DP200 7 - 54MHz 500W Portable Dipole HF Antenna - Better than a GP Antenna?

DP200 7 - 54MHz 500W Portable Dipole Antenna - Better than a GP Antenna?
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[@watersstanton]

Hairpin match with probably 1:1 balun. Horizontal or V configurations would have no effect on DX capability, but a small change azimuth pattern.

[@BalticLab]

Amateur radio operators call it Hairpin Matching, RF engineers call it stub matching. Hams have a tendency of creating their own terminology for broadly used concepts, which makes it more difficult to find reliable, scientific information outside of the amateur radio bubble. How Stub tuners, be it a single stub, double stub, open or short stub tuner, there's a nearly inexhaustible amount of information out there.

[@TechMindsOfficial]

Thanks!

[@Steve-GM0HUU]

That's an interesting point about ham terminology. I wonder if many of the RF Engineering ideas incorporated for ham use have actually came from Engineers using everyday terms in an attempt to make the concepts more easily understood by less technical hams? Hairpin, flowerpot antenna, antenna tuner, cans, j-pole, Pixie, window line, dead bug, the list goes on 😀.

[@ayieAbj]

What band he can work

[@defizr]

Hams also have a habit of making up their own phonetic alphabet which can be confusing for those of us who were trained to use it professionally.

[@elberttanner6189]

the 40m matcher as was mentioned is a Hairpin Match tuned to adjust resonance. Put a slider on it and check SWR on 30 meters

[@VK3TWO]

Simple Hairpin matching. 40m is likely narrow because of the inductor loading. Definitely won't be a 9:1 Balun. More like 1:1. In the V is more likely to be NVIS.

[@TechMindsOfficial]

Cheers!

[@WessexWeather]

Such a great location you have there Matt! I’d love an open sky like that, not just for ham radio but also for my weather-related projects! 73, Simon, WessexWeather, M7WWX

[@seeharvester]

Yes, I was thinking that too.

[@mikewillis1592]

Just to note they are loading coils Matt, not induction coils. It looks well made, in a shed, by a keen amateur rather than mass produced. Fundamentally it is a dipole with a built in balun, which should be a 1:1, not a 9:1 for a resonant dipole. You can see it from the twisted pair used. With a 10m dipole is would be resonant on 20m. The loading coils extend this, but because they are in the centre the losses are high (radiation resistance vs ohmic resistance) but with this design there isn't anywhere else to put them. These coils are also the reason for the narrower bandwidth. You won't notice the loss of efficiency on receive because you will be limited by noise. Stainless steel isn't an ideal antenna material, nor is chrome plated steel, but it is hard to make a telescopic whip out of anything else. I agree with your analysis. To me it looked very floppy, OK for portable use, convenient to deploy, but it won't last long in a permanent installation. Should be great for 10m portable. IT is a pity they used an SO239. Most decent portable radios use BNCs these days but old bad habits die hard. I wouldn't want to use it at 400W. There is no cooling for the balun. SSB perhaps but FM/FT8 no. As you have a thermal camera, perhaps you could test that. Might be interesting. Mike

[@GoonyMclinux]

Loading coils are inductive coils, same thing. Ham terminology vs industry terminology as described by another post.

[@Steve-GM0HUU]

👍Thanks for review. Antenna is maybe a similar idea to the Buddipole. Agree that the plug in "hairpin" for 40m is a tuning stub - it will be shifting the feedpoint impedance closer to 50 Ohms at resonance. I wonder if it could be made to work on 60m or 80m by attaching hamsticks instead of the telescopic whips. I was impressed how well it performed compared to your EF.

[@TechMindsOfficial]

Another suggestion by someone else was to put a piece of wire between the tips of the two elements, essentially making it a loop. However I have something else coming up which is designed for just that. I do have a couple of moonraker multiband antennas, maybe I could try them if they fit in the thread. Cheers!

[@LB0FI]

I’m guessing that that balun is a 1:1. Having a 9:1 on a dipole doesn’t really make any sense to me. It looks like an interesting design though.

[@TechMindsOfficial]

A 1:1 would defo make more sense. Thanks!

[@LB0FI]

@@TechMindsOfficial Keep up the good work!

[@keithrushforth4019]

It's far to short to be a resonant dipole even with those big loading coils at 40m so it's impedance will be far higher than 50 ohms. That's why it has a 9:1 balun.

[@LanWolf]

As for the sagging of the elements, you might as well make a delta loop out of it by adding a wire between the radiating elements and change the 1:1 unun for a 4:1. Would be very interested if that would improve the low to ground also

[@seeharvester]

I concur. I think he said the balun was 9:1, but I don't see how that could be 1:1 makes more sense. And yes, a 4:1 for a delta loop. You'd probably have to find a way of locking the telescoping units so they wouldn't collapse in with the top wire pulling on them.

[@SuperVirus1978]

The structure and color of the plate absolutely look like FR4 PCB material without any copper plating.

[@krzysztofsoja5301]

Colour roughly matches FR4 PCB material but there is no fiberglass visible (material is transparent + no signs of fiberglass on the edges), so I don't think it is FR4.

[@SuperVirus1978]

@@krzysztofsoja5301 I was thinking about FR4 because of the surface texture visible @1:15. And FR4 is often translucent. But it is of cause only a guess...

[@aaronlindemann2669]

Looks like a hairpin match like what we use on yagi antennas. Never seen it used like this, but that's clever if it works.

[@arampak]

Shortened antennas may be fine for receiving, but the real test is the transmission. Low SWR tells just the part of the story as the inductances may introduce substantial loss and large part of the signal may go vertically which is equal to being lost.

[@MrMesospheric]

That's exactly how it will behave. WSPR tests, specifying short, medium and long skip stations in play, will soon reveal this.

[@ghope10000]

I measured the impedance of this antenna without the stub. Measured 8 ohms. (for 40m band)

[@vu3mes]

Did you try it in making contacts, how was the performance. Thanks

[@m7trsradio]

Hi Matt its a hairpin match like you would find on the bottom of a 2M slim jim or yagi. 73

[@shanehean1]

Maybe some fishing braid between the two elements when in a V? You could put loops in the braid for each band to maintain the V? Braid covered fiberglass rods may be better for a permanent install? I am seriously considering for VKFF in Tasmania as a better alternative to the Endfedz loaded 40-10 EFHW I use currently.

[@TechMindsOfficial]

That's not a bad idea, the hardware is there to experiment with for sure. Cheers :-)

[@ghope10000]

For 40m band the stub can be replaced with a high-voltage capacitor +- 500pF

[@super66craig]

A V dipole is very efficient in radiation loss. A sagging antenna or below 1/² wave from ground at resonance loses power to reflect on ground. When your above a 1/² wave the returning ground wave joins in the radiation and your bananas are going up. Lol, Decibels for those don't follow Callum. If you can NOT get 10 meters above ground then a 20m dipole is not best. A 1/4 wave vertical will radiate better, even a vertical dipole at 1/⁴ wave feed point is better than having your dipole too low. That returning ground reflection reduces your near field energy by subtraction. Maxwell decided this with math and physics not my opinion. Dont let anyone say its fine if your too low. Unless you really want local comms only then drop it for NVIS and enjoy reduced power and upward half power beam at 50 degrees above horizon.

[@MrMesospheric]

Not to mention the massive environmental gain that is available anywhere near water; about 10dB over fresh water/marshy ground but up to 25dB at long path time from the seaside (this is from real WSPR tests, not wishful guesstimating). None of that is realisable for a horizontal antenna, though a bit of sloping ground will help by a much lower factor.

[@christophersmith1155]

I want this for 11 meters . especialy now that the band is open. All of Europe is coming in great in the mornings here in New York City. I can take this to the East River Park.

[@la7dfa]

You can use it as a regular dipole I assume. Just use 260cm for each leg and just the balun. But I suppose you can make it easier if you make an end-fed that you can toss over a tree.

[@radiotests]

Great video, but it's now $140 with $66 shipping to Chicago USA. Too close b to the price of USA made dipoles but I love the review and showcasing a great antenna as you do so well.

[@JonathanAdami]

OMG, I checked ebay A$368, I then checked your link A$158 hmmm okay! haha I have an MFJ 2289 which is a little similar, designed for 1kW tho. I also saw the MA-50 which is a 200W version of the same thing. Cool antennas I reckon, they work well!

[@k1mgy]

Wind? Wonder how much it can take.

[@MrMesospheric]

The hairpin match is very common. But, it's rather irrelevant: those whips will snap the minute the wind gets up - which is pretty much all the time in the UK. And no, it will not stand a chance against a 1/4 wave vertical, more so if you run the comparison at a beach, where I expect, from experiments, it would beat the metal tube monster by up to 25dB on long path DX. How about a side-by-side challenge between the two types, on specified paths? WSPR, preferably with two 200mW WSPRlites would be ideal. Anything else is just assertion, really.

[@AdamosDad]

If you would have left the antenna in the original v configuration it would raise the ends higher possibly giving better swr and bandwidth. edit; spoke to soon.

[@jakob5481]

Interesting antenna, have you also checked the 6m performance?

[@TechMindsOfficial]

I’ll defo check that out as I’ll test it with Meteor Scatter.

[@chrisw1462]

You've done a lot of antenna videos. You've never seen the matching stub on the driven element of a beam? The loop match is the same idea.

[@TechMindsOfficial]

Nope, beam antennas is something that I have not yet ventured into. Mainly due to my last QTH. But here, at my new QTH I have the space. So there is a possibility of me experimenting with beams in the new future. Plus, it’s a good talking point for video comments.

[@2e0txe]

Its a 1:1 balun as the two conductors are twisted together. In a 9:1 or other styles they are not twisted all around the core.

[@off-trailseeking3965]

Where is this antenna manufactured? I looked but cannot find the answer.

[@mdwestlund1]

The 40mtr matching unit known as a hairpin match. Per arrl hand book.

[@pauls8456]

Looks like it would benefit from a mast extension and some rope to the elements to support them, the first bird on them would likely bend them too far…

[@TechMindsOfficial]

Absolutely, I wanted to test like this as it was the most convenient at the time. I do have a 15m mast I could try it on one day and then do another comparison against my EFHW.. Cheers

[@petronilojr.solayao4897]

can I use it for my icon V100 Repeater?

[@redeyegooner]

If you connected a wire to the tip of each antenna in the V config ,it could be a delta loop also(??)

[@48pluto]

It could. But you would need another balun. Not a 1:1 as it came with. Good idea though.

[@susanlodges48]

The two matches are a Pausey Stub.

[@vwestTube]

Such activity you people have down there in Europe, here in US not so much

[@moozoowizard]

Toroid just looks like a common mode choke to me. Ie twisted pair of enameled copper wrapped around a toroid.

[@MrMesospheric]

It would be interesting to see return loss measurements on that choke. I'd expect it to be fairly poor, getting worse up the bands.

[@alteriaautomation6867]

I don't think so, The Vee configuration radiates NVIS. The horizontal is a normal dipole, radiation depends on the heigth.

[@MrMesospheric]

Exactly. I built a 20m vee like this as a lunchtime experiment once. It was absolutely useless for anything other than NVIS and noisy. A 1/4 wave wire up a light fishing pole is an infinitely better performer, can be made for pocket money and can also benefit from watery ground gain, which is substantial (I live by the sea, and I've done the experiments; only those who don't live by the sea argue it's not possible).

[@la7dfa]

If it is a Vee or a horizontal dipole does not really matter. What matters is the average height. Once you come up above 0.5 lambda you get those sweet DX angles. If you have a dipole or a Vee near ground, you introduce ground losses and the antenna basically becomes a sky-warmer. Unless you just want to have a quiet antenna where you only hear locals on low bands, I would avoid those at all costs :) If you can not raise a dipole high enough, a GP is probably better.

[@alteriaautomation6867]

@@la7dfa Sorry. But that V angle does matter beyond heigth. Just made a simulation with nec and you will see ... V is much worse than horizontal for low angles of arrival.

[@la7dfa]

@@alteriaautomation6867 V has both vertical and horisonal components. So it can help a bit more for long distance when it is closer to ground. But if you mount it high, a horisontal dipole will have more groundgain. Up to 6dB over vertical

[@dieseldes6578]

I have always found end fed antennas to be extremely noisy. An antenna of last resorts if you will. Just my experience.

[@cdrobson]

This is not end fed. It is a center fed dipole, plain and simple as they come.

[@TechMindsOfficial]

@cdrobson I think they were referring to the antenna I was testing it against.

[@dieseldes6578]

@@cdrobson Yes sorry I wasn't clear. The antenna being used to compare this telescopic dipole to was an end fed dipole I believe. My experience of these is that they are noisy. Try a loop around your garden or house with a 4:1 for a very quiet antenna that also talks well.

[@kwladek]

Every Ham radio operator should constantly repeat out loud to himself: "The most important thing, idiot, are the antennas."

[@davidelrick3131]

Can this be used on cb band

[@48pluto]

Yes it can.

[@엄영수-e5x]

안녕하세요

[@P.SeanCoady]

Looks fragile almost to the point of single use😢

[@TechMindsOfficial]

Not at all, its very sturdy. The elements bend a bit when using 40m though as its quite long.

[@MrMesospheric]

@@TechMindsOfficial It's going to be very limiting in windy weather. It will want to turn, for a start.

[@gliderrider]

Looks fragile!

[@ricsanders69]

The transformer looks more like a 1:1 Common-Mode Choke (CMC) and the two parallel matching dealio is stub match.

[@chuxxsss]

Stub matching, at frequency, they become inductance and capacitance resonance to match the connectors.

[@thebrain4239]

6 meter has been dead in north America for years now with the exception of some sporadic E skip now and then??

[@thebrain4239]

Maijor compromised antenna

[@GunawanAhmad-y5l]

❤❤ DARI YG8RQE kreeeeen