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
Beside good design the presenter gives very educative and high quality lecture.This is something we are missing not only on RUclips but generally at universities nowadays. Thanks for that!
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.
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.
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
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!
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.
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??????
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.
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).
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
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.
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.
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
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.
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.
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! :)
@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! :)
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! :)
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 RUclips channel and the link to my website is in the upper right corner. Thanks for watching and 73! :)
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! :)
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.
@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! :)
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.
@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! :)
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
@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.
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 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.
There are links to antenna calculators and modeling software on my website. Please visit my RUclips channel for the link. Thank you for watching! 73! :)
Dave, my name is Jim, N2OWM and I've got a question. Does the Plexiglas have to be 18" long. I have a 12" in length piece of Plexiglas laying around. Can this be used? Or is the 18" length critical?
I would have put each element on one side of the plexiglass arm, using the 2 screws to secure it down. That would make a more secure hold on the antenna (w/ 2 points of contact). But the antenna's feed lines might short out the connection, due to the metal screws?
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.
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?
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.
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.
Hello, I am curious because I am trying to learn, but how is the harmonics of the length figured out? are each of the measurements a fraction of 70cm and 2m? Thank you!
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 am new to HAM.. I haven't even picked up a radio yet. I want to make this antenna. The question I have ...Does the bend have to be 3/8" from O.D. or I.D? I have some stainless tubing and not sure I can bend it that close without crimping the tubing. Is is critical to make that tight of bend or can they just run parallel ? Thank you for your video..I want to watch every one you have to learn.
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
All of the calculators for dipole element length say that each element should be 19.5 inches for resonance at 144Mhz. I noticed you specified 18 5/8". Was this because it gave you a better SWR reading?
+Jonathan Rogers different metals are resonate at diff freq and as copper flows better than ss the distance of the copper will be longer (as the electrons will move further) hope this helps this has been my findings. I keep notes of antenna projects length vs materials and swr.
It looks like the boom is almost exactly 1/4 wave @ 2meters and the coax is at 90 degrees along the boom to the mast, is that why you don't need a balun?
Follow up question. Do you have a calculator that shows how to build this? For example, if I make this out of 1/4" copper rod, does that change the spacing between the elements?
It shouldn't change it as long as you're measuring from side to side of the elements, not the centers. Usually the spacing isn't too important because its two separate bands. I hope this helps!
Or if you're up for some math set up a proportion equation. Diameter over Gap equals (Your diameter) over unknown gap and solve for the gap. Or set up Gap = Your Diameter x (His Diameter over His Gap)
Does such antennas have better UHF reception because the antenna is larger. Because it includes VHF dipole? Or does it not affect UHF reception or may it fail to receive UHF?
I realize this is an old video, but perhaps you could shed light on something. I'm wondering if the horizontal/plexiglass part is part of the actual antenna, or if it's just a hold off to move the dipole away from the mast? I'm just curious, as it seems like it would be mechanically stronger (and smaller) to mount the dipole close to the mast. Sorry for the questions--I'm very new to this. In fact, my radio hasn't even arrived yet! Just trying to decide on which upgrade antenna would best suit my needs. Thanks for the vid.
Not the OP, but my reasoning for such. It is a dipole and no ground needed. The dipoles cancel each other out. Bring in a ground close by would just create an unknown situation is what the OP was most likely thinking with the plexi standoff from the antenna mounting pole (which is most likely ground).
Technically, you can hook up any antenna you want to any transceiver you want, but performance is likely going to suffer, at best. At worst you could seriously damage your radio by transmitting through an antenna that is not designed for the frequencies you are operating on. No matter what antenna you hook up, though, if the radio is only built to operate on 2m/70cm, those are the bands you will be limited to, without radio modification of course.
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!
Whats the significance of the plexiglass length and thickness? Can wood or any other materials be used? Can the antenna elements be coated so they don't rust?
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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
Beside good design the presenter gives very educative and high quality lecture.This is something we are missing not only on RUclips but generally at universities nowadays. Thanks for that!
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.
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
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.
A big hand to you for helping to keep an old ham on the air!
Our personal thanks..
Jimmy, ARRL TS, WX9DX
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
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!
2m/70cm Vertical Dipole Antenna the best i have seen so far keep up the good work from m3mic manchester uk
73s
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.
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.
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.
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).
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
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.
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.
Awesome video it’s nine years later but thank you.
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
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.
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.
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 this video. will be experimenting with this design in 2024 👍
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.
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.
Really enjoy watching your video's on building antenna's; keep them coming.
73's
VE3VPC
A very nice build. I'll have to try that one when I get my Tech. license.
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! :)
@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! :)
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! :)
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?
one of my fellow SCAN homebrewed this. I plan to give it a try later.
Another in a string of great videos which I know satisfy many other people's needs as they do mine.
Thanks!
73's
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.
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 RUclips channel and the link to my website is in the upper right corner. Thanks for watching and 73! :)
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! :)
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.
Finished mine today. Works GREAT!
Nice little project.Very educational.Will build one soon myself.Thanks for sharing it.
73s from Belgium.Wim.
@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! :)
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.
A very cool project and well produced!
@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! :)
beautifully elegant dual band antenna. thanks.
Today I built this antenna using aluminum rods. Works perfectly. 73, PA0PUB
Going to try and build one
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.
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! :)
I used brass rod for mine, which seems to work just fine.
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
@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.
@cl4yd0h Oops. By shortening the antenna I mean to adjust the elements inwards and not by trimming them. ;)
What is the comparison between J-pole and this Dipole design?
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!
Great video I'm going to make a couple. 1 for my go bag 1 for the house. Your awesome thanks
I'll have to make one like that. I love the SWR readings! Full power out! Good design.
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 post some new videos on how to build antennas. Looking forward to it.
great antenna
From Brazil thank you the project;
Great build and vid! Sorry to hear about your friend, the silent key, R.I.P. -KJ4JAE
Oh and you just got a sub!
There are links to antenna calculators and modeling software on my website. Please visit my RUclips channel for the link. Thank you for watching! 73! :)
I like that antenna
Dave, my name is Jim, N2OWM and I've got a question. Does the Plexiglas have to be 18" long. I have a 12" in length piece of Plexiglas laying around. Can this be used? Or is the 18" length critical?
I've heard that the vertical antenna should have at least a 1/4 wave standoff from the mast. Which would be 1/2 a meter or 1.5 feet.
Brilliant and elegant design. Thanks, 73, KC3BXZ Joe
I would have put each element on one side of the plexiglass arm, using the 2 screws to secure it down. That would make a more secure hold on the antenna (w/ 2 points of contact). But the antenna's feed lines might short out the connection, due to the metal screws?
Why don't you add two reflectors? the boom seems has enough length for reflectors.
73 de kd2avu
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.
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?
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.
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.
This definitely needs a balun. A couple ferrite chokes around the coaxial right before connecting to the dipole will do the trick.
Excellent video
Hello, I am curious because I am trying to learn, but how is the harmonics of the length figured out? are each of the measurements a fraction of 70cm and 2m? Thank you!
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 am new to HAM.. I haven't even picked up a radio yet. I want to make this antenna. The question I have ...Does the bend have to be 3/8" from O.D. or I.D? I have some stainless tubing and not sure I can bend it that close without crimping the tubing. Is is critical to make that tight of bend or can they just run parallel ? Thank you for your video..I want to watch every one you have to learn.
Brilliant Dave!! 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
i made one... Thanks its works great... 73
SWR is not plural. Neat project.
You must be a blast at parties.
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
All of the calculators for dipole element length say that each element should be 19.5 inches for resonance at 144Mhz. I noticed you specified 18 5/8". Was this because it gave you a better SWR reading?
+Jonathan Rogers different metals are resonate at diff freq and as copper flows better than ss the distance of the copper will be longer (as the electrons will move further) hope this helps this has been my findings. I keep notes of antenna projects length vs materials and swr.
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?
It looks like the boom is almost exactly 1/4 wave @ 2meters and the coax is at 90 degrees along the boom to the mast, is that why you don't need a balun?
Follow up question.
Do you have a calculator that shows how to build this? For example, if I make this out of 1/4" copper rod, does that change the spacing between the elements?
It shouldn't change it as long as you're measuring from side to side of the elements, not the centers. Usually the spacing isn't too important because its two separate bands. I hope this helps!
Or if you're up for some math set up a proportion equation. Diameter over Gap equals (Your diameter) over
unknown gap and solve for the gap. Or set up Gap = Your Diameter x (His Diameter over His Gap)
Does such antennas have better UHF reception because the antenna is larger. Because it includes VHF dipole? Or does it not affect UHF reception or may it fail to receive UHF?
excellent video i am taking your design and making a 2.4GHz / 5GHz dual dipole.
What would the gain be on this?
Nice job!
Aw... Your link for the instructions is broke: the domain name has expired. Do you have the instructions anywhere else?
I wonder how much the lobe pattern is directed having the elements this close together in the radiation pattern.
I realize this is an old video, but perhaps you could shed light on something. I'm wondering if the horizontal/plexiglass part is part of the actual antenna, or if it's just a hold off to move the dipole away from the mast? I'm just curious, as it seems like it would be mechanically stronger (and smaller) to mount the dipole close to the mast. Sorry for the questions--I'm very new to this. In fact, my radio hasn't even arrived yet! Just trying to decide on which upgrade antenna would best suit my needs. Thanks for the vid.
Not the OP, but my reasoning for such. It is a dipole and no ground needed. The dipoles cancel each other out. Bring in a ground close by would just create an unknown situation is what the OP was most likely thinking with the plexi standoff from the antenna mounting pole (which is most likely ground).
Technically, you can hook up any antenna you want to any transceiver you want, but performance is likely going to suffer, at best. At worst you could seriously damage your radio by transmitting through an antenna that is not designed for the frequencies you are operating on. No matter what antenna you hook up, though, if the radio is only built to operate on 2m/70cm, those are the bands you will be limited to, without radio modification of course.
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!
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.
Hi Dave,
May I use the 50w of my old Kenwood tm241 e with this antenne? Thanks
Whats the significance of the plexiglass length and thickness? Can wood or any other materials be used? Can the antenna elements be coated so they don't rust?
Hi Dave and thanks for these great videos. How many watts would this antenna take?
I'd like to know this too.
i am looking for 2M Vertical that will fit into a 1" pvc tube. any ideas pls?
ola buenas tardes ue medidas tienen cada braso del dipolo voy hacer uno grcis