or you can model it in a software application but really you don’t need to do that. It’s known lengths that have already been determined over years and years. For instance a halfwave antenna requires a 49:1 unun, random lengths of 29’, 35.5’, 41’ etc require a 9:1 for shorter random wires 25’, 20.5’, 17.5’ use a 4:1 and a perfect Quarterwave antenna should have a perfect 50 ohm match and thus a 1:1
As a noob, I also want to make my own unun. I got a unun kit from China for $11. Now to make the balanced line for 50 ohms from my connect point. At, least I think it is all about the windings around the magnets. Anyone for comments?
Great explanation Walt, concise and to the point to help beginners understand the fine points of antenna building. This is why I really like and recommend the videos on your channel. Also that's a nice Hammarlund in the background, I have an HQ-160 that I have had since my teen years in the mid 1970s! I started out with it listening to shortwave in my teens and it stoked my interest in ham radio.
Thanks! I was heavily into shortwave in my teens as well. I got that HQ-180 by luck a couple years ago. My neighbor across the street found it in his attic and gave it to me.
@redstickham6394 @COSTALWAVESWIRES Similar situation here. I listened to short-wave in the late 1960s getting many DX broadcast stations using a long wire antenna in my parents attic. But I didn't get into Ham radio until very recently.
New guy here. Trying to build my shack and scared to death of lightning strikes as we get them fairly regularly. Antennas seem to be the most complicated part of radio. Proper grounding is the concern I'm trying to learn about most.
It is a coupler when the antenna is directly connected to the "output" end of the device. The coupler is typically remotely operated. If the matching device is close to the radio, and directly controlled, then it is a tuner.
Walt.. Thanks for this.. I'm about to do a "Choke" video and was doing some research and this popped up! Still confused when I would EVER use an Unun..!! LOL
The only part that I'm missing is how we figure the impedence of the random wire? Do we actually use an ohm meter and test it? Please show me how an antenna anylizer works?? I know I've asked this before but still not getting this part.
We don’t figure the impedance of the random wire. That’s overthinking it. Random wire lengths are known values that are not resonant on the ham bands we want to use. www.hamuniverse.com/randomwireantennalengths.html
@@COASTALWAVESWIRES Thanks for taking the time to answer. After reading that I give up. I'll just stick to buying antennas I guess. I didn't understand any of that article. Now I have all this stuff I bought and nothing to do with it.
@@COASTALWAVESWIRES No I'm done with it. I have a whole box full of stuff I bought since watching your channel. Would you like to buy all of it at a discount? Then I can afford to just buy a Tram mag mount. That's probably the one thing I should have bought instead of all this stuff.
"Drive-by-engineer". As a long time machinist, that got a laugh. Many learned people forgot their beginning and just assume new students already have the teachers basic knowledge. Thanks Walt.
I think the confusion arises between the balun types. Transmission line baluns(to stop common mode current)....a physical wired connection,and transmission line transformers, to match impeadance, through magnetic flux(no physical connection). Perhaps this is a topic for a video all in itself? 73!.
I've been trying to find how to calculate that for years. I've always thought the equation would be way more complex. I thought you'd need to know if the impedance mismatch was capacitive or reactive. Gee so simple.
Please let me know, If I use 1:1 Balun for a 40MB Dipole, By using ATU, Can I use that antenna for 10, 15, or 20MB? Will the performance be good? #VU2XFD
Thank you for your inspiring video. I am starting with HF and have space for a End Fed Random Wire of about 12 meters. I hope this will give me some possibilities on 10, 20 & 40 meter. How do i measure what the impedance of that wire is, so i know what ratio of Unun i need in order to transform it down to 50 Ohms. Thank you and 73's ... Bert
You can calculate the impedance with a VNA (vector analyzer) or by modelling with antenna software but that really isn't needed. there are known values for wire lengths already. check out this video and I think it will answer your questions: ua-cam.com/video/_cL4iHiVoGY/v-deo.htmlsi=vjKTsGkpAza77j-_
Thanks Walt. I’m a new ham and finding simplified information isn’t easy. Too many content creators talk over the new guy’s head. I don’t know if they fear that dumbing it down will cost them views by more experienced operators, or if they just assume that we come in with a certain amount of knowledge. Anyway, I truly appreciate your content. Your DXing videos are what pushed me to get my general ticket and buy a G90. Hopefully I will catch up to you on the air sometime. Thanks and 73!
I think the simplest explanation is that a balun matches a balanced element to an unbalanced element. And an unun matches an unbalance element to another unbalanced element. I hope that helps. 73 Tom KC3QAC
Just getting back into the HF side of the hobby after some 20 years of inactivity. Originally licensed in 1980. This video is a great example of why this is my favorite ham radio YT channel. Thanks much, Walt, and 73. Tim, W4TAF
Thank you, Walt. 🙂 I got the basic thought (matching the feed point impedance to the impedance of the coax, and to what the transceiver expects). However, what I do not yet understand is why the 1st random wire antenna in the video has 300..360 Ohms, whereas th 2nd one has 150..250 Ohms and thus they need different UnUns. The table you showed suggests that it has to do with the length of the driven element, as the ones above 8 m require 9:1 as opposed to the 4:1 of the shorter ones. Is that feed impedance something that one can calculate/measure to make the right choice for the UnUn ratio? If so, how? 🤔
I fail to understand how a coax cable can have an impedance. I can understand ohms per foot because it has capacitance but how can any length of coax have the same impedance?
Hey, me again. Just subscribed. Great channel. Working towards my first ham license in the US. Re the Rybacov, I recall you mentioning in your "10 best..." vid that it is a multiband antenna requiring the use of a tuner and also requires ground radials. In the case of your simple vertical rods inserted in a lawn/ground umbrella with the balun at the bottom, would I be right in assuming the radials should all be connected to the balun ground terminal and radiate out? As I've begun to understand, most verticals one buys commercially tend to have a metal ground plate at the base from which said radials, well, radiate. Thanks in advance.
Yes the radials or let’s call them counterpoise wires are connected to the ground side of the balun. Here’s a video I did a while back that describes “RF ground” which is what you are describing as “radiating”: ua-cam.com/video/KjEOUZS_5sw/v-deo.htmlsi=BJLIZXMHbPqJTrqN
Walt, THANKS! As you know, I have been a long-time Ham, but I am new to building antennas. And you were right. This is the video I needed to watch. I have a list of notes to stick in my POTA case to help me in the field. Thanks again for all you do to help this amazing community. 73s.
I think I get it - then i don't. UnUn makes sense for situations with an unbalanced match (49:1, 4;1 etc.). Then BalUn for 1-1 balance scenario (dipole example). But why would the Delta Loop not use a UnUn? It's 200 ohm t0 50 ohm, using a 4;1. Shouldn't that be an UnUn since it's unbalanced? YOUR CHANNEL HAS BEEN THE MOST HELPFUL/FUN/INFORMATIVE I've found. Can't express my gratitude enough. I'm on the list for a FX-4CR so I can't really start playing.
Oh wait, is the balance relating to the physical design of the antenna rather than the Ohms? Endfed uses an UnUn since the feed point is at the extreme end of the atennas, vs a dipole or delta loop where the feed point is in the physical middle of the antenna, and thus, sues an Balun. That would make sense. I hope I'm correct.
Paired wire, like ladder or Swedish lines, the RF are equal and opposite, balanced. Coax, center wire and shield have different physical characteristics,so have unbalanced RF signals. Right?
Do you have an opinion on ( for receiving only) what UNUN ratio would be good for 200 ft wire antenna with a ground rods on the ground terminal. i want to wind my own UNUN and have a low noise floor
I do know that 203 feet and 9:1 are a good match for a transmitting random wire antenna. You might want to try 9:1 as I'm sure it would probably do well as a receive antenna.
For the $30 an LDG UNUN or BALUN costs, you also get their product literature. This page supplies a nice quick reference chart for which transformer ratio to use with which antenna and when to use a 1:1. The reference is almost worth the $30 by itself!
Thank you for simplifying this for newbs like me. Follow up question: how do you know the impedance of your antenna? Where’d you get 2450 ohms for the end fed half wave?
Check your Balun/Unun. I bought a cheap 4:1 balun and installed it on a 17-5 antenna. Could not get the antenna to work properly. Narrowed the problem down to the balun. Took the balun apart and realized it was wired just opposite. It was a 1:4 instead of a 4:1. Simple to unsolder and rewired. That fixed the problem. SWR on 20 meters was less than 1.5:1. Probably rare problem but it can occur.
Walt, I understand the difference between a choke and a transformer, but on a dipole that's close to 1:1 already (well with the tuner's ability) is one preferred over the other to deal with RF issues?
Hi, I think you might be a little confused. An antenna tuner doesn’t have a balun built into it. It’s all about reducing the impedance down at the feedpoint of the antenna with the balun and then tuning the coax at the other end with the tuner to have a match.
Walt, do you have good luck with the LDG baluns/ununs? I bought a 1:1 choke/unun to prevent RF problems with my portable setups and while it worked for that, it also made my antennas behave in unusual ways. They no longer tuned up correctly at the frequencies they were designed for, so I became suspicious of the choke. So, I attached a 50ohm dummy load to one end and a NanoVNA to the other and was surprised that with the choke inline, the SWR rapidly climbed with frequency, hitting about 2.5:1 on ten meters. I opened up the choke case and found it was rather shoddy inside...and odd choice of winding method, overall sloppy winding, cold solder joints and the core was only supported by the soldered wires. There was a piece of double-sided tape inside, but it wasn't touching the core! This surprised me, as LDG's tuners are build wonderfully, very solid. Anyhow, I replaced the core with a FT-140-43, wound it with 11 bifilar turns (with a crossover winding in the middle) and now the SWR is completely flat across the HF bands. I'm a big fan of LDG and they have been VERY generous to me with their support, in both time spend and even sending replacement parts free of charge. Great company, but this choke was sure a disappointment.
My question is How do you determine the impedance of the driven element to know which Balun or unun to use? Asking for a friend 73 K2RSF, PS Love your channel.
This video helped me for sure. One thing that would have made it the GOAT Bal/Un/Un video would have been to tie in the mantra that you should just try it. Show us the impact of no Bal/Un and then show the beatiful matching impedence after. So, will you still make a contact using a 4 to 1 instead of 9 to 1? Will you make a contact with a 49 to 1 or without?
The real question is “would your transceiver’s tuner tune the antenna with a 9:1 instead of a 4:1 or 49:1” the answer is probably not because the purpose of using a 4:1 versus a 9:1 versus at 49:1 is to make the feedpoint impedance as close to 50 ohms to match the coax and radio. You may even be able to tune one of the others with a different transformer but have greater loss in the coax and out of the antenna meaning not making that contact.
@@COASTALWAVESWIRES the good news is, I totally understand now. In theory anyway. I'll be putting it into practice very soon! Love the videos. Keep em coming.
I find the LDG a little overpriced for what they consist of, but they're nice little packages and seem to work well and reliably, so the convenience is there and I have a few. I made a 1:1 choke balun for dipole and it works fine, but I got to thinking, for my time, I could just buy one.
Question, most of your videos assuming multiband and Ham radio, but with CB gear suddenly a SHTF issue, i keep having people ask me about low profile antennas. The flagpoles with tuners are insanely expensive for what you get. May i request you make up the best performing low profile antenna for CB / 11 meter use and hopefully would do as well at DX as a 10 meter you will already have made. Name the video keyword well and you will get a lot of traffic. You make great videos and are a true walking library of useful info and experience.
I think the confusion comes from people taking two electronics functions and not separating them for teaching. Circuit one is balun. You create a circuit to connect a balanced device to an unbalanced device. i.e. a balanced dipole to an unbalanced coax. Circuit two is an impedance match.
So are baluns and ununs the same a loading coils? Is it just terminology? I'm thinking about the vehicle antennae that are motorized to adjust their length. As I understand it, the loading coils change the electrical length of the antenna wire.
I’m interested in going with my rain gutters (hip roof) on my single story house, does total length of my gutter matter in figuring out the unsung/balan?
It helps to know what unun and balun mean: unun is unbalanced to unbalanced, and of course, balun is balanced to unbalanced. A coax is grounded, it is unbalanced. Think of a teeter-totter, if one side is on the ground it is unbalanced.
A random wire antenna is an end fed antenna but is not a resonant antenna, its length is cut to make it tunable on multi bands. An End Fed Half Wave is a resonant antenna that is cut to a specific resonant frequency or frequencies. So they’re both “end fed” it’s just the terminology that’s used.
@@COASTALWAVESWIRES thank you that helps. If I cut several lengths of wire for several bands and attached all the ends together ate the end of a feed line how far away from each other should the wires be held apart, so that each one would act as an antenna for its band without being interfered with by the other wires? What BALUN or UnUn would be needed?
Good simple explanation, I understand now the need and differences between baluns and ununs and what antennas they are used on. As a shortage listener only, will I notice a difference if I match the balun/ununs to my antenna type?
Simple, explained well for the beginner, your channel is great as its no nonsense to the point with simplicity, well done Walt. Im sure we all appreciate your time.
I've been searching for a while now for a simplistic, concise, yet understandable explanation of UNUNs and BALUNs. You have provided it in this excellent video. Thank you so much for this. Subbed!
A proper 9:1 random wire should not be resonant on any band & requires an ATU, For each band of operation, This why there are non resonant lengths of wire you should use depending on the bands it is to cover.
Roger that, not resonant on any band or it's multiples. I think I may have been a bit confusing as what I was saying was after attaching the 9:1 to the random wire there may be a band or two where you can actually transmit without the ATU as the SWR is under 2:1.
Hi Walt. Happy New Year. I noticed that at 3:58 you said a dipole has an impedance of 50 ohms, but I think that is for an inverted-V antenna. A dipole is 73 ohms. I've heard that many hams in the days of tube rigs used 75 ohm coax (TV type) and just tuned their tube transceivers to match that without a tuner. So with a modern 50 ohm solid-state rigs, would SWR on a resonant dipole be lower when using a 1.5:1 balun instead of a 1:1 balun? This would drop the impedance from 73 to about 50 and produce the lowest possible 1:1 SWR at resonance antenna length for the frequency in use, right?
@@COASTALWAVESWIRES I love the way you explain things in a very approachable way. I definitely learn something from your videos every time I watch them. That's what is great about ham radio. It is a hobby of continuous learning and experimentation. It brings out the playful kid in me......which is a good thing.
The actual feedpoint impedance of a resonant dipole depends on the height of the wires above the ground, how they're routed (straight, bent, angled up, angled down, flat, folded back, sloped, etc) and how conductive your ground is. That's why changing the wire height above ground by going from flat to inverted V changes the impedance. In other words, it is extremely hard to predict, so you can't really say a real life dipole will be 75, 50, 150 or 25 ohms until you put it up and actually measure it.
Thank you, first time I think I understand the difference between UNUN and BALUN. I get lost quickly when David Cassler starts drawing on the whiteboard giving likely correct but very complicated answers to simple questions 😅
Thanks for the great comment!
That’s exactly what I was referring to 😂
Agree with you I don’t care much for Dave. I just can’t relate to him, no disrespect
Different learning styles. I need to have the “why” stuff to internalize information. But I understand that most people learn better with technique vs theory. So this video left me unsatisfied. But it works for many (most) people. Awesome that we have so many Elmers right here in one place (UA-cam)!
@@Frisky0563 I like Dave. He's like a gnome in his workshop trying to explain the hardships of Santa to the elves. Honestly, I mean that in a good way. But yeah, he talks in his language from his perspective. I have noticed that sometimes even he isn't technically correct even if in a practical sense he is. I think it comes down to what people are familiar and comfortable with. I like gnomes. ☺Cheers.
@@mewintle I'm the same way in needing to know the why and how of things for them to fit and stick into their place in my understanding of things to see and figure out how things work in relationship with each other and what needs to be done when. While it isn't perfect of course, things such as the water analogy for electrical circuits have gone a very long way for me. Taking that further, RF is perhaps a bit like sonar... 🙊Cheers.
This is the stuff every other Armature Radio UA-cam channel just glosses over because they think it's common knowledge without thinking of the newbies trying to get into the hobby. Thank you for explaining things in simple terms beginners can understand. This is also the best video I've watched on the subject!
I didn't get into armature radio to nerd flex on other nerds. I'm into armature radio because I'm legitimately excited on how it all works. We all want more people to play radio with. Thank you again for helping more people get into the hobby.
Nerd flex - excellent and absolutely right.
not to nerd flex but armature doesn't mean what you think it does
We live on the far eastern fringe of the Los Angeles area, in San Bernardino County, and my stereo systems AM/FM receiver struggles to pull in even the mighty KFI 640kz signal with their tower located not that far away. Everything else is just noise. So far, I'm just using the wimpy post-card sized wound wire antenna that came with my receiver, which only excels at bringing in noise from our lights and other electronics.
Now I'm no ham operator. I was an avionics tech and airborne radio operator on USCG aircraft in the distant 70's, and I've been a fan of the AM band, static and all, since I was a kid.
I recently found a Radio Shack longwire antenna kit amid my garage debris, and thought I might string it up on the roof, going from one chimneys the other and then across the roof a bit more. The twisted copper antenna wire in the kit is about 75-80 feet long. Way short for full wave or even half wave
So I'm not TXing here, just RX. Should I go with the full 80 feet or trim it down?
To use the full length, I'd have to dog-leg it, up to 90 degrees or so. Would this degrade my reception, or possibly improve off axis reception?
I'll be using maybe 20 feet of 50 ohm coax for a lead-in. Would I benefit from a unrun? (Something I never even heard of before).
Anyway, any help is greatly appreciated. Great and Informative video.
George
Rancho Cucamonga, CA
Good explanation. Many former Elmer's are smiling down on you from the great beyond. I agree that the KISS way of explaining things is the best approach.
Thank you so much! 73, Walt
Many years ago (during my CB days) I learned a balun can be a really neat thing. But you have to be willing to experiment a little. Someone gave me a 4-element beam which had an insulated dipole driven element with a hairpin match (He did not know how to feed it). Not wanting to try and feed it directly with coax (did that with another similar beam one time with poor results), I decided to try and feed it with a 1:1 balun. Since the dipole driver would have a 75-ohm feed point impedance, I connected the balanced side to the hairpin, and used 75-ohm coax to feed it (not CATV coax). All I can say is 'wow'! Not only did the antenna work very well, it was also the quietest antenna I have ever had. The SWR measured at 1.3:1, and I could hear signals others could not, especially in dry-air Santa Ana conditions when the air becomes 'charged' and a lot of static is present. The hairpin match provided an awesome DC ground which, in combination with the balun, provided a virtually noise-free beam. I used it for many years before a wind finally blew it down. Wish I still had it!
Nicely explained. I understand them now, bit of a mystery before. Now I'm motivated to build one.
I especially liked the use of the hands and arms to demonstrate the matching of the antenna and feedline... ;)
Hahaha I’m one of those guys that talks with my hands.
thank you at last someone who gives it over simply.
Thank you so much for watching! 73, Walt
Thank you… my confusion is no longer there. Your explanation is simple and correct. Your material (IMO) should be thought and provided in our question pools. So many ridiculous questions that are not relevant. 🎙️W1FYG
Thanks so much for the kind words my friend! Hope you are doing well.
Great explanation on baluns/ununs.....thanks!! For wire antennas though, are baluns and ununs primarily just a tool for connecting the wire to the coax....and doing that in a way that will closely match up the two with a transformer, (as well as to keep RF from making its way back to the radio)? I have my first HF radio on the way, and I ordered a manual tuner as well, since I thought it was a good idea to always use one. If I'm understanding correctly, the two options are....1) to use a balun/unun so you don't need a tuner and 2) to use a tuner with a choke so you don't need a balun/unun and just connect with a banana clip? In other words....using balun/ununs keeps the equipment to a minimum and gets you on the air quicker? Seems obvious now that I think about it.....but confirmation that I'm thinking correctly is appreciated.
Very nice simple to understand explanation.
Thank you!
And here I was scared you were going to pull up a Smith chart(kidding!). Thanks for the simplified approach of impedance matching coax/feed line to the antenna.
hahaha thanks for watching!
The Delta Loop raw impedance is closer to 100 ohm than 200 ohm. I've had better luck with a 2:1 balun and no tuner. Nevertheless a 4:1 balun will work... Txs for the video, very useful and well made. Keep on the great work!
Yes that was just a general overview to explain impedance. Thanks for watching!
Excellent, simple overview! Very helpful Walt! KC1RVK
Thank you!!!!
Thanks for another really informative video. Where did you find that chart of the wire lengths and corresponding transformer? Also do you have a video showing when you might need a counterpoise, vs radials? Now that the weather is a little nicer I’m going to actually start building these antennas.
Excellent explanation! I really enjoy all your videos, cheers!
Thank you! 73, Walt
thanks for the post, as always it was very helpful.
Thanks for watching!
Nice overview, Walt.
Thanks Mike!!!
Good overview on baluns 😊
Thank you!
Big Thanks!!!!
Thanks for watching!
Hi Walt, Happy New Year!! Hop you had a great Christmas too!! 73's VK5FCHM.
Thank you and Happy New Year! I had a great Christmas, hope you did as well my friend! 73
Nicely explained:)
Thank you!
Very interesting & detailed vlog, Walt. Thankyou very much. 73 de Pete GI0FZT.
Thank you Pete! 73 my friend!
Thanks!
Thank you so very much for supporting the channel!! All the best and 73, Walt
How do you know or calculate impedance of the antenna at the connection point?
Great question, you can use a VNA, antenna analyzer or you can model it in a software application but really you don’t need to do that. It’s known lengths that have already been determined over years and years. For instance a halfwave antenna requires a 49:1 unun, random lengths of 29’, 35.5’, 41’ etc require a 9:1 for shorter random wires 25’, 20.5’, 17.5’ use a 4:1 and a perfect Quarterwave antenna should have a perfect 50 ohm match and thus a 1:1
Thanks for explaining that. Drive by Engineers HAHAHAHAHA
dBe hahahaha
If i just want to listen to hf on an sdr would i need an unun? To be more specific, running an end fed antenna across my back yard.
No you will be fine for just receiving
@@COASTALWAVESWIRES Cool, thank you, just diving in to all this
Ok how do you know or measure the Impedance of your random wire antenna? So you can pick an UNUN.
www.hamuniverse.com/randomwireantennalengths.html
@@COASTALWAVESWIRES thanks’ again. You are the best!!
As a noob, I also want to make my own unun. I got a unun kit from China for $11. Now to make the balanced line for 50 ohms from my connect point. At, least I think it is all about the windings around the magnets. Anyone for comments?
Transformer: it transforms what in to what?
4 hours before my amature radio exam tonight.. the text book gave a way too complex explanation, so your 9 minutes here may have saved my bacon :)
Great explanation Walt, concise and to the point to help beginners understand the fine points of antenna building. This is why I really like and recommend the videos on your channel. Also that's a nice Hammarlund in the background, I have an HQ-160 that I have had since my teen years in the mid 1970s! I started out with it listening to shortwave in my teens and it stoked my interest in ham radio.
Thanks! I was heavily into shortwave in my teens as well. I got that HQ-180 by luck a couple years ago. My neighbor across the street found it in his attic and gave it to me.
I did SWL as a teen as well using a Heathkit. It later got me interested in ham radio as well.
@redstickham6394
@COSTALWAVESWIRES
Similar situation here. I listened to short-wave in the late 1960s getting many DX broadcast stations using a long wire antenna in my parents attic. But I didn't get into Ham radio until very recently.
Some friends use the autotuner and a 9' whip on their trucks to operate HF. I would like to find out how they compare with the Hustler.
New guy here. Trying to build my shack and scared to death of lightning strikes as we get them fairly regularly. Antennas seem to be the most complicated part of radio. Proper grounding is the concern I'm trying to learn about most.
Earth grounding is important for permanent installs. Most of what I'm showing here are portable antennas.
Thanks for being "not that guy" and wanting to help people, not elevating yourself!
Thank you! 73, Walt
I agree he's my favorite to watch
In aviation we call the tuner an antenna coupler. I always like that name as a better description of what it actually is doing. 73
I absolutely agree! 73
It is a coupler when the antenna is directly connected to the "output" end of the device. The coupler is typically remotely operated.
If the matching device is close to the radio, and directly controlled, then it is a tuner.
How about current and voltage baluns? Thanks for a great video! 73 SM6YEC
I used to stomp around OB! I miss Newport, and sunset cliffs.
So they're just like DI boxes in audio engineering
That transformer is a robot in disguise.
Hahaha a magic robot!
Walt.. Thanks for this.. I'm about to do a "Choke" video and was doing some research and this popped up! Still confused when I would EVER use an Unun..!! LOL
Thanks for watching Callum! Yes you definitely do not need an unun with your antennas hahaha All the best and 73 my friend!
Un is unbalanced and Ba is balanced, nice !
The only part that I'm missing is how we figure the impedence of the random wire? Do we actually use an ohm meter and test it? Please show me how an antenna anylizer works?? I know I've asked this before but still not getting this part.
We don’t figure the impedance of the random wire. That’s overthinking it. Random wire lengths are known values that are not resonant on the ham bands we want to use.
www.hamuniverse.com/randomwireantennalengths.html
@@COASTALWAVESWIRES Thanks for taking the time to answer. After reading that I give up. I'll just stick to buying antennas I guess. I didn't understand any of that article. Now I have all this stuff I bought and nothing to do with it.
@mobiltec don’t give up, I think you’re just overthinking it. Take that stuff, build antennas and make them work. That’s what it’s all about
@@COASTALWAVESWIRES No I'm done with it. I have a whole box full of stuff I bought since watching your channel. Would you like to buy all of it at a discount? Then I can afford to just buy a Tram mag mount. That's probably the one thing I should have bought instead of all this stuff.
"Drive-by-engineer". As a long time machinist, that got a laugh.
Many learned people forgot their beginning and just assume new students already have the teachers basic knowledge. Thanks Walt.
Thank you!! 73, Walt
I think the confusion arises between the balun types.
Transmission line baluns(to stop common mode current)....a physical wired connection,and transmission line transformers, to match impeadance, through magnetic flux(no physical connection).
Perhaps this is a topic for a video all in itself? 73!.
Yes indeed, was trying to make this one very simple.
@COASTALWAVESWIRES of course, I have to re-read my own comments, just to make sure I have it right myself hihi. Keep em' coming, 73.
I've been trying to find how to calculate that for years. I've always thought the equation would be way more complex. I thought you'd need to know if the impedance mismatch was capacitive or reactive. Gee so simple.
Thanks for watching! 73, Walt
Please let me know, If I use 1:1 Balun for a 40MB Dipole, By using ATU, Can I use that antenna for 10, 15, or 20MB? Will the performance be good? #VU2XFD
Yes you will be able to use it on all those band with an ATU. You probably won't even need the ATU on 15. 73, Walt
I didn't even need to watch the whole thing and knew this video was needed. Thanks Walt for putting it together. Great primer for LDG products!
Thanks!!!
Thank you for your inspiring video. I am starting with HF and have space for a End Fed Random Wire of about 12 meters. I hope this will give me some possibilities on 10, 20 & 40 meter. How do i measure what the impedance of that wire is, so i know what ratio of Unun i need in order to transform it down to 50 Ohms. Thank you and 73's ... Bert
Hi Bert, checkout this website. It will give you a better understanding:
www.hamuniverse.com/randomwireantennalengths.html
Thank you so much for your explanation! K7AMJ
Thanks for watching! 73, Walt
How do you calculate the impedance of a wire antenna.
Also when do you use an unun vs. a balun?
You can calculate the impedance with a VNA (vector analyzer) or by modelling with antenna software but that really isn't needed. there are known values for wire lengths already. check out this video and I think it will answer your questions: ua-cam.com/video/_cL4iHiVoGY/v-deo.htmlsi=vjKTsGkpAza77j-_
Thanks Walt. I’m a new ham and finding simplified information isn’t easy. Too many content creators talk over the new guy’s head. I don’t know if they fear that dumbing it down will cost them views by more experienced operators, or if they just assume that we come in with a certain amount of knowledge. Anyway, I truly appreciate your content. Your DXing videos are what pushed me to get my general ticket and buy a G90. Hopefully I will catch up to you on the air sometime. Thanks and 73!
I think the simplest explanation is that a balun matches a balanced element to an unbalanced element. And an unun matches an unbalance element to another unbalanced element. I hope that helps. 73 Tom KC3QAC
Roger that!
Can I make a 20M EFHW with a 49:1 balun?
Yes I actually have a few videos doing this as a vertical antenna
Thank you for delivering! Great video as always Walt.
Thank you for watching and commenting!
please also explain what baluns also do to choke transmission line current
Did a video on that:
ua-cam.com/video/8nMorH3UKzg/v-deo.htmlsi=WoN9w0JxWdb4HLMi
Just getting back into the HF side of the hobby after some 20 years of inactivity. Originally licensed in 1980. This video is a great example of why this is my favorite ham radio YT channel. Thanks much, Walt, and 73.
Tim, W4TAF
Really useful presentation thank you
Thank you! 73, Walt
Great explanation Walt. Thanks.
Thank you! 73 my friend
Thank you, Walt. 🙂 I got the basic thought (matching the feed point impedance to the impedance of the coax, and to what the transceiver expects). However, what I do not yet understand is why the 1st random wire antenna in the video has 300..360 Ohms, whereas th 2nd one has 150..250 Ohms and thus they need different UnUns. The table you showed suggests that it has to do with the length of the driven element, as the ones above 8 m require 9:1 as opposed to the 4:1 of the shorter ones. Is that feed impedance something that one can calculate/measure to make the right choice for the UnUn ratio? If so, how? 🤔
Wait - seems like my question is obsolete: I just found your other videos "Antenna Wire Length - Demystifying Feedpoint Impedance" ... 🙂
Oh that’s great and thank you for supporting the channel!!! 73, Walt
I fail to understand how a coax cable can have an impedance. I can understand ohms per foot because it has capacitance but how can any length of coax have the same impedance?
Hey, me again. Just subscribed. Great channel. Working towards my first ham license in the US. Re the Rybacov, I recall you mentioning in your "10 best..." vid that it is a multiband antenna requiring the use of a tuner and also requires ground radials. In the case of your simple vertical rods inserted in a lawn/ground umbrella with the balun at the bottom, would I be right in assuming the radials should all be connected to the balun ground terminal and radiate out? As I've begun to understand, most verticals one buys commercially tend to have a metal ground plate at the base from which said radials, well, radiate. Thanks in advance.
Yes the radials or let’s call them counterpoise wires are connected to the ground side of the balun. Here’s a video I did a while back that describes “RF ground” which is what you are describing as “radiating”: ua-cam.com/video/KjEOUZS_5sw/v-deo.htmlsi=BJLIZXMHbPqJTrqN
@@COASTALWAVESWIRES Great, thank you! Nice to know I'm at least along the right lines. I'll check it out :-)
Hey man, thank you for this video. Very helpful. I’m an SWL trying to learn more about antennas. TYFP!
Thanks for a no nonsense, no ego video. One of my favourite channels. 👍🏻
Thank you so very much! 73, Walt
Walt, THANKS! As you know, I have been a long-time Ham, but I am new to building antennas. And you were right. This is the video I needed to watch. I have a list of notes to stick in my POTA case to help me in the field. Thanks again for all you do to help this amazing community. 73s.
I think I get it - then i don't. UnUn makes sense for situations with an unbalanced match (49:1, 4;1 etc.). Then BalUn for 1-1 balance scenario (dipole example). But why would the Delta Loop not use a UnUn? It's 200 ohm t0 50 ohm, using a 4;1. Shouldn't that be an UnUn since it's unbalanced? YOUR CHANNEL HAS BEEN THE MOST HELPFUL/FUN/INFORMATIVE I've found. Can't express my gratitude enough. I'm on the list for a FX-4CR so I can't really start playing.
Oh wait, is the balance relating to the physical design of the antenna rather than the Ohms? Endfed uses an UnUn since the feed point is at the extreme end of the atennas, vs a dipole or delta loop where the feed point is in the physical middle of the antenna, and thus, sues an Balun. That would make sense. I hope I'm correct.
You are correct! But it doesn’t necessarily have to be in the middle, an OCF dipole uses a balun as well.
Paired wire, like ladder or Swedish lines, the RF are equal and opposite, balanced. Coax, center wire and shield have different physical characteristics,so have unbalanced RF signals. Right?
Another great video. Would love if you did a basic video on how to get the G90 on the air and what sets to start at and what they do.
Thanks! I will try to di that soon.
That would be awsome! Thank you@@COASTALWAVESWIRES
Do you need either if your match is flat?
No, not if you have a good match
Do you have an opinion on ( for receiving only) what UNUN ratio would be good for 200 ft wire antenna with a ground rods on the ground terminal. i want to wind my own UNUN and have a low noise floor
I do know that 203 feet and 9:1 are a good match for a transmitting random wire antenna. You might want to try 9:1 as I'm sure it would probably do well as a receive antenna.
OK Thank You.@@COASTALWAVESWIRES
For the $30 an LDG UNUN or BALUN costs, you also get their product literature. This page supplies a nice quick reference chart for which transformer ratio to use with which antenna and when to use a 1:1. The reference is almost worth the $30 by itself!
Does an antenna’s impedance change with frequency?
A measured end fed antenna for one band must be a random wire antenna for any other band?
Yes, impedance absolutely changes with frequency.
@@COASTALWAVESWIRES thank you
This is the best explanation I've gotten, I think I finally understand it! Thank you and 73 de KC1JMH
Thanks so much for watching and commenting! 73, Walt
Thank you for simplifying this for newbs like me. Follow up question: how do you know the impedance of your antenna? Where’d you get 2450 ohms for the end fed half wave?
Check your Balun/Unun. I bought a cheap 4:1 balun and installed it on a 17-5 antenna. Could not get the antenna to work properly. Narrowed the problem down to the balun. Took the balun apart and realized it was wired just opposite. It was a 1:4 instead of a 4:1. Simple to unsolder and rewired. That fixed the problem. SWR on 20 meters was less than 1.5:1. Probably rare problem but it can occur.
Walt, I understand the difference between a choke and a transformer, but on a dipole that's close to 1:1 already (well with the tuner's ability) is one preferred over the other to deal with RF issues?
Are you considering that a tuner has a 4 to 1 balun built in would one then be using two baluns and is that advisable ?thanks for video
Hi, I think you might be a little confused. An antenna tuner doesn’t have a balun built into it. It’s all about reducing the impedance down at the feedpoint of the antenna with the balun and then tuning the coax at the other end with the tuner to have a match.
@@COASTALWAVESWIRES thanks for reply
Walt, do you have good luck with the LDG baluns/ununs? I bought a 1:1 choke/unun to prevent RF problems with my portable setups and while it worked for that, it also made my antennas behave in unusual ways. They no longer tuned up correctly at the frequencies they were designed for, so I became suspicious of the choke. So, I attached a 50ohm dummy load to one end and a NanoVNA to the other and was surprised that with the choke inline, the SWR rapidly climbed with frequency, hitting about 2.5:1 on ten meters. I opened up the choke case and found it was rather shoddy inside...and odd choice of winding method, overall sloppy winding, cold solder joints and the core was only supported by the soldered wires. There was a piece of double-sided tape inside, but it wasn't touching the core! This surprised me, as LDG's tuners are build wonderfully, very solid. Anyhow, I replaced the core with a FT-140-43, wound it with 11 bifilar turns (with a crossover winding in the middle) and now the SWR is completely flat across the HF bands. I'm a big fan of LDG and they have been VERY generous to me with their support, in both time spend and even sending replacement parts free of charge. Great company, but this choke was sure a disappointment.
My question is How do you determine the impedance of the driven element to know which Balun or unun to use? Asking for a friend 73 K2RSF, PS Love your channel.
This video helped me for sure. One thing that would have made it the GOAT Bal/Un/Un video would have been to tie in the mantra that you should just try it. Show us the impact of no Bal/Un and then show the beatiful matching impedence after.
So, will you still make a contact using a 4 to 1 instead of 9 to 1? Will you make a contact with a 49 to 1 or without?
The real question is “would your transceiver’s tuner tune the antenna with a 9:1 instead of a 4:1 or 49:1” the answer is probably not because the purpose of using a 4:1 versus a 9:1 versus at 49:1 is to make the feedpoint impedance as close to 50 ohms to match the coax and radio. You may even be able to tune one of the others with a different transformer but have greater loss in the coax and out of the antenna meaning not making that contact.
@@COASTALWAVESWIRES the good news is, I totally understand now. In theory anyway. I'll be putting it into practice very soon! Love the videos. Keep em coming.
@@tsp2jxd thanks! Hope to catch you on the air!
I find the LDG a little overpriced for what they consist of, but they're nice little packages and seem to work well and reliably, so the convenience is there and I have a few. I made a 1:1 choke balun for dipole and it works fine, but I got to thinking, for my time, I could just buy one.
Question, most of your videos assuming multiband and Ham radio, but with CB gear suddenly a SHTF issue, i keep having people ask me about low profile antennas. The flagpoles with tuners are insanely expensive for what you get. May i request you make up the best performing low profile antenna for CB / 11 meter use and hopefully would do as well at DX as a 10 meter you will already have made. Name the video keyword well and you will get a lot of traffic. You make great videos and are a true walking library of useful info and experience.
Finally I understand thanks 🙏🏻 👍🏻👍🏻
Thanks for watching!
Thank you for taking the time to make, explain and publish the video.
Thank you for taking the time to watch!
I think the confusion comes from people taking two electronics functions and not separating them for teaching.
Circuit one is balun. You create a circuit to connect a balanced device to an unbalanced device. i.e. a balanced dipole to an unbalanced coax.
Circuit two is an impedance match.
I'm in Massachusetts, love to drive down and watch you operate someday as a newbie.
So are baluns and ununs the same a loading coils? Is it just terminology? I'm thinking about the vehicle antennae that are motorized to adjust their length. As I understand it, the loading coils change the electrical length of the antenna wire.
Which one will work best for an indoor speaker wire antenna for connection to an IC-705?
I’m interested in going with my rain gutters (hip roof) on my single story house, does total length of my gutter matter in figuring out the unsung/balan?
With gutters it's pretty much trial and error. I would start with a 9:1 unun, that's probably going to give you your closest match.
@@COASTALWAVESWIRES unsung vs unun…stupid spellcheck lol
@@celebmrk9 hahaha I knew that was what happened
It helps to know what unun and balun mean: unun is unbalanced to unbalanced, and of course, balun is balanced to unbalanced. A coax is grounded, it is unbalanced. Think of a teeter-totter, if one side is on the ground it is unbalanced.
What is the difference between an End Fed antenna & and Random Wire antenna?
A random wire antenna is an end fed antenna but is not a resonant antenna, its length is cut to make it tunable on multi bands. An End Fed Half Wave is a resonant antenna that is cut to a specific resonant frequency or frequencies. So they’re both “end fed” it’s just the terminology that’s used.
@@COASTALWAVESWIRES thank you that helps. If I cut several lengths of wire for several bands and attached all the ends together ate the end of a feed line how far away from each other should the wires be held apart, so that each one would act as an antenna for its band without being interfered with by the other wires?
What BALUN or UnUn would be needed?
LDG sadly don't seem to make a lot of their products anymore they all appear to be discontinued.
If you're building an antenna, how do you know what the feed point impedance is going to be? Is there a formula to calculate it or something?
Good simple explanation, I understand now the need and differences between baluns and ununs and what antennas they are used on. As a shortage listener only, will I notice a difference if I match the balun/ununs to my antenna type?
Simple, explained well for the beginner, your channel is great as its no nonsense to the point with simplicity, well done Walt. Im sure we all appreciate your time.
Thank you so very much! 73, Walt
I've been searching for a while now for a simplistic, concise, yet understandable explanation of UNUNs and BALUNs. You have provided it in this excellent video.
Thank you so much for this. Subbed!
Thanks for subscribing!
How do you find the input impedance at the feed point of the antenna to know what balun/unun to use?
A proper 9:1 random wire should not be resonant on any band & requires an ATU, For each band of operation, This why there are non resonant lengths of wire you should use depending on the bands it is to cover.
Roger that, not resonant on any band or it's multiples. I think I may have been a bit confusing as what I was saying was after attaching the 9:1 to the random wire there may be a band or two where you can actually transmit without the ATU as the SWR is under 2:1.
@@COASTALWAVESWIRES If it is under 2:1 VSWR, Then the random wire length is not correct.
@@TantalicdavidIt could be. What's the reason it shouldn't be? It could be a perfect 450 ohm load on one of the bands. Or maybe even more than one.
@@paulsengupta971 If it is then the wire length is wrong, A proper 9:1 random wire should not be resonant on any of the band & requires an ATU
Hi Walt. Happy New Year. I noticed that at 3:58 you said a dipole has an impedance of 50 ohms, but I think that is for an inverted-V antenna. A dipole is 73 ohms. I've heard that many hams in the days of tube rigs used 75 ohm coax (TV type) and just tuned their tube transceivers to match that without a tuner. So with a modern 50 ohm solid-state rigs, would SWR on a resonant dipole be lower when using a 1.5:1 balun instead of a 1:1 balun? This would drop the impedance from 73 to about 50 and produce the lowest possible 1:1 SWR at resonance antenna length for the frequency in use, right?
Yes that was just a simple explanation example, in theory you are correct.
@@COASTALWAVESWIRES I love the way you explain things in a very approachable way. I definitely learn something from your videos every time I watch them. That's what is great about ham radio. It is a hobby of continuous learning and experimentation. It brings out the playful kid in me......which is a good thing.
close enough@@COASTALWAVESWIRES
The actual feedpoint impedance of a resonant dipole depends on the height of the wires above the ground, how they're routed (straight, bent, angled up, angled down, flat, folded back, sloped, etc) and how conductive your ground is. That's why changing the wire height above ground by going from flat to inverted V changes the impedance. In other words, it is extremely hard to predict, so you can't really say a real life dipole will be 75, 50, 150 or 25 ohms until you put it up and actually measure it.
Nicely done Walt! Thanks, Don / KM4SON
Thanks Don!!
Hey Walt - a masterful job. These aspects of antennas, etc. always seem to elude me, but NOT anymore! Thanks, be well and 73, Rich W2FKN
Thank you for the kind words Rich! 73 my friend