Beside good design the presenter gives very educative and high quality lecture.This is something we are missing not only on UA-cam but generally at universities nowadays. Thanks for that!
Hi Dave, great video. I have just completed construction of this antenna using a couple of old CB antenna whips which are also made from stainless steel and a length of timber for the boom. My antenna is mounted in the loft and it works great I can open a 2m repeater 60 miles away using my handy running 5 watts. This is my first ever homebrew and I'm really pleased with the result. 73 Dean M6BYF
Dave, I built this antenna in 2021 and installed in my attic. With a Baofeng HT I could reach repeaters 40 miles away. I have since used it in my mobile radio trailer for field day and other mobile ops. I elevate it about 30 feet and have made simplex contacts 65 miles away. This antenna works great and is an excellent project for new hams as I was at the time. Thanks!! KO4MkD
So I built an antenna based off this video but very different. Used the idea of the elements and attaching them but most of the rest was my own design. Friday an Elmer came by with a very fancy analyzer and after checking it all through the 2 meter and 70 centimeter bands he said "don't change a thing" as he'd never seen an antenna perform that well....and he's been telling everybody about the new HAM that built an amazing antenna! The most impressive operational test was with a Baofeng handheld on low power (1 or 2 watts). It is hitting a repeater 30 miles away off of a 12 1/2 foot (from the ground) PVC mast and running through 100 feet of RG8x coax. Signal report was fully readable but "not as good" as the transmissions with higher power on the Baofeng and my mobile rig. THANK YOU DAVE for the inspiration to build an AWESOME antenna!!!!!!! MY VERSION: Gray PVC 3/4" electrical conduit "T" (with the removable cover) 18" 3/4" schedule 40 PVC for the standoff 1" x 1" x 3/4" slip "T" at the end of the standoff with the elements mounted on the outside of the "T" 18' of RG58 coax from the element feed point, passed through the PVC standoff though holes drilled in it then wrapped around the 3/4" pipe standoff, then into the pipe at the end of the wrapping so it can pass into the conduit "T" where it is soldered to an SO239 that protrudes through the "T" 3/4" schedule 40 PVC opposite the elements as a counterbalance to keep from putting stress on the mast....i.e. balance it out. The bottom hole of the conduit "T" is used to mount to the mast which is built from 1" and 1 1/4" schedule 40 pipe. I'll be doing a video on the whole thing when I start building the next one which will first be analyzed without the RG58 choke and then with it unless it gives amazing performance without it. KG7TUO, Medford Oregon.
OH...I bent my elements around a drill bit of the proper diameter which I mounted in a hole on a piece of equipment in my garage as I loaned my vise to someone and it never came home. After getting the bend started, I used a pair of Vise Grip pliers to finish the fold. Then I cut the elements to length with a hack saw. I got the stainless rod from a local welding shop. About $21 for 10 pcs of 3' long 1/8" thick stainless welding rod.
Thanks for sharing this! I've been looking high and low for an easy home-made antenna I could make without a lot of specialty parts, and this one is perfect! I was able to put it together with some 1/8" copper wire I had left over from a previous project, and a spare coax cable from our TV. Better still - it works perfectly! I love that it can be tuned without additional trimming. Great design, thanks again!
Hi Dave, Thank you for sharing this video. I have constructed one a few months back just for receive and have it mounted about 20ft off the floor. I passed my foundation license a couple weeks back and now being able to transmit I have been getting very good results. Thanks once again 73's M6OOL - Stef
Built this antenna last weekend and it works great. Thank you for the video. The only thing I did differently was used a piece of uni strut bolted to the plexi in place of the pole clamp for more mounting options.
An outstanding presentation - theory is all very well but there's nothing like making something and trying it with scope for adjustment. Topped off with metric units for us Europeans! Perfect practical guidance with the proof that it's works exceptionally well - with a real radio! My vote for the best antenna project on the web.
Great video. Built one with 1/4" alum rod I had in the shop. Mounted on my roof on a tripod, SWR of 1.1 - to 1.27 across most of the 2 m band. Very happy with the results. KK4VXL. 73.
I built this antenna for scanner monitoring and its the best receive antenna of any that I own. Thank you for sharing your knowledge with us. FYI I used 308/308L 31" Stainless steel welding rod. (PGK of 8 at $10-12 from local weld shop).
You are a Ham always sharing your knowledge. Thank you! I am building this antenna today. I had to use aluminium rods instead, I could not find the stainless steel rods local. I got the plexiglas for free. I cost me less than $15.00 to make this antenna. Most of the cost is the aluminium rods. The nuts and bolts ect..where less and $1.50. Hope to hit the repeater the afternoon.
Thank you very much! I was researching for a cheap DIY fixed antenna on 2m/70cm for my Yaesu 857d, good enough to hit the repeaters around my QTH using low power, so I built one using your measurements and it works fantastic. 1.02-1.08 swr on 2m band and 1.3 to 1.4 swr on 70cm without any tweaking or tuning. The only difference is that I used 4mm aluminum rods. Total cost under the equivalent of 35USD and about 3 hours from start to first QSO. 73 de YO4YPC
Well what can I say I dont have a 2metre 70cm antenna for home but Ive been looking to build one, this is so simple and a brilliant design and I will gave it a try. Thanks for showing us how it was done and If you done mind Ill put it on my radio forum to show the members how you did it. 73's from Daryn 2E0DKD
Thanks for sharing your creation! I built one using 1 12' x 1" PVC and 1 12' x 1 1/4" PVC pipes ( Telescoping Antenna Mast), 1" PVC 90 and PVC Box. 1/8" Copper wire and 90' coax... I am getting 1.1 SWR on all 2 meter and 1.2 on all 70cm frequencies.
Great video. Thanks for sharing. I have a +2 db gain rubber ducky on my hand held. I can say the gain with this dipole is considerably higher. Super easy to build. I used 1/8" solid copper with stainless hardware. I don't have a SWR meter to test it. So far so good.
You can use copper, aluminum, or what ever you have on hand but the resonate frequency will probably be different if the element diameters are not the same. BTW, the first one of these antennas that I made was built for 2 meters only and had elements made of steel coat hangers. After scraping some paint off the coat hangers to connect the feed line, I used two screws to fasten the elements and connect the coax to a 1x2 mounted on another board (the mast). It worked - but it did rust. 73! :)
Spacing for a reflector is mentioned in the comments below. On the yagi calculator page it says to use equal spacing for three elements and the amount to space the elements is displayed in the fourth box.
Thank you Dave, I made your antenna over the weekend. I will be putting it on the roof probably this coming weekend. Thank you for the great videos. KG5OFV.
Good video, Dave, thanks! Thanks also for using in paralel the metric system. I get lost every time I hear something like 23 and 17/32 th inch ;) you must be master mathematicians in the USA, to be able to decode those fractions :) Keep up the good work, Dave!
Usually we use baluns in larger HF dipole antennas. For a small antenna such as this a balun is not critical. Using a balun with this antenna may cause more problems in terms of loss rather than be of any real benefit to matching impedance.
@darynsax Glad you enjoyed it. Feel free to embed the video in your forum. Like all vertical antennas for ground wave the higher you mount it the better it will work. 73! :)
Thanks for the great vid. I used your write up, so thanks for that too. I used wood, 1/8th steel, and 1/4" bolts for a first run test. I'm restricted, so this one is in my shack for my baofeng uv-5r. I'm 11 miles from a local repeater. My handheld duckie could barely activate the repeater if I sat right, and the qso was almost completely one sided. Now I get much better rx clarity and my contact reported almost full quieting along with some brief notes about low tx volume of the uv-5r. Next: di
going to have a go at making one of these for use at our caravan, nice and light and not intrucive , thanks for the very easy instructions, best 73 de m6lbi
Reflectors can be added to the antenna giving it an extra 2 - 3 db gain and about a 58 degree beam width. The reflectors can also be stainless steel rods and can be attached with small u-bolts, from wire rope clips like I used to hold the coax on the end of the boom. A reflector for 2 meters might be spaced 15" back from the driven element and made about 40-1/4" long. For 70 cm a rough guess would be a 13" long reflector mounted no more than 6" back from the driven element. Thanks and 73! :)
Dave i thank you for sharing the wisdom of making this wonderful antenna but can you give me a dimension of how long is each element from the bolt bend till theyr tips for 2 m and the 70cm end??????
@cl4yd0h You're getting much closer. :) Try another 1/8" or so. I suspect that your HT antenna may have a more gain than a simple dipole antenna if testing it at the same height. This antenna will work better the higher it is mounted.
Hi Dave, thank you very much for your video. I built this antenna and it works perfect. Later I will try with another for 10/15/20 if posible. I will look at your videos to get information.
@cl4yd0h You're not far off and the antenna just needs a little tuning. Remember "Lower, Longer." If SWR goes continuously higher from 1.6 (144 MHz) to 2.2 (148 MHz) then the antenna is working better at lower frequencies. So shorten the antenna elements just slightly to tune it higher in frequency. Try adjusting the antenna until you see at least 1.1:1 SWR at 146.000 MHz. 73! :)
Steel rods or coat hangers will work but they do rust and have different electrical properties that may make the elements a slightly different length. Fastenal, and possibly Grainger, sells stainless steel rods. I've added a webpage to my website with links to these and other antenna parts. Click my username to visit my UA-cam channel and the link to my website is in the upper right corner. Thanks for watching and 73! :)
Yes, copied today and works brilliantly. I had 8mm stainless rod, so harder to bend, but got there eventually. 70cm SWR came in at 1.7, but 2m hardly moved the needle, so not going to adjust at all. Thank you, G0WKT
Hi David, You have the lengths correct but may have missed seeing the diagram. Right now there is a picture of the antenna on my main page of my web site. Click on the picture to go to the project page then scroll down to the diagram. Sometimes I do make a mistake in a video and so always check my website for construction notes. Thank you for watching and 73! :)
@MacintoshWizard My U shape bends are not exactly perfect but are within about a millimeter or so measuring from center to center. Place the rod about 8 or 9 inches into the bench vise and start bending at a right angle. Then take the rod out and place the short end horizontally in the vise and finish bending it. It may take an extra try with another rod to get two that are similar in shape but it shouldn't take much to get the hang of it. Good luck and have fun. 73! :)
Hello Dave. Great build. Thank you. I just finished building one of these antennas and made very subtle changes to your design. (I actually designed it to materials I already have. 4' mast to 1 1/2" angle iron, then to the plexi. I installed an SO 239 female connector in the plexi and ran 2 pcs of short 18 awg wire to the bolts for the rods.) Question: I am getting a high SWR reading no matter where I place the 2 elements. Can't manage to get it below 1.6 on 70cm and almost the same on 2meter. What are my next options? Trimming? Extending? Also, how critical is the 3/8" (center to center) of the 2meter and the 70cm legs? I couldn't quite get it to 3/8". I'm right about 1/2"
Grounding the shield side of the coax at the base of the mast should not be a problem. Use the same or similar connecter that I show in my video Dipole and Inverted V Antenna Basics. Thanks and 73! :)
Hello Sir, you videos are very generous and wonderful--thank you!! Could i make this antenna and add reflector and directors so i turn it into a handheld for the satelites? If yes any idea of where i can calculate the spacing?
Re. using the cable tie instead of a the U-bolt to keep your cable at 90* from the antenna: That's not advisable for long-term use, because the UV from the sun will damage the cable tie quickly. It'll only last a season or two in the summer, I bet. Tell me Dave, for using inside a ground floor condo with a 2m/440 HT, to need minimal construction time and space, but a good trade-off in gain, what do you recommend? Coffee can? J-Pole? Dipole? Thanks again for the great videos.
I built this with brass rod and it works great at 25' on a mast on my roof. 5w handheld is all I use. I can work repeaters up to 80mi away easily BUT there is one repeater I can only make with a lot of noise. Could I use this same design with longer elements for more gain or would you suggest a different design? Thanks!
I like your vid. A newbie to home brew antennas I have a problem. You mention in the vid that the 70cms rod is finished to 6 1/4" and the 2m to 18 5/8th". When I check your mounted antenna on your web site the rods do not appear to be cut to those lengths. Am I missing something? Excuse my ignorance please. 73's.
Hi Dave - just discovered your channel. Got my Foundation licence a few weeks ago (it's the entry licence in Australia) and I've been looking for a multi-band antenna for my rig (currently only an HT), and this looks ideal. Would there be any benefit in making the spacing between the two elements larger for more adjustability ? Jon VK2FBID
Nice Videos Dave. I'm just getting started (I take the test in the AM) and I live in a apartment. So, do you have any ideas or videos on us apartment dwellers? Also, do you know of any other Hams, who has a good YT channel? Thanks, Dave
I noticed that when it rained, that my magmount antenna on roof would start showing a poor swr.. I measure resistance at 9.2 ohms. between ground connector and center terminal... am thinking of changing to a different antenna.
I really like the single feedpoint. I am new to Amateur radio and am wanting to get into LEO satellite with a HT. Could a reflector(s) and director(s) be worked into this design to make a single feed, dual band yagi for satellite operation? If so, how would the specs probably look?
Does this require a balun? Also, I'm considering using this on top of my shed which is around 2.5 meters high, would this be ok? Also I am using a cobra cb and would this be suitable with this type of antenna?
Hi Dave,Would appreciate your thoughts about grounding this antenna. In addition to grounding the pole, I would like to ground the coax shield connected to the bottom pole . Would that affect the characteristics of the antenna? Thanks Paul
Hi Dave, for the 70cm band would you recommend an air choke balun or can this antenna be used safely without? Cheers for the video. Very much appreciated.
i found your wonderful site and the calculator. My problem is, the calculator doesn't tell me where (what distance or proportion) to put the reflector. Or maybe reflector is not compulsary and it will work just well without it? I got all the materials and will probably do the wonderful U shapes you show here and then add on the same plane directors spaced for the two bands... Thanks alot for your wonderful videos!
This antenna is good, I can reach a repeater 50 mile away, but my radio doesnt have the punch to get a audio signal there 20 watts maybe, I can reach other repeaters 30 mile away and get good response, same 20 watts, I am a member of a 2 meter group in Hiawatha, first antenna I ever built.
I went to get the parts for this and Home Depot nor Lowe's (close to me) have stainless rod. Got all the bolts & washers in SS though. They have 1/8" steel rod or 1/4" aluminium rod. Can I use the steel and then paint it black? Neither of them carry roof top TV antenna parts any more but I'm sure I can find some U bolts in plumbing.
Thanks for sharing this idea of a combined dipole for both bands.🙂 I am a newbie and I am building a similar antenna. Can anyone give me some advice regarding adjusting the length of the 2 combined dipols? I mean - can they just be adjusted each one (using a Nano VNA or something like that) on their own or do they influence each other so that a "special procedure" or order should be applied to get the SWR to a good level on both bands?
Beside good design the presenter gives very educative and high quality lecture.This is something we are missing not only on UA-cam but generally at universities nowadays. Thanks for that!
Hi Dave, great video. I have just completed construction of this antenna using a couple of old CB antenna whips which are also made from stainless steel and a length of timber for the boom. My antenna is mounted in the loft and it works great I can open a 2m repeater 60 miles away using my handy running 5 watts. This is my first ever homebrew and I'm really pleased with the result.
73
Dean M6BYF
Dave, I built this antenna in 2021 and installed in my attic. With a Baofeng HT I could reach repeaters 40 miles away. I have since used it in my mobile radio trailer for field day and other mobile ops. I elevate it about 30 feet and have made simplex contacts 65 miles away. This antenna works great and is an excellent project for new hams as I was at the time. Thanks!! KO4MkD
So I built an antenna based off this video but very different. Used the idea of the elements and attaching them but most of the rest was my own design. Friday an Elmer came by with a very fancy analyzer and after checking it all through the 2 meter and 70 centimeter bands he said "don't change a thing" as he'd never seen an antenna perform that well....and he's been telling everybody about the new HAM that built an amazing antenna!
The most impressive operational test was with a Baofeng handheld on low power (1 or 2 watts). It is hitting a repeater 30 miles away off of a 12 1/2 foot (from the ground) PVC mast and running through 100 feet of RG8x coax. Signal report was fully readable but "not as good" as the transmissions with higher power on the Baofeng and my mobile rig.
THANK YOU DAVE for the inspiration to build an AWESOME antenna!!!!!!!
MY VERSION:
Gray PVC 3/4" electrical conduit "T" (with the removable cover)
18" 3/4" schedule 40 PVC for the standoff
1" x 1" x 3/4" slip "T" at the end of the standoff with the elements mounted on the outside of the "T"
18' of RG58 coax from the element feed point, passed through the PVC standoff though holes drilled in it then wrapped around the 3/4" pipe standoff, then into the pipe at the end of the wrapping so it can pass into the conduit "T" where it is soldered to an SO239 that protrudes through the "T"
3/4" schedule 40 PVC opposite the elements as a counterbalance to keep from putting stress on the mast....i.e. balance it out.
The bottom hole of the conduit "T" is used to mount to the mast which is built from 1" and 1 1/4" schedule 40 pipe.
I'll be doing a video on the whole thing when I start building the next one which will first be analyzed without the RG58 choke and then with it unless it gives amazing performance without it.
KG7TUO, Medford Oregon.
OH...I bent my elements around a drill bit of the proper diameter which I mounted in a hole on a piece of equipment in my garage as I loaned my vise to someone and it never came home. After getting the bend started, I used a pair of Vise Grip pliers to finish the fold. Then I cut the elements to length with a hack saw. I got the stainless rod from a local welding shop. About $21 for 10 pcs of 3' long 1/8" thick stainless welding rod.
A big hand to you for helping to keep an old ham on the air!
Our personal thanks..
Jimmy, ARRL TS, WX9DX
I just want to thank you for taking the time to make this wonderful video of such a simple, yet functional antenna. 73.
Thanks for sharing this! I've been looking high and low for an easy home-made antenna I could make without a lot of specialty parts, and this one is perfect! I was able to put it together with some 1/8" copper wire I had left over from a previous project, and a spare coax cable from our TV. Better still - it works perfectly! I love that it can be tuned without additional trimming. Great design, thanks again!
Hi Dave, Thank you for sharing this video. I have constructed one a few months back just for receive and have it mounted about 20ft off the floor. I passed my foundation license a couple weeks back and now being able to transmit I have been getting very good results. Thanks once again 73's M6OOL - Stef
i would just like to say thank you so much for this knowledge. i am just about to get into amateur radio and i found this incredibly informative
Built this antenna last weekend and it works great. Thank you for the video. The only thing I did differently was used a piece of uni strut bolted to the plexi in place of the pole clamp for more mounting options.
Awesome video it’s nine years later but thank you.
An outstanding presentation - theory is all very well but there's nothing like making something and trying it with scope for adjustment. Topped off with metric units for us Europeans! Perfect practical guidance with the proof that it's works exceptionally well - with a real radio! My vote for the best antenna project on the web.
2m/70cm Vertical Dipole Antenna the best i have seen so far keep up the good work from m3mic manchester uk
73s
Great video. Built one with 1/4" alum rod I had in the shop. Mounted on my roof on a tripod, SWR of 1.1 - to 1.27 across most of the 2 m band. Very happy with the results. KK4VXL. 73.
I built this antenna for scanner monitoring and its the best receive antenna of any that I own. Thank you for sharing your knowledge with us. FYI I used 308/308L 31" Stainless steel welding rod.
(PGK of 8 at $10-12 from local weld shop).
I made the Antenna exactly as your specification and the swr was1.1 works great thats 2 projects of yours made keep up the good work.
Charlie 9H4cm
I built one of these this afternoon and it works great. Roughly $20.00 in parts, and less than half the afternoon to construct. Great design.
You are a Ham always sharing your knowledge. Thank you! I am building this antenna today. I had to use aluminium rods instead, I could not find the stainless steel rods local. I got the plexiglas for free. I cost me less than $15.00 to make this antenna. Most of the cost is the aluminium rods. The nuts and bolts ect..where less and $1.50. Hope to hit the repeater the afternoon.
Thank you for your very quick response to my question. I've had a good look and feel confident to go ahead. I trust you had a great Thanksgiving.
Thank you very much! I was researching for a cheap DIY fixed antenna on 2m/70cm for my Yaesu 857d, good enough to hit the repeaters around my QTH using low power, so I built one using your measurements and it works fantastic. 1.02-1.08 swr on 2m band and 1.3 to 1.4 swr on 70cm without any tweaking or tuning. The only difference is that I used 4mm aluminum rods. Total cost under the equivalent of 35USD and about 3 hours from start to first QSO.
73 de YO4YPC
Finished mine today. Works GREAT!
A very nice build. I'll have to try that one when I get my Tech. license.
Well what can I say I dont have a 2metre 70cm antenna for home but Ive been looking to build one, this is so simple and a brilliant design and I will gave it a try. Thanks for showing us how it was done and If you done mind Ill put it on my radio forum to show the members how you did it.
73's from Daryn 2E0DKD
Thanks for sharing your creation! I built one using 1 12' x 1" PVC and 1 12' x 1 1/4" PVC pipes ( Telescoping Antenna Mast), 1" PVC 90 and PVC Box. 1/8" Copper wire and 90' coax... I am getting 1.1 SWR on all 2 meter and 1.2 on all 70cm frequencies.
Another in a string of great videos which I know satisfy many other people's needs as they do mine.
Thanks!
73's
Great video. Thanks for sharing. I have a +2 db gain rubber ducky on my hand held. I can say the gain with this dipole is considerably higher. Super easy to build. I used 1/8" solid copper with stainless hardware. I don't have a SWR meter to test it. So far so good.
A very cool project and well produced!
Nice little project.Very educational.Will build one soon myself.Thanks for sharing it.
73s from Belgium.Wim.
Really enjoy watching your video's on building antenna's; keep them coming.
73's
VE3VPC
You can use copper, aluminum, or what ever you have on hand but the resonate frequency will probably be different if the element diameters are not the same. BTW, the first one of these antennas that I made was built for 2 meters only and had elements made of steel coat hangers. After scraping some paint off the coat hangers to connect the feed line, I used two screws to fasten the elements and connect the coax to a 1x2 mounted on another board (the mast). It worked - but it did rust. 73! :)
Spacing for a reflector is mentioned in the comments below. On the yagi calculator page it says to use equal spacing for three elements and the amount to space the elements is displayed in the fourth box.
Thank you Dave, I made your antenna over the weekend. I will be putting it on the roof probably this coming weekend. Thank you for the great videos. KG5OFV.
one of my fellow SCAN homebrewed this. I plan to give it a try later.
Good video, Dave, thanks! Thanks also for using in paralel the metric system. I get lost every time I hear something like 23 and 17/32 th inch ;) you must be master mathematicians in the USA, to be able to decode those fractions :) Keep up the good work, Dave!
I'll have to make one like that. I love the SWR readings! Full power out! Good design.
Usually we use baluns in larger HF dipole antennas. For a small antenna such as this a balun is not critical. Using a balun with this antenna may cause more problems in terms of loss rather than be of any real benefit to matching impedance.
beautifully elegant dual band antenna. thanks.
I built this antenna a few weeks ago, it works. havent tried it for distance, I used brss rods from homedepot
Were your lengths the same with using brass?
Today I built this antenna using aluminum rods. Works perfectly. 73, PA0PUB
From Brazil thank you the project;
@darynsax Glad you enjoyed it. Feel free to embed the video in your forum. Like all vertical antennas for ground wave the higher you mount it the better it will work. 73! :)
Thanks for the great vid. I used your write up, so thanks for that too. I used wood, 1/8th steel, and 1/4" bolts for a first run test. I'm restricted, so this one is in my shack for my baofeng uv-5r. I'm 11 miles from a local repeater. My handheld duckie could barely activate the repeater if I sat right, and the qso was almost completely one sided. Now I get much better rx clarity and my contact reported almost full quieting along with some brief notes about low tx volume of the uv-5r. Next: di
I added the $25 Btech microphone to my 8 watt Baofeng and got much improved audio.
going to have a go at making one of these for use at our caravan, nice and light and not intrucive , thanks for the very easy instructions,
best 73
de m6lbi
Brilliant and elegant design. Thanks, 73, KC3BXZ Joe
Reflectors can be added to the antenna giving it an extra 2 - 3 db gain and about a 58 degree beam width. The reflectors can also be stainless steel rods and can be attached with small u-bolts, from wire rope clips like I used to hold the coax on the end of the boom. A reflector for 2 meters might be spaced 15" back from the driven element and made about 40-1/4" long. For 70 cm a rough guess would be a 13" long reflector mounted no more than 6" back from the driven element. Thanks and 73! :)
marco poggioli piacere antenna 88 108 fm pacco
Dave i thank you for sharing the wisdom of making this wonderful antenna but can you give me a dimension of how long is each element from the bolt bend till theyr tips for 2 m and the 70cm end??????
hello can you show me a drawing of the reflector for this? thanks
that's really a great idea can you share a detailed diagram, please
73
DE VE7JAI
@@HaRedVlogs same here, I want to know how to install the reflector.
I used brass rod for mine, which seems to work just fine.
@cl4yd0h You're getting much closer. :) Try another 1/8" or so. I suspect that your HT antenna may have a more gain than a simple dipole antenna if testing it at the same height. This antenna will work better the higher it is mounted.
Great video I'm going to make a couple. 1 for my go bag 1 for the house. Your awesome thanks
Hi Dave, thank you very much for your video. I built this antenna and it works perfect. Later I will try with another for 10/15/20 if posible. I will look at your videos to get information.
@cl4yd0h You're not far off and the antenna just needs a little tuning. Remember "Lower, Longer." If SWR goes continuously higher from 1.6 (144 MHz) to 2.2 (148 MHz) then the antenna is working better at lower frequencies. So shorten the antenna elements just slightly to tune it higher in frequency. Try adjusting the antenna until you see at least 1.1:1 SWR at 146.000 MHz. 73! :)
Steel rods or coat hangers will work but they do rust and have different electrical properties that may make the elements a slightly different length. Fastenal, and possibly Grainger, sells stainless steel rods. I've added a webpage to my website with links to these and other antenna parts. Click my username to visit my UA-cam channel and the link to my website is in the upper right corner. Thanks for watching and 73! :)
Yes, copied today and works brilliantly. I had 8mm stainless rod, so harder to bend, but got there eventually. 70cm SWR came in at 1.7, but 2m hardly moved the needle, so not going to adjust at all. Thank you, G0WKT
Hi David, You have the lengths correct but may have missed seeing the diagram. Right now there is a picture of the antenna on my main page of my web site. Click on the picture to go to the project page then scroll down to the diagram. Sometimes I do make a mistake in a video and so always check my website for construction notes. Thank you for watching and 73! :)
hola David muy buen video, solo una pregunta, el positivo del cable coaxial es el que va a la varilla de arriba? muchas gracias
@MacintoshWizard My U shape bends are not exactly perfect but are within about a millimeter or so measuring from center to center. Place the rod about 8 or 9 inches into the bench vise and start bending at a right angle. Then take the rod out and place the short end horizontally in the vise and finish bending it. It may take an extra try with another rod to get two that are similar in shape but it shouldn't take much to get the hang of it. Good luck and have fun. 73! :)
Brilliant Dave!! 73
This one might be a better "backpackable" antenna than your original. I wanna build one that folds up and fits into the back hatch on my sea kayak.
Hello Dave. Great build. Thank you. I just finished building one of these antennas and made very subtle changes to your design. (I actually designed it to materials I already have. 4' mast to 1 1/2" angle iron, then to the plexi. I installed an SO 239 female connector in the plexi and ran 2 pcs of short 18 awg wire to the bolts for the rods.) Question: I am getting a high SWR reading no matter where I place the 2 elements. Can't manage to get it below 1.6 on 70cm and almost the same on 2meter. What are my next options? Trimming? Extending? Also, how critical is the 3/8" (center to center) of the 2meter and the 70cm legs? I couldn't quite get it to 3/8". I'm right about 1/2"
Grounding the shield side of the coax at the base of the mast should not be a problem. Use the same or similar connecter that I show in my video Dipole and Inverted V Antenna Basics. Thanks and 73! :)
Thanks alot--going to the site!!
Nice job!
Excellent video
Thanks alot--goingto the site!!
Great build and vid! Sorry to hear about your friend, the silent key, R.I.P. -KJ4JAE
Oh and you just got a sub!
Hello Sir, you videos are very generous and wonderful--thank you!! Could i make this antenna and add reflector and directors so i turn it into a handheld for the satelites? If yes any idea of where i can calculate the spacing?
Thanks for the video..good project
I do have some video of making the ends of the cable. It's from a different project. Give me a day or two to put it together and I'll post it. 73! :)
Re. using the cable tie instead of a the U-bolt to keep your cable at 90* from the antenna: That's not advisable for long-term use, because the UV from the sun will damage the cable tie quickly. It'll only last a season or two in the summer, I bet. Tell me Dave, for using inside a ground floor condo with a 2m/440 HT, to need minimal construction time and space, but a good trade-off in gain, what do you recommend? Coffee can? J-Pole? Dipole? Thanks again for the great videos.
I built this with brass rod and it works great at 25' on a mast on my roof. 5w handheld is all I use. I can work repeaters up to 80mi away easily BUT there is one repeater I can only make with a lot of noise. Could I use this same design with longer elements for more gain or would you suggest a different design? Thanks!
I like that antenna
excellent video i am taking your design and making a 2.4GHz / 5GHz dual dipole.
I like your vid. A newbie to home brew antennas I have a problem. You mention in the vid that the 70cms rod is finished to 6 1/4" and the 2m to 18 5/8th". When I check your mounted antenna on your web site the rods do not appear to be cut to those lengths. Am I missing something? Excuse my ignorance please. 73's.
great antenna
Excellent!
Dave, I have watched many of your videos. how well do you think it would work on a vehicle using pvc rather than plexiglass?
Hi Dave - just discovered your channel. Got my Foundation licence a few weeks ago (it's the entry licence in Australia) and I've been looking for a multi-band antenna for my rig (currently only an HT), and this looks ideal. Would there be any benefit in making the spacing between the two elements larger for more adjustability ?
Jon
VK2FBID
Great Video! Thanks.....
Enjoyed very good !!!
PU1 PCS Paulo César
73
Brasil-Rio de Janeiro
The antenna was so cool thanks for the sharing, can you please give the measurement of the dipole and i gonna make my own. Thank you 73's
Hi Dave post some new videos on how to build antennas. Looking forward to it.
Nice Videos Dave. I'm just getting started (I take the test in the AM) and I live in a apartment. So, do you have any ideas or videos on us apartment dwellers? Also, do you know of any other Hams, who has a good YT channel? Thanks, Dave
When bending did you place a round pipe into the bend to make the bends match?
I think to make it last a long time the stainless metal parts are best.
I noticed that when it rained, that my magmount antenna on roof would start showing a poor swr.. I measure resistance at 9.2 ohms. between ground connector and center terminal... am thinking of changing to a different antenna.
@cl4yd0h Oops. By shortening the antenna I mean to adjust the elements inwards and not by trimming them. ;)
Got to build one of these. Be get for a.r.e.s. or just to use at the park.. thanks
Thank you sir for the informative video.
But i had a question. Can we use any other material then stainless steel?
Can i use copper rod?
Hi Dave and thanks for these great videos. How many watts would this antenna take?
I'd like to know this too.
I really like the single feedpoint. I am new to Amateur radio and am wanting to get into LEO satellite with a HT. Could a reflector(s) and director(s) be worked into this design to make a single feed, dual band yagi for satellite operation? If so, how would the specs probably look?
Does this require a balun? Also, I'm considering using this on top of my shed which is around 2.5 meters high, would this be ok? Also I am using a cobra cb and would this be suitable with this type of antenna?
Congratulation very good
Hi Dave,Would appreciate your thoughts about grounding this antenna. In addition to grounding the pole, I would like to ground the coax shield connected to the bottom pole . Would that affect the characteristics of the antenna?
Thanks
Paul
Hi Dave, for the 70cm band would you recommend an air choke balun or can this antenna be used safely without? Cheers for the video. Very much appreciated.
Thank you m8
i found your wonderful site and the calculator. My problem is, the calculator doesn't tell me where (what distance or proportion) to put the reflector. Or maybe reflector is not compulsary and it will work just well without it? I got all the materials and will probably do the wonderful U shapes you show here and then add on the same plane directors spaced for the two bands... Thanks alot for your wonderful videos!
This antenna is good, I can reach a repeater 50 mile away, but my radio doesnt have the punch to get a audio signal there 20 watts maybe, I can reach other repeaters 30 mile away and get good response, same 20 watts, I am a member of a 2 meter group in Hiawatha, first antenna I ever built.
I went to get the parts for this and Home Depot nor Lowe's (close to me) have stainless rod. Got all the bolts & washers in SS though. They have 1/8" steel rod or 1/4" aluminium rod. Can I use the steel and then paint it black?
Neither of them carry roof top TV antenna parts any more but I'm sure I can find some U bolts in plumbing.
Since I plan on mounting this in an attic and not exposed to the elements. Can I use 1/8" galvanized rods instead of stainless steel for the elements?
This definitely needs a balun. A couple ferrite chokes around the coaxial right before connecting to the dipole will do the trick.
Thanks for sharing this idea of a combined dipole for both bands.🙂
I am a newbie and I am building a similar antenna. Can anyone give me some advice regarding adjusting the length of the 2 combined dipols?
I mean -
can they just be adjusted each one (using a Nano VNA or something like that) on their own or do they influence each other so that a "special procedure" or order should be applied to get the SWR to a good level on both bands?
I wonder how much the lobe pattern is directed having the elements this close together in the radiation pattern.