WOW!! What a great video. All you you tube video producers should watch listen and learn. 1. Great audio, nice and even and at a proper level. 2, Great subject, something people may really be intrested in. 3. To the point and not endless talking heads. 4. Showed proper assembly, quick to the point assembly instructions, not a 2 hour video of some guy who left his camera on. 5. Great presentation and commentary, not some guy saying UUh and whatnot for and hour. GREAT video keep up the good work, and Thanks. (I'm Gonna build one)
Thanks for the compliments, I'm glad you enjoyed the video. It's been my experience that there is a dearth of good amateur radio DIY videos. So I'm using my expertise in video production and experience of amateur radio to create tutorials that are interesting and well produced.
Subbed. This was probably the most concise video on building your own yagi I have seen. I pulled a hat trick on Saturday and went from unlicensed to Amateur Extra in one shot. Now I'm just waiting for a call sign.
I know it's almost a year later, but I would like to know how you passed all three exams in one shot. Did you already have some background in the field?
I have a BS - EEE, and have studied a bit, so that I'm hitting 90% on Tech practise exams, but only 65% on the General practise exams. Doing all three at once is a great achievement.
@@CycleRayinOK for sure. I decided to pace myself since it was all new subject matter for me. I studied hard for the technician license. I aced that, so they offered me the general exam. I missed it by two questions, having not studied for that one at all. No regrets though. I didn't want to overwhelm myself and fail the tech.
6 years later your video's still helping people. Built my first yagi following your directions and it works great! Hope to find a fox hunt this summer. Thank you!
@@Chalan_Chitramu I can't help you, sorry. I just followed the instructions provided in the video, and that was a year ago, so I don't recall them of the top of my head. If he doesn't provide that info in the video, I wouldn't know it anyway since that's where I got my info.
Great video! I did laugh out loud when you used a tape measure to measure the tape measure to cut it... I'm fairly new to ham radio, but im fascinated by antenna and antenna design. Thanks for the information...
Agree, I though that was insulting to the tape. If you have to cut up a tape for this, at least have the decency to use it to determine its own length!
I built one of these and my first attempt on 2m simplex was a brand new ham calling out! He had just got his technician license at the DARA hq just a few days ago. He was super excited to reach me as his first contact ever, and I was super excited because he proved this new antenna worked fabulously!!!! Thanks for posting!
I just wanted to say Thank you! I used your design here and substituted a wooden yardstick in place of the PVC pipe because I couldn't get PVC pipe where I was deployed. The antenna was fantastic! Using my Yaesu FT-817 I was pushing 5 watts QRP with zero watts reflected as measured on a Bird Thruline wattmeter making contacts that I never would have thought possible. Great design that has me wanting to make more antennas in the future when I get home. Thanks again. 73's KX4IG
I built one of these at a local ham club meeting. They talked about it being great for fox hunts, but nobody mentioned you could use it with an HT to hit a repeater 60 miles away! This thing may become part of my go kit, since it folds up pretty easily. Thanks for the step by step walk through... excellent video how-to! 73, Brett
You are correct‚ you can transmit with them. I did a video last month where I used mine to make a sideband contact 40+ miles away: ua-cam.com/video/uvH8NQy-T84/v-deo.html
Michael, I watched this a couple times last night (friday.) I managed to copy a rough idea of this (2 meter, tuned with the nano) and made a contact 52 miles away with a UV5R, yes you heard that right, a little 3 watt radio. I think the real lesson here can bring up a multitude of topics which I will discuss with some other people soon here: hams have the privilege of building their own stuff, our signals can travel much farther, that topic of possible interference could possibly happen if it's zipping around the earth or bouncing off of things and lastly and most importantly never underestimate the ability of underrated equipment in the right conditions. I really think this was dumb luck but I did use a Google distance calculator, a compass bearing and found a good spot. Thanks for all you are doing with this channel and being a servant to others. The information you taught might save somebody else's life one day.
I built this antenna last month and i just sent my APRS beacon to the International Space Station with this. It works perfectly well. Thank you. TB1CLR, 73.
A friend of mine built one of these. This is only based on a test of one antenna. I measured performance in a clear open area. Since the intended use was hidden transmitter hunting, my only concern was the antenna pattern. I found two important things with the antenna brought to me: 1.) It had terrible common mode on the coax. I could touch the VNA analyzer case, or slide my hand along the coax, and see a fairly large change in impedance. 2.) It had generally poor directivity in the 2M Ham band. It lacked a good deep null off the rear. It actually seemed to have better directivity on the weather band than2 meters. I did two things. 1.) I altered the spacing. We just swapped the director and reflector around on spacing so the reflector is wider spacing like almost all 3 element Yagis are. This improved the back null quite a bit. I made no efforts to trim elements, but suggested he make the elements slightly long in a future model so we could trim them in. 2.) I grounded the coax shield to the center point of the reflector. We had about 18 inches of coax spiraled around the boom to the hairpin match. This forms a high impedance on the shield at the hairpin. This completely eliminated the noticeable SWR changes as I moved my hands along the coax.
I just built this and it looks like I am hitting towers about 50 miles away. However, please tape up the ends of the tape measure, my ten year old son was holding the antenna while I taped the cable and he dropped it on my leg, And it cut an inch and half gash, I am headed to the clinic now to see if it needs stiches.
I built one of these over the weekend and it works very well. I got the SWRs down to 1.1:1 and instead of soldering the coax to the driven elements, I decided to use an SO-239 connector with 3 inches of wire for the center conductor and ground, each. My house is in a 100 ft valley (compared to surrounding terrain) and I am still able to talk to my brother 4 miles away on 1 watt of power. Also, I'm using RG-8X coax to connect to the antenna.
UPDATE: Picked up a MicroFox (15mw output) and built a couple of these using an active offset attenuator. I use them specifically to teach scouts for Merit Badge Requirement #9, partake in ARDF, but I also use it as a DEMO for a variety of youth events. I set the FOX a distance away, and show them how to use the setup. My attenuator offsets the main frequency by 4MHz, making it cleaner to find the fox. The original antennas still work, but I am building a couple more so multiple sets of Scouts can look at the same time. I also have a few full power HTs (6watt) that are crossband I have used for a greater distance fox hunt. However, this is still, as far as I am considered, the gold standard for the homebrew Yagi. It is simple, it is cheap, and it is fast to assemble. I used my NanoVNA and tuned it to 1.2:1 on 2Meter, and it was also 1.8:1 on 70cm I use it to contact the ISS Repeater and have had a QSO from FMo5 to EM26 through the ISS Repeater. NOW THAT WAS COOL!!! Thanks, Chris Cancilla de W4CEC
Your build is very similar to the way I typically make them. I like to dip the ends of each element in that liquid plastic stuff they sell at hardware store for coating tool handles. It makes the ends more visible and prevents the ends from scratching or poking anyone. Also, I always put a cross on the director end as well. Once you’re close to a hidden transmitter, it’s often easier to zero in on the location using the null on the reflector end, so the extra cross allows you to hold the antenna ‘backwards’.
Great Ham Radio project Michael. Excellent easy to understand video. Especially like the method you use to speed up the construction portions of the project. It is refreshing for a ham to give the parts lists and step by step instructions. FIRST CLASS PRESENTATION. Very professional, I thought you must be a teacher with many years of experience. I built two of the antennas for an upcoming ham club fox hunting event. No problems, worked just as you said and showed in your video. Other Amateur Radio operators could learn many good tips and methods to present and do videos on ham radio projects if they watched your videos. Keep up the good work Michael. Great Job! Howard WB0ATB
Thanks for the compliments. I'm glad you found the video easy to follow and were able to build working antennas by watching it. I never was a professional teacher, but I did stay at a Holiday Inn Express once :). I do have a degree in Communication Arts, so it's good to put my Liberal Arts education to use in benefitting the amateur radio community.
Just made contact with the ISS via APRS using this tape measure antenna and my Yaesu FTM400XDR. Thank you for posting this video Michael! 73s from KI5BWY.
Cool... Great presentation. As a former teacher, I can really compliment your style and AV methods. Solid and easy to understand instructions. I don't even really need one, but it looks like a fun project. I think I will build one to keep handy. I wonder how much of Harbor Freight's business is from hams? 😀
Hey I've been a wood flooring contractor for 32 years that little tape measure you got from Harbor Freight is one of the best tape measures you can spend three bucks on better than a Stanley I originally bought three of them one lasted like 3-4 months and it was just so dirty that It was hard to read but it still worked nice project I'm going to build me one thanks
If anyone new is in doubt, cut the metal tape, tape to plywood sheet, position on wood saw horse, off the floor away from other metal, then hook up the feed line and check results on a NanoVNA! Then cut your boom material!
You build the antenna yourself to learn how antennas work (and save money in the process). That is what this is about. Those who buy "off the shelf" really do not learn anything regarding Amateur Radio, only create excessive cost and no knowledge regarding antennas as a whole. We can try to build our transceivers and do a pretty good job of it, but those who build antennas really know radio.
Thank you for sharing your knowledge and expertise with your videos. I’m just getting back into amateur radio and the new technology and information that is available is staggering and somewhat overwhelming at times. I find your videos to be clear, concise and welcoming to those of us who are new to this great hobby. Living in an apartment building makes antennae’s somewhat challenging as I have to be rather stealthy with them. Most of my activity ( when I’m licensed in the new year ) will be field transmitting and I’m gathering various radios and antenna styles to experiment with. I’m really looking forward to using my QRP radios as well as my stronger radios under field conditions. 73 John in Toronto Canada. 😀
This is a very informative and clear video. I built this antenna with one minor modification -- instead of soldering coax directly to the feed point, I instead soldered an N-type socket, and use an N-type to SMA cable to connect to my HT. (I have bad luck when it comes to stripping and separating coax. My approach ain't pretty, but it works.) I also covered the tips (last 1/2 inch) of the elements with electrical tape to avoid cuts and scratches. Analysis with a NanoVNA showed my version had an impedance of 52 Ohms and minimum SWR of 1.1:1 at 148.5 MHz. The SWR increases rapidly from that minimum, but still seems reasonable within the 2-m amateur band. On 70 cm, the antenna has an SWR of 1.6:1 at 449 MHz. I'll try playing around with the spacing of the driven elements to see if I can bring the resonant frequency/ies into the right range.
Thanks for the video. I just finished building this antenna. My regular 17in omni on 2 meter was only receiving at 1/3 scale this receives at full scale, full quieting to a repeater. I'm really amazed that this works, now I just need to tune it so I can Tx with it. Great video and thanks for the parts list on your blog, I took a picture of the list and found everything at home depot. The list does say 10Ft of PVC I got away with 2 2FT pieces, I'm not sure what the extra would be for unless you were making a stand for it.
Glad to hear the antenna is working well for you. I mentioned 10 feet of PVC in the parts list as that's the length you usually but the tubing at the home improvement store. But really any amount of scrap tubing will work, it doesn't have to be a certain thickness or diameter.
Great video, however plumbers don't use a 3/4" cpvc cross piece. So our local stores don't sell these. I had to cut down a 3/4" nipple and glue it to a "T" to make a cross piece. I haven't used it yet, so don't know how durable it is.
I used schedule 40 PVC for my mast and cross pieces. I don't believe you can get CPVC in 3/4 inch, but 1/2 inch CPVC should be sturdy enough for this antenna. But is sounds like your modifications to the mast should do the job.
Neat trick I learned for cutting the tape measure: you don't need any tools at all! If you fold the tape back on itself inwards (numbers touching numbers), and then press the fold flat to make a crease, it will snap and leave you with a perfectly straight line! Unfortunately, I learned this too late to save myself from a half-hour long battle with my dremel (most of it searching for the pieces).
I am stunned by the excellent presentation on the subject. Believe that you covered all the bases of a video. Last but not least, I am amazed of you thinking out of the box using such simple materials and making a really nice Yagi. Good day too.
It is unfortunate public high schools have eliminated basic electronics shops along with wood, metal and auto shops. Thank you for the videos. I don't know anything about anything related to electronics. Can I ask why are the "elements" (?) cut at such a precise length? Why are broadcasts called "2 meter"? If an antenna element had to be exactly two meters would it matter if you took the two meter antenna and rolled it into a coil? There certainly is a plethora of panel antennas and antennas of every configuration. It would be nice to have an illustrated up to date book with photos of every sort of antenna with a paragraph of the name, type and function of an antenna. Satellite and other antennas are popping up everywhere.
I'd agree with you that technical education is lacking in many high schools. Bucking the trend, our local high school just expanded its technical and industrial arts program. They did it in partnership with the area technical college. As for antennas, a 'field guide' of types of antennas would be really handy. I'll have to do some research to see if anything exists. What makes an antenna work is its resonance to a particular frequency. Radio Frequency energy travels in waves. When an antenna is resonant, it will easily transmit and receive the RF energy that is traveling at that frequency. That is why the elements of an antenna are precisely cut. These RF energy waves are described by the frequency they travel at, such at 146 MegaHertz, or by the size of their wavelength, like 2 meters. 146 Mhz is a frequency that has a wavelength of 2 meters. We could use a coil of wire to detect the radio waves, but fashioning the elements of the antenna in the style and orientation described in the video is more efficient than a coil of wire. This is a very simple explanation, but hopefully it answers your question.
Short description... 2 meter refers to a frequency band where the "center freq" is around 146 MHz (144 MHz - 148 MHz, allocated by FCC in USA for ham radio).... the length of the electromagnetic wave used to transmist and receive is around 2 meters (some calculation required). In order for the antenna to receive/transmit efficiently their lengths must be precise (although some >5% tolerance is usually accepted). Antennas are some diverse and so many.... depending mostly on applications.... The American Radio Relay League (ARRL) is a good start to look for antenna books.... look in their site and in Amazon.
Nice video, and thanks for the quality J-Pole. I'm wanting to build a Yagi for the GMRS band. My question concerns the hair pin match. Is it only required here because it's a 2-meter build, or would the same apply to a GMRS build?
Thanks for posting this...very clear, concise and easy to follow. I do have a question thought...what would the changes be...if any...if this was made with the tape fixed at 90 degrees to how you have made it? That is, the flat side of the tape would be directed to the repeater, not the thin side of the tape as you have made it.? I'm thinking it would fold up better and be easier for transport as the tape could be folded along the boom. Just a thought. Thanks again for posting. de Ian VK3YIC
The is K4DGC Chris in Tampa Fl. I built my own 2m yagi per your instructions and it turned out great. I am the Deputy EM for Hillsborough Co ARES/RACES and I recently brought this idea to my training officer who put together a class to build and test these tape measure antennas. We were able to get a few made and tested each one and they worked perfect. The steed TS were so thrilled that they proposed a Fox Hunt with their antennas so that is in the works as well as a possible build class for a 70cm yagi. Great job sir!! 73!!
That is just plain cool! This is why I like the ham radio hobby! Simple, field expedient and gives your signal from the ht a kick in the butt!! Thank you for sharing your project!!
Built one today. I don't have the means for tuning so i just measured and assembled it as precisely as i could. I was able to receive voice from AO-92 (VHF downlink) and SO-50 (UHF down) loud and clear. However, it is not a magic wand! and I was NOT able to transmit successfully to a friend 1 mile away through medium dense forest/trees (this is not surprising). Without so many trees blocking, I was loud and clear TXing at 4 watts from 1 mile. Don't expect to beat the laws of physics or anything with this, but even without tuning you'll be able to recieve MUCH better than you might with the rubber ducky. Tune it for best possible TX capability! Thanks VBR for the awesome design! de N0CALL ;)
Just built five of these antennas with my students today and they work great! Sadly, the cost of each antenna was $40 😢 Darn inflation! Thanks for making these videos!!!
I'm not a Ham but seeking info for a directional antenna for different purposes. The measurements you gave were very precise. I'm assuming the antenna you built was designed for a specific frequency. Where can I find out how to change the measurements for a different (but very close) frequency? What kind of frequency range would this antenna manage? Thanks for the great video!
Michael thanks for the outstanding instruction. I plan on building this for SOTA activations. Do you think you could repeatedly roll this up in a Fly rod case for strapping to a backpack?
Kids are wanting to try a fox hunt so we will be building this first. How narrow of a single azimuth would we be able to detect. Never done a fox hunt and wanting to understand how it correlates to map and compass navigation.
What an awesome yagi, but i noticed toward end of video how the tape measure fluttered in the wind/breeze! Would this affect it's performance? Cheers! VBQ543 Mick
Thanks for posting, this looks really interesting and easy. Quick question, even though the repeater you hit was 60 miles away it was still better for you to use that with vertical polarization rather than horizontal? I'm relatively new to ham radio and still learning. Thanks! WØMDK
Hi. For better results you’d want to match the polarization of the station you’re attempting to contact. Repeater antennas tend to be vertically polarized.
Hello, love your video. I'm looking to build one for a homemade reciever in 216.055 mhz. Just curious how I would have to change the instructions yo get into that frequency? Or where I may learn that info. Thank you for the help
I'd love to see a build video on a larger yagi, something like 4-6 elements, something that could be hiked up to a summit but be relatively lightweight
Thanks for the wonderful, clear, concise video! I'd like to make one of these to attempt voice contact with the ISS from my Baofeng handheld - talking to space on a shoestring, if you will. I will be transmitting on 144.49 MHz. Would I need to make any changes to the measurements outlined in your video, or do I just need to find an SWR meter and "tune" to 144.49 by adjusting the driven element gap? Thanks again!
Hi Michael, Nice Video. I notice at the co-axial feed point to the driven element the loop of wire connects between the 2 halves of the driven element. I thought that would short out the co-axial cable. Can you explain - I may be dumb haha.
The hairpin match is easy to construct, lightweight, and works well for this antenna. Other matches commonly found on Yagis, like gamma or coax shunt matches, are heavier and more cumbersome.
Would the flexing of the measurement tape affect the SWR or the radiation pattern? Why is there a wire soldered between the drive antenna? Why is the power should be limited on this antenna? Sorry for the endless questions. lol I’m curious about building my own yagi antenna.
Thanks for sharing due to which I cud build mine. I have a query though.(Am pretty new to this hobby).. Mine uses a 1/2inch wide and another one uses a 3/4th inch wide tape. You had mentioned a 1inch wide tape. Will the lower width affect the performance marginally or significantly? Thanks in advance for your response.Keep coming up with more such videos which is an inspiration to me.
Glad you enjoyed the video. The width of the tape doesn't make a difference, you can use the 1/2 inch tape if that's what you have. When you take the measurements to lay the elements on the boom, you measure from the center of the tape, not the edges. The wider tape will give you a bit more bandwidth and it will be be more rigid than narrow tape. Otherwise it should work fine.
Great! I really enjoy your videos and the detail you put into them. I'm going to build one of these to try to work the FM satellites. For us new hams, can you put together a video on how to prep the RG-58 cable for a project like this?
@@KB9VBRAntennas awesome thankyounfor getting back, I'm freshly retired from the Army and need a hobby now, so watching your videos trying to get going.
Awesome video and fun project! While adjusting the gap in the driver element between 0.75-1.00" my SWR is between 1.7-1.9, which I would like to improve. What would you recommend trying?
With a bargain bin tape that quit retracting and a mop handle that came with the house, got 1.09 swr (nanovna h4) at 145.4, useable from 144 to 147. This is with 6' of rg58 feed line and a solid 12 ga copper hairpin.
There is a link in the video description that takes you to a blog article with more information on how the measurements were derived. As for the the connecting wire, it's called a Hairpin Match. It raises the impedance of the feed point to 50 ohms so it matches the transceiver. I've got a follow-up video that better addresses your question: ua-cam.com/video/bQndXvCW54Q/v-deo.html
I have been watching videos on making a tape measure Yagi antenna. Yours is by far the best. No one ever addresses stowing the antenna for transport. Can the elements just be rolled into coils? This would allow the antenna to be stored in a tube or bag.
Great video and demonstration. Could adding extra elements 4,5,6 etc... elements yield higher gain using the same "Tape measure" material?. Thanks for reading!. Eric Dee.
Adding elements will certainly increase the gain and narrow the beamwidth of the antenna. Two meter antenna elements are short enough that you could use the 'tape measure' material for the extra elements. With a direction finding antenna, you don't necessarily need a high gain antenna, but you want one with deep nulls, so three elements are a good compromise between gain and nulls.
KB9VBR Antennas : Thank you for your reply, that makes perfect sense. Now if using the antenna from a direction finder, RF transmitter detector to an actual transceiver antenna, will the shape of the elements have any adverse effects on the audio modulation or is the shape irrelevant?. Kind regards, Eric Dee.
Great video, thanks. Can you explain the purpose of the short wire joining the two elements please? To my simple mind that looks like not having cut the tape, just like the other elements. I'm obviously missing something! [edit.... I scrolled further and found you hd answered that question for someone else, hi] 73 de Jim ZS6JMB, Johannesburg, South Africa.
Jim. Great question. The reason why the driven element is cut into pieces, is that it serves the purpose of radiating the RF energy. If you were to take away the other elements and just concentrate on the one element that's connected to the coax, you would have a simple 1/4 wave dipole antenna. One half is the radiator and the other the ground plane. That's why the element is split in that manner. Since a 1/4 wave dipole antenna is omnidirectional, adding the other elements act to focus the energy is one particular direction. They technically don't radiate, so they can be constructed as one longer piece of material. But getting back to the driven element, the short piece of wire helps change the impedance of the feed point to the 50 ohms necessary for the transmitter to operate efficiently. This is a simplistic answer, but I didn't want to go into too much detail here. I hope this helps. Michael
I did my soldering tonight on my tape measure Yagi-Uda during a 10m net. Can you give me an analogy of how the hairpin match works? I am trying to visualize the information I've learned. Does the keep impedance low on the antenna at the feedpoint because of the short?. Thanks for posting the great video. I was able to easily follow this and had it running for several stages. Thank you for the greta video. 73
The hairpin match raises the impedance of the feed point to 50 ohms so it matches the transceiver. I've got a follow-up video that better addresses your question: ua-cam.com/video/bQndXvCW54Q/v-deo.html
Thanks for getting back to me. First test was successful. I hit a repeater approximately 39miles away with 5watts and had a nice qso. Thanks for making and sharing your video. Great job.
Great video. Will make one but wonder if with a 0,78 inch (1,9 cm.)wide steel tape measure would be ok? Problems in finding stell tape measure of 1 inch.Thanks from Barcelona
Yes, the .78 inch steel tape will work fine. The width of the tape really doesn't make a difference. When you measure the spacing of the elements you do it from the center, not the edge of the tape.
Thanks for clarifying measure the spacing of the elements. Frequency range of my Kenwood TM 241 is 144 to 146.Supose I will have to adjust the distance between the two pieces of the driven element. What does it mean 14 ga ?. Sorry but I have to translate inch to cm and english to spanish and as you can see I have no idea. Many thanks for your help.
If you make a 3 element yagi and tune for the greatest gain, ignoring swr and f-b/f-s ratios, it might be possible to achieve 7.2 dbd gain, but if you strive for good balance in all those parameters, then 5-6 dbd gain is all you can hope for!
You are correct. Since this antenna is designed for fox hunting, it's been optimized for a high front to back ratio, hence the higher gain and deep nulls to the sides. But a more 'balanced' antenna would have a little lower gain.
How effective would this antenna be for satellite repeater communication of talking to the iss space station when there over my area🤔 this looks easy to build I want a Yagi antenna for satellite communication fun🤔😁
I built this and got the swr down to 1.2, but I still can't get into any distant repeaters. It works with the more local repeaters, but so does the rubber duck.
The store here only had cross pieces in 1 1/2" and larger, they were tapered for drain purposes, not what we need. Oh, I'm KL4PR on the air, try DMR on Alaska statewide. Thanks.
I enjoyed the video but I found something confusing. I don't have much experience with antennas so maybe this is a very naive question. I understood where you connected the core of the coax to the left side of the driven element, and then took the shield part of the coax and connected it to the right part of the driven element. The part that I didn't understand was the wire that arced above. Isn't this just shorting the shield and core elements of the coax? In other words, why would any self-respecting electron be bothered to follow the path into the tape measure when you have a short? I must be missing something
The connecting wire is called a Hairpin Match. It raises the impedance of the feed point to 50 ohms so it matches the transceiver. I've got a follow-up video that better addresses your question: ua-cam.com/video/bQndXvCW54Q/v-deo.html
Michael, would the antenna change in performance if you used plastic zip ties instead of metal hose clamps? This is a cool antenna. Thanks for the video projects. 73s
I don't believe there will be a change in performance if you use zip ties. The hose clamps aren't factored into the antenna calculations so you can make a substitution.
Thanks for this informative video. One question, as I,m just starting with antenna theory. The jumper between the driven elements seems to be shorting out the coax. What is the purpose of that jumper and is the length and gauge of it critical? Hmmm... that was two questions.
The connecting wire is called a Hairpin Match. It raises the impedance of the feed point to 50 ohms so it matches the transceiver. I've got a follow-up video that better addresses your question: ua-cam.com/video/bQndXvCW54Q/v-deo.html
@@KB9VBRAntennas thanks so much for the quick response. That sure took me down a rabbit hole that still has me wondering. Do I concentrate on getting my general license first or order and start studying the AARL Antenna book? Today, it’s build my tape measure Yagi.
Great video and cool idea. I’m new to ham and antenna building and have a noob question. What is the purpose of the reflector and deflector when they are not even connected to the coax?
The reflector and director elements on a yagi antenna are what are considered to be parasitic elements. They alter the radiation pattern of the main dipole element. Without them the antenna would radiate in a uniform fashion. But with the addition of the elements, they will passively resonate slightly out of phase, creating nulls in the radiation pattern. This causes your signal to be highly directional.
KB9VBR Antennas so much the same way as a string on a guitar will vibrate in sympathy when the same note is played on a different string. Cool. Thanks!
Just learning about this hobby. Few questions... Can the antenna be painted or would that disrupt/muffle the signal in any way? Also for "tuning" the gap between the tapes could you solder a nut onto it and use a bolt to easily and quickly adjust the distance between them? The further you thread it in the smaller the gap.
That sounds like a good winter project video. I've seen some plans online, I'll see if I can adapt one that doesn't require a lot of specialized tools.
@@KB9VBRAntennas Yeah I think it would be especially helpful to new hams trying to get into fox hunting. I've been looking at www.qsl.net/z33t/rf_step_attenuator_eng.html and it seems like a nice setup and fairly simple. Great job on the videos. The calm and clear explanation of things along with a detailed parts list make your videos a pleasure to watch. I am doing the yagi video you made right now (which is why I need an attenuator). I think I also used one of your videos for my first ground plane antenna. Which is working better than my commercial ones. Thank you
enjoyed your video, I built one and enjoyed the build, after adjusting the driven for swr, I can hold a qso on a repeater 30 miles away on my handy talkie on 5 watts, without additional elevation. This thing is a beast. and cheap too. This brings up the question, can we make this a 5 element yagi ? I assume it would give more gain and reach. the spacing on the elements in this one is not standard, so I am unsure what spacing would be correct for a 5 element conversion. Any hint or help with spacing and element length for the next to directors would be great. keep up the great videos. Thank You. 73's. KE4PJM
You could certainly use the same technique for building a 5 element Yagi. There are plenty of calculators online that will help you experiment with different designs. Here's one such calculator I've found: www.k7mem.com/Electronic_Notebook/antennas/yagi_vhf_quick.html Good luck and let me know how it turns out.
Hi Michael, I love this antenna design, and im looking at building it. One question, I want to add 2 directors to it. What would be the final measurements?
WOW!! What a great video. All you you tube video producers should watch listen and learn. 1. Great audio, nice and even and at a proper level. 2, Great subject, something people may really be intrested in. 3. To the point and not endless talking heads. 4. Showed
proper assembly, quick to the point assembly instructions, not a 2 hour video of some guy who left his camera on. 5. Great presentation and commentary, not some guy saying UUh and whatnot for and hour. GREAT video keep up the good work, and Thanks. (I'm Gonna build one)
Thanks for the compliments, I'm glad you enjoyed the video. It's been my experience that there is a dearth of good amateur radio DIY videos. So I'm using my expertise in video production and experience of amateur radio to create tutorials that are interesting and well produced.
i was wondering what mount u used to mount the yagi while you was testing it
Yep, and he talks at a good pace. Many times I have to crank up the speed to 1.25 because of slow talkers.
@@KB9VBRAntennas please please don’t ever stop making videos 😊
Subbed. This was probably the most concise video on building your own yagi I have seen. I pulled a hat trick on Saturday and went from unlicensed to Amateur Extra in one shot. Now I'm just waiting for a call sign.
Congrats on the license!
I know it's almost a year later, but I would like to know how you passed all three exams in one shot. Did you already have some background in the field?
@@tradedate -- Most certainly, as there's enough info at each level to prevent guessing at the answers and passing.
I have a BS - EEE, and have studied a bit, so that I'm hitting 90% on Tech practise exams, but only 65% on the General practise exams. Doing all three at once is a great achievement.
@@CycleRayinOK for sure. I decided to pace myself since it was all new subject matter for me. I studied hard for the technician license. I aced that, so they offered me the general exam. I missed it by two questions, having not studied for that one at all.
No regrets though. I didn't want to overwhelm myself and fail the tech.
6 years later your video's still helping people. Built my first yagi following your directions and it works great! Hope to find a fox hunt this summer. Thank you!
Could you give the formula for calculating the reflector and boom length @matthewnovak5440 ??
@@Chalan_Chitramu I can't help you, sorry. I just followed the instructions provided in the video, and that was a year ago, so I don't recall them of the top of my head. If he doesn't provide that info in the video, I wouldn't know it anyway since that's where I got my info.
@@matthewnovak5440 Could you suggest any book for designing the yagi uda antenna ??
Great video! I did laugh out loud when you used a tape measure to measure the tape measure to cut it...
I'm fairly new to ham radio, but im fascinated by antenna and antenna design. Thanks for the information...
Combustion Kills : I agree, couldn't get any easier could it???.
Agree, I though that was insulting to the tape. If you have to cut up a tape for this, at least have the decency to use it to determine its own length!
@@AlessioSangalli Heck no! That would be savagely!
I built one of these and my first attempt on 2m simplex was a brand new ham calling out! He had just got his technician license at the DARA hq just a few days ago. He was super excited to reach me as his first contact ever, and I was super excited because he proved this new antenna worked fabulously!!!! Thanks for posting!
Just made this antenna with the stuff I had in my shop. Was my first antenna build and worked great out of the box. Hit a repeater 32 miles away.
I just wanted to say Thank you! I used your design here and substituted a wooden yardstick in place of the PVC pipe because I couldn't get PVC pipe where I was deployed. The antenna was fantastic! Using my Yaesu FT-817 I was pushing 5 watts QRP with zero watts reflected as measured on a Bird Thruline wattmeter making contacts that I never would have thought possible. Great design that has me wanting to make more antennas in the future when I get home. Thanks again. 73's KX4IG
I'm curious how far that 5 watts will reach out with this thing?
I built one of these at a local ham club meeting. They talked about it being great for fox hunts, but nobody mentioned you could use it with an HT to hit a repeater 60 miles away! This thing may become part of my go kit, since it folds up pretty easily. Thanks for the step by step walk through... excellent video how-to!
73,
Brett
You are correct‚ you can transmit with them. I did a video last month where I used mine to make a sideband contact 40+ miles away: ua-cam.com/video/uvH8NQy-T84/v-deo.html
Michael, I watched this a couple times last night (friday.) I managed to copy a rough idea of this (2 meter, tuned with the nano) and made a contact 52 miles away with a UV5R, yes you heard that right, a little 3 watt radio. I think the real lesson here can bring up a multitude of topics which I will discuss with some other people soon here: hams have the privilege of building their own stuff, our signals can travel much farther, that topic of possible interference could possibly happen if it's zipping around the earth or bouncing off of things and lastly and most importantly never underestimate the ability of underrated equipment in the right conditions. I really think this was dumb luck but I did use a Google distance calculator, a compass bearing and found a good spot. Thanks for all you are doing with this channel and being a servant to others. The information you taught might save somebody else's life one day.
I built this antenna last month and i just sent my APRS beacon to the International Space Station with this. It works perfectly well. Thank you. TB1CLR, 73.
Just finished building this antenna and it is amazing. Thanks for putting this video together. Made a few contacts over 50 miles away with an HT.
Good to hear that the antenna is working great for you.
Was that a simplex contact?
A friend of mine built one of these. This is only based on a test of one antenna. I measured performance in a clear open area. Since the intended use was hidden transmitter hunting, my only concern was the antenna pattern.
I found two important things with the antenna brought to me:
1.) It had terrible common mode on the coax. I could touch the VNA analyzer case, or slide my hand along the coax, and see a fairly large change in impedance.
2.) It had generally poor directivity in the 2M Ham band. It lacked a good deep null off the rear. It actually seemed to have better directivity on the weather band than2 meters.
I did two things.
1.) I altered the spacing. We just swapped the director and reflector around on spacing so the reflector is wider spacing like almost all 3 element Yagis are. This improved the back null quite a bit. I made no efforts to trim elements, but suggested he make the elements slightly long in a future model so we could trim them in.
2.) I grounded the coax shield to the center point of the reflector. We had about 18 inches of coax spiraled around the boom to the hairpin match. This forms a high impedance on the shield at the hairpin. This completely eliminated the noticeable SWR changes as I moved my hands along the coax.
I just built this and it looks like I am hitting towers about 50 miles away. However, please tape up the ends of the tape measure, my ten year old son was holding the antenna while I taped the cable and he dropped it on my leg,
And it cut an inch and half gash, I am headed to the clinic now to see if it needs stiches.
I built one of these over the weekend and it works very well. I got the SWRs down to 1.1:1 and instead of soldering the coax to the driven elements, I decided to use an SO-239 connector with 3 inches of wire for the center conductor and ground, each. My house is in a 100 ft valley (compared to surrounding terrain) and I am still able to talk to my brother 4 miles away on 1 watt of power. Also, I'm using RG-8X coax to connect to the antenna.
UPDATE:
Picked up a MicroFox (15mw output) and built a couple of these using an active offset attenuator. I use them specifically to teach scouts for Merit Badge Requirement #9, partake in ARDF, but I also use it as a DEMO for a variety of youth events.
I set the FOX a distance away, and show them how to use the setup. My attenuator offsets the main frequency by 4MHz, making it cleaner to find the fox.
The original antennas still work, but I am building a couple more so multiple sets of Scouts can look at the same time.
I also have a few full power HTs (6watt) that are crossband I have used for a greater distance fox hunt.
However, this is still, as far as I am considered, the gold standard for the homebrew Yagi.
It is simple, it is cheap, and it is fast to assemble.
I used my NanoVNA and tuned it to 1.2:1 on 2Meter, and it was also 1.8:1 on 70cm
I use it to contact the ISS Repeater and have had a QSO from FMo5 to EM26 through the ISS Repeater.
NOW THAT WAS COOL!!!
Thanks,
Chris Cancilla
de W4CEC
Your build is very similar to the way I typically make them. I like to dip the ends of each element in that liquid plastic stuff they sell at hardware store for coating tool handles. It makes the ends more visible and prevents the ends from scratching or poking anyone. Also, I always put a cross on the director end as well. Once you’re close to a hidden transmitter, it’s often easier to zero in on the location using the null on the reflector end, so the extra cross allows you to hold the antenna ‘backwards’.
Great Ham Radio project Michael. Excellent easy to understand video. Especially like the method you use to speed up the construction portions of the project. It is refreshing for a ham to give the parts lists and step by step instructions. FIRST CLASS PRESENTATION. Very professional, I thought you must be a teacher with many years of experience. I built two of the antennas for an upcoming ham club fox hunting event. No problems, worked just as you said and showed in your video. Other Amateur Radio operators could learn many good tips and methods to present and do videos on ham radio projects if they watched your videos. Keep up the good work Michael. Great Job! Howard WB0ATB
Thanks for the compliments. I'm glad you found the video easy to follow and were able to build working antennas by watching it. I never was a professional teacher, but I did stay at a Holiday Inn Express once :). I do have a degree in Communication Arts, so it's good to put my Liberal Arts education to use in benefitting the amateur radio community.
Just made contact with the ISS via APRS using this tape measure antenna and my Yaesu FTM400XDR. Thank you for posting this video Michael! 73s from KI5BWY.
Me too!
@@1TylerM Did you mail in for your postcard?
Cool... Great presentation. As a former teacher, I can really compliment your style and AV methods. Solid and easy to understand instructions. I don't even really need one, but it looks like a fun project. I think I will build one to keep handy. I wonder how much of Harbor Freight's business is from hams? 😀
Thanks for the great video. Thanks to this antenna I was able to participate in the ISS SSTV event this morning. Thank you
I could listen to funky music and watch people build antennas all day. Great stuff man. Can't wait to try this out!
The music is great for sure!
Hey I've been a wood flooring contractor for 32 years that little tape measure you got from Harbor Freight is one of the best tape measures you can spend three bucks on better than a Stanley I originally bought three of them one lasted like 3-4 months and it was just so dirty that It was hard to read but it still worked nice project I'm going to build me one thanks
If anyone new is in doubt, cut the metal tape, tape to plywood sheet, position on wood saw horse, off the floor away from other metal, then hook up the feed line and check results on a NanoVNA! Then cut your boom material!
You build the antenna yourself to learn how antennas work (and save money in the process). That is what this is about. Those who buy "off the shelf" really do not learn anything regarding Amateur Radio, only create excessive cost and no knowledge regarding antennas as a whole. We can try to build our transceivers and do a pretty good job of it, but those who build antennas really know radio.
Super brand new to this hobby.... thank you for using plan English... easy to understand
That looks like too much fun. Going to Harbor Freight to get my free antenna tape measure
Just got back from harbor freight.
Good luck building. Edges are sharp
@@frankwc0o I'd go with non-metallic paint
Thank you for sharing your knowledge and expertise with your videos. I’m just getting back into amateur radio and the new technology and information that is available is staggering and somewhat overwhelming at times. I find your videos to be clear, concise and welcoming to those of us who are new to this great hobby. Living in an apartment building makes antennae’s somewhat challenging as I have to be rather stealthy with them. Most of my activity ( when I’m licensed in the new year ) will be field transmitting and I’m gathering various radios and antenna styles to experiment with. I’m really looking forward to using my QRP radios as well as my stronger radios under field conditions.
73
John in Toronto Canada. 😀
This is a very informative and clear video. I built this antenna with one minor modification -- instead of soldering coax directly to the feed point, I instead soldered an N-type socket, and use an N-type to SMA cable to connect to my HT. (I have bad luck when it comes to stripping and separating coax. My approach ain't pretty, but it works.) I also covered the tips (last 1/2 inch) of the elements with electrical tape to avoid cuts and scratches.
Analysis with a NanoVNA showed my version had an impedance of 52 Ohms and minimum SWR of 1.1:1 at 148.5 MHz. The SWR increases rapidly from that minimum, but still seems reasonable within the 2-m amateur band. On 70 cm, the antenna has an SWR of 1.6:1 at 449 MHz. I'll try playing around with the spacing of the driven elements to see if I can bring the resonant frequency/ies into the right range.
Thanks for the video. I just finished building this antenna. My regular 17in omni on 2 meter was only receiving at 1/3 scale this receives at full scale, full quieting to a repeater. I'm really amazed that this works, now I just need to tune it so I can Tx with it. Great video and thanks for the parts list on your blog, I took a picture of the list and found everything at home depot. The list does say 10Ft of PVC I got away with 2 2FT pieces, I'm not sure what the extra would be for unless you were making a stand for it.
Glad to hear the antenna is working well for you. I mentioned 10 feet of PVC in the parts list as that's the length you usually but the tubing at the home improvement store. But really any amount of scrap tubing will work, it doesn't have to be a certain thickness or diameter.
Never thought about using tape measure as an element. Great idea.
Great video, however plumbers don't use a 3/4" cpvc cross piece. So our local stores don't sell these. I had to cut down a 3/4" nipple and glue it to a "T" to make a cross piece. I haven't used it yet, so don't know how durable it is.
I used schedule 40 PVC for my mast and cross pieces. I don't believe you can get CPVC in 3/4 inch, but 1/2 inch CPVC should be sturdy enough for this antenna. But is sounds like your modifications to the mast should do the job.
Neat trick I learned for cutting the tape measure: you don't need any tools at all! If you fold the tape back on itself inwards (numbers touching numbers), and then press the fold flat to make a crease, it will snap and leave you with a perfectly straight line! Unfortunately, I learned this too late to save myself from a half-hour long battle with my dremel (most of it searching for the pieces).
I am stunned by the excellent presentation on the subject. Believe that you covered all the bases of a video. Last but not least, I am amazed of you thinking out of the box using such simple materials and making a really nice Yagi. Good day too.
It is unfortunate public high schools have eliminated basic electronics shops along with wood, metal and auto shops. Thank you for the videos. I don't know anything about anything related to electronics. Can I ask why are the "elements" (?) cut at such a precise length? Why are broadcasts called "2 meter"? If an antenna element had to be exactly two meters would it matter if you took the two meter antenna and rolled it into a coil? There certainly is a plethora of panel antennas and antennas of every configuration. It would be nice to have an illustrated up to date book with photos of every sort of antenna with a paragraph of the name, type and function of an antenna. Satellite and other antennas are popping up everywhere.
I'd agree with you that technical education is lacking in many high schools. Bucking the trend, our local high school just expanded its technical and industrial arts program. They did it in partnership with the area technical college.
As for antennas, a 'field guide' of types of antennas would be really handy. I'll have to do some research to see if anything exists.
What makes an antenna work is its resonance to a particular frequency. Radio Frequency energy travels in waves. When an antenna is resonant, it will easily transmit and receive the RF energy that is traveling at that frequency. That is why the elements of an antenna are precisely cut. These RF energy waves are described by the frequency they travel at, such at 146 MegaHertz, or by the size of their wavelength, like 2 meters. 146 Mhz is a frequency that has a wavelength of 2 meters. We could use a coil of wire to detect the radio waves, but fashioning the elements of the antenna in the style and orientation described in the video is more efficient than a coil of wire. This is a very simple explanation, but hopefully it answers your question.
Short description... 2 meter refers to a frequency band where the "center freq" is around 146 MHz (144 MHz - 148 MHz, allocated by FCC in USA for ham radio).... the length of the electromagnetic wave used to transmist and receive is around 2 meters (some calculation required). In order for the antenna to receive/transmit efficiently their lengths must be precise (although some >5% tolerance is usually accepted). Antennas are some diverse and so many.... depending mostly on applications.... The American Radio Relay League (ARRL) is a good start to look for antenna books.... look in their site and in Amazon.
Nice video, and thanks for the quality J-Pole. I'm wanting to build a Yagi for the GMRS band. My question concerns the hair pin match. Is it only required here because it's a 2-meter build, or would the same apply to a GMRS build?
Thanks for posting this...very clear, concise and easy to follow. I do have a question thought...what would the changes be...if any...if this was made with the tape fixed at 90 degrees to how you have made it? That is, the flat side of the tape would be directed to the repeater, not the thin side of the tape as you have made it.? I'm thinking it would fold up better and be easier for transport as the tape could be folded along the boom. Just a thought. Thanks again for posting. de Ian VK3YIC
The is K4DGC Chris in Tampa Fl. I built my own 2m yagi per your instructions and it turned out great. I am the Deputy EM for Hillsborough Co ARES/RACES and I recently brought this idea to my training officer who put together a class to build and test these tape measure antennas. We were able to get a few made and tested each one and they worked perfect. The steed TS were so thrilled that they proposed a Fox Hunt with their antennas so that is in the works as well as a possible build class for a 70cm yagi. Great job sir!! 73!!
That is just plain cool! This is why I like the ham radio hobby! Simple, field expedient and gives your signal from the ht a kick in the butt!! Thank you for sharing your project!!
It’s ALIVE! Followed along and built my first antenna. Thanks!
Very good video, the pace was great. Simple down and dirty Yagi and you could easily add a couple more elements for 9db of gain.
After following your instructions it works great! Any plans to put out a video on building a 70cm Yagi?
Built one today. I don't have the means for tuning so i just measured and assembled it as precisely as i could. I was able to receive voice from AO-92 (VHF downlink) and SO-50 (UHF down) loud and clear. However, it is not a magic wand! and I was NOT able to transmit successfully to a friend 1 mile away through medium dense forest/trees (this is not surprising). Without so many trees blocking, I was loud and clear TXing at 4 watts from 1 mile. Don't expect to beat the laws of physics or anything with this, but even without tuning you'll be able to recieve MUCH better than you might with the rubber ducky. Tune it for best possible TX capability!
Thanks VBR for the awesome design! de N0CALL ;)
Very nicely done. Just one question, what's all that white stuff on the ground? We don't get that here in the desert of Southern Nevada. Looks fun!
Just built five of these antennas with my students today and they work great! Sadly, the cost of each antenna was $40 😢 Darn inflation! Thanks for making these videos!!!
They shouldn’t have cost that much. Harbor Frieght tape measures are cheap and work great.
Just bought a J pole from you on ebay yesterday and stubled on this video! Looking forward to using it! Great video! Small world!
Glad you enjoyed the video and thanks for your purchase.
I'm not a Ham but seeking info for a directional antenna for different purposes. The measurements you gave were very precise. I'm assuming the antenna you built was designed for a specific frequency. Where can I find out how to change the measurements for a different (but very close) frequency? What kind of frequency range would this antenna manage? Thanks for the great video!
Michael thanks for the outstanding instruction. I plan on building this for SOTA activations. Do you think you could repeatedly roll this up in a Fly rod case for strapping to a backpack?
Love this antenna idea! Any thoughts on making a 70cm version? Or making this a dual bander by putting 70cm 90° off from the 2m elements?
I like this design!. Do you know if painting the whole thing would ruin any of its characteristics?
I built this antenna today per your instructions and it turned out amazing! Thank you for the clear and concise video. 73, KF0OVB
Kids are wanting to try a fox hunt so we will be building this first. How narrow of a single azimuth would we be able to detect. Never done a fox hunt and wanting to understand how it correlates to map and compass navigation.
I like how you you use one tape measure to measure the other tape measure.
What an awesome yagi, but i noticed toward end of video how the tape measure fluttered in the wind/breeze!
Would this affect it's performance?
Cheers!
VBQ543
Mick
Thanks for posting, this looks really interesting and easy. Quick question, even though the repeater you hit was 60 miles away it was still better for you to use that with vertical polarization rather than horizontal? I'm relatively new to ham radio and still learning. Thanks! WØMDK
Hi. For better results you’d want to match the polarization of the station you’re attempting to contact. Repeater antennas tend to be vertically polarized.
Great video! By changing the gap you would change the distance between the elements but leave the length of wire the same length ?
Hello, love your video. I'm looking to build one for a homemade reciever in 216.055 mhz. Just curious how I would have to change the instructions yo get into that frequency? Or where I may learn that info. Thank you for the help
A very nice build of a tape measure yagi antenna. I wanna build one myself after I get my Tech. license and a HT.
I'd love to see a build video on a larger yagi, something like 4-6 elements, something that could be hiked up to a summit but be relatively lightweight
Hi from IU4OOB. I’ve just built mine and it works great! It doesn’t look as good as your but it works. Thx a lot!!
Thanks for the wonderful, clear, concise video! I'd like to make one of these to attempt voice contact with the ISS from my Baofeng handheld - talking to space on a shoestring, if you will. I will be transmitting on 144.49 MHz. Would I need to make any changes to the measurements outlined in your video, or do I just need to find an SWR meter and "tune" to 144.49 by adjusting the driven element gap? Thanks again!
Hi Michael, Nice Video. I notice at the co-axial feed point to the driven element the loop of wire connects between the 2 halves of the driven element. I thought that would short out the co-axial cable. Can you explain - I may be dumb haha.
My concern as well.
Gonzo Buddy so is the “shorting wire” required? I can accept they are different, but can you tell us how and why? It still looks funny to me.
Hello Mike nice tape yahi video ,i he one question,,,, why you use hairpin connection to driven element ??
The hairpin match is easy to construct, lightweight, and works well for this antenna. Other matches commonly found on Yagis, like gamma or coax shunt matches, are heavier and more cumbersome.
Wow that's very impressive. I could use this for some other projects. Having a 2m 70cm yagi is a good idea anyway
Would the flexing of the measurement tape affect the SWR or the radiation pattern?
Why is there a wire soldered between the drive antenna?
Why is the power should be limited on this antenna?
Sorry for the endless questions. lol I’m curious about building my own yagi antenna.
Thanks for sharing due to which I cud build mine. I have a query though.(Am pretty new to this hobby).. Mine uses a 1/2inch wide and another one uses a 3/4th inch wide tape. You had mentioned a 1inch wide tape. Will the lower width affect the performance marginally or significantly? Thanks in advance for your response.Keep coming up with more such videos which is an inspiration to me.
Glad you enjoyed the video. The width of the tape doesn't make a difference, you can use the 1/2 inch tape if that's what you have. When you take the measurements to lay the elements on the boom, you measure from the center of the tape, not the edges. The wider tape will give you a bit more bandwidth and it will be be more rigid than narrow tape. Otherwise it should work fine.
This is the best video I've seen for a beam antenna beautiful job well explained!
Hey! Very cool build. Do you have this in dual band?
Great! I really enjoy your videos and the detail you put into them. I'm going to build one of these to try to work the FM satellites. For us new hams, can you put together a video on how to prep the RG-58 cable for a project like this?
W4CEC here......I am building a couple of these for the Legion Club, WF4TAL. I think this is fun!
Great video, can I spray paint the tape measure or would that cause interference?
A coat of non metallic spray paint won't affect the performance of the antenna.
@@KB9VBRAntennas awesome thankyounfor getting back, I'm freshly retired from the Army and need a hobby now, so watching your videos trying to get going.
My 12 year old son and I just built this. Thanks for a great how to vid.
Awesome video and fun project! While adjusting the gap in the driver element between 0.75-1.00" my SWR is between 1.7-1.9, which I would like to improve. What would you recommend trying?
Do you know what you are getting for a resonant frequency? You may need to either lengthen or shorten the driven element bit.
With a bargain bin tape that quit retracting and a mop handle that came with the house, got 1.09 swr (nanovna h4) at 145.4, useable from 144 to 147. This is with 6' of rg58 feed line and a solid 12 ga copper hairpin.
Sir what is hair pin math in the process of making antenna, why it's required ?? and how it's calculated??
Please guide me sir.
Thank you 😊.
i made this antenna a week ago and its strong its about 80km thanks KB9VBR
Hello fantastic video. It'd be cool if you explained how you got the measurements for that frequency and especially the matching circuit. Thanks!
There is a link in the video description that takes you to a blog article with more information on how the measurements were derived. As for the the connecting wire, it's called a Hairpin Match. It raises the impedance of the feed point to 50 ohms so it matches the transceiver. I've got a follow-up video that better addresses your question: ua-cam.com/video/bQndXvCW54Q/v-deo.html
@@KB9VBRAntennas thank you so much!
I have been watching videos on making a tape measure Yagi antenna. Yours is by far the best. No one ever addresses stowing the antenna for transport. Can the elements just be rolled into coils? This would allow the antenna to be stored in a tube or bag.
You can roll the elements up. I usually fold them in half and tuck them into the open holes of the PVC connectors.
Great video and demonstration. Could adding extra elements 4,5,6 etc... elements yield higher gain using the same "Tape measure" material?.
Thanks for reading!.
Eric Dee.
Adding elements will certainly increase the gain and narrow the beamwidth of the antenna. Two meter antenna elements are short enough that you could use the 'tape measure' material for the extra elements. With a direction finding antenna, you don't necessarily need a high gain antenna, but you want one with deep nulls, so three elements are a good compromise between gain and nulls.
KB9VBR Antennas : Thank you for your reply, that makes perfect sense. Now if using the antenna from a direction finder, RF transmitter detector to an actual transceiver antenna, will the shape of the elements have any adverse effects on the audio modulation or is the shape irrelevant?.
Kind regards, Eric Dee.
Great video, thanks. Can you explain the purpose of the short wire joining the two elements please? To my simple mind that looks like not having cut the tape, just like the other elements. I'm obviously missing something! [edit.... I scrolled further and found you hd answered that question for someone else, hi] 73 de Jim ZS6JMB, Johannesburg, South Africa.
Jim. Great question. The reason why the driven element is cut into pieces, is that it serves the purpose of radiating the RF energy. If you were to take away the other elements and just concentrate on the one element that's connected to the coax, you would have a simple 1/4 wave dipole antenna. One half is the radiator and the other the ground plane. That's why the element is split in that manner. Since a 1/4 wave dipole antenna is omnidirectional, adding the other elements act to focus the energy is one particular direction. They technically don't radiate, so they can be constructed as one longer piece of material.
But getting back to the driven element, the short piece of wire helps change the impedance of the feed point to the 50 ohms necessary for the transmitter to operate efficiently. This is a simplistic answer, but I didn't want to go into too much detail here. I hope this helps. Michael
KB9VBR Antennas, wait, all I can see is the jumper shorting the center to the ground. Are there other ways to hook up a dipole?
I did my soldering tonight on my tape measure Yagi-Uda during a 10m net. Can you give me an analogy of how the hairpin match works? I am trying to visualize the information I've learned. Does the keep impedance low on the antenna at the feedpoint because of the short?. Thanks for posting the great video. I was able to easily follow this and had it running for several stages. Thank you for the greta video. 73
The hairpin match raises the impedance of the feed point to 50 ohms so it matches the transceiver. I've got a follow-up video that better addresses your question: ua-cam.com/video/bQndXvCW54Q/v-deo.html
Thanks for getting back to me. First test was successful. I hit a repeater approximately 39miles away with 5watts and had a nice qso. Thanks for making and sharing your video. Great job.
Great video. Will make one but wonder if with a 0,78 inch (1,9 cm.)wide steel tape measure would be ok? Problems in finding stell tape measure of 1 inch.Thanks from Barcelona
Yes, the .78 inch steel tape will work fine. The width of the tape really doesn't make a difference. When you measure the spacing of the elements you do it from the center, not the edge of the tape.
Thanks for clarifying measure the spacing of the elements. Frequency range of my Kenwood TM 241 is 144 to 146.Supose I will have to adjust the distance between the two pieces of the driven element. What does it mean 14 ga ?. Sorry but I have to translate inch to cm and english to spanish and as you can see I have no idea. Many thanks for your help.
Joan Simarro 14 Gauge is the thickness of the wire. The thicker the wire to lower the gauge number. 14 gauge can be found in most extension cords.
These DIY antennas are great for qrp camping or for use in direction finding fox hunts
If you make a 3 element yagi and tune for the greatest gain, ignoring swr and f-b/f-s ratios, it might be possible to achieve 7.2 dbd gain, but if you strive for good balance in all those parameters, then 5-6 dbd gain is all you can hope for!
You are correct. Since this antenna is designed for fox hunting, it's been optimized for a high front to back ratio, hence the higher gain and deep nulls to the sides. But a more 'balanced' antenna would have a little lower gain.
How effective would this antenna be for satellite repeater communication of talking to the iss space station when there over my area🤔 this looks easy to build I want a Yagi antenna for satellite communication fun🤔😁
I built this and got the swr down to 1.2, but I still can't get into any distant repeaters. It works with the more local repeaters, but so does the rubber duck.
The store here only had cross pieces in 1 1/2" and larger, they were tapered for drain purposes, not what we need. Oh, I'm KL4PR on the air, try DMR on Alaska statewide. Thanks.
Thank you Mike, i’m working on building my third 2m tape measure antenna, they work great!
I enjoyed the video but I found something confusing. I don't have much experience with antennas so maybe this is a very naive question.
I understood where you connected the core of the coax to the left side of the driven element, and then took the shield part of the coax and connected it to the right part of the driven element. The part that I didn't understand was the wire that arced above. Isn't this just shorting the shield and core elements of the coax? In other words, why would any self-respecting electron be bothered to follow the path into the tape measure when you have a short? I must be missing something
The connecting wire is called a Hairpin Match. It raises the impedance of the feed point to 50 ohms so it matches the transceiver. I've got a follow-up video that better addresses your question: ua-cam.com/video/bQndXvCW54Q/v-deo.html
EXCELLENT camera skills and dimensional graphics! How much larger would a 40M Yagi be?
A 40m Yagi will be quite large. The driven element of a Yagi antenna is the equivalent of a 1/2 wave dipole, which is 67 feet from end to end.
@@KB9VBRAntennas Thank you.
Michael, would the antenna change in performance if you used plastic zip ties instead of metal hose clamps? This is a cool antenna. Thanks for the video projects. 73s
I don't believe there will be a change in performance if you use zip ties. The hose clamps aren't factored into the antenna calculations so you can make a substitution.
Thanks for this informative video. One question, as I,m just starting with antenna theory. The jumper between the driven elements seems to be shorting out the coax. What is the purpose of that jumper and is the length and gauge of it critical? Hmmm... that was two questions.
The connecting wire is called a Hairpin Match. It raises the impedance of the feed point to 50 ohms so it matches the transceiver. I've got a follow-up video that better addresses your question: ua-cam.com/video/bQndXvCW54Q/v-deo.html
@@KB9VBRAntennas thanks so much for the quick response. That sure took me down a rabbit hole that still has me wondering. Do I concentrate on getting my general license first or order and start studying the AARL Antenna book? Today, it’s build my tape measure Yagi.
Great video and cool idea. I’m new to ham and antenna building and have a noob question. What is the purpose of the reflector and deflector when they are not even connected to the coax?
The reflector and director elements on a yagi antenna are what are considered to be parasitic elements. They alter the radiation pattern of the main dipole element. Without them the antenna would radiate in a uniform fashion. But with the addition of the elements, they will passively resonate slightly out of phase, creating nulls in the radiation pattern. This causes your signal to be highly directional.
KB9VBR Antennas so much the same way as a string on a guitar will vibrate in sympathy when the same note is played on a different string. Cool. Thanks!
Yes, you've got it. That's an excellent analogy.
I love your videos. You make them understandable! I’m working on my antenna now. I used plastidip on the ends to prevent cuts. 73 and thank you!
I thought about the plastic dip as well. I will probably also round off the sharp corners with a Dremel or a file first.
Just learning about this hobby. Few questions... Can the antenna be painted or would that disrupt/muffle the signal in any way? Also for "tuning" the gap between the tapes could you solder a nut onto it and use a bolt to easily and quickly adjust the distance between them? The further you thread it in the smaller the gap.
Great videos. Might you consider doing a video on building a 5 switch attenuator? I haven't found any good videos on that. Thanks again.
That sounds like a good winter project video. I've seen some plans online, I'll see if I can adapt one that doesn't require a lot of specialized tools.
@@KB9VBRAntennas Yeah I think it would be especially helpful to new hams trying to get into fox hunting.
I've been looking at www.qsl.net/z33t/rf_step_attenuator_eng.html and it seems like a nice setup and fairly simple.
Great job on the videos. The calm and clear explanation of things along with a detailed parts list make your videos a pleasure to watch.
I am doing the yagi video you made right now (which is why I need an attenuator).
I think I also used one of your videos for my first ground plane antenna. Which is working better than my commercial ones.
Thank you
enjoyed your video, I built one and enjoyed the build, after adjusting the driven for swr, I can hold a qso on a repeater 30 miles away on my handy talkie on 5 watts, without additional elevation. This thing is a beast. and cheap too. This brings up the question, can we make this a 5 element yagi ? I assume it would give more gain and reach. the spacing on the elements in this one is not standard, so I am unsure what spacing would be correct for a 5 element conversion. Any hint or help with spacing and element length for the next to directors would be great. keep up the great videos. Thank You. 73's. KE4PJM
You could certainly use the same technique for building a 5 element Yagi. There are plenty of calculators online that will help you experiment with different designs. Here's one such calculator I've found: www.k7mem.com/Electronic_Notebook/antennas/yagi_vhf_quick.html Good luck and let me know how it turns out.
My copper J Pole stopped working, got a new one, same issue,, cut the ground wire to my TX/RX, fixed everything
Hi Michael,
I love this antenna design, and im looking at building it.
One question, I want to add 2 directors to it. What would be the final measurements?
I'm going to try this one. Looks like a fun project to get started with.
Just made it today - works a treat! Cheers!