Build a Dipole Antenna Center Insulator - Ham Radio Q&A
ฝัง
- เผยแพร่เมื่อ 13 มิ.ย. 2024
- The dipole is a common antenna for the amateur radio operator; and with good reason- dipoles are easy to build and are proven performers. Recently I wanted to build a dipole but didn't have a center insulator. Instead of paying $25-45 and waiting days for delivery‚ I decided to build my own for about $12 using common parts (with the exception of the SO-239) and tools available at your local home improvement store.
Parts List:
1 - ¾ x ¾ x 1 inch PVC Tee connector
2 - ¾ inch PVC plugs
1 - 1 inch PVC plug
3 - 3/16 x 1 ½ inch eye bolts
3 - Number 10 washers
3 - 10 x 24 nylon lock nuts
SO-239 bulkhead connector. Order: amzn.to/2EwFHbH
Rosin core solder and flux
14ga stranded insulated wire
20/40m Linked Dipole Antenna Project: • Parks on the Air (POTA...
Support Ham Radio Q&A by shopping at Amazon: amzn.to/2kO6LH7
Read my blog: www.jpole-antenna.com
Colophon:
Camera amzn.to/2GV2Og1
Lens amzn.to/2GWC5zU
Wireless Microphone: amzn.to/2qt3vDc
Microphone: amzn.to/30lJheO
Music by license: www.premiumbeats.com
#dipole #Antenna #HamRadio - วิทยาศาสตร์และเทคโนโลยี
I like your straight-to-the-point approach of describing/ showing each step. No rambling. No fluff. Just an efficient how-to video. Thanks!
This I've been looking for. Others don't really explain this part
My man only blinked twice during the entirety of the video. There is a great chance that you are a Staring Competition World Champion in an Alternative Reality. Thanks for the video. Really helpful by the way.
Good explanation. I modified the structural parts a little based on what I had available but it's just what I need and cheaper than ordering the part on its own. Great explanation, you're a good teacher. Very clear instructions, great angles for seeing how you did it. Nice and simple.
I became a Ham almost 3 months ago, my first homebrew antenna was a 20 meter centerfed dipole similar to yours but the PVC was just a short tube, it's still in use and I make great contacts with it. 20 meters is my favorite band, I'm going to add two more legs and use spacers for 40 meters soon. 73! KI5JCO
Thanks Mike! I think you've made the most detailed and easy to follow video I've been able to find on the internet for how to make a center insulator. I'm working on a fan dipole and I was struggling with picking the right hardware and assembling the insulator. Your video helped tons!
Great idea. I strongly recommend the use of stainless steel over the cheaper zinc plated junk so common at the big box stores. Even though zinc is often considered for outdoor uses, it also rusts quite happily and well after awhile. The rust will add impedance at those points as well as fostering corrosion on conductors. I built this exact same thing many years ago in my Jurassic period using zinc plated eye bolts, which is how I began a journey to the dark side only to be saved by stainless steel.
Hi, I do recommend using SS stuff in antenna projects.
I know you are concerned about the rusting process of the galvanized eye bolts mainly thinking (mistakenly) that the dipole arms are connected electrically to them.
No it's not.
The eye bolts on either side is just a strain relief to the connection between the wire radiators (on either side) and the pig tails from the SO-239 centre connector.
You may want to watch the video again to understand the contraption.
De VU2RZA
Excellent video Michael. I like this version (using a "T") much better than other PVC center insulator builds I've seen. Great explanation of the build too.
Michael, I just used this design to make a 10m dipole this morning. I used it for a POTA activation this afternoon and made DX contacts in Spain, France & PR, as well as several in the US. Simple easy center insulator, excellent instructions. Thanks for your help.
Really appreciate your detailed instructions and parts list. Built a tape measure yagi based on your article the other day. Thanks again.
hey Michael!! im a brand new ham radio licensed past november 2022 (XE2AKL) here in san luis potosi mexio, and your video was the most easy of all!! thank you for your time and I am already your fan as soon as i get this done i ll send you a pic
So why would this video get voted down??? Free information, well presented, thorough, clear and concise. Very good sound and video quality with clear instructions..... Some people just can't be pleased. Sad. Thank you for your effort anyway sir.
Great video! Very nice design and construction build! TYFP!
I have made a few of these. I made some with multiple antennas hooked to the same center. They worked great. I spread out the different antennas on different lines. One was for the bottom of 10, 15, and 20 . One was for top of 10, 12, and 17 meters. KG7IRJ Ohio.
Good explanation, with attention to safety.
this looks way easier than what i was thinking of doing.
thanks for showing me the light.
great video. great channel.
having the parts list and picture up front is useful. you're very organised!
I use a 40m/20m fan dipole and 100 watts and have worked the world in the last 12 months.
What kind of coax do you use
lmr-400, about 100 feet
🎉🎉
I built on of those in the mid 80's... still have it. Worked well
Another awesome video! Thanks for posting and 73’s...
Real nice build and great video Michael! Thanks! 👍📻⚡👍
Michael this was another great DIY antenna project. Looking forward for the second part of this awesome video and then will start building my own. If it does 20 and 40 metres then it would be simply great. Hope you would also show how to correctly host this antenna on top of a terrace. Really appreciate all your hard work in creating homebrew projects that keeps us so much engaged and differenciates from other tons of similar channels. Have learnt so much from your videos and appreciate your prompt responses to my queries in the past. Have a great day ahead. Greetings from New Delhi, India.
73
This is a great video! You brilliantly demonstrate why sometimes its simply better to buy something from someone than to make it yourself. With all your parts costs, tools and time, you spent about 5x the cost of just buying one online.
I like to watch woodworking videos, so I know what you mean. I'll probably never own many of the power tools they use, mostly due to the lack of space. But it is good to have the knowledge on how something goes together. But then again, a trip to the home improvement store and scavenging a few junk box parts kept me from waiting 3-5 days for something I ordered online to arrive.
Great stuff! Love your channel. I'm currently studying for my General and am looking to get into HF on the cheap with a home brew antenna. This dipole project you're working on is right along the lines of what I was thinking so can't wait to see the next episode. Keep up the great work and thank you! 73, KD9PXF
Very good! I liked the instructions and the vital parts list. Thanks
Good project. I knew I was making this part way to complicated. I knew there was an easier way.
he explains the build so anybody can built enjoy his methods not to many are able to do that 7 3
Great idea. The strain on the end caps is depending on the adhesive though. I would drill through and stick a pin in to bind them and seal with glue or hot melt tape. I hope that helps.
Thanks for your time!,
Clear instructions, good job. This was helpful.
thank you for the DIY, I will do the same. Very informative channel
Great timing! I just pulled down some old Christmas lights and got two good wires out of the bunch. I'm not sure on the lengths, but it might be 2 m antenna or maybe a 40m if I'm lucky. I know how to make a dipole, but I wanted the center a bit better than soldering on the coax. This is perfect!
They are fun! My first dipole was made out of a vitamin bottle! The SO239 was mounted on the lid!
Still works today 11 years later!
I will have to give this a try, thanks for putting out another informative video!
I made a dipole antenna for the CB Band back in around 2008. I used a triple female coax T connector for the center part. I used two PL-259 connectors to attach the dipole wires to it. One connector used the center pin and the other connector used the shield hole. It worked pretty good and I got a good match after trimming down the wires. I took a nylon coated clothes line and taped the dipole to it and used the clothes line to stretch it out and tie it off to the fence clothes line poles in the back yard. I taped the lenght of the feed coax from the center connector going down to the ground to a clothes prop and hooked the prop to the clothes line at the center to support the antenna. I called it an invisible dipole because it looked like I just had a clothes line and clothes prop stretched out across the yard.
That is how I used to make mine. Simple and works well. Now I make them by only using a cap and reducer. The cap version is also simple to make and a bit lighter. I like to make more than one when I do it so I have them on hand. It seems be just as easy to make 3 or 4 as it is to make one. Excellent video!
What size do you prefer?
@@WW5RM I prefer the full size like the one shown in the video for home use. The smaller, cap version is good for taking in the field. It is lighter and smaller.
Cheap and easy to use I like it. Thanks for the great tip. Now ive gotta visit the plumbing section for my new antenna LOL :)
This was very helpful information.
Perfect timing!
nice job.. will last for years,, thank you..
Great job!!! Love the point and nothing more. Keep it up.
Appreciate your detailed explanation it’s time to replace my current dipole antenna. My current center insulator has been in use for 20 years. 73 de AA4SH
Well put together how to video...thank you,
Nice build Michael.
Awesome . Thanks for sharing
Thank you Michael
I really like your design for this center insulator! After watching this, the only thing I'd do different is use a step (cone shaped) drill bit instead of the spade bit to drill the 5/8" hole.
As always, thanks for an excellent presentation! I look forward to seeing the rest of the antenna come together. 73 - N1NUG
A step bit would be an excellent option. PVC is pain to drill big holes in- if I had a drill press‚ I'd be using that.
As a fellow Wisconsinite, very aware of our "accent", I loved the outtake at the end.
"Oh Jeez louise!"
I should have thrown a Criminey in too.
@@KB9VBRAntennas tell yer folks I says "hi"?
this is awesome! thanks for the tutorial
Dipoles can be used in VHF/UHF as well. Granted they are smaller but in a beam antenna they are used with parasitic and reflective elements. Also SSB contacts on VHF are made with dipole or folded antennas to save space. As you have said they are mostly HF/LF band antennas, they are more common in lower bands.
Thanks for the good information.
Super simple👍
I know I have seen a movie with you in it. Some comedy I swear
I enjoy your videos - please keep them coming. I was thinking about adding a 4" section of pipe to the arm where the coax connects and building and inserting an a air core wire choke. I want to use the feedpoint with balun / choke for a multiband (40/20m) inverted V antenna.
Great information, thank you.
I've been using this design for years, works great. Great video!
Thanks for informative video.
Great video thanks.
Great video
Great Video.
Great idea.
Thank you for this helpful video! :)
Well done!! thanks!
Nice job. Coast effective and easy to build. 73; Leo
Wow...your lock down mullet is coming on a treat...looks like I have competition , I'm about 2 weeks away from a full on 1985 George Michael...nice build BTW, great video.
I'm working towards the Back to the Future Doc Brown mad scientist look.
@@KB9VBRAntennas I'm expecting to see you dressed as Ben Franklin flying a kite with a key on it any day now...
I like that. 18th century ham radio reenactor
Excellent
Michael, Thanks for another great video! What are your thoughts on whether instead of connecting a SO 239 connector at the bottom of the insulator, it would be better to connect a Window feed line with a SO 239 connect at the end of it to connect the coax?
Great video, Michael - and the outtake at the end was a hoot! I think I'm going to see about getting some parts from the plumbing section at the box store and get started on that fan dipole I've been meaning to put together. 73, KO4AZY
Quick update - I went ahead and built a 2-element fan dipole for 80 and 20 meters, using your center insulator. I got the center point up into a tree at about 25 or so feet. The ends of the 80 meter wires ended up about 3 feet above the ground, with one running straight but the other needing to loop around a railing on my deck and back toward the tree, so it's more-or-less an inverted V. I find that I have to use the tuner in my Xiegu G-90 for 80 meters, but 20 meters works beautifully without the tuner. I can also use the tuner to get a match on 40 meters.
The broadsides of the dipole are oriented North/South, but I have been able to speak to a fellow in Croatia on 20 meters from NC which surprised me greatly since that is East of me and about 4800 miles away. Remarkable what 20 watts and a wire dipole can do when propagation conditions are right!
Thanks again for the education and inspiration for this project, Michael! 73, KO4AZY
@@theElderberryFarmer Dwight are both of your runs the same size? if not how did you divide them? I'm guessing you have a total of 137' ??
@@GmanfromTexas Hi - yes, both runs were the same length. I don't recall what the final lengths ended up being after tuning/trimming. I'd check, but that antenna is long gone now. I have moved on to using a home-brewed end-fed 1/2 wave antenna with a 49:1 matching transformer. I get tired of using the same antenna and start itching to try building something new.
I've had very good results from the end-fed 1/2 wave antenna. It was easy to build, uses less wire than the dipole, and is quick to deploy and break down.
To me, much of the fun of the hobby is building new antennas.
@@theElderberryFarmer i hear you. Do you have any videos of your new antena? Or any specs?
I'd really like to see instruction on the best ways to tie the antenna cable to the eye bolts, it's never covered in these dipole center videos
Nice design, looking forward to the follow up one on the actual antenna build. As for suggestions, I'd say to use deep well sockets or hollow shaft nutdrivers to tighten up the hex nuts and SO-239 nut, easier than using the pliers.
Back in 1975 I was using CB radios, and had a base ground plane antenna get mangled in a windstorm. I ended up making a temporary dipole using RG-58 coax. I measured off a 1/4 wavelength from the end of the cable, sliced around the outer jacket without knicking the braided shield, and pulled the jacket off the cable. I then spread the braid where the jacket ended, creating a small hole, and pulled the center conductor out through that hole. I then cut the old jacket into two equal lengths, and tied one end of each piece onto the end of the shield and center conductor. I then tied the other ends of the jacket pieces to two trees, spaced the right distance apart, creating a horizontally polarized center fed dipole. Since I'd used the CB band center frequency of 27.185 MHz (and done the math, measuring and cutting correctly) when I checked the SWR across the band it was essentially 1:1. We ended up using my temporary fix for months. (Here's hoping this story inspires someone!)
Inspiration accomplished!
@@bigjai Glad to have inspired someone (even after a year! 😁). Hard to believe it's been that long since I posted...
Stop back with an update if you do build up your own versions!
I made mine maybe 18 yrs ago and still up but did make it and looks like a 1 to 1 balun and also feed three dipoles from just the one. A 160M , 75M, and also a 40m and cut for the center of the band that I operate. Need a tuner at the ends but dipoles are hard to beat!!! N4JOJ
Great video, and spot on. Any subjections on how to make this center insulator to work for a 5-fan dipole, I looking at making. Thanks again for the video.
It should work fine for a fan dipole, all of the elements would have to terminate at the eye bolts. You may need a larger eye if you have a lot of wires.
I like this center insulator but I made a small addition. I put in a small screw (with the head on the inside of each arm). The wires from the connector in the base come out in the armpits of the T as shown. I put a ring connector on each of those wires and run to the screw. Each of the wires for the fan dipole also have a ring connector and attach to the screws and then i put a num on to hold the ring connectors in place.
I love your approach. The only thing I would do differently is instead of drilling the two holes for the wires to exit the center connector. I would have soldered ring terminals to the ends of the wires and used the eye bolts as a place to hock the wire to on the inside of the T fitting. Then I would have added 2 washers between to regular nuts on the outside of the Eye Bolts for a place to attach the dipole wire to, allowing for future wire repairs or to make the dipole for a different band.
That's a little more work but a great way to upgrade the project. Thanks for sharing.
Michael, I I tried that with a 4 band fan dipole. I added lugs to the antenna legs and stacked the lugs with star washers on the eye bolts. I filled them with dielectric grease to prevent corrosion. Looked really good. Worked really poorly. On further research, I decided that the dissimilar metals oxidized much faster than expected - weeks, not years. I reconfigured with copper wires as shown in the video and Bob’s my step-uncle. Still have a few tuning issues with the fan, but I made it to the Czech Republic a week ago on 40 with 80w SSB.
Earl Griffith what about using brass hardware? Or Stainless Steel since it doesn’t oxidize as fast.
I used as much stainless hardware as I could find. Lowes didn't have ss star washers. So I had to use plated steel. My lugs on the wires were tinned copper, so a 3rd metal in the mix. I cut the lugs off and twisted the wires together and soldered.
Instead of a spade bit use a step bit. You can make a variety of hole diameters and the cut is clean and quick. Perfect for SO-239’s.
Nice work. Thanks!
Wish you were my neighbor. We could "compare notes" on our radios & antennas 😊
I’d recommend a chassis mount so-239 because you can bolt onto the ground part instead of trying to solder to it.
Best way to get from tree to deck
Hey Michael, good show. Thanks. KC3BXZ Joe 73
Homemade antennas are the best
Another great video Mike!
73 George KB3WAQ
Very useful tip. I can either do it exactly as shown or use it as a reference. Hope you come up with a video of how you build a 1x1 balun. 73 from PY5WHO.
You may want to check out my latest POTA video. I build the linked dipole antenna and put it on the air: th-cam.com/video/zvtKlqQ6DSo/w-d-xo.html
Hello and thank you for the nice video I have a question ,I bought a 10 meter dipole long wire center fed I want to put this long wire about 4 foot above my metal roof building is this a good idea or bad idea? will it help with reflection? Thank you again.
cool. Always wanted to make a dipole and this thing works great
I'm curious where you found your power block with the Anderson connectors in it maybe you can share that I know it's off topic
The balun needs to have an impedance matching transformer to "balance" the load at 50ohms.
You also need to make sure, when you erect the Dipole, you have several layers of insulators at uneven wavelengths to reduce noise and attenuation
As a noob to antenna building can you explain what those to wires connect to that you soldered to the so239 connector? As always love your videos
Those two wires will each connect to a leg of the dipole antenna. It may make more sense when I build the dipole in the followup video.
I very much enjoy your videos. Does it matter if the wire is stranded or solid?
Standed or solid makes no difference. Stranded is easier to work with and is more flexible, but it is prone to stretching. Solid is stiffer and doesn't stretch so much, but it is a bit more brittle. I typically use stranded wire for portable or temporary antennas and will use a stronger wire for permanent installs.
Do you have a video on how to make a fan dipole?
great video.
but do not use silacone, as sure it will plug up a hole but never really sticks to most everything, water will get past it. better to use caulk. also around the base/threads of the I bolts as a added protection.
Question: what is the purpose of the eye hooks if the dipole is suspended by the end insulators? I can see having one on top if it is going to be hung as an inverted vee, but I’m confused what the side ones will do. Thanks!
Do you not need a ground wire? Also are those wires your antenna or are you planning on connecting them to something else?
Very Informative Michael Thanks but what if i use end cap instead?
73s From DU6KD & DW6XLC
You could use end caps‚ but since end caps are the same diameter as the Tee connector‚ you will need a small section of PVC to join the two pieces.
Good job.Bravo.18 sv 134.Dimitris the Greek.73.
This was simple enough that I might just be brave enough to attempt it after I obtain the necessary tools. I think I might trim the 3/4" end caps though so that they sit flush with the T-connector.
I hope you will do a follow-up video on making the wire portion of the antenna. I'm not feeling quite comfortable with that yet.
468 divided by your operating frequency. If you only remember one formula, remember this one. That gives you the length of your dipole. So, a dipole for 40m, say 7.180; 468/7.180 = 65.18, that's your length in feet. Cut that in half (32.59) and you have the length of each wire. make them a little longer (33 feet) to allow for wrapping the ends around an insulator and strain relieving the connector ends and there you have it. One thing to keep in mind, if you use insulated wire, the antenna will end up needing to be a little shorter due to the decreased velocity factor, but this gets you in the ball park.
At 20ft or higher you will never notice if the end caps protrude. Once you get on the air you wont care either! =]
@@toddschutter6535 For newbies it would be great to actually see what you describe above. Thanks for adding it tho, will hopefully get me close.
OK can anyone tell me what happens to the two black wires...do you twist them together? What do you do with the top eye hood...hang from a pole? Thx.
Can You tell me the type of cable used??? Thanks.
yes
Why not connect internally and keep it reasonably sealed? Make the wires into a loop, solder the loop closed, and put the loop beneath the washer for each side of the dipole before cementing the cap.
Hi Michael,
Nice homebrew Center insulator.
Lack of such piping material here in Germany.
I ordered my center insulators ready made from the british company moonrakerukltd on eBay or the German company WIMO.
They are about 9$ or 7.5€.
Homemade would be a lot better, I agree, because you can put an small 1:1 balun inside.
73 and stay healthy
Stefan DG4RBS
Plus shipping I assume?
@@WW5RM Yes, of course.
But if you try, like me, to build a lot of different Dipole, you can order 5 or 10 at one time and the shipping reduces 😊
Thank Sir. How can I connect with function generator?
Is a balun needed for a 20M Dipole antenna? I will not be using this 20M dipole for any other frequencies other than the 20M that it was made for. I made mine the exact way you made your antenna in this video. I also have an isolater. Would I need both? Do they pretty much do the same job?
The purpose of a 1:1 balun is to prevent common mode currents from returning down the feed line. If the dipole is properly tuned, common mode should not be an issue. I don't use a balun at all with my dipoles. Occasionally I've added a common mode choke by either coiling the cable or adding ferrites near the feed point and a line isolator serves the same purpose as a common mode choke.