Parasitic Antenna Array with 2 Verticals
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- Опубліковано 25 сер 2024
- The 2-element parasitic array follow same principles as the Yagi. One of the verticals is parasitic and is the reflector. Delivers around 4-5 dB extra gain and has reasonable f/b. Easy to make for /P or temporary work. Have one facing USA or EU. Lots of fun. 73, Callum.
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Next time you visit Cal, come ion for a beer. !!
Haha.. Yeah sorry Roly, I had to "fly"..!! :)
that trip to new zeland part was funny. i know i am not alone in loving to tinker with antenna. thanks again for your videos!
Thanks for watching!!
Great video as always Callum
The doorbell skit was like watching The Two Ronnies! Haha
Great concept to fix one direction and attenuate the other. Very cool and interesting.🍻🤠
More to come!
The more I watch you , the more I can understand this miracle they call the Antenna.
You're very easy to listen to. And your content is always spot on.
Keep up the good work!
From California
You are very welcome. Thanks for saying hello.
I built a half-wave vertical for 10m and a longer parasitic with a switch in it. No radials needed, and I can switch the parasitic element to reflector or director and swap directions. Works a treat.
Diamond!
If its longer doesnt it have to be the reflector? or do you somehow electrically shorten it with a circuit with the switch?
@@ZiggleFingers Yes, the switch is about 10% up from the base. Switch on - longer than driven element - reflector. Switch off - shorter than driven element - director. Exact dimensions - not very critical. Spacing - not critical. Vertical alignment - not critical.
Hi Cal,
Always enjoy these What If videos when you use MMANA. Hope Wendy is feeling better and you all stay safe. 73 WJ3U
Thanks Don👍- Wendy feeling 99% now old friend. Thanks.
Callum I appreciate your time. I can't thank you enough. 🙌
Any time! I love it :)
Last time I was out on the beach my 12 year old 10m, very, very old, well used pole broke, so now I have a brand new pole and a the slightly shorter, old pole, so I can try this myself… but maybe not in a howling gale! ( Note to self… will have to ask Dave next door if he’ll lend me his fishing rod rest) Corrrr! Food for thought! Brilliant! Thanks Cal! 💐
Watching for switched phasing!👍
Soon!!!
I've built a 2m phased array years ago and man did that thing get out.
Oh nice!
That's what I use on my vehicle minus the groundplane radials. Love the bounce back setup!
Right on!
That explains a great deal !
In the new QTH I sank a couple of aluminium tubes ( 2" ID ) into the back lawn about 8 metres apart so I could play radio quickly and easily ( and take them down so as not to upset my new neighbours ! ).
One I used as the base for my Signature 9, and the other I used as a temporary mount for collinear atop of a 8 meter scaffold pole.
Using WSPR on the Sig 9 over a number of bands I was getting some lopsided results.
I have recently moved the Collinear to another location ( the new neighbours are getting used to the erections ! ) and the WSPR plot changed to be more even !
I have said it before, but this antenna stuff is Voodoo !!!
Voodoo! Haha yes..!
As has already been commented on… dropping by to see Roly… brilliant, and so
funny!
Keep up the good work!
Cheers, Peter VK3ACZ
Legend!
Love your vids, going to give this a shot before the snow flies. Cheers!
Awesome Laird McC.
Bostin!
My fam started in Durham, many gens ago; so we were probably hurling things at one another across the wall. Lol.
Love you man, and your vids.
How's the book coming?
So you knocking on guys door. How many takes did take. So you 2 kepted a straight face without laughing 😊😊😊😊😊
This is fascinating - love this video! Cheers. Mark 2E0MSR
Glad you enjoyed it!
Lol like the trip to ZL land Cal another vid to keep the grey matter working and the interest flowing... 73
Yeah.. Roly and I had a bet and wondered if ANYONE would actually think I went there! LOL
@@DXCommanderHQYou mean you didn't?!
I appreciate your journalism, I was concerned that phased verts didn't work until you went and double checked with Roly. Nice bit of editing there :D
Yeah, he played along..!
Editing ?@@DXCommanderHQ
Thank you for sharing this info. This is what I am just going to do to form HF vertical beam😀
Good luck!
Wanna hear crazy? Try it with 3 vertical antenna in the shape of an " L ". The longest element is the meeting point of the other two.lines. I've built exactly that for 15m. One side with maximum gain towards EU and the other side towards the US/ middle America. Lots of fun experimenting. I haven't walked mine around using an Am radio tho.. something new to try. From Alaska - I need to Null out the OTHR (Russian Over the Horizon Radar). Bored ?... try it with Phasing cables. You're a smart guy Callum... You'll get it. GREAT videos....
You can do an L alternatively 3 in 60 degrees more fun.. Watch for next video - then one after.. :)
As always another interesting presentation !
Thank you! Cheers!
Good stuff Cal!
Appreciate it!
I keep meaning to try this with some 5.6m telescopic whips when I go POTA. Should really work well for 17 and 15 DX into EU.
That is exactly what i do on my POTA outings on 20mtrs everyday from ZL-0003
@@ZL1BQDRoly no wonder I have you in the log a bunch of time :)
You could actually use that one reflector and put different band length verticals on all four sides . Try that experiment It should work to .extend the reflector radial for each band when needed.
I guess!
love this stuff. thanks cal!
You bet!
A 1/4 wave between the driven element and the parasitic reflector seems a bit too far spaced apart to energize the parasitic reflector. I think a slightly closer spacing is more traditionally used.
Guess you didn't watch the whole video.. 8.5 to 8.75 is best.
@@DXCommanderHQ Guilty. My watching was interrupted by a family member. I'll watch it the the whole through now.
really cool brother !!! God bless family !!!
Thanks! You too!
very interesting experiment
Thank you! Cheers!
Hi Cal interesting video, but would be nice to see more videos of you making/doing stuff, the theory is a bit boring, sorry not being negative but really used to enjoy your videos in the workshop, field ECT,
Just beware that workshop and build videos can take a whole week to sort over multiple days then a 2-night editing job. However, we still need ther theory, eg; velocity factor, phasing harnesses and how they work - before we can make the build video.. I would LOVE to do more build videos but I really only get a few hours a week..
Not sure I have ever seen anyone mention the pseudo-Brewster angle on any UA-cam Videos so you might want to address that at some point. I don’t think very many hams are aware of it. In my ARRL handbook (19th Edition) it’s on page 3-6. It’s also addressed in the ON4UN Low Band DXing Book under vertical antennas. I know the latest ( 5th edition) is correct. Some of the very early editions had a couple incorrect statements so I only recommend the latest editions to be certain of accuracy.
73,
N4DJ
Good point... Need a catchy title for that!
Great stuff. Thanks.
Glad you enjoyed it!
Shame you did not really visit NZ. We don't have yellow number plates here. Some others were fooled.
I had the car flown out!
Cal, what if you wanted to do that with an antenna that doesn’t have radials, such as a gainmaster or a vertical end fed half wave?
Actually, I looked at the Gainmaster and it wasn't so happy with a 5/8th.. But you could easily doi 2 x vertical dipoles.. Well, one vertical and another 5% longer as a reflector. Basically a vertical yagi.. Sure.
Callum, can this also work with a man-made object as reflector? Such as an aluminum light pole or other items sticking out the ground and 8.75m away from the radiating element. Specifically what if its a mobile vertical whip antenna for 80m/40m/20m and you've parked the car about 9m away from a 10m tall light pole. would there be some gain?
Yes but it would absolutely need to be tuned at or around 200-250kHz below your TX antenna..
The 8 plus meter spacing was to maximize front to back along with good gain. For a vertical with radials spacing the parasitic element farther away would be a benefit for getting longer radials on the ground. Would spacing exceeding 1/4 wavelength provide good gain if one is not concerned with front to back? At what spacing does gain start to drop?
Actually, the 8.5m seems to do both f/b and gain.. There's not a lot in it..
@@DXCommanderHQ Got it. Thanks for doing the modelling and the video!
Great video, have you done any videos on the mmana-gal program? I just downloaded it and need some help with it.
Yes.. Search dx commander mmana on YT. There's a load.
What about trying a hb9cv style on the 2 verticals ???
Well.. You could do that vertically on say 10m I guess.
I've just remembered I had a similar experience of this 2 vertical setup. Had a 2/70 magmount in the middle of the car roof (landrover discovery mk2)and 27mhz long whip at the rear gutter mount . On driving around chatting to a mate being just 6 or so miles away .l discovered if pointing his way the signal went up, driving away the signal went down and he reported back the same . Oh thanks for the memory lol. ( 2eocak )
Could you provide me with a link to any articles related to driving two vertical antennas from one source, using a phasing network to allow of beam steering? Using just a fixed reflective parasitic element isn't worth it for me, as you can't steer the beam. Thanks!
Yes, just search for "phased verticals".
I just installed MMANA. Someone needs to explain to the author that you don't install stuff in the root of the C drive. There is a programs folder for that.
Callum, here's a challenge...
Using all your skills with antennas and their modelling :-
Create a 2 element array using DX Commander elements to cover 2 bands - say 40 & 20, or ones of your choosing.
73 Stewart G3RXQ / G3Q
Almost impossible without getting into serious delay lines for the "wrong" band because of the distance.. Saying that, I know someone who is working on exactly that issue for ALL bands, using 2 x DXC antennas.. More on that when it appears :)
Tried this with Bouvet on 17m and still had no luck from the West Coast of the US...maybe I had something set up wrong. But I set it up at the proper headings and all...
Well, Bouvet was a hard graft... Maybe you had it right..
Hey. I got an idea of what to try. two pieces of half-wave dipole that are half-wave apart. impedance matching so that both antennas have a quarter-wave length 75 ohm cable and from the center with a 50 ohm cable to the radio. what do you think about this ?
It'll depend on how they are oriented. Look up phased antennas.
@@DXCommanderHQ I thought they were vertical dipoles. I found another article on the same topic that mentioned 180 degree phase shift with a coax cable. I still haven't quite figured out how to do that, but I'll try this first.
I've even tried the 3el parasitic array for 40m, not impressed with the results compared to a 43m endfed at 10m horizontal. I wouldn't recommend it but YMMV.
I did three in a row. Spacing is paramount. I was so loud that some US stations told me they'd never heard such a strong EU station ever!
would this work with endfed half wave, no radials,, say for 10 or 15. ? might be worth a play with..
Hmmm. I might take a look at this..
hears a thought .. we know about the VDA.. vertical dipole array that these dx expeditions use. which work fantastic is you put them by the sea.. Why do they insist on centre feeding them.. would it not be easier to feed them from the bottom.. the easyiest way to do this is would be to use the T2LT method. 50 ohms ish feed.. or if your a end fet purist you could use your 49:1 or what ever it works out as transformer..the third was is to use the J pole system but instead of ladderline you make the transformer out of coax. Regards .g0vxe
Would that work with a vertical dipole
Yes.. Just like a yagi in a vertical plane.
@@DXCommanderHQ thank you! I live about 900 meters away from a quarry. I have moved my antennas around and unfortunately they best spot for the antenna picks up the rock crusher when its running. It would be nice to null it out a bit.
Nice thumbnail. Did you catch a foul wiff?
Don't understand sorry
Cal,is there any way of switching from one antenna to the array so as to check it on air the difference someone receives you from one antenna compared to the array??
Difficult unless you made them BOTH slightly smaller - then switched in a coil to make one longer and at the same time, switch the coax over.. Better instead to do Phased Verticals.. Next video!!
@m0mcx loving this antenna series:) don't suppose you've got building a loop antenna in the pipeline??
So a one element yagi?
2 element.. The ground is the other half. But sort of yes!
It works better if it is all a metre or two above the ground. There is no improvement beyond two metres.
There's nothing between on the ground to about half a wavelength above the ground - then you get good increases. Been there. Tried that.
2 quick comments... classic yagi spacing is 0.15 lambda to the 5% longer reflector (ie 6m for 7MHz) but you can also add a 5% shorter director too 0.1 lambda out the other side for a full size 3 element unbalanced 40m "yagi"...... point 2, you are 100% right about problems with low angle radiation "loss" as you try & take off nearly along the ground... BIG trick if you are going portable simply solve this by building your vertical antenna on ground that slopes down in the desired direction...bingo the radiation towards the horizon is now "elevated" from going along the descending ground so gives you effective gain (OK NOT gain strictly, more reduced ground proximity loss, but still "better" regardless).
Talking of "parasitic" elements, the ground is also a big parasitic reflector for horizontal signals too.... so a compromise 40m horizontal dipole just 6m off the ground isn't a poxy antenna... it is a radiating element 0.15 lambda away from/above a reflector so it is actually a full size 2 element yagi (with a parasitic ground reflector) firing straight up.. which is perfect for NVIS (hence low dipoles being surprisingly good for short-haul inter-G).
Indeed.. I made a video about sloping ground..! Great trick!
Don't forget to take your tablets 🤙
I did :)
@@DXCommanderHQ the amount of times I cancel my alarm and forget. I've gotten into a habit of taking a key chain pill capsule with 3 or so in. Then if I get to work and start clucking, I've got some 😆
Sir, I wish to complain about your apparent complete disregard for your carbon footprint. In my opinion, travelling to New Zealand was totally unnecessary in this particular instance. I shall be seriously considering whether I follow this channel in future. Yours…
Haha Ian!