4 Phased Verticals for Extra Gain and F/B

This amazing discovery was highlighted and proven to work by a Caribbean station many years ago. They built one for 20m band and pointed it towards North America. I promise to get around to building this and also pointing at NA. If I had the room, a certain winner for 80m - but 40m would also be great fun! It's a PAIR of parasitic verticals, phased together - so very easy to make. See what you think! Callum.
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[@JoshColletta]

Fun bit of history: this technique was developed in 1929 by an engineering firm to create a null in what was then the shared signal of WFLA and WSUN in the Tampa Bay area. That year, the Federal Radio Commission (precursor to the modern FCC) realigned all the broadcast frequencies, and they WERE going to allow WFLA/WSUN to operate at 1,000 watts at night, but they were moving the stations from 900 kHz down to 620, which was also to be occupied by WTMJ in Milwaukee to the north. WTMJ strongly objected, so the FRC decided to reduce the Florida stations to just 250 watts at night... which, naturally, the Florida stations were none too happy about! So the Florida stations got in touch with an engineer in Washington D.C., who himself enlisted the help of a British engineer who had experimented with radio direction finding. They put up one the in-phase tower on the south side of the Courtney Campbell Causeway bridge and the out-of-phase tower on the north side, and included a switch so that the station would only be directional during the nighttime hours. When they fired it up and threw the switch, sure enough, there was a null toward Milwaukee, and all three stations were happy! Today, it's just one station on 620 in the Tampa area, (WFLA long since moved to 970) and it now uses the call letters WDAE, but they still only go directional at night... now with 5,500 watts. WTMJ, themselves, are directional 24/7 today, with two different patterns for day and night. Their nighttime pattern includes a null to the southeast to protect WDAE. In fact, it looks very much like the four-element design you've drawn up! ( radio-locator.com/cgi-bin/pat?call=WTMJ&service=AM&h=N ) And even though they run 10 kilowatts at night, I know their setup works, because I can't pick them up at night from my town just north of the Michigan / Ohio / Indiana state lines. Radio World's John Schneider did a great write-up about it a few years ago: www.radioworld.com/columns-and-views/roots-of-radio/the-development-of-the-directional-am-broadcast-antenna

[@DXCommanderHQ]

Brilliant comment. Thank you!

[@milosnovakovic4942]

Instead of making that kind of shape, i would choose a circle. And in the middle put a driven element. With a use of simple switch, you would get directivity, and much wider slope. 2db of gain versus plus 20 degrees more where you can operate...i always choose 4 over 4 el stack on 20m and up, over 5 or 6 over 6. Just ny 2 cents

[@jameski5oeb668]

This is so interesting!

[@jasonjames6076]

I find myself watching these antenna modeling videos a dozen times through each! Keep up the good work Callum, I plan on buying a dx commander soon and these videos are like antenna Christmas 🎉

[@DXCommanderHQ]

Nice one!

[@WECB640]

Cal, on the phasing lines.... Don't feed them all at 0 phase. Instead, experiment with the software and slightly alter the phase between them ie. the two in the middle at 0 degrees, then the OUTER 2 at 30 or perhaps -30 degrees. You can focus the pattern. This is somewhat related to "beam tilt" that we use on an FM tower to push the RF slightly lower than the horizon to saturate the target audience area. You may also be able to place the verticals skewed a bit from your target, and then steer the pattern by delaying the phase from tower 1 a bit more each time as you get to tower 4. (ie. Ant 1 - 0 deg, Ant 2 - 10 deg, Ant 3 - 20 deg, Ant 4 - 30 deg) PS. It would be great to have the model available and we could each tweak it as a collaboration effort. 73 OM

[@DXCommanderHQ]

Yes, I have been looking at that. Good idea. Initially, it'll be parasitic anyway, phasing opnly the front driven ones.

[@LarryEmery-K1UO]

If you open the coax to the center vertical it would be better. That would detune the vertical in the middle from the resonant antennas in the 4 square. I think grounding the center vertical would interfere more due to your using other passive grounded elements. The inteference amount, I think, would depend on the actual length of the center verticals and 20M element total length.

[@LarryEmery-K1UO]

meant radial lengths of center antenna.

[@DXCommanderHQ]

Yeah.. I'm wondering how I might do that easily - from inside the shack! Still thinking!

[@LarryEmery-K1UO]

@@DXCommanderHQ I had to use a rf DPDT relay out at the antenna base placed in a small 4X4 box (about size of a UNUN) and controlled via bias T. Just needed to operate the relay to open the ckt (both center conductor and ground to the radial field) to keep the center vertical from re-radiating interference to my surrounding 40M 4- square elements..

[@FreshAirWaves73]

Love this video Calum ! I think the same way you do I love crunching the numbers and design things ! Good one ! Cheers from Hawaii!

[@DXCommanderHQ]

Awesome! Thank you!

[@MAV8865]

Cal.. you have to try it!!, 99% of use can't and I might even get to hear you on 20m - the only band I can't with your friday pile up. - by the way, cracking video has always. 👍 (M7MNP -Blackpool should be Newton, Preston but no-bugger knows where that is hahaha)

[@DXCommanderHQ]

Indeed, we don't know where half the places are. "Opp North" is fine for me!

[@michaelpolimer2128]

my phased 40 meter verts distorted the pattern of my home brew W1FV/VE6WZ 5 active element circle Rx array, we opened the center conductors of both Tx verts and eliminated the distrotion. Ultimate solution was to move the circle array after I killed off all the poision ivy in the far corner of my yard. You could model it and see what you see...............cheers from New England to Old England..........73 Mike, K1FNX near Boston

[@DXCommanderHQ]

Open up.. Yes OK..

[@quantumradio]

Good video Cal. I've wondered about modeling in MMANA GAL a 5 element vertical Yagi-Uda. Essentially a single driven element vertical, e.g. a DXCC, plus a single parasitic reflector & 3 parasitic directors. Not an array like you've got, but more of a Yagi-Uda turned 90 degrees to make it vertical using the ground as a reflecting plane. Interesting stuff. 73!

[@joekrepps]

I’ve always been interested in a vertical yagi as well. If we get a nice, low takeoff angle for a vertical, could we further direct the RF in a favorable direction? It would do wonders for QRP, for example.

[@quantumradio]

@@joekrepps Agreed. I did a quick modeling in MMANA-GAL and found that the best bang for the buck may just be a single reflector behind your driven element. Callum's video shows an array of these pairs which should definitely focus the beam as his model shows. More directors will help out, but to me the gain curve (dBi) at 5 degrees elevation starts looking like it hits a "gain plateau" after 1 director. Fascinating topic. 73!

[@DXCommanderHQ]

and @quantumradio - you keep it up. Great thoughts..!

[@thanielsibula6189]

@quantumradio So how about a small array of two active elements, each with a single reflector and a single director. If space and number of elements available is limited, could that work?

[@quantumradio]

@@thanielsibula6189 I get a marginal ˜10% (1.9 to 2.1 Peak dBi) improvement with the small array you describe when compared to the array of two driven elements and two reflecting elements. This for a Freq.=7.150MHz, Elev_angle=5.0deg., Height=0.0m, Material=Cu wire, Ground=Real (dielect.=13 & Conduct.=5mS/m), enabled 11 radials in the simulation. Best of luck in your project & 73!

[@jamescstanley5018]

Hi Cal, interesting project! Just a daft thought, you say by dropping to 20m, you can get in an 8 pole array, and then dangled the thought that 16 would be fun. As you are constrained by space, why not try the 16 pole array, but on 10m, from what you say you have the room for refectors as well! There would also be a cost advantage on 10 as the poles would by half the height of the 20m array, although the field would look like a porkupine with 16 2.5m poles sticking up. A Foundation holder could have a legal kilowatt station with it!!! As I said, just a thought, maybe a bit daft, but it would be fun to try. I would be happy to drive up the 50 miles from North Oxfordshire to join the fun and games! 73 Jim M7BXT

[@Scotscan]

Wow, just wow

[@DXCommanderHQ]

We could call it the Pork-Opine :)

[@DXCommanderHQ]

PS - I quickly modelled that.. 13dB more than a straight vertical.. Needle nosed pattern. Very tight. 10 Watts becomes 200 Watts.. 400 Watts becomes 8,000 Watts :)

[@FromthehamshackwithNJ4Z]

can you please send me the file on that layout I would like to look at it@@DXCommanderHQ

[@cfsyoutube5799]

Hi Cal, in my old day-job we used circular antenna arrays called "Pusher" arrays, the smaller brother of the Wullenweber (look it up on Google, this wouldn't fit in your field :-)) like the one that used to be at RAF Chicksands near Bedford. Any metal object in the vicinity would alter the beam shape/direction on a pusher... It might be worth mentioning in your next "phased array" vid that the reason you need specific lengths of feeder on this type of set up is that you're trying to maintain a usable impedance for the complete array, if you just use T pieces and equal/arbitrary co-ax lengths you end up with a very low impedance (all elements simply in parallel). That's why for example the 2 vertical Christman method uses 84 degree feed-lines plus a 71 degree phasing loop. 73, Craig, 2E0HXF

[@Rubedo777]

Callum your a cleaver Barnstable on the QT…. The Antenna Alchemist… you’re good to go exploring like this and inviting us along… I nominate you for an award… don’t know which one,,, maybe I’ll send you the secret to the Philosophers Stone,,, or a magic wand… huh ! If I did you’d probably tune it up on 20 mtrs 🤪 Yerraguddun 💙

[@DXCommanderHQ]

Magic Wand sounds cool!

[@g4lmn-ron401]

The 20 m element on the sig 12.5 is vertical but its coax feeder is at 90 degrees and on the ground. It's within the area that is the whole phased array antenna, it has to have an impact on the radiation pattern. I don't see an easy way to model the situation But Ham Radio is a practical hobby so: You can do real world tests when you build it by dropping the sig 12.5.

[@KeepEvery1Guessing]

I don't know. But I do know that it's going to depend on the (electrical) length of the coax between the feed point and the switch that's grounding the other end. And if you have an old school dip meter, you may be able to figure out where it is resonant, holding the meter coil close enough to the element to couple (and being that close will effect the resonance.

[@DXCommanderHQ]

Yes.. Now that might work.. Calculating the resonant freq whilst it's grounded is annoying me!

[@lexheath8276]

Yep, the electrical length will be greater than the vertical radiator.

[@alexjh47]

I would be really interested in seeing more details on how you tune the reflector in the real world. There's two dimensions you can change with the reflector - distance from the driven element, and length of the reflector. What do I measure, and what do I change, to make sure it's performing well?

[@DXCommanderHQ]

Measure the tune on an SWR meter, just like you were tuning a real vertical - then short out the ground to the element..

[@charlesi3284]

sounds Good try it

[@metalhalokj7vzy164]

Interesting resonance and radiation pattern question for the 20 m element Lord Callum, Lol maybe an antenna analyzer would show you. IDK.

[@DXCommanderHQ]

It won't show me the pattern unfortunately..

[@wildbill1]

ya got to do it lol !!!

[@gtretroworld]

Brilliant video and Super interesting but God knows who has the room for this…😂

[@DXCommanderHQ]

20m maybe..?

[@Hydrostream1972]

Scarlett warrior 27 cb antenna . Ever tried it. Liked to buy a couple but I live in the United States You should do a review on that antenna looks like a good trucker antenna 🚚 6 feet tall. Mike from Minnesota. 772 Minnesota kidd

[@Scotscan]

Be interesting to see if there is an interaction with the current tx antenna (sorry can't answer the question can the modelling software indicate?). It'll be an impressive station that's for sure. Nice Xmas pressie for all us subscribers!

[@robertmeyer4744]

great. that work both ways. the RX comes up in the direction of TX as well. that antenna in question will be effected buy length of coax that short. cause a delay . take some measurements and put it in model . That feedline length to antenna switch will be a factor. if you put delay lines in phasing harness you can steer your beam. may be a bit fun. I am in NY,USA may be a big difference to me. 73's

[@DXCommanderHQ]

Nice

[@mixxndj]

Ya gotta do it so I can make the contact with you out here in California…

[@TheRdeanpeek]

could you compare your array here to a rhombic...tks

[@mattstosh6960]

Thanks for this Cal. I've been waiting for this after my comment about having a 3 vertical poles (phased system for 15m). I'll be switching to your 4 vert poles this summer. Ground is frozen right now... Can you give some detail/info on how YOU build a phasing harness.

[@DXCommanderHQ]

I need to make a video about that :)

[@BobHolowenko]

When you modeled the flamethrower there was no radials included. Is that going to throw off the measurements? Also, in the question about the signature poll, would just the unused elements be grounded or would the whole unit be grounded? And that's what you're asking about because I don't think it would be part of the master antenna based on what you said. If you could clarify that, it would be easier to answer the question at the end of the video

[@alexjh47]

My understanding is that radials are accounted for in the 'ground' settings of the modelling software.

[@DXCommanderHQ]

What Alex says.. They are accounted for in the ground setup button.

[@davidbowering9820]

Model it, build it, use it and then post the results on you tube!

[@48pluto]

It isn't that easy you know. Theory and practise don't go always hand in hand.Yes it will be interesting if he could pull this of

[@rayhill1855]

Hi Cal good day to you. Will you be making the phasing harnesses or purchasing them?

[@DXCommanderHQ]

Making.. I am currently sourcing the right coax right noiw..

[@kbroadstock]

At 10:35 on the video you said we could add refectors, don't you mean add directors as you already have refectors.

[@DXCommanderHQ]

Both :)

[@paulsengupta971]

Wonderful how this array sounds, I had this niggling feeling that your long wire, 160m end fed, gave similar results. I looked up the video and it was about 5.7dB at 5 degrees on 20m, or, as you said at the time, about 10dB more than the vertical. I know you went on to change the design, but would it be worth revisiting the end fed 160m for transmit and receive? This array seems like an awful lot of work and expense to get similar results to a bit of wire chucked in some trees.

[@paulsengupta971]

Maybe use the drone to get the antenna up in the treetops.

[@DXCommanderHQ]

Yeah.. So something has happened to that long wire.. I'm not getting anywhere the gain I used to.. I shall inspect today and see what happened..

[@justinrayguitars6024]

I would like to ask an uneducated question. On 11 meters using Antron 99 for the antenna could I place another antenna say a Sirio next to it and use it as a reflector to make it more directional?

[@DXCommanderHQ]

Try it! However spacing and tuning will be important else you could end up going backwards :)

[@CC-hk6vy]

WOULD LOVE TO USE DX COMMANDER AS a driven element, either re-engineering on lengths and bands, with another pole as a director or reflector. Vertical stationary array, or maybe even 3 elements. Not as easy problem, but if you use great circle bearings, it could be a great way to overcome the exorbitant cost of a beam.

[@ThinKkBIGG]

4 square multi-band with 4 DX Commander.

[@FromthehamshackwithNJ4Z]

Spacing between the antennas becomes a problem on other bands.

[@DXCommanderHQ]

Yep.. Just what John says :)

[@ThinKkBIGG]

@@FromthehamshackwithNJ4ZIndeed, the problem with a 4 square multiband is the choice of spacing, a bit like a multiband HF beam but also the phase shift network. This is why I asked Calum if he could try to model such a system to see if he was able to find an acceptable compromise so that such an arrangement works in multiband, which we do not see usually.

[@JayN4GO]

It’s been made hundreds of times. Do it. Yeah the sig will affect it though. 20m will be easier to manage

[@DXCommanderHQ]

I model it agaion with the 20m vertical in the middle at the back.. Rather than off to the side. Today I'm putting up the Parasitic for 40m to USA..

[@9A4GEMilan]

Why bother putting 4 or 8 verticals for just only one direction? Yesterday just made calculation in MMANA-GAL for phased array 2x2 vertical. So, if I use four relays, I can switch direction. With plenty of radials, this antenna array can give 8 dBi gain (with 4x16 radials). Forward/backward up to 9.79 dB. Direction angle (-3dB) is about 108 degrees (+/- 54 deg.). Good thing is that this way 5 degrees elevation is really great gain. I got some calculation (40m band) for 10x10 meters spacing, 9.65m tall aluminum tubing 4 mm (bottom part is 16 mm, then inserted many narrower elements). Phasing is done using 1/4 lambda matching coax + 71 degrees phasing delay line(s). So, 4 direction is possible by switching relays. Even if all 4 antennas are in phase (0 degrees delay), it acts as a single vertical, but with much better pattern - especially for 5 degrees DX work. Just need to collect all materials and build array. I hope that directed reception will give me 1/4 of the noise as I have right now with single vertical for 40m band. Depends where it is switched, various noise sources are at various places.

[@DXCommanderHQ]

Do it! I enjoy economical experiments. Very few of my antenna builds actually stay put, I move on to something else..

[@9A4GEMilan]

@@DXCommanderHQ I understand this part about moving to next idea. Previously I made vertical antenna without any radials. Then made mistake and rise it 5 meters up, with only 4 radials. The problem was in length of active element - 7 out of 10 meters required for 40m band. Coil at the bottom does not helps because it was maybe out of resonance. Now I removed this ugly antenna and made proper 10m tall pole with 18 radials (1/8 lambda, approximately 100m copper wire, 1 mm diameter). Much better. Just noise level is the highest during afternoon period. Over night and early morning it is okay. So, I hope directed vertical array may reduce noise by 'subtracting' 3/4 of the available noise sources.

[@wilfredprins9718]

which software you use to calculate? will this work on UHF band?

[@DXCommanderHQ]

It would work.. But there are easier solutions up there like a Yagi.

[@wilfredprins9718]

@@DXCommanderHQ I use for data signals between shore and vessels working near shore (25km_ish) from the shore. as the vessel has no fixed location I was wondering if this setup have more reception as with a directional antenna

[@Richard_OKeeffe]

Bonkers ................... but sounds like great fun de G0FFL

[@M7EUP]

I don’t want to correct anything you’re saying Cal, but you made one big mistake in my opinion…. As I’m watching this it’s not a grey and miserable day at all, it’s blue skies and cold. Apart from that, bloody brilliant. I can’t wait to see this build.

[@janvisser8452]

And nobody knows or understands DX Enginering ? And a phase harnas is not in the books.

[@DXCommanderHQ]

DX Engineering sells phasing harnesses and all explained explain in Low Band DX Book by ON4UN.

[@davidfradley12]

His this a 4 square in the make in