Don't forget that the impedance of the driven element is an important consideration. The currents at the end of a transmission line should be equal and opposite. So (for example) an End Fed Halfwave can get away with a minimal grounding system (sometimes just a short dangling counterpoise wire in some minimal designs), as the feed point impedance of an EFHW is so high, there's not much current. All this to say, at the opposite end of things, if you're using a short antenna that represents nearly a dead short on the frequency, then you'd an acre of copper to have any efficiency. I mention this because the charts presented here seem to skip over this very important consideration.

Thank you, thank you, thank you!!! I'm new at this and such a simple explanation. The gain stats are relative to the type of antenna. It's like saying adding an additional battery to your pocket flashlight will increase lumens 5%. Adding a car battery to your spotlight will give an increase of only 3%. No matter that the spot light will blind a deer at 100 yards regardless. K5PML 73's from over here.

@timg5tm941

2 ай бұрын

No problem!

Thank you Sir! You saved me, Time, Money and reduced my stress level by more than 20 dB's !!

@timg5tm941

Жыл бұрын

That’s great!

Good presentation. I have done a lot with verticals as well as dipoles ( not as detailed as Rudy) and I wish to note that Rudy’s findings are definitely consistent with all I have done. I just hope no one thinks the 7.5 foot antenna has more gain than the 1/4 wave antenna! It’s just that the worst antennas benefit the most from the first set of radials.

@timg5tm941

10 күн бұрын

Indeed - totally agree.

Well done Tim. 73 - Rick, DJ0IP

@timg5tm941

Жыл бұрын

Thank you Rick!

nice info

Yet another excellent video with really interesting content. Thanks for posting. 73.

@timg5tm941

Жыл бұрын

Thank you!

Raise it and use far fewer radials. Or set it up in the sea. Or install a bent vertical / sloping dipole, with the lower element as the counterpoise. Lossy dirt is probably not our friend. Trying to intermingle wires into the dirt is inherently not a great approach, but can be made to work with much effort and money. Future archeologists are going to be mystified, LOL.

@timg5tm941

Жыл бұрын

Good points!

I laid out about 6600ft of radials on my 160m system in the early 90s, with more wire in the directions I wanted to favour, and also they are up to 100 metres long in those directions. I was trying to pull down the main lobe towards the Pacific islands, US West Coast and SE Asia and it did seem to work, using a folded monopole with a broadband matching transformer. I also laid out about 50 metres of chicken wire, but that's long since dissolved. After working 300 DXCC in the 90s, I lost interest in 160 and played on LF and SHF instead, but a lot of that wire is still there at the bottom of the big mast, so maybe I'll get interested again one day. I ran a balloon-supported 5/8ths vertical on 80m, using aluminium wire tied to the top of the 70 ft mast. That was not as effective as I hoped, because it wouldn't stay vertical, despite all that wire in the ground, even with two fishing-line tethers about 200m long. I couldn't hear much on the 160m TX antenna, I ran rotatable phased square terminated loops with phased preamps and Vactrols to control the loop impedance, but they were only about 90 metres from the transmit antenna and I had to fit a detuning relay to reduce the reradiated noise from the big pole. It was a whole lot of fun at the time. I ran a double-extended Zepp on 160 for a while, that's over 200 metres long and was amazing for greyline into VK/ZL/9M, but after I laid out the radials, it was heavily compromised, so I turned it into a dipole as far from the vertical as I could managed. It was often 6 dB better into VK6 than the vert, despite the ground mat, but I always suspected it was causing shock excitation of the vert and getting a bit of help. Interesting vid, thanks! Neil G4DBN

@timg5tm941

8 ай бұрын

Wow I wish I’d have tried half of what you have .. fabulous information

@MachiningandMicrowaves

8 ай бұрын

@@timg5tm941 on receive, I had a rotatable pair of phased square loops with Vactrol variable resistance loads (LED plus LDR). The two loops had balanced preamps and the outputs were phased and combined into a balanced feed using IBM twinax cable scrapped from a big System/38 installation. That gave me steerable nulls in az/el to suppress local signals at higher angles. It was a bit fragile though. 30 ft boom with central 10 ft fibreglass section and 12ft pole, then four vertical ally poles with insulated split centres and wire tops plus guys. Mechanical nightmare, but I could hear stuff that few others could, unless they had Beverages. It was fun working strings of JAs on CW. if I was doing 160m again I might look at a ring of e-field antennas with individual SDR front ends on a common clock and processing the outputs digitally, but I have a load of microwave projects to do first!

Hello Tim ... as always, very well explained and useful Thanks for sharing / 73

@timg5tm941

Жыл бұрын

Thanks Jose!

Hello Tim. I recently put together a long wire to experiment with. The wire was 127 feet coupled to a 49:1 unun. We strung it up on a Dx commander 10mtr pole and out to a tree. Recieve was poor initially until i added 20mtrs of radials ( 4x5mtr lengths from the dxc). The recieve immediately rose by several S points. We were at sea level and surrounded by buildings and trees. I didn't add any more as we were pressed for time, but on the next experiment, I'll add more to see if i can get any improvement.

@timg5tm941

Жыл бұрын

Great info Matt

Thanks Tim

@timg5tm941

Жыл бұрын

Cheers!

Hi Tim, well explained. As we know 16 quarter radials or 32 eight work the same. Adding radials , now 300 for all bands reduced my noise also. Verticals plus radials = dx. But regardless of everything else, just put up what you can and get on the air and have fun. 73 mate.

@timg5tm941

Жыл бұрын

73 Brian!

i’ve got 16 4m radials that i lay out when using a Rybakov or long wire antenna and you notice the difference if you take some up, I also notice the noise floor reduces with 1/4 wave verticals at my qth if the radials increase from 8 to 16. all good stuff👍

@timg5tm941

Жыл бұрын

Thanks Dave great info

Great video. I have 160m of radials on a DXC which I run at 40-10m. Performs really well. I spent hours banging these radials into the ground. After two years they are consumed. One day after taking the DXC down for maintenance, and putting back up I forgot to connect the radials again. Then got back on the radio and all seemed to be working well. Only later did I discover the missing radials and reconnect. so I assume the coax was acting as a single radial? Whatever, it worked. Mark, 2E0MSR.

@timg5tm941

Жыл бұрын

Juist shows - any antenna is better than none!

32 quarterwave radials for 20M will give the same performance on 40M as if you had 16 quarterwave radials. Similarly, if you fitted an 80M quarterwave vertical over your original field of 32 x 16ft radials, it will give roughly the same performance as if you had 8 quarterwave radials cut for 80M. That's why you should put down as many as possible, you are increasing the performance on the lower bands more significantly, should you choose to change your vertical for a lower band, i.e for winter time. 73 EI5JS

Currently I'm using 16 x 3m radials under my linked vertical (17, 30 & 10. 10 is used as a 3/4 wave). It works like a charm. PSK reporter has me being heard globally on

@timg5tm941

Жыл бұрын

Nice stuff!

More radials = less holes (between the radials) in the Earth for the RF to be absorbed and turned into heat. The radial field is there for 2 reasons. 1. To give the vertical something to "push" against. 2. To act as a mirror to reflect the RF that would otherwise be absorbed in the lossy ground and send it out to the horizon (or up to the ionosphere, depending on the takeoff angle from the vertical radiator).

@timg5tm941

Жыл бұрын

Great points

Wonder how many radials a vehicle body is equivalent to. Also would a VW T5 be better then a Fiat 500 ? 🙂In relation to the mobile whip, however we do often use the vehicle body as a ground for antennas when we work /P too. Interesting thought. Or not as the case may be 🙂Nice video, as always Tim, thanks very much.

@timg5tm941

Жыл бұрын

Thanks Chris!

I saw a video on YT about using a metal door screen as a ground “radial” KB9VBR, you used a mag mount in a similar fashion on your sloper, definitely food for thought

@timg5tm941

Жыл бұрын

Nice idea!

Radials simulate having your antenna on a 1/4 wave size metal sheet. The more radials you add the antenna thinks it is connected to a solid metal sheet, Once you get to 32 radials adding more won't give much more gain as by then the antenna is seeing a 1/4 sheet of metal under it.

@timg5tm941

Жыл бұрын

Absolutely agree

@Paul_KG

Жыл бұрын

That really gave me a good visual on this topic... Thanks

@Tantalicdavid

Жыл бұрын

@@Paul_KG Your welcome Paul, here is another one, A good ground is like putting a mirror under a candle.

Im currently using about 130sq ft of hot dip galvanized 1/4 mesh, with way more radial wires than I care to admit. I’ve noticed that the ground radials seem to lower the SWR slightly, but not much. I need to do some more testing so I can quantify the differences a bit more. I should also note that where I live is considered to be average ground conductivity.

@timg5tm941

Жыл бұрын

Great info Kevin thank you

I have noticed that a 17ft. telescopic whip works perfectly (QSOs with VK amateurs /P and 100W, EFHW on their side) on an 18mHz band when installed on the magnet base on the metal roof of my car. I wonder what amount of ground radials is equal to the body of my car. I never install additional radials with this mobile setup.

Excellent video Tim 😊👍 73 G0HFL

@timg5tm941

Жыл бұрын

Cheers Nick!

I’ve done a lot of experimenting on this subject & I call bs on it all. Using both a ground spike & a low profile tripod. Using the WRC Sporty Forty with a 17’ telescoping whip. I made 3 bundles of 4 16.5’ radials, laid out as evenly spaced as I can and the SWR was still high. I removed 1, then 2 bundles and the SWR went down to 2.0:1. Although acceptable, it isn’t for me as this is where most radios start to fold back power. With the one bundle on the ground, I folded them all in half (now 8.25’ each) and the SWR dropped like a rock, 1.2 on 7.175 & 7.300 and 1.0 in the middle. So I started adding more folded bundles but the SWR once again climbed. Even after sweeping 1 MHz on either side of the center frequency the best resonant point was where it was tuned for with only 4 radials. I’ve, watched hours of videos and read so many articles on this subject, it’d make your head spin. The consensus of most is length doesn’t matter when lying on the ground and the more shorter is better than less longer. I call bs on all of it because that’s not e what I’m seeing. Ground mounted vertical antennas are finicky at best, especially with all of the different ground types. Elevated vertical antennas are a whole different animal all together. I have a BuddiStick for that and it doesn’t hold a candle to an EFHW up in a tree. With that said trees aren’t always an option so I’m still hunting for a close to perfect vertical antenna setup for POTA!

@timg5tm941

Жыл бұрын

Nice 👍

Rudy Severns is da man.

@timg5tm941

Жыл бұрын

He sure is!

Hi Tim, Callum M0MCX recommends at least two wavelengths at the lowest frequency for his DX Commander verticals. He mentions Rudy's experiments and also notes that anything more than four wavelengths doesn't make much of an improvement. Stay safe. 73 WJ3U

@TheREALJosephTurner

Жыл бұрын

How do you figure the length for radials on multiband verticals like the DXC? Does it need different lengths depending on the band, or are all the radials one set length?

@DonDegidio

Жыл бұрын

@@TheREALJosephTurner Hi Joseph, They can all be one length for ground radials. Callum had recommended 1/8 wavelength at the lowest frequency for a total amount to equal two wavelengths. WJ3U

@DXCommanderHQ

Жыл бұрын

@@TheREALJosephTurner OK, so I don't THINK Tim covered this but Rudy did an experiment when he halved the 1/4 radials into 1/8 wavelengths - but added them back in.. Essentially negligable difference. This is handy for a DX Commander because we can start by putting in say 5m long (1/8 wave) radials for 40m but the same radials on 20m, you would be getting the full q/wave radials.. And the other rule of thumb is 2-wavelengths at the lowest frequency will give you excellent ground all the way up.. Hope that helps.. I happened to be cruising Tim's video and spotted most of the guys that normally comment on my videos, also commenting on young Tim's video :)

@timg5tm941

Жыл бұрын

Good point Don 73 friend

I use ampro hamsticks with a mag mount on a small bed of chicken wire at home with good results. Xyl refuses to let me use the chicken wire on the car!

@timg5tm941

Жыл бұрын

Ha! It works!

I know one can't always do this, but elevated radials work a lot better. It takes a lot less wire requiring three to four ground radials. The folks at Motorola found that two elevated radials work just fine. Of course this is without knowing how high and what frequency these antennas were modeled on. In short, soil is lossy and should be eliminated from the antenna as much as possible.

@timg5tm941

10 күн бұрын

I agree

Having a heap of chicken wire/net, pegging this down would it detrimental as a mesh opposed to linear?

@alzeNL

Жыл бұрын

corrodes and soon becomes useless is what I have seen happen, will work for a while then the solder joints will start to go.

@Superfandangoo

Жыл бұрын

@@alzeNL This is galvanised and wound no solder joints. This can be put in the ground to stop animals digging under it. It'll last years

@alzeNL

Жыл бұрын

@@Superfandangoo be intresting to try :D

Good choice of topic, and God knows you have to get creative when the bands are absolutely terrible. I think it's about time you dabbled with a Hex beam though. Now the high bands are a thing, a small Hex beam is probably achievable. A 20m Hex beam, not so much.

@timg5tm941

Жыл бұрын

Ooohh if I had the room…

I need none! I avoid 1/4 and 5/8 wave vertical antennas because of the mess that are radials.

@timg5tm941

Жыл бұрын

Nice.. I’m a big fan of 1/2 wave verticals myself

@M0RMY

Жыл бұрын

No mess here - my radials disappeared in 2 weeks under my lawn.

@brianfields4479

Жыл бұрын

Hi Tim, what a subject . I must have gone mad here with 300 radials cut for 40m and 80m hi, but as you know my tests last year on 20m, 16 quarter waves radials worked exactly the same as 32 eight wave radials. I have noticed more radials here = reduced noise. It's all horses for courses I think, but vertical ants here have gave me more long haul dx than any other wire ant I have ever tried. Put up a vert and as many radials as your space allows and watch the dx come in. 73 mate.

Hustler - who suggests 64 radials gor their multi band verticals - must operste from an area with exceptionally bad ground conductivity ?