How To Tune A 10 Meter Dipole
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- Опубликовано: 6 сен 2024
- The Technician class has access to a part of the 10 meter amateur radio band. They can operate CW, digital and phone. Antennas for 10 meters are small and easy to build. A dipole antenna is one of the easiest antennas to build.
The length of the dipole is 468/ frequency in MHz. I made this antenna for 28.3 MHz, which made the antenna 16.5 feet long.
I now show you how to tune the dipole using a MFJ antenna analyzer.
I used this formula to figure out the correction:
New length = (Measured resonant frequency / desired frequency ) * current length of the antenna.
I'm taking the Technician test in May and I find these videos fascinating. I'm just now waking up to how expensive the gear can be.
Hope you pass.
The math part was the key. Very nicely done.
i have been a ham 4 over 40 years and a simple wire antenna just blows me away when i can talk to someone around the world 73 jerry kg6mn.............good job randy....
Randy, this video is brilliant! I don't know how many videos I've watched where the guy hacks off a few inches and expects everyone to know what he's doing and why. I loved your using the antenna analyzer. You've convinced me I need one. Having seen this video, I'm thinking I'll go for the MFJ-259 instead of putting out a couple hundred bucks more and getting the full sweep plot of SWR vs. frequency in one fell swoop.
When I lived in the Denver, Colorado area a few years ago I lived in an apartment on the second floor and it had a balcony with wooden railings and I had a fan dipole, One cut for 10 meters and the other dipole cut for 6 meters which were both thumbtacked to the balcony railing and that arrangement worked very well. I was using a Yaesu FT 950 which had a built-in auto tuner.
Bill, KI7F, Payson Utah.
Hi Randy, im getting ready for my Technician licence and have been reviewing something from you almost everyday for a while now. These two videos are very good and helpful. I know that the videos are effort and time for you and just want you to know how much your elmering is appreciated. It truly is. Youre a very kind man and professional always, a great example for newcomers to follow so that they can also become professionals one day and pass it down the way you do. My name is Charles and from my heart, thank you!
They say 10 meters is dead...
Dead until a contest starts, then it's magically open for the day.
Seriously, folks... tune to 28.4 SSB in the evening and call CQ. You might be surprised at what you find.
Yes, get on there and call CQ. Also check the beacon area of the band. Google 10 meter beacons.
i just purchased a HVT-600 multiband antenna. its a whip style antenna. no tuner is needed. you simply change a jumper for what band you want to use. then to select the frequency to change the length of the whip part. i received it today and just have to make a ground plane. its very well made seems to be a great antenna
Thank you! The easy way you explained the math part was great. I took some quick notes and know I will use them over and over.
Very nice! I built the 10 m dipole this morning; my first antenna. Checked it with a MFJ-269 and the SWR is really high (3+) and best resonance is at 27.350. So, I’ve some adjusting to do. The feed line I’m using is ancient (inherited from a friend) so I’m going to make up a new one. Fun stuff; appreciate the videos!! 👍
Randy I love watching your ham radio videos for the most part they are easy to follow,comprehend and understand 73's KC9QVE
Thank you for sharing with newcomers to Ham radio...some of the information out there for DIY antennas, tuning them, etc. is overwhelming to the new Ham...you make this easy to understand and make the whole hobby more "approachable" for someone just learning. Thank you.
Question : What is an Antenna Tuner ?
Answer : A person with a set of wire cutters.
An Antenna Tuning Unit is an Impedance matching device.
Thank you for another calm video Randy.
7 3 de VK4SOE - Clandestine Radio
Good video, Randy. Hi Ade - we meet yet again. Nice to see Randy physically tuning the antenna by altering the dipole leg lengths - although he agreed elsewhere on this page that he ought to have shortened it even further for better working on the 28MHz (10 meter) band.
Picking up on what Ade says regarding Antenna Tuners, Hams out there, take note: dealers and manufacturers have been guilty of conning Hams for years that an ATU (Antenna Tuning Unit) tunes an antenna - it does not. As Ade says, it should be called an IMU - Impedance Matching Unit, or IMD - Impedance Matching Device, as that is what it does - matches the impedance of the antenna system to the 50 Ohm impedance of the radio. IMHO, better to buy an antenna analyser than an ATU.
Tremendous video - so helpful..nice hands on lesson. Thanks much.
It's worth pointing out that you can do this by just QRPing your transmitter, keying down, and spinning the dial. If the SWR meter (in-line or built-in) rises, you're headed away from the resonant point, if it drops you're headed toward it. Trim wire as needed. A little trial and error and you're in business. (Like Randy says, you should always start with a slightly too-long wire, cos it's easier to cut some off than stick more on.)
As he also said, an antenna analyser makes everything easier but they're expensive and beginners in particular rarely have one. I've got by for 30 years using the key-down and cut method.
Great video, Randy! Thanks!
"QRPing your transmitter" - does that mean adjusting it for low power?
"Keying down" - does that mean to hold down the PTT on the mic, and to do this while changing the frequencies within the band?
ANYONE??????
@@usernamemykel "To QRP" means to reduce transmitter power out. In this case you'd want no more than 5W. Keying-down means to close the code key. (You'll also hear it used metaphorically to mean "to begin transmitting", but here I mean closing and holding the key while spinning the tuning knob up or down.)
I suspect you could accomplish the same end by keying a mic instead of a straight key, but as a lifelong brasspounder, I've never had to try.
@@RobMacKendrick Thank you for the very clear response!
Dogbone insulators, like most other stressed insulators, are designed to work via compression. Wiring up a dipole with the ends being pulled apart is a surefire way to break the insulator as it is being stressed at its weakest point. If you attach the end of the dipole and the suspension wire (preferably nonconductive) at opposite ends such that they are pulling towards each other through the insulator (compression), the insulator should not break. If it ever DOES break, the way the insulator holes are opposed at 90 degrees will ensure that the suspension wire and dipole end "hook" keeping your antenna up in the air.
See: www.mtechnologies.com/dipole/bvc-007f.jpg
These were the ones that I had. For a permanent installation I would use the compression style of insulators. Thanks for the tips.
Thank you Randy. These two videos on 10-meter amateur radio has in interesting and helpful. We'll see in a couple weeks whether I pass my General class ticket and that will influence my thoughts on what to do next. Cheers and 73, KC1DIW
John, thanks and good luck with your General
Randy, thank you for the mathematical approach to figure length of wire.
Randy, thank you for the info. It is obvious, and so simple...
Thanks for this video Randy. Your stuff is always have great information and you give it in such easy to understand terms. You took the time to show the simple math that allows for quick tuning. Great stuff!
Hello from up the Hill in Tahoe. Nice videos on a 10 meter dipole build and test. I may share this with some High School kids. I just built one for them to listen on using an SDR until they can get licensed. 73 from KM6SSK
Great project for your students. I moved to Oregon!
Timeless advice Randy, thank you for sharing! Davey - KU9L
Hey, thanks a bunch Randy! Just got my General license a few days ago, but haven't looked at a whole lot of antenna building techniques. Very helpful and easy to follow. Definitley gonna be trying one of these guys at the next field day. Keep up the great work with this channel! 73 de KD9LGP
Thanks for the math! Spot on. I have a question. You shortened the antenna on both ends by 6", you just moved the insulator and wrapped the wire, you didnt cut off the extra 6". any reason why? Would it be the same results if you cut it off versus wrapping it? Thanks.
Great video. I would have added a comment regarding wrapping wire onto itself when the wire is insulated vs when the wire is not insulated, you definitely have some effect there
Hey RANDY, just wanted to say I enjoyed the video on the 10 meter dipole. And yes definitely the analyzer is a blessing keeping you from having to put the antenna up& down so much . Makes tuning the antenna a lot easier. 73 AE4OY WILLIAM A. Peacock,Sr. EM-81UF
New sub here. I just passed my Technician & General Test’s at the Cowtown HamFest last weekend. I watched your into to 2M to see the HT operation. Thanks. I am interested in making my own antennas and learning. 73 (Still waiting on my call sign) from Texas.
Thanks for the update. Welcome to the hobby
Very clear and easy to understand Randy. Thanks.
Hi Randy.I've seen a few of your videos.
Ten metres is opening up now so I'm putting up a dipole. The MFJ tuner is very nice but expensive and after tuning an aerial how often would I use one again? I can't justify the cost. I cut the aerial long then keep folding back as you did until the SWR on my homebrew resistive SWR meter comes right down.
Mine worked out at 7 feet 4 inches each side but it is indoors and quite thin wire, SWR about 1.2:1 at 28.500 MHz.
I just called S51DX, he later said he's using 1 kW. Compared to my 5 Watts it's a huge difference. I didn't work him. Why does anybody want that much power? I wouldn't like to pay his electricity bill.
73, Bill, G4GHB.
Great video!
Thanks ever so much for the nifty formula to figure out how much to shorten the antenna. I had never seen that one before and I'm sure it will come in handy around here. ~N4TYX~
Another excellent video sir! Thanks for taking the time and sharing your knowledge!
Thanks for these videos. I am basically brand new right out of the box, so these are really helpful.
I have a metal roof and no room to put antenna anywhere in yard. Will this system work over the house? If so how high off the metal roof? Or should I go with a different antenna altogether? Any help would be greatly appreciated.
Great video. Simple and easy to follow. Just the way I need it.
Randy another excellent video extremely informative!!!!
Good tutorial. I just got one recently for my All Mode Galaxy.
Enjoyed your video on the dipole !
I would have liked hearing the radios receive on ssb with that antenna. I’m a rag chewer that likes local talking so a vertical would be better for me I believe.
Great job on video. This method works on all dipoles. 73, N7JFP
Just out of sheer curiosity, Where did you run across this formula, was it in a book or something someone taught you? I plan on reviewing this over again so I can pass it on to fellow hams who need to know this. Thanks again. ~N4TYX~
Not sure. Maybe Gordon West, or maybe I found it on some web site.
Great video randy I wish your China trip was in better resolution it's one of my favorites
The China video was before I was producing in HD.
Well explained 😀, TNX+73 de Manfred, DC2FK, North-Germany
thank you very much for the enjoyed it learning video I know that and it a old video
Great videos i like it !! very usefull for me beginner i start right now with the licence, i thought you must cut the dipole end for adjusting the swr ?? is it only the length between the insolators ?? thank you
Frank Koller yes, only the wire between the isolators. The RF doesn't see the wire bent back and wrapped around itself.
Cool video! I wish I had seen this a few years ago.
Awesome stuff
Terrific info, presented very well.
What other bands would a 10M dipole be resonant at?
None. A different length for each band.
@@K7AGE Thanks
cool video, the 10m band is my fave band to play on, and i'm looking at going porable with my anytone 10m radio,an old battery from a mobility scooter and something like this sort of antenna,
thanks for the info and making it easy to understand
73 de M6LBI
Have fun when the band opens
Great video. Thank you!
New ham here.
After your recalculation you say 6 inches off each end, but your new length is only 6 inches shorter than the original length. Is this correct? Or is it 3 inches off each end? Is it the difference between adjusted length and original off each end?
Thanks.
Oh boy, I made this so long ago that I don't remember. I probably made a mistake. Not sure what is correct. It is best to just shorten up each end by the equal amount and wrap the extra back over itself. Then recheck and re-adjust if needed. Thanks for the comment. Randy
K7AGE is there a 10 meter vertical? I’m thinking using white 3/4 pvc & feed the line inside & the end cap holding it @ the top. That pvc is stiff.
1/4 wave vertical and 4 1/4 wave radials
thanks Randy
GREAT VIDEO THANK YOU VERY MUCH
Fine work 73
I’m a new ham and I sure appreciate your videos. Kj7ezh
nice!
Thanks for the video. Question: I bought a 10m full wave antenna on ebay. Its very roughly 16 ft long on both sides. Would I have better results if I trim it to the sizes you were talking about to make it a 1/2 wave antenna? The seller said if I have the room to hang it I should be fine. Looking for a a second opinion. I'm new to all of this so I don't have any swr or antenna meters yet. Thanks!
I don't think a half wave will be at 50 ohms without a tuner or fed with open wire. You will need to check it. Your radio may have a SWR meter. Just don't use full power. Best to have someone with an antenna analyzer help you out. Look here - forums.qrz.com/index.php?threads/is-a-full-wave-dipole-a-good-idea-or-not.179752/
Randy,
Great lesson and demonstration...Thank You!
Because the feed line is part of the circuit, which feed line would you suggest for this antenna?
73
KD2HYA
Tony
Tony T. Basically, any 50 ohm coax.
K7AGE Thank you for the reply!
The only thing I need is a $500 analyzer
For really cheep you can use PVC pipe for insulators
Randy, what type wire do you recommend for dipoles? Copper conductor, aluminum, copper clad? I assume this is regular ground wire I can get at Lowes? Thanks.
+chalemi I just bought a spool of #14 AWG stranded at Home Depot the other day. Black plastic insulation. I believe that the insulation will make the antenna abut 4% shorter.
+K7AGE Cut long, check SWR then trim. You don't need to cut the to trim. Just pull more through the insulator and wrap it back on itself.
+K7AGE
OK thanks for the response Randy, Is there a reason you prefer the stranded over solid? Easier to work with maybe? Also, there seems to be alot of debate of analyser vs tuner. If you could have just one, (like me) what what it be? Thanks.
More flexible, less chance of it breaking due to bending.
Why not shorten up the antenna a little bit more still yet and make it little better. Like 1.2 or better?
shartne You could. That exercise is left to the student!
K7AGE I leaned from your video about how to adjust the swr by shorting or lengthening the length of antenna wire on the insulator. I was going to move the place where the coax connects to the ladder wire and resolder it. The tape marker was a good tip for making the basic length. I am getting ready to make a J pole antenna. And that will be helpful. Thanks for this video. Good thing I didnt cut off the length yet.
Have fun building antennas.
Thanks Randy I have been watching your video how to build a 10 meter Antenna my call sing KI7VTP my name is Frank .Guam Guam USA
73 HOPE to catch you up on the air ways.
tq sir....
awesome dude de KK6M
*facepalms* i didn't put end insulators on mine...
why can't you guys from the US keep things in Meters ??
Because the BRITS gave us feet, inches and yards!! Don't blame US.
Hmm and to think I was under the impression that the purpose of the FCC licensing exam was so prospective hams could demonstrate that they had the basic skills and knowledge to do things like Hmm oh say maybe build a simple dipoles or operate their equipment safely, So please explain to me how is it that people today are actually passing their FCC exam and getting a ham radio license without actually knowing anything about radios and simple dipoles ? The bottom line is is, Handing out ham radio licences to people who cant even build a simple dipole without an instructional video kinda makes that piece of paper from the FCC worthless.
+Dan Nelson Oh well, back in the day you had to draw schematics for your test.....
+K7AGE Yup I remember those days and to be brutally honest the radio service was better for it.
Hams are allowed exclusive use of extremely valuable radio spectrum to practice their “radio art”. Why ?
At one time this exclusive use was justified because the ham radio service provided an invaluable asset to the nation. The dumbing down of the ham radio service has changed all this.
The average ham can't even build a dipole without google, they no longer have the tools nor education or skill to provide any value whatsoever to the nation,
What’s worse, is this new generation of hams have no desire to educate themselves. Many new hams actually look down upon science, engineering and math and chose rather to place their confidence in subjective personal opinion rather than science. They wear their ignorance as though it were a badge of honor.
So ask yourself what value or asset does the ham radio service today provide to the nation which justifies our existence and use of the valuable radio spectrum we occupy and use free of charge. NONE !! that’s the answer !!
+Dan Nelson There are many situations where a "basic" video like this can be helpful. My daughter is working on getting her Tech license. As nice as the ARRL study books are, sometimes a good video like this can demonstrate the concepts more clearly than written material.
I can also see it useful to hams who haven't been active for some years. Videos like this provide a quick refresher.
It may also be useful to existing or hopeful radio operators in other countries who have different testing requirements.
All in all a clear, easily understood video. Great job K7AGE. 73 from N4IXT
I can see your point and agree that videos like this serve a purpose. I guess I'm somewhat disheartened by all the right wing nutjob prepper "coms" videos here on youtube where they dumb down ham radio for their subverted purposes. I personally think this excessive focus on Ecom and doomsday prepping is going to be the final nail in the amateur radio services coffin.
In my area on the local repeaters we actually have prepper and tea party nets. These nutjobs are a serious embarrassment to ham radio. Nothing like turning on the radio at a boy scout meeting during a demo just to accidentally expose a group of kids and their parents to a bunch of ranting right wing nut jobs spewing illiterate nonsense about the Arab in the white house or one of their conspiracy theory diatribes. It's no better than CB.
It's so bad around here that most of the local served agencies including almost every hospital have severed ties with the local ARES group. The hospitals have lost so much faith in the technical competence and mental stability of local ARES groups who by the way are now mostly either ecom whackers or doomsday preppers that they have gone so far as to demand the local ARES groups remove all their equipment from the hospitals. Exactly how can associating ourselves with a bunch of right wing nut jobs and wanabe cops be good for the image of the amature radio service ?
+Dan Nelson I think this is an exception and not the norm. Just because it has happened around you doesn't mean it is happening everywhere.
I think Randy's videos and others are very helpful. Videos like these expand on what is in the ARRL manuals. Actually these videos have more useful information than the ARRL even provides. I am speaking of the License Manuals.
I will also add that this is what happens with advancement in a technology. I come from an IT background from the early 90's. Today's IT person doesn't have a clue what DOS is. They give you a blank stare when you mention an IRQ or IRQ conflict. They have never read a jumper block or bank switches.
I also hold a Commercial Drivers License. I drove semi trailers for 10 years cross country. I entered that field with no experience. Some drivers looked down upon me. Just because I didn't come from a family. Where my father was a driver and his father was a driver and his father was a driver, etc. I learned from experience. The same way I did when I finished my formal education. I didn't know how to fix/build a computer. I didn't know how configure network firewalls.
Just because a HAM doesn't have interest in a particular aspect of the hobby. Doesn't make him or her an incompetent HAM. Many of the members in my club have had their licenses for 20 and 30 years. They will even say that not many people work on their own radios. They are so intricate and complicated that you really need to be VERY careful. Now granted they can work on their vintage radios obviously.
As far as ECOM goes. My ARES group is very well respected and appreciated. We provide radio communications for many events. Once April arrives. We are busy with events up until November. Our AREA Section Manager is very busy. Along with our Emergency Coordinator.
The basics of your video are good but you went through all that trouble so you should have taken an extra 10 minutes and shortened the antenna one more time. Seeing a dip of 1.1 at a lower frequency makes it worth the effort to move that dip to where you will do most of your operating. There is no reason to settle for a 1.5 when you know the antenna is capable of a 1.1.
Your are right. One more time would have gotten it spot on..
thats to much math,I'm confused
Duh
Thanks for the videos.