Why Do Some Verticals Have Radials and Some Do Not (

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Күн бұрын

This question came up during the live stream: Why do some verticals have radials and others don't. We answer this in some depth.
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Пікірлер: 116

@420bakersarmy 3 жыл бұрын

Just passed my extra exam today. Your educational videos were a huge help to me as well as your "lighter" videos on the practical (more fun) side of radio. These were particularly motivating as they showed me what I was working towards as well as breaking up the monotony of the more tedious parts. Thanks again for all you do Dave and please keep it up so you continue to inspire a new generation of hams.

@davecasler 3 жыл бұрын

Congratulations on your upgrade!

@Barracuda48082 3 жыл бұрын

Your contributions are always welcome Dave. 73, Kb8qlz Gary

@tahoma6889 3 жыл бұрын

It is great you bring this up at this time. A friend and I are working with an AR-10 modification, and we have addressed this very discussion.

@Calico5string1962 3 жыл бұрын

Hey Dave, Very informative presentation, thank you! My only addition to the "disadvantage" column might be that verticals (in general), and particularly those that don't have a "real" radial field, are also a bit [electrically] noisier than those that do have radials, or than traditional horizontal dipoles. I realize the topic here was radials, but thought I'd throw it out there... I use a HyGain AV-680, which works quite well, but I've have found it has a noticeably higher noise floor than some other antennas I've used/built (with radials). I currently use an inverted-V, and also the AV-680 vertical, and I can switch quickly between them when required. The vertical picks up a lot more noise than the horizontal antenna. And I'm out in the country, without much around. My noise floor is typically S-0 to S-1 (except for the occasional T-storms, which increases it substantially). Anyway, thanks again for sharing your knowledge. Always good stuff! 73 ~Alan W0ARM

@HitchHiker4Freedom 3 жыл бұрын

Good video. One of my first builds years ago was a double bazooka hung vertical. It was very quiet to the point I thought it didn't work, until DX rolled in. Surprise! Man that antenna worked the treat. I had it hung so the bottom was a little over half wave up. Used it til I switched to beam antennas.

@havok4103 Жыл бұрын

Great video dave!! I just recently purchased a DX Commander, this helps understand why im cutting so darn many radials... First contact was Indiana from Oregon!!

@twong689 3 жыл бұрын

Thank you for the video! Earlier, a ham showed me his HF dipole and explained that the vertical is the dipole put straight up, without the other half.

@mathewhorney3303 2 жыл бұрын

Great video ! Easy to understand. Thanks for taking the time. 👍👍

@donnakano282 2 жыл бұрын

Thank you! Just passed 50 years as a ham (11/9/71). While not new, it was a delightful review. When operating mobile, I would park next to the beach a drop a metal plate into the ocean. It’s amazing how much of a difference that could make. When I had an old 18V vertical mounted at ground level with a ground rod, performance was excellent. When I was forced to move the feed point up by 6 feet, performance dropped off significantly.

@ReedAB8AS 3 жыл бұрын

Thanks for another informative video Dave. We will be looking forward to the firmware video for the 7300.

@kiweekeith 2 жыл бұрын

Thanks a Stack .... Greetings from New Zealand ..... What a Brilliant Vidclip .... So well, yet simply explained .... Have passed it on to quite a few .... Thanks again .... Cheers from Christchurch, NZ

@DucatiMTS1200 3 жыл бұрын

A very informative video Dave. Thank you.

@johnmayer158 Жыл бұрын

Hi Dave, Thank you for putting out this information. I'm trying to learn more on the effects of the matching box on these antennas... One thing that you might want to mention, especially to newer hams, is the radiation take off angle on various wave length antennas. For example, a 1/4 wavelength has a take off angle of roughly 45 degrees, where as a 1/2 is about 22.5 degrees, and even lower for a 5/8 wave. These can all come into play for the type of terrain, and theoretically figuring trying for dx, not to mention ground planes. It took me many years to wrap my brain around these concepts. Maybe could help newer hams. Good luck, sir, John, N8SGM.

@donalfinn4205 3 жыл бұрын

Excellent and thank you. Going to keep this video as a reference.👍☘️

@TesserId 2 жыл бұрын

Once took apart a WiFi antenna when I head the claim that they were vertical dipoles. I hadn't learned about end fed dipoles yet. There's a reason that WiFi dipoles often have a fat section going half way up from the bottom. It's section of copper or brass tubing, and the feed goes up through the middle. So, the tubing is the lower half of the dipole, with the upper have being any other reasonable antenna material.

@paulkish007 3 жыл бұрын

ThankYou David!

@d3jake 3 жыл бұрын

Thanks Dave!

@GrinsInc 2 жыл бұрын

Thanks for posting. Cheers, SV Good Karma

@skinny4070 2 жыл бұрын

Very helpful. Thanks

@SherwoodSchwartz123 Ай бұрын

Excellent. Thanks.

@AlexandrGubanov Жыл бұрын

Very usefull video. It should help to understand antenna theory. Thank you!

@donaldsmith3048 3 жыл бұрын

I live in South Florida and my water table is only about 10 feet down. It has a lot of sulfur and other things and I would not drink it. But may be a good ground. I have a ground rod for my lighting suppression.

@ShreyasFulkar 3 жыл бұрын

Hi Dave, Can we electrically shorten radials using capacitors and inductors just like center monopole/dipole?

@bero2 3 жыл бұрын

Is there any way to position the radials to adjust the takeoff angle such that the vertical antenna behaves more NVIS?

@timmack2415 2 жыл бұрын

This is interesting, but I was recently coordinated for a 10 meter beacon. My "ground" is between 1-2. I'm looking at elevated 10 meter antennas (not ground mounted) I'm looking at A-99 or Imax2000 antennas which have no radials. This doesn't really apply to 10 meter antennas and I'm looking for some ideas from the crowd.

@peredavi Жыл бұрын

Thanks!

@miker8379 2 жыл бұрын

I’ve wanted to try the av-640 for some time but they sure are pricey. It’s my understanding they work pretty decent. I may have to bite the bullet when I move and try one. Don’t think I’ll be taking the Hy gain HyTower with me. Got 32 34’ radials on it and love it. No traps or coils.

@randman32 3 жыл бұрын

My main vertical is a 6BTV with 36 - 15’ grounded radials. This antenna is incredible and doesn’t require a tuner for 10, 15, 20, 30 and 40. 80m has a sweet spot but i use a tuner. On a 20m WSPR transmitter (200mw), I’ve reached Antarctica, Europe, Australia, Aftica. Nothing into asia.

@rsluggy6485 3 жыл бұрын

I have a similar setup. I was able to put out longish radials, either 32 x 36 feet or 36 x 32 feet. Long enough ago I dont remember for sure hehe

@twong689 3 жыл бұрын

I am in China. The mystery for me is I can work New Zealand and Australia, but not the West coast of US.

@debbiemartin8523 11 ай бұрын

Debs husband says I am currently using a Comet cha-250b vertical about 15 feet from the ground with no radials. I am able to make contacts all over the United States and Canada. Last night I made contact with Wales and Hungary. As everyone knows lot of the success in making contacts is band conditions.

@dr.nunzio_improta 3 жыл бұрын

Please Sir, explain me the difference between Radial and Counterpoise. Thank you so much and scuse me.

@8thspirit 3 жыл бұрын

From my poor knowledge - radials are on the ground and use earth reflection and counterpoise is above ground. Rat tail for handhelds is counterpoise.

@charleswoods2996 3 жыл бұрын

Thumbs up. I'd like to see a video about using mobile antennas mounted to an apartment balcony railing; the radiation patterns at different bands, height above ground, (like the 2nd floor maybe!), and using a matcher like what I am from Chameleon, the CHA-MIL Hybrid rated @ 500 watts. And maybe more specifically with the No. 8 soil quality of Akron, Ohio where I'm about 1,100 feet ASL. Thank you for all your videos, they have demystified things other Hams told me in the past that were completely wrong and yet still had to boast about elmering me. With my apartment mobile antenna set up, I've become the "Hustler Man".

@frankwc0o 2 жыл бұрын

Which HF mobile antenna would you recommend? It wouldn't matter if I had to break it down to transport.

@jaimecollado138 2 жыл бұрын

Hi David. Thanks for you antenna class. I bought HF vertical antenna Taurus RO 109, (with out radials) one week works fine and after emissions went down. Reception it's ok. What could I do, to get better. Maybe conect a ground wire from soil to negative plug? Please your help to increase Tx.

@mumi009 3 жыл бұрын

Does the vertical antenna need to stand in salt water? I live on a small island in the Aegean Sea, about 160 meters above sea level, lime rock ground. I would expect that my antenna would have good propagation. Or am I seeing it wrong?

@davidenglund 2 жыл бұрын

Dave, if I mount a vertical dipole antenna on my wood deck, which is already 8 feet off the ground, by the time I set it in a tripod for mounting it'll be at least a couple more feet off the ground. Does that equate to about ten feet off the ground? Thx K0nOC

@thomashabetsse 3 жыл бұрын

So the half wave vertical, it connects both ground and the capacitative plane to the ground lug of the balun?

@chrissewell1608 3 жыл бұрын

It seems like a ground plane antenna with 32 radials attached to it, would almost equal something like a disc-conal antenna with an attached vertical.

@TFuzz58 3 жыл бұрын

Great explanation and the best I’ve seen so far. I live about 2 hours north of the N Dakota/Montana boarder in Canada so by the map you showed, we should have pretty good soil in our area. Cheers from Moose Jaw in the middle of the prairies. Tim

@prestonshute7243 3 жыл бұрын

Great example Dave. 73 wd4dda

@flash001USA 2 жыл бұрын

Great video! You put this in layman's terms. Question about radials. You were mentioning that you could actually get signal improvements by taking an antenna using 4 radials and switch it up to using 8 or more shorter radials. Would that concept translate over to experimenting and doing a modification to an off the shelf 5/8 wave vertical antenna if someone had something like a MACO v 5/8 or even something like a Tornado 27 5/8 wave antenna? I'm always tinkering with antennas and I figured I would put the question out there no matter how dumb but it sounded. Thank you for this video and once again this was extremely informative.

@davecasler 2 жыл бұрын

I'm not familiar with those particular antennas, but some other viewer might have some ideas.

@flash001USA 2 жыл бұрын

@@davecasler Thanks for the reply. One of the companies that makes vertical ground plane antennas does make an antenna with 16 ground planes compared to their other models which use 4 ground planes and after looking at their configuration it looks like someone could do a mod on one of these antennas and probably see an improvement probably with both a smoother radiating transmit pattern and maybe better results on the receive. I can also understand why they would keep their antennas simple because of the extra cost of materials vs the benefits of the extra radials. That would be a good project to try out somewhere down the road.

@02vLxcZF 7 ай бұрын

Thanks for this very intuitive explanation. Dumb question: for non-resonnant verticals that (e.g. a 17' rod) that you typically use with an unun and/or tuner for multi-band use, what would your diagram look like? Is the end result equivalent to either a 1/4 wave or 1/2 wave assuming that the system can be tuned?

@johanrosman11 Жыл бұрын

Thanks Dave, as always very helpful.admire your knoeledge. 73 de VK6BLU

@doesstuffoutside 3 жыл бұрын

Any reason you couldn't turn a hang a doublet from one end for a multibanded vertical?

@denp54z Жыл бұрын

Do you have a link to that map you showed at min 7:15? Thanks

@jesseobrien5864 Жыл бұрын

I'm 4 stories up in the city trying to make a clandestine 11 meter cb antenna. I'm new. Any advice?

@terrymurphy4177 3 жыл бұрын

👍

@joolz989 3 жыл бұрын

Great explanation thanks. What would happen if you were to make radials out of insulated wire and fold some of the length of the radial back on itself to get the antenna sited in a small area. What effect would this have if any? I have a home made 1/4 wave for 40M that I have in my very small back garden. I have 34 radials however some of them are really short due to space. Would having them longer and folded back on itself have any effect?

@davecasler 3 жыл бұрын

Folding radials back on themselves just shortens them electrically. Just trim them and use the extra wire for additional radials.

@joolz989 3 жыл бұрын

@@davecasler Thanks for the reply and information. Much appreciated.

@izzzzzz6 Жыл бұрын

One question may people ask themselves is weather their metalic masts are messing with the design of the ground plane antenna. I have an old 11M Sirio 2020 with 20 aluminium radials horizontal, they didn't make these for long they downgraded to the 2016, some of the verticals with super long radials were also pretty decent. On 11M I used an Avanti Sigma IV which was very nice. Performed well at all heights but worked differently at various heights, handy to go over all of the locals heads when looking for dx mounted between 30 and 40 feet but only 10ft of the ground it worked local stations amazingly, scarily good.

@scottcooper578 2 жыл бұрын

I live in a RV where laying radials is impractical. Can I use an artificial electrical ground like the LDG with success?

@cylurian 2 жыл бұрын

Would you call the buddistick a 1/4 wave vertical antenna? If so, why is it that it only needs on Radial? Sound like it's not a ground plane vertical, but more like an L-shape dipole. But, which if we took that radial that is float and created more counterpoises, would that be enough to "reflect" or "push off"? I've tried two radials so far in the buddistick where the radials are touching the ground, and boy it's not that great. Would you think if I placed more radials it would make a difference? I guess it goes back to is the BuddiStick a ground plane vertical. thx.

@davecasler 2 жыл бұрын

The Buddipole does work, but it's a compromise antenna, as you would expect for something so portable.

@dennyk1969 3 жыл бұрын

Hi Dave! KB3ONN Here! quick question, I purchased a MFJ-1796 antenna, any way to " Convert " it to use on 80 meter?.. Would Love to hear your response!

@jeffwolkovephotography5306 2 жыл бұрын

Dave, I'm considering laying artificial turf in the back yard. Can I place radials under it? I'm considering a DX Commander type of antenna, but I have very limited space for radials. Can I create an effective ground plane by laying down chicken wire or similar mesh under the turf and connecting it to the shield?

@ericdee6802 2 жыл бұрын

Thats an excellent question, did you get an answer to it?, iam curios to know myself, id say yes you can, i cant see artificial turf being insulative.

@eddy2561 3 жыл бұрын

Dave, are you saying the laws of physics haven't changed much from different ARRL Antenna Handbook editions?

@chrissewell1608 3 жыл бұрын

Right. Just our understanding of the laws of physics, and newer antenna designs, have changed.

@eddy2561 3 жыл бұрын

@@chrissewell1608 Dave gave a great, detailed description of the R5000 - 1/4 vs 1/2 wave, those designs have been around long before I was born. I appreciate his assessment of the R5000 design compared to a standard 1/2 dipole

@LTVoyager 2 жыл бұрын

Have you covered the topic of vertical monopoles with asymmetrical ground planes? I assume this makes the antenna fairly directional in the direction of the larger ground plane, but I am not sure.

@davecasler 2 жыл бұрын

Yes, you're correct

@theoutdoorsliving3949 2 жыл бұрын

Sir I would first like to thank you for sharing such a wealth of information. I have a question for you but I would like to premise the question with the fact that I am not even currently a license ham, but I am working on it, now here is the question. How is it that when I hear about ground planes antennas, they are almost a talking about 1/4 wave antenna? Can ground plane antennas be build 5/8 or even full length wave?

@matthewlyon5771 2 жыл бұрын

Think about the most basic antenna, a half wave dipole. A 1/4 wave antenna needs its “other half” to make it function similar to a dipole.

@ericdee6802 2 жыл бұрын

Now doesnt the length of ground radial change the takeoff angle?

@americaswayout4489 3 жыл бұрын

We all know no one makes radials for their mobile radios, even 80 HF has to use the metal in the vehicle. I realize some large trucks sometimes on CB use a loaded dipole a few feet long on each side, but that is rare. Anyway, my point is my home could be imagined as a vehicle with a 32ft x 28 ft metal coving and some way using it the same as the car or truck body needs addressing. One fellow posted on a forum that his roof was metal with a 10,000 ohm resistance and he claimed he used a vertical of some kind with no radials and just attached it to all this metal. Locally the code requires the metal be attached every few inches with screws so all that metal is well attached to each piece? What are your thoughts using the roof?

@andyfritchen6409 Жыл бұрын

Can we use chicken wire for the radials? I have a ton of used chicken wire and can lay it down and throw some dirt over it.

@georgealbertacanadaeh1038 2 жыл бұрын

hello Dave. I have a CB Dipole tuned for 28mhz and would like to know if this antenna can be modified to any other frequency? Same for a 3-element CB 28mhz beam antenna, can this be modified to work on any other frequencies. Thanks, George Alberta Canada

@davecasler 2 жыл бұрын

If you have your Technician license, you can trim it for 10 meters.

@trooper2221 4 ай бұрын

Ok, so I’m stupid😂, will my mfj 1792 40 mtr vertical need radials? It’s 1/4 wave. I really just wanna use some pig wire fence for coumterpoise.

@b4a9ksy 3 жыл бұрын

Is there any advantage to mount a 1/2 wave antenna higher than 10 feet? Thanks.

@miker8379 2 жыл бұрын

At HF, not really unless for local ground wave which is not usually the case.

@tracyrreed 3 жыл бұрын

Can I put a vertical on the roof of my house and lay out radials on the roof? Couldn't a 40m vertical also resonate on 20, 10, etc? I've been looking for a good HF antenna for my small suburban back yard. I am considering hex beam or no radial vertical. No HOA. Whatever I put up will be on or beside the roof of the house. A multiband up to 40m hex beam sounds great but I'm concerned about how such a monster will look above my 1400sq ft house and the size of mast it will require to support it. A no radial vertical might be slightly more inconspicuous and easier to put up on a simpler guyed mast.

@davecasler 3 жыл бұрын

A 40m radial will be resonant on odd harmonics, such as 3rd (21 MHz), 5th, etc. 15 meters is the only practical harmonic to use.

@chrisscott1547 3 жыл бұрын

Good explanation. But all single ended ground mounted monopoles will need lots of radials to avoid flowing current through lossy soil. A vertical, center fed dipole, kept balanced will waste less power.

@davecasler 3 жыл бұрын

In practice it doesn't matter much. Personally I prefer the ground-mounted vertical with radials.

@chrisscott1547 3 жыл бұрын

@@davecasler Yes, it's more practical. But most hams skimp on radials resulting in the poor performance reputation.

@greglawrencemusic 3 жыл бұрын

Up-thumb this video!

@hcy0 3 жыл бұрын

Can you say which type is "better" (has more gain) - λ/2 or λ/4?

@davecasler 3 жыл бұрын

It will be about the same.

@billlamb8944 3 жыл бұрын

Thanks for another great show. 73 KD9HWH

@onewolf3750 2 жыл бұрын

Dave, I have learned so much from your videos, However, after watching this one, I have no idea why some verticals don't need radials. I have a comet 250HB (or something like that) that says no radials needed and it works ok, just not as good as my Par end fedz 80 M EFHW sloper, but I don't understand why the comet doesn't need radials. I must have missed something you said.

@cesarastiz9691 2 жыл бұрын

Go to the begining under de title "Two Basic Types of HF Verticals".

@louisseaman8455 2 жыл бұрын

Remember, in a conventional system, the antenna feed-point impedance just needs to be close to Z=~35-75 ohms to keep you under 2:1 VSWR and any design can do that through an LC network...just like an an antenna tuner would do, except in the case of your Comet, like lots of other antennas, the coil, and/or capacitor is built into the antenna.

@donalddavis581 3 жыл бұрын

You missed the best vertical of them all.... GAP Challenger DX. My first one lasted 17 years and went thru a near miss tornado..unguyed. My current GAP challenger is about 6 years old... has done more than it's part to populate the pages of my log book! LOTS of DX worked. Only requires 3 radials 25' long each

@miker8379 2 жыл бұрын

Yoga’s better luck with your gap challenger than I did with my gap challenger dummy load.

@jeromegrzelak8236 2 жыл бұрын

WHY DOES MU 4 VT ANTENNA WORK ON 6 MTRS

@tedclapham4833 3 жыл бұрын

Dave, on a quarter wave what is the advantage to drooping the radials?

@tfrerich 3 жыл бұрын

Drooping the radials increases the impedance for a slightly easier match.

@davecasler 3 жыл бұрын

On VHF it seems to raise the feedpoint impedance from 30 ohms to something a little higher.

@tedclapham4833 3 жыл бұрын

@@davecasler It works the same on the lower bands, on my 20 Metre G.P. using 4 radials drooped approximately 45 degrees my feed point impedance was 49 ohms wit very little reactive component!

@glenmartin2437 3 жыл бұрын

Thank you. The Titan DX is a centerfed. that seems to work ok.

@BartVanAllen 3 жыл бұрын

and a number of others, but the Titan is well regarded along with the R9, AV680, etc.

@glenmartin2437 3 жыл бұрын

@@BartVanAllen I worked on a Titan DX. Some complain about the directions, but to me rather simple. Just study it out carefully, then do it right, the first time. N0QFT, Glen

@cowboy6591 Жыл бұрын

Why not just use a "Disk"? that would simplify things. Or will it not work?

@maxheadrom3088 2 жыл бұрын

A title to rival The Smiths "A Hatful of Hollow" and Pat Matheny's "As Fall the Wichita, so Falls the Wichita Falls".

@jeromegrzelak8236 2 жыл бұрын

Why does my 4vt

@Bigbadwhitecracker 3 жыл бұрын

How am I going to pass the tech licence test when all of this comes across to me like Charlie Brown's teacher? (Criticism of the student not the great teacher.) This just doesn't compute in my brain at all.

@chrissewell1608 3 жыл бұрын

Study it. All you need to know is the basics, to pass your Tech test. You don't have to have a masters degree in physics. ( just that electrical engineering degree...) just kidding.

@davecasler 3 жыл бұрын

Don't over-complicate things. Just go through the tech manual and work on what's there.

@timbacchus 3 жыл бұрын

How about aluminum foil as radials?

@davecasler 3 жыл бұрын

It would work but is not very sturdy.

@JITProductions 23 күн бұрын

A different camera angle would serve you well. I got tired of noticing your nose hairs. LOL! Okay, enough of that... good job on explaining the differences. It is amazing to me how many hams who do not understand basic antenna principles. Not a criticism just an observation.