Antenna Wire Length - Demystifying Feedpoint Impedance
HTML-код
- Опубликовано: 26 апр 2024
- A simple discussion on antenna wire lengths, feedpoint impedance and which balun or unun to use. #hamradio #hamradioantenna #antenna
Link to the FireStik SWR chart:
www.firestik.com/Tech_Docs/SWR...
Link to the Random Wire Antenna site mentioned:
www.hamuniverse.com/randomwir...
Link to @TheSmokinApe video and channel mentioned:
• Impedance and Ham Radi...
This is the only video I have seen that would inspire a new Ham to actually build their own antenna. Am an older ham and I am excited to try out your recommendations. This is what Amateur Radio should be all about. Thank you very much...
Oh wow, thank you so very much! 73, Walt
You never know what you can do with some wire and insulators!
Wonderful video and illustrations Walt. I know it answered a lot of questions I have had concerning building antennas. Keep up the good work!
Drive by expert here: I got nothin', you nailed it out of the park and I learned quite a bit.
Thanks Walt!
73
😁
Haha thank you my friend!
It's great to see some one who explains the technology in easy to understand terms. So many tutorials are geared to the already experienced and goes completely over a new hams head. In my 47+ years I have always tried to teach on the level of the student. Great job! By the way, I may be an "old dog" but you have taught me a new trick or two as well. Hi Hi! Keep up the great work. 73s DE wb7veq
Thank you so very much! The one thing about physics, engineering and almost anything that involves science is that humans will overthink it. I really just try to keep everything simple. 73 my friend
This video reminded me of the radiomen in the Navy while tuning up the FRT-39s. They had to drive the PA, then use dials connected to the caps and coils while looking at voltage and current meters. (basically tuning the antenna) Occasionaly they would connect the wrong antenna, get high SWR and the caps would start snapping and arcing. It would scare the crap outta them.
I always feel like I'm starting to get a grab on this after watching your videos, Walt.
Yours are the best for simple, practical explanations. This one really is excellent.
Thanks for this.
merci beaucoup Alain! 73, Walt
This was the most common sense and easy to understand explanation on this topic I’ve ever seen/heard. Thank you!
Thank you for watching and for your kind words! 73, Walt
Learning to use the antenna analyzer in sweep mode really helped me to see what was going on with my antennas. Thanks for all the helpful information.
Thanks for watching and commenting! 73, Walt
I watch a lot of videos to further my education on antennas and some of those old guys are real smart but have the most horrible drawings and handwriting, you have the cleanest illustrations and I know it may be a small thing, but I really appreciate being able to make out what you are drawing. Hey that brown Uke behind you looks a lot like my mahogany Martin Tenor! Aloha , AL
Thanks! That uke is an old Conqueror that belonged to my wife’s father. It’s a special one for me.
Thanks Walt. You hit a good one today. As a newer licensed ham, you see people using these all over RUclips, but no explanations as to why or under what Circumstances they should be used. This is a good basic intro and I for one will be culling through this video numerous times and taking notes. Love the background. It looks to me like you love your instruments as much as the radio. I have the same bug with a wide collection of stringed instruments. My strum stick is my late night just before bed go to for playing. 73’s my friend.
Thanks for the kind words. Yes I have the strumstick addiction too my friend. All the best my friend. Keep on strumming and hamming! 73, Walt
I agree, amazing work you have done with inexpensive equipment, g90 and all your antennas. I love the g90 radio. AA2BD thx. 73
@@revbikerbigd8664 thank you so much my friend!
Excellent video Walt. You explained the basics very well. If people watching have questions, I suggest they do research before making stupid comments. I love low cost, homemade antennas that work and you show so many very good ones. You don't need to spend $200. to $500. for the latest "New" or "Tactical" antenna to make solid contacts, especially when working portable. Thank Walt ! 73
Thank you so much! 73, Walt
Thanks again Walt! Great information. I know manual tuners aren't popular these days but making and using one really does help a person understand theory and practice of how matching works.
Thanks! I agree
Great video getting into the thick of things. Not exactly an adventure in the typical sense, but a productive exploration all the same. Thanks. Cheers and 73!
Thank you and cheers! Walt
Great information. I got a little distracted by the cigar box guitars. Love it!
Thanks! I’ve been building CBGs for a few years. I’ve got a couple from other builders as well. Fun to play.
My daughter and I built one a few years ago for a school project. I almost enjoy playing it more than my six string. They're such a versatile instrument. Enjoy your videos, keep them coming, please. I've been studying for my technician license and hope to be on the air soon.
@johnbonner4430 thank you! Good luck and hope to catch you on the air soon my friend
@@COASTALWAVESWIRESI think you need to do video overview on them and their construction!
Walt, the difference between your videos and other guy's videos is, I don't have to fight falling asleep while watching and listening to their 'dull' presentations. You keep it lively and chuckle from time to time. Others? Not so much. I'm brand new to HF and am soaking up all I can, especially from your videos. Thanks for making the un-understandable understandable.
Thanks so much for the very kind words! 73 my friend
Super helpful. Thanks, Walt. Always look forward to your videos.
Thank you so very much! 73, Walt
My god this made more sense than anyone else has explained thank you so much brilliant again...this is the way of the ham
Thank you my friend! 73, Walt
One of my favorite, lowly wire antennas for POTA is the multiband 29’ EFRW with the 9:1 unun. It’s quick to set up and effective.
Thanks Walt. You made this really easy to understand and I look forward to using this info for my antenna projects and experiments. That's half the fun of HF for me. 73
Thanks for watching and for the kind words! 73 my friend
Thanks for yet another great video that stays out of the weeds. Greatly appreciated.
Thank you very much for watching! 73, Walt
Less-young (78) ham here and I keep learning from you every video. Love your enthusiasm for our fantastic hobby. You also encourage me to try new antennas so when I go off in my caravan in a few days I'll be trying a wire vertical or two. Maybe see you on the Southern Cross 14238 net again. 73 from VK4BOB
Hi Bob! I’ve been tuning in to the Southern Cross Net as much as possible. I can guarantee to will catch me there soon as conditions are starting to favor it. 73, Walt
My brother and I just had this conversation. Good info.
Thank you!!
Walt - really appreciate how you use simple gear and are constantly experimenting. I recently set up an end-fed 41’ random wire with a 9:1 Unun. Pretty good results. After adding a 1:1 Unun RF choke, I was surprised by the improvement. Now getting tons of international QSOs on 5W. I recognize this antenna knowhow is widely available, but you make it accessible and approachable. Thanks and keep up the great videos.
Thank you so much for the kind words my friend! 73, Walt
I put up a 20 meter long wire cut to length, using the nanovna-f, don't get me wrong it did work but not effectively. Till i learned about reactance. Swr was not every thing , resistance and capacitive balancing was quickly learned about. I guess digging deeper helped me understand why just swr is just a reference to other values. As i understand tuners are great given compromise antennas, however I wanted not to waste energy as heat. Great tutorial !
So down the rabbit hole I go again. Lol 😊
That's another very useful summary video, Walt. Saved for future reference ! 73, Pete
Thank you Pete! 73 my friend
Well done Walt, another informative video. Keep up the good work.
Well said and explained, I have done some 12K miles contacts on garbage antennas I made in the past.
Thanks for the breakdown! Love the CBGs on the wall!
As always Walt a great video with great info. Sometimes hams need to use compromise antennas such as myself, people need to realise not all have the space to put antennas up, i have a random wire that runs up a 12 meter pole that is strapped against a tree yet i have contacts from around the world... for me the Unun's work along with the Baluns. Im on air so thats what counts. You have great info Walt, thanks and 73 de ZL1MY
Thank you so much for the kind words my friend! 73, Walt
I always enjoy your videos, but sometimes they are especially informative. Thanks!
Thank you and thank you so very much for supporting my channel!!!! 73, Walt
Great video. Thank you very much, Walt. I watch your videos the most. I made my first DX contact yesterday with Maritime Mobile Service Network using your 29 ft vertical, 9:1 unun, 1:1 unun, with the classic DX Commander design. The net control operator was in Texas. I used the Xiegu G90 at 20 watts. I was using the flagpole tire support to support the DX Commander pole on my back deck. I used weights as an anchor. You have a treasure of information and it helped me very much. It was simple and it worked great.
Thank you and it so awesome you made your first DX contact! Congratulations! There will be many many more to come! 73, Walt
Well done Walt. Love your antenna projects...
Thank you so much my friend!
Walt, not only are your explanations great, your drawings are works of art. Have you ever considered publishing an antenna design booklet? I'd buy one!
Thanks so much! Yes I’m actually putting my sketchbook together and will definitely self publish it. Hopefully I can find the time to finish it soon. I appreciate your kind words my friend! 73, Walt
@@COASTALWAVESWIRES I'm so happy to hear that, Walt. I hope this serves as a tiny incentive. Posters would be cool, too. Pin-ups for nerds, hi, hi. Looking forward to that first QSO, my friend. 73, N7BWB
This information is GOLD. Thank you for taking the time to make it.
Most needed video ever! Many thanks once more!
Thank you for watching and for the great comment! 73, Walt
Great video Walt, thank you.
Thank you very much! 73, Walt
Excellent work, Walt! Thanks so much!
Thank YOU so much!
Good video man. You are killing it as always. Lots of great advice.
Thank you my friend! 73, Walt
I love your videos. Keep up the good work!
Thank you very much! 73, Walt
Another great video. Thanks Walt.
Thank you so much! 73, Walt
It is a delightful explanation into each type of antenna and the matching feed-line impedance. I have now built ten different antennae for my amateur fun and this is a great place to start! Thanks for the great video!
Great video! I go back to them all the time. Thanks for sharing.
Thank you so much! 73, Walt
Crawl by amateur here, another good vid, Walt. I always enjoy the results of your experiments. I'm getting antsy to get outdoors and play portable radio too. Still kinda winter here in New England.
Thanks! It’s winter one day summer the next here in the Mid-Atlantic
Excellent video Walt.
Thank you very much! 73, Walt
Great video Walt!
Thank you! 73, Walt
Thank you Walt. Your videos are always very helpful. I appreciate what you do and the time you take to do it.
Thank you for the kind words! 73, Walt
Excellent explanation Walt !! 😉👍
Thank you! 73, Walt
thanks Walt best explanation ever
Thank you! 73, Walt
Well done Walt. I keeping watching and learning and then forgetting...is it an age thing? Then i have to watch again. All good fun. cheers 😅😊
THANK YOU!!!!! Very helpful to me.
Thanks for watching! 73, Walt
Excellent video and one of my favorite Ham channels. Thank you for this explanation. I'm new to amateur radio and you're videos have helped me tremendously with antenna building and understanding terminology and theory.
Walt thanks for spreading the truth. Slightly compromised antennas are great, only compromised by an unnoticeable amount. That means they WORK. I have used 29 foot wire with my home-built 49:1 unun on multiple successful portable adventures. Also other wire lengths for avoiding resonant wires, and the tuner makes it work GANGBUSTERS. Thanks Walt for encouraging people to try and see for themselves. It WORKS if you follow basic principles. And it's FUN. Keep striving, keep trying, keep having fun, Dave WA4NID
Fantastic information and without getting dizzy friend -👍.
You do great work and on top of that you demonstrate its positive results.
It's a pleasure to follow you.
Thank you very much for the kind words! 73, Walt
Dude, you nailed it. Am recommending this video....
Thank you so very much!
Thank you, helped this rookie a bunch.
Thanks for watching! 73, Walt
Thanks Walt this is the explanation I needed!
Thanks for watching! 73, Walt
I really enjoy your videos. Have always enjoyed tinkering with wires. Those who tout resonate antennas seldom have a resonate match. Love my tuners. The proof is in the received signal that peeks when tuned. I've seen test that prove that theres little to no loss in a tuner in the hf bands. I'm down with medical issues so going out with you, through RUclips is great. Keep them comming!
Walt, thanks! Learning more with every video you produce.
AC3EA
Thank you for watching and commenting my friend! 73, Walt
Great video Walt! Keep up the good work. 73 John
Thank you so very much! 73, Walt
Got to love Single Stroke Gothic Lettering. Make me want to get back on the drafting table. Another great lesson Walt even for the semi seasoned ham.
Thank you! I started on the drawing board a long time ago
Great video Walt. I have a 55ft vertical up a tree with a 9 to 1 UNUN about 3ft off of the ground with 1 36ft counter pois elevated off the ground. It works great.
Thank you! That sounds like a great setup.
Not much to add. You covered things pretty well. If you operate on the go it's really hard to beat a 49:1 and/or a 9:1. Most of the time at home that is what I put out. The ability to band hop is worth the 20 odd percent loss implied in the transformer.
Roger that! 73, Walt
Just what I needed to know about which UNUN to use for what wire.....Thanks Walt....VK2BMV
Thanks for watching! 73, Walt
I've looked through all of your videos and unable to find your video on rf ground. Thank you for your GREAT videos!
Thank you! Here’s a link to the video:
ruclips.net/video/KjEOUZS_5sw/видео.htmlsi=KTXkEfCiYyNHcx7x
Great video Walt 73
Thank you! 73, Walt
*LOT'S OF GREAT INFORMATION*
Thank you!
Nice job explaining things. I added the 1:1 and 4:1 LDG baluns to my list of things to look for at Hamvention. Last year, Gigaparts had a nice sale on them.
Thanks! I’ve got two LDG 4:1 baluns. I’ll bring one to Dayton. You can buy me a couple beers lol
@@COASTALWAVESWIRES 🍻sounds good to me!
I had an SWL antenna with a single wire feed which I converted for ham use by connecting the wire direct to the tuner. It worked pretty well and it was attic mounted, but had some RF in the shack on some bands. Fun times.
Awesome, I’m thinking about making a 5/8 wave vertical and use one of my tuners at the feedpoint
Thanks Walt. My 29ft vertical was a perfect match on 10m with a 9:1 unun and a few ground radials. Tuned down into 40m though it didnt work real great it worked. 40m to 6m on 1 antenna was fun to play with. Also a good shtf antenna to have handy on a DX Commander pole
Roger that Jon! I got a 9:1 balun from a really cool dude and I think I’m going to build a dipole with two 29ft long wires which would come to 58ft long overall which is another good random length. Stay tuned lol
Hello! The closer the wire size is to 1:1, 1:2, 1:4, to the wavelength, the lower the losses in the antenna will be. Also, in order to reduce losses when adjusting resistance, it is easier and more convenient to use L-Match than transformer rings that heat up and give significant losses.
Roger that, thanks for sharing.
Great video!
Thank you! 73, Walt
I plan to start collecting them like pedals... Or wall hanger axes! Love it man! 73
Hahaha that’s what I do and as you can see on my wall I have some pedals I use with my little axes haha
I make cigar box guitars and other instruments, cant believe you have a wall full of CBG and strumstiks etc. something else we have in common. Nice informative video.
Thanks! Yes I love CBGs, Ukes and Strumsticks! 73, Walt
Saving this one! Thanks Walt! Taking the test for general on Saturday. I want to make my own antenna(s) eventually but will ease into it. I’m using two 10 meter hamsticks in a dipole configuration now and have two 20 meter sticks in reserve for when I pass my test. These two set ups will get me started. But I want to make an EFHW that I can use on multiple bands that will work with the built-in tuner in the FT-710 I’m planning to purchase. Right now I use a 60 watt single band 10 meter radio.
Thanks for your videos!
Good video. I was working on the 25 foot with 4 to 1 and was having trouble with swr. Did not want to cut. I had a single wire connected to ground terminal on the UNUN to a plate with about 25 radials. My swr was not very good. so I finally took one group of radials off the plate and connected it directly to the ground on the UNUN things got better. Still not as good as I hoped but it's raining now so will wait until another day. fair weather antenna builder lol
Thank you! Antennas sometimes just have more moving parts than a clock lol
This helped a lot Walt. Of course this too shall cost me money. But like they say, you can't take it with you. I'm just going to get them all and save money on shipping.
It’s a good collection to have!
Home run 😎 thanks good info
Thank you!!! 73, Walt
In my experience a simple 1/2 wave dipole fed in the center will typically give you about 70 ohms which will at best give vswr of 1:1:5, and is ok, like your man says if your under 2:1 the antenna will work ok. Ive used a 9:1 unun with 84ft of wire and had great results.
Yeah, I understand. This was done to simplify what we’re trying to do at the feedpoint
thank you!
Thanks for watching!
Great video
Thanks! 73, Walt
Great video, concise and straight to the point. Makes a good reference.
By the way, "drive by experts" are everywhere! lol
Thank you! Yes the experts are everywhere!
Great,thanks Walt 👍
Thanks Andy!
Walt, this video is great and to the point. I have tried various types of configurations over the 60 years of being a ham and had so much fun. Still looking for the perfect antenna (Hi Hi) but everything is a compromise due to all the unseen variables! I currently use a 29ft vertical with a 9:1. It works great and matches my environmental requirements while living in an HOA. Thank you for your practical and useful videos. Harv K5NR
Thank you Harv! I think we will always be looking for the perfect antenna Hi Hi
Thanks for the explanation, Walt! Just want to add a little thought: if you are using a balun or unun with a ferrite core, the core can become over saturated after a period of time and work less efficiently, which could lead to failure. It's very unlikely if you are a person who just making voice contacts or whatnot for a period of time similar to what you do, but if you're running a digital mode like JS8Call 24/7 where your radio is transmitting a lot, it can be a concern. In that case, maybe a resonate antenna might be better choice than say one which you need a balun or unun.
Thanks! Great input, thanks for sharing
I was impressed when I read that end fed halfwave will work on every harmonic -- not just the odd harmonics. For example, my 66 ft / 20 meter long end fed halfwave at 7 MHz will also work on 14 Mhz and 21 Mhz and 28 MHz too. The SWR is very acceptable and many times I don't need to use a transmatch. I can also use it on the WARC bands with a transmatch. It's a very versatile antenna.
It’s a great antenna
👍Nice overview, thanks Walt. I think your results on air are evidence that these "compromise" antennas work. If you think about it, arguably, every antenna is a compromise in some aspects.
Thank you and Roger that my friend! 73, Walt
Thanks Walt, I keep missing you somehow...
Thank you! Catch you soon
I remember the military standard was anything at or below 4:1.
Love the Ukes ;-)
Walt, this is a "must save" video for most hams. You've done all the math and explained feed point impedance in an easy to understand manner. Question: what is the name of the antenna app that you use? I have an Android phone and could use an app like that. 73!
It’s called “Antenna Tool”. I have it on my iPhone but I’m pretty sure it is available for Android. Thanks for the kind words! 73, Walt
great job, should be wicked helpful, especially for beginners. I personally don't use 1:1 baluns, I've always used coax chokes for dipoles instead. 73 de KB1TCD
Thank you! 73, Walt
Good short perfect
Thank you! 73, Walt
Well done Walt. VK4F👀 - Being a Local Tourist for a while. 🏝.
Thank you my friend!
I think that one parameter has been omitted - that is that most modern transceivers will cut back on their output power when the swr rises. That should be a consideration in my opinion
Haha! A few points that cleared some things up for me. Thanks.
You've got some good stuff. It's always fun to see what concoction of an antenna you've come up with.
I was listening to a few guys in state on 75M last night and one fellow who's not far from me is having problem with a 75M delta loop. He has it cut right he thinks, but the SWR goes through the roof when he tries to run his amp on it, but if he runs it barefoot it's ok. I tried to jump in several times and was going to offer to stop by with a SWR meter and analyzer. The analyzer sure would be a good way to see what was going on, but I couldn't get acknowledged. Ah well....what can ya do?
Thanks! Ah well, you tried. I wonder if it just needs to be better choked at the feedpoint to keep all that energy in the loop itself. Just my first thought, who knows.
@@COASTALWAVESWIRES The impression I was getting from listening was that there might not be any balun at all at the feed point. It wasn't real clear to me.
Oh yeah...being able to hook up an analyzer and see what's going on sure is nice, that's for sure! If he has a balun we could have figured out real quick if his antenna was fine or if his meters were screwy.
Walt ... great rules of thumb for the real world. Couple what you mentioned with the realization that a doubling of power is 3 db or 1/2 S unit, even SWRs between 4:1 - 6:1 would hardly be noticed on the receiving end. However, the transmitter would not like them for long!
73 - KF6IF
Roger that, thanks for sharing. 73, Walt
Thank you very much for all your videos and hunting me on the 26th.
Moe KO4GBB
Hi Moe! Great to get you in the log my friend.
Hi Walt, the quarter wave vertical, just the wire on the red connection off the ldg 1:1 balun and from the so239 a coax cable to the transceiver .. nothing connec!ted to the black connection on ldg 1'1 balun ..?
Keep posting great work!
You need to put counterpoise wires on the black connector.
Very interesting video! Thanks Walt! I wonder if you have ever used a RX noise bridge to adjust your antennas? I don't think Palomar sells them any more, but MJF does but they are $$$. I see used Palomar's on the E-auction site for $20-30. And there is not much involved in building one if you have a good parts junk box, so even building one in an evening is not out of the question. I had a noise bridge quite some time before I got an antenna analyzer and had a lot of fun using it.
Thanks! I have not but now you have me researching them. 73, Walt
Great video Walt, as always. I had asked this question to other YTers and want your input. A balun or unun is a transformer of sorts which helps match the impedance. A choke is used for common mode currents. However, I’ve been told that baluns and unun’s are also chokes. Please give me your insights. Thanks
Thanks! My understanding is that both baluns and ununs act as a choke somewhat as well. I typically put a 1:1 choke inline with a unun but I’m really not sure how much it is really needed.
Hello , my friend ! Yes , after UNUN and BALUN 4:1 , 6:1 , 9:1 , 16:1 , 49:1 , 64 :1 ALWAYS !!! you also need instal BALUN 1:1 for suppressing currents on cable braid . 73 ! Alexey , US8QQ
@@omgy750 Question: does it need to be a 1:1 balun? Could you use ferrite beads or an air choke (coax cable wrapped around pvc with the proper amount of turns) to stop common mode currents?
@@richiec7602 Yes , of course , you can use ferrite beads on the coax , and a separate 1:1 balun on FT-240-43 according to the DG0SA scheme . The air balun is not very effective .