20 Meter Dipole Covers Entire Band (

[@lomgshorts3]

The thicker the wire, the lower the antenna "Q", the more broadbanded the reasonance will be. I learned this in the Navy in 1976.

[@Stevesmith-yw7cr]

The question was....how thick wire for bandwidth. I have found that when I use #10 stranded insulated wire, my bandwidth is better when using 12 gage wire and way better than 14 gage wire. Did not do the numbers but I have noticed that on 75 meters, I can get a cross the entire band a 1:3 or better SWR. No tuner on 75/80. I use the same dipole on 40 meters with a Dentron MT2000A tuner to get an SWR of 1:1 all across the band. I could not do that with 12 or 14 gage wire. W1WCR (silent key) who was an electronic engineer, used 6 gage wire for his dipoles and had a flat 1:1 SWR for all of the 75 meter band with no tuner needed. His signal was impressive. I like 10 gage wire because it tangles less than thinner wire and it is just easier to work with. As of July of 2022, 500 feet of 10 gage stranded at Home Depot is $156. Not cheap but I have been able to put up 5 resonant antennas, 1 for each band, (75/80, 40, 20, 17, 10) with that 500 feet. I never use baluns and I do use clamp on ferrite beads just to be safe. Have not had any RFI problems at all even without the beads. The beads are just in case. So does wire thickness make a difference? In my opinion, it seems to be yes. I could be wrong and your mileage may vary. Every station is different. There are so many variables.

[@timmack2415]

I've always used 10awg THHN. My OCF dipole is 90' one side, 180' on the other and it's been up for 11 years without any issues. I attach dakron rope to the ends with an insulator and run it through pulleys at each end with a suspended weigh. It just "rides" along with the swaying of the trees. My 80 Meter dipole has been up since 2004 and it's never had an issue either. I live atop a mountain in the Pocono mountains of Pennsylvania and we get lots of storms, icing & wind. Just my existence and I hope it helps others. 73

[@jchintor]

I use bungee cords at the ends of the rope. Same effect but it saves me needing to put up pulleys and weighing it down.

[@n9viw]

Bungees or weights, I like both ideas! Planning to put up some sort of dipole this summer, and we have plenty of trees but no tower to get over them. Bungees... brilliant! Where do you find them that are UV stable, though, so you don't have to climb up there more than twice?

[@Stevesmith-yw7cr]

@@jchintor I tie off on small trees. They bend and take any movement well without degrading. And they are free.

[@DonDegidio]

Hi Dave, 2.5mm squared wire is equivalent to our 14 AWG. Formula for dipole in meters is 150 / frequency in MHz. WJ3U

[@norrinradd8952]

Don gives solid answers. 73 buddy

[@mthc85]

Do people not watch the whole video before commenting? Dave does a fantastic job and all his videos. They are very informative. Not to mention take a lot of time. Dave thank you.

[@a2phil]

You don't have to have a 10+ minute video explaining everything, but you need SOME time...

[@jamescollier3]

ideas for most are emotions today

[@petertate3436]

As someone that is from the broadcast industry. The thicker the better.. I notice skin effect doesn't get a mention. When I say "thicker" I mean more surface area. In my world skin effect means all the power travels in the outer 30% of your conductor.... This is why you see Lattice towers and flat strap..... Don't forget copper rusts like all other metals and this is why the expensive big boy coils are coated copper pipe or flat coated ribbon as the surface resistance will change and thus the tune. I too took the video on it's title.... maybe that's the wrong title? But ever wonder why Shortwave Arrays used for the likes of the Russian Woodpecker look like they do (for example)? There's part of your answer.... The cage broadens the tune, and the power handling.... 73's all

[@joewilson2258]

Another way to get the same answer in meters is 300/14.175 divided by 4 and you will get the length as you would by 468/14.175 .

[@Quoodle1]

Your answer is correct and proper to the question asked. The antenna geek in me took the question literally and thought of a cage dipole. But that would be overkill on 20m.

[@mikesmith5139]

Thanks Dave for a neat description. Excellent advice about making a Fan Dipole for multi-band operation. 73, Mike M0MTJ

[@727jetjumper]

I made a RL EFLW out of some scrap insulated stranded 18 awg wire. So far, I’ve received WAS and 21 countries running less than 20w pep.

[@REKlaus]

You did a good job on answering the question you read but after watching the video 4 times, I didn't hear the question in the title talked about.

[@wynandwolmarans6689]

Me also waiting f that I believe have a effect because of skin effect that's why cage dipoles may be implemented

[@manfredcaranci6234]

He quickly uttered something near the beginning that the thickness did NOT matter.

[@ericdee6802]

@@manfredcaranci6234 there isnt a "Recomended must have" specific wire gage until you start adding Kilowatts. Ive used anything from 18awg to 12awg sucessfully, stranded wire ofcourse.

[@jamesburton1050]

@@manfredcaranci6234 hmm, trying to figure out why my antenna doesn't seem to do anything then...

[@Gruuvin1]

It's known that you DO get a wider bandwidth from a thicker radiating element, so the video title is the subject of curiosity. Take, for example, the jpole designs that use twin lead or those that use 12ga solid copper, which produce sharp swr drop and narrow bandwidth, versus the more common 1/2 inch copper pipe jpoles which produce a much wider bandwidth.

[@teresathomley3703]

I totally dig your opening music!! Good ol' big band stuff. Valuable info as well- thank you very much.

[@glenmartin2437]

For receiving short wave radio as a kid, I used solid tinned antenna wire about 20 or 22 gauge. It held up well in southern California, even with the Santa Ana winds.

[@Ben--David]

I use a 2.5 lb. barbell weight on one end to keep the wire tight. As wind blows it will adjust up and down. I live on the Gulf Coast so on a nice spring day we will have 70 MPH winds, If a hurricane comes my way I can bring the entire mast and antenna down in less than 5 minutes. I use Flip-Tite Tie-Down Straps on my mast so it can be brought down in less than a minute after I get the wire antenna off it.

[@cioiart1]

Hello Dave. I think in the metric system it is pretty easy. If you want a half wave dipole on 20m band, you just calculate 20m/2 which is 10m. No need to make the feet calculation before. It is not a critic. I really appreciate your work a lot. Thank you for doing all these information rich videos.

[@cioiart1]

@ojizarco zurdo You are perfectly right. Because Dave’s videos reach people worldwide, it is worth mentioning the metric system too. In many parts of the world you can only buy metric system tape measures

[@bill-2018]

Luckily I'm o.k. with both, having used the Imperial system and then we went Metric. I still find I prefer to measure things in feet and inches though.

[@GordonHudson]

In my experience, when using a balun the inductance in the balun will result in the elements being slightly shorter. On element thickness I experimented on 144MHz by glueing aluminium foil to cardboard. A very wide strip was shorter than a thin one for a perfect match. The wider strip had a wider bandwidth. With HF antennas thin coax cable shorted together gives under 2:1 across the whole of 10m. A thinner wire would not. Unless the balun was very lossy.

[@norrinradd8952]

The question of how thick the wire needs to be was both asked and answered by Dave @ 1:37. It was previously stated that the wire available was about 14 AWG. Dave spent most of the rest of the video answering the actual question, which is far more critical to the antenna working on 20 meters.

[@MakeDoAndMend1]

Hi David. We use metric in the uk and divide the speed of light by freq. I have been told that radio waves travel through air better than copper for example. So the wire used has a propagation delay and has to be used in the calculation of wavelength. In coax manufacturers quote a value of propagation delay. Big question from me. As not sure. Cheers from old George

[@norrinradd8952]

Good comment. There are a few online calculators that take into account the velocity factor of the wire, if you happen to know the specification of the wire you are using. This variable can potentially alter your required element length by quite a bit. I tend to round up and cut long, but yes it is good to know what you're working with for more accurate calculations.

[@MakeDoAndMend1]

@@norrinradd8952 Many. Thanks for info. I can remember having to change the cable length from my CB radio to SWR meter at one time to correct it. But seems to be 100years ago. Cheers from old George

[@zoran9a3hpdiy]

On HF + - 5cm doesn't make any effect. On VHF or UHF any millimeter is important(1/25th inch, so inch is not good measure unit, OK on HF)

[@nealbeach4947]

Awesome video. I use 12 Guage solid for all of my antenna projects for the simple reason that i already have tons of it and I refuse to pay what they want for new wire now days.

[@berettamod961]

Hi Dave, I want to thank you for your series of videos over the years. I started watching your study guide series in 2015 and in the summer of that year I passed the Tech and General levels. More recently I have started teaching local ham classes with a small group of instructors and this past summer I passed my Extra as well. Now It looks like I need to get my VE certification so I can proctor the tests at the end of the class sessions. I hope all is well with you and yours. 73s! KG7UUJ

[@davecasler]

Fantastic! Thanks for sharing!

[@alexandernevalainen]

nice keyboard you have on your left, i have one like it but in Swedish layout and i love it.

[@TH-oh8cw]

Hello Dave. When figuring length for an off center fed dipole antenna would you still use 468? Or a different number? Secondly, how do you calculate the correct ratio of length for each side being that it is an off center antenna?

[@danmyself5341]

I always wondered about a few of those questions you answered them very well thank you very much

[@wildweasel6898]

I have dogs that love to dig so my plan was to mount an antenna on an old tv antenna mast on my roof. Am I understanding correctly that I should mount it 33ft from the ground to achieve half wave? Also I was going to ground the antenna by a 15 ft or so wire snaking down my drain pipe and staked into the dirt next to it. Is this way too long? Im very new to this so forgive me if im asking silly questions. I plan on taking a basic electronics class soon because alot of this is over my head. God bless.

[@Roddy1965]

Incredibly, once you know that a dipole is 1/2 wavelength....dispense with formulas, and add a bit for cutting.

[@oscarwbrown4431]

Good review thanks Dave

[@BaldurNorddahl]

Should be part of the test for the license? Speed of light 3E9 m/s divided by frequency 14.2E6 1/s equals wavelength in meters.

[@davecasler]

Yes, but don't forget to throw in the 0.95 velocity factor for wire.

[@manfredcaranci6234]

Speed of light is 300E6 m/s which is equivalent to 3E8 m/s, not 3E9 m/s.

[@BaldurNorddahl]

@@manfredcaranci6234 yes thanks for the correction. I must have typoed that.

[@tilmar120]

Great videos Dave.

[@ThinFreddysFlop]

Hi thanks for the videos. Quick question. I have made a long wire antenna out of fine copper wire. I figured low current so thickness wouldn't matter. Am I wrong and a thicker wire would make a much better antenna? Thanks in advance.hanks for the videos. Quick question. I have made a long wire antenna out of fine copper wire. I figured low current so thickness wouldn't matter. Am I wrong and a thicker wire would make a much better antenna? Thanks in advance.

[@nelane31]

Wery helpful thanks, what will be the best diy antenna for 2 meters ?

[@bhamptonkc7]

Help, I use an AH-4 random wire tuner on 80 or 40 and have been using ace hardware clothes line for a couple years I was wondering if switching to copper clad or copper wire, it is portable so up and down every time and often pie one end to a tree and pull it up to a slight sag.

[@allenmiddendorff2068]

thank you!

[@jgwimmer]

Did I miss the part where you discussed the video title, wire diameter vs bandwidth?

[@davecasler]

maybe I was a bit subtle on that. On 40 meters and above, no matter the wire diameter, the antenna should cover the entire band.

[@Gruuvin1]

@@davecasler please edit the video title. It's misleading and frustrating.

[@a2phil]

Funny, can't seem to get below 2:1 match on 10 meters on my "as seen on Ebay" cb dipole no matter WHAT I do!! No big deal, 10 is deader than a doornail here anyways...

[@harlanhair9893]

Good info😃

[@johncseward]

Great video!!! What about left nostril nose hair???

[@Bayou_State_Outdoors]

I’m in the process of putting up 90ft of tower. Plan to hang dipoles off the side for 40m at approx 75ft. And 80m dipole at approx 60ft. Dipoles made from 12ga thhn stranded wire cut for resonance at 7.200 and 3.9. I live in the central part of Louisiana and hope to work as much 40m DX as possible. How well should I realistically expect the 40m dipole to work at that height? Thanks in advanced. TERRY K5CPL

[@davecasler]

If it's angled as a sloper, it should work pretty well. If it's level, that might be a bit high. I think getting any antenna in the air can really help.

[@criper80]

hey , I an not real HAM but I want reliable communication between Mexico and Romania, what frequency and antenna would you choose ? By now I tried on 14 and 28 mhz in good propagation hours, with a Moxon and an 100 W IC 718 and they do not hear me . what is to do?

[@Atomshamradio]

Love this content about antennas⚡⚡👏

[@bill-2018]

Interesting, as I was talking to an amateur last night on 2m who was going to try thicker wire on his h.f. long wire thinking it might be more efficient. I thought it might give slightly better bandwidth than very thin wire. Over many years I've used very thin wire and thicker wire and noticed no difference. It does seem to make a difference to the resonant length though. Very thin wire could actually burn out I suppose with very high power, maybe more so at insulators. How about cage dipoles? Many years ago, 40+, as a short wave listener I read somewhere that single wire was better than stranded because with stranded wire the r.f. is jumping from one wire to another. I've used both and found no difference. However, for low frequencies Litz wires strands are insulated from each other and twisted, to increase the surface area as I understand it. G4GHB.

[@rodneyjohnson4794]

as i read it, he is asking how THICK (not long) the wire must be to give max coverage of a band. so, is 1/2" thick wire giving more bandSPREAD than 1/4"?

[@norrinradd8952]

The question asked was "How many meters must I have on each side [of a balun] for 14 MHz." He wanted to know how much wire to attach to the balun to create a dipole that would work between 14 and 14.35 MHz.

[@rodneyjohnson4794]

@@norrinradd8952 the title reads 'how thick...'.

[@norrinradd8952]

@@rodneyjohnson4794 1:37 The question of thickness was proposed by Dave himself as a hypothetical, which he then answered. I stated the viewer question above as verbatim as I could. He is clearly asking for length. In fact, he mentioned to Dave that the thickness of the wire available to him is about 14 AWG.

[@robertrose3305]

I don't understand how the thickness of the antenna wire relates to bandwidth. BTW, a 1/2" thick wire would be a solid bar of copper.

[@kx4jv900]

Bandwidth is the question! .....

[@brotheradam]

what thickness wire is needed for full badwidth coverage on 40 or 80 or 10 meters? with no tuners

[@mewrongwayKOCXF]

I like the 7 strand 14ga hard drawn copper.

[@psychodad11]

Awesome video, thanks Dave! I enjoy and get a lot out of your videos. 73 N2SCD

[@Gruuvin1]

Dave probably made a mistake and put the wrong question on the video title. I hope he fixes it, and releases another video that addresses the question in this title. THAT is why we clicked.

[@a2phil]

AMEN!!! I ALREADY know how to figure out the length (ANY licensed ham should know it) but would the THICKNESS of the wire make a difference??? THAT IS THE QUESTION!!!

[@charlesatanasio4363]

Here's a question: Can someone hook up a radio setup of some kind to a lightening rod, could it theoretically act like an antenna for the radio? Assuming power requirements are moot? trying to figure this out for a book. Any input welcome.

[@bill-2018]

I believe it is possible to use a radio mast by tapping at a point up the mast. A bit like a gamma match. So yes, I'd say a lightning rod would work. G4GHB.

[@robertrose3305]

It should be noted that converting between frequency and wavelength is a subject on two questions on the Technician grade exam: Questions T9 A08 & T9 A09. Not trying to be a smart ass, but it is still bouncing around in my head. KN6UXD

[@RicSteelfans]

Awesome!

[@bhamptonkc7]

I have a AH-4 random wire tuner and I was wondering what would be the optimum length, I know 20f will work and 800ft will work but no one can tell me that is best. No 1/2 ~ allowed, I have seen talks of multi band sweet spots.

[@OzzieKev]

The manual for the AH-4 is a little bit vague about lengths. Partially, the limit is what fits on your property while avoiding half wavelengths or multiples of half waves on any band. I have a "random wire" fed through a 9:1 unun. The recommended lengths for this were (in feet) 53, 59, 72, 88.5, 98.5 124.5, 146, 162 or 175. There were also alternate lengths of 58, 71, 84, 107, 119, 148 or 203 feet. I have a 72 foot length of wire at present, as that's what fits in my yard. My other HF antenna is a Diamond BB7V vertical. I switch between them for which ever works better with the other station.

[@bhamptonkc7]

@@OzzieKev thanks keven that is about the same answer others have provided I know the ah-4 can tune anything but that does not mean the antenna is 100% that said I may aim for 107ft. Next question I started thinking of wire materials I have been using Ace clothesline insulated stranded steel I believe for years, I recently got some 26 wag stranded copper from DXengineeering just wondering your thoughts on steel vs copper and gauge. This will be supported on the ends and would be deployed with each use.

[@OzzieKev]

@@bhamptonkc7 Most antenna books suggest hard drawn copper wire for antennas. However, this is usually based on resonant antennas, not wanting the wire to stretch and change length. In reality, you would Most likely not notice any difference in performance between the steel and copper wires. That being said, I personallywould look for something stronger than 26 awg copper for a 107 foot span. In my location, it would likely break in the wind. I would be more inclined to try the steel wire and see how it works.

[@bhamptonkc7]

@@OzzieKev very very helpful, thank you

[@tglenn3121]

Hello, Dave, I'm wondering if you've ever done any videos on working 2200m or 630m bands?

[@davecasler]

I have not. Antennas are the issue. Plus I don't have the radio.

[@72chargerse72]

Is there a reason not to make it 1/4 wave at 40 m which would make it 1/2 wave at 20 m? VE3SAK.

[@deankoerner2436]

What is that perfect height for the diepole, you said 33' ,someone told me 17 feet , ground to top of antenna

[@kd5you1]

A half wave of the frequency 10 meters would be ideal. Using a lower antenna causes it to act like an NVIS antenna, and more of your radiation will go up at a steeper angle instead of shooting just above the horizon. It really depends on where you want your signal to go.

[@dalealanbryant7062]

Knowing, nothing about antennas - why does it have to be split in half? (dipole?) Why not just keep it in one piece?

[@bill-2018]

It's about impedance matching, especially for transmitting. G4GHB.

[@michaelmacdonald3408]

Just wondering i have lots of microwave transformers can i use the primary winding as it is aluminum for shortwave aerial about 1mm diameter.

[@ianharling9569]

Any type of wire will work.

[@robertrose3305]

The surface area of the wire is what is important, not the composition. That is why, for example, grounding straps are used -- more surface area than wire.

[@michaelruther9175]

Notice how easy the math was in metric system ?

[@michaelruther9175]

Notice that using the metric system was easy to find the dimensions.

[@paullalli7774]

The diameter of wire has little to no affect on bandwidth. It does determine how long that wire can be.

[@anonhollmuller4032]

sorry only i can tribute is my thump! i am poor and sick....so i never go to my Job again:( but the thump is yours! 73, from Germany

[@stevewuelfing6326]

The formula you gave to calculate the length of a 1/2 wave dipole in feet had some numbers transposed. It should be L = 468/f (MHz) Not 486/f Easy mistake. Using 486 will give you about an extra 1.5 feet per side (More tha 3 feet overall) on 40 meters and will require extra unnecessary pruning to tune it. But that's better than being too short and adding wire.

[@kd5you1]

He corrected himself in the video.

[@stevewuelfing6326]

@@kd5you1 Sorry for not looking further and seeing the correction. Good job.

[@donaldsmith3048]

I use 234 divided by the frequency in MHz gives me length of each side! Less math.

[@markramsay6399]

Nice resource indeed, thanks. M7MSR

[@1shARyn3]

sounds like #13 wire

[@timmack2415]

Hi, Gwen! I believe that you're spot on! 73, AA2HA

[@G3PWP]

The larger the cross sectional area the lower the resistance !

[@williamsmith5303]

468 not 486

[@paulkazjack]

How high does a horizontal end fed wire have to be?

[@norrinradd8952]

If you are talking about an EFHW, in general you should try to hang it as high as the wire is long (0.5 wavelength). You could also try it vertical or put one end of it in a tree and angle it down to the ground. Experiment with different configurations such as inverted L or V to see what works better for you.

[@paulkazjack]

@@norrinradd8952 thanks for that.

[@n5ifi]

What's a Balum?

[@manfredcaranci6234]

A balun (not balum) is a BALanced-to-UNbalanced transformer used here to convert from coaxial cable (shield grounded) to a two-wire line which is the antenna. Neither half of the dipole is tied to ground.

[@n5ifi]

@@manfredcaranci6234 No shit.. it was called a balum

[@lyfandeth]

At least TOUCH on the question of wire diameter versus bandwidth. HF/VHF/UHF.

[@kingduckford]

I think Mr. Casler may have not considered the potential main point of the question. I would hope he might do something on the subject later, especially if he is notified of this.

[@norrinradd8952]

The question of wire thickness was both asked and answered by Dave.

[@jctedsap]

I was told heavier wire would give slightly more bandwidth.

[@DonnyHooterHoot]

Doesn't matter! My MLA30+ is a tiny stainless wire and it pulls them all in!

[@sclerismockrey8506]

Of course it freaking matters if you're TRANSMITTING. You keying up into that cheap Chinese thing?

[@TheZimberto]

You could always rehearse saying his name before you start recording. Just saying.

[@Orvulum]

λ = 468 / f

[@Davidjb37721]

Does technician have 40 Mater privileges

[@norrinradd8952]

Technicians can operate (CW only) above 7.025 and below 7.125 MHz.

[@Davidjb37721]

They can now operate on 40 m

[@Davidjb37721]

40 m 7.225-7.300

[@Davidjb37721]

Jul 2020

[@TonyYarusso]

@@Davidjb37721 That was a PROPOSAL. It has NOT been approved.

[@AllanBProductions]

The number should be 468

[@ianharling9569]

Dave did correct his initial mistake.Yes it's 468 (or 143 if you want metric)

[@brentrudderham3060]

I believe the number is 468 not 486

[@glenmartin2437]

Thank you. A good video. Have a great week. N0QFT

[@sleeve8651]

Isn't that : 468 / fmhz ? Equals a Half wave ? 🫲🧐🫴 Oops ! You caught it ! Hi !