They DID It! TWO Phased Multiband Verticals!
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- Опубликовано: 19 май 2024
- Antenna Beast! Roly and John explain how they have phased a PAIR of DX Commander antennas based on a spacing of 7.8m and some phase lines and relays. This is a superb piece of engineering design and math! Good work boys! Callum.
* Note* : This is Proof of concept, still in development & testing and is not ready for the market yet.
Important Back-Story Videos:
• Switchable Array in Tw... Phased Array
• Parasitic Antenna Arra... Parasitic Array
• What is a Coax Phasing... What is a phasing line
• What is Coax Velocity ... Velocity Factor
John was first licensed as a Technician in 2016, Gendron quickly advanced to the General- and Amateur Extra-class licenses. At the same time, he helped revitalize the Amateur Radio Emergency Service® (ARES®) in his area, as well as the York County Amateur Radio Society (YCARS) in Rock Hill, South Carolina. Gendron's story about reinvigorating YCARS is featured in the "Club Station" column in the September 2022 issue of QST . He also has a RUclips channel, "From the Hamshack," is an avid DX chaser, and can often be found activating parks for Parks on the Air (POTA).
/ @fromthehamshack-radio... (John's channel)
Roly is a retired Broadcast Engineer and avid Pacific DXpedition leader. In his working life, Roly was tasked with keeping all the AM (and VFH) stations running throughout the many of the islands dotted around the Pacific. He often used his "downtime" to fire up on the Ham Bands. His stories are legendary!
/ @zl1bqdroly (Roly's channel) 
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Check description for back-story videos to phased arrays, phasing harnesses etc. Further, this is Proof of concept, still in development & testing and is not ready for the market yet.
Off topic but Roly’s camera resolution is insanely good. Absolutely enjoyed the video and sincerely appreciate the mathematics involved. Antenna building and modeling has been part of ham radio I gravitated to upon receiving my license. 20 years later, I continue to find myself pulled in this direction. I appreciate the time and effort behind this one!
Yes, he has his contrast wound right up!
From my model on 40M....Tower #1 gets 33% power at 0 phase. Tower #2 gets full power at -60 phase. This provides a null at the rear of -18dbi with a forward gain of 6.8dbi. There will always be interaction between towers on the net impedance when both are fed power. This is easily corrected with a lumped constant L match at the switch for that band. Hope that helps the build. Great work gentlemen! 73
Great to see the plots and 3D as in my head I had the two verticals working on a driven and reflector basis but it turns out it’s working as a drive and director. Very cool… Great works guys.
So... when is the DXCommander Phasing Kit kit going to be available? Need a beta tester? Sign me up! Re-inventing what's possible with verticals. Love it.
I would love to see this. More than willing to do beta testing also. This would make a phase array very desirable compared to a single band.
Brilliance abounds @ DX commander
Congrats fellas.
Nice colab, can’t wait to see a video of Cal constructing one, maybe with Mike’s help. Next test should be to string up a chicken between the array and see how many DX contacts it would take at a 1KW to cook the chicken.
Haha!
Brilliant!!!! Look at you wizards making magic happen. Well done gentlemen. So a couple of Signature 9s, some M&P coax and connectors, and the magic box of relays and that would be an awesome setup. Cheers
Tim VE5THF
Yes.. But either Roly or John (I can't remember) sugggested it's a big box with about 14 x SO239s!
There are so many interesting things in our future. Thanks for sharing the dream.
Ahh!! coffee from a DxCommander mug ☕🤘🤘
I love it!
Awesome, I have seen that Roly has been going crazy on FT8, this explains it. 😊
Indeed!
Nice work gentlemen.
Nice work guys, congrats
Such a tease!
Incredible work from Roly and John, those guys know their onions! M7EZS
Fantastic work gentlemen nice team.
Brilliant!
Really fun idea. I'm curious though, with an additional 50 meters or coax you're looking at losses, you otherwise wouldn't have, would be interesting to see the final figures with coax losses in the mix
@@KQ4PSR it boggles my mind that it's possible to do this kind of phasing where you're able to move the reflector to either end. Electrically longer but not physically, I guess the delay is ultimately what ends up affecting the pattern
All that coax is split up between bands losses are insignificant, just like any phased array.
Those "output" relays being always connected will leave large lengths of coax stubs in parallel to the antenna which will mess up the feed impedance and therefore also the current distribution, totally messing up the pattern. Remember, the MMANA-GAL model does not include the "as built" phasing system. Plugging in phase values in MMANA-GAL is very different than showing as-built results, as I've found when I've played with it.
Setting up the phasing box with those output relays only connected on one side would probably give you a proper unidirectional band-switchable array, but not bidirectional, unless other relays are added.
Call me doubting Thomas but I am not convinced this circuit, as designed, would work as intended.
73 VE3GKT
Agreed, the stubs being left in circuit will mess up your impedances of the antenna feeds, you will need to add an additional set of relays to isolate each band input to the antenna's basically yo can set it up in a daisy chain mode so that one switches itself to the antennas and the others then become isolated. I was working down the line of using basic band pass filters, more complex in design but the beauty is that there is no switching bits there for from the users point of view you just tune away. But if we go down changing beam direction then you just need a single relay at the output stage to swap the antennas over.
ZL2DEW
Very cool!.. Gonna be a long 8 hours to wait 😊
Now taking a second, more relaxed viewing 🤓
Brilliant work on this gents, really impressive - As the DXC's are in close proximity would you advise bonding the two sets of ground radials together and if so would this help to balance the impedance ?
yes bonding those radials are important
Thanks it seems logical to do this, I have done this with parasitic verticals but nice to get it confirmed. Thanks for doing the hard work guys this has been in my head all day ...
for me this is what the hobby is about. great stuff
that really nice work. I thought it would work. just was not Shure of the delay lines and math for each band. looks like Callum got that extra 3 DB he wanted. getting 75 ohm coax is easy but finding it to handle 1Kw is hard. will be the all copper stuff .the extra 50 ohm coax not bad. making this for 1 KW will take some big relays and good coax. The phasing box will be getting big for this KW array. great work Roly and John . 73's
Coax numbers: Since it's effectively a monobander for each band, the amount of coax is about the same as a regular phased array which is pretty much tried and tested. Quick calculation here.. You are probably looking at around 0.1dB or maybe 0.2dB loss on 40m.
Wow....
Great work, I wonder if this is why Roly was the strongest I've ever seen him (20m) the other day.
Yes, he's been on this for the last few weeks! :)
It would be really interesting to fly a drone around this system with a a field strength meter to confirm the computer models
Yes it would.. You would find it would build almost same picture! :)
Cool beans fellows.
I became extremely interested in antennas when as a graduate student in pure mathematics I took a class in Partial Differential Equations and found the modeling of vibrations to be incredibly fascinating which obviously led to antennas and acquiring a ham license so I could put into practice what waa realized by the math models.
I'd love to put up a phased antenna but unfortunately all the hardware required even when home brewed is outside my pocket book.
Have fun guys & I will follow your progress. Best wishes....
kc2wvb....
Great comment. Nice to have your "brains" on side!
Happy to test and build a beta box….
Just waiting for Peter W****s/Dave C****r to announce that "you've got it all wrong" :-)
😂
Oh God.. FFS. Can you imagine!
Are they going to put this on the market.
Proof of concept.
John, instead of a vacuum relay would a sealed enclosure with an inert gas (nitrogen) be as effective or a reasonable substitution?
Pretty sure economical automotive stuff works..
@@DXCommanderHQ Hi Callum, I think the vacuum relays help prevent oxidation of the contacts. Do you think automotive relays can handle more than 100 watts? Ed N6WJA.
Would the radial field for each of the verticals need to be identical?
Yes impedance at each vertical antenna must be as close to matching on each band as possible.
Why 75 ohm coax? Is that for an impedance match?
Yes, that's it.
Isn't this the same as phasing multiple hygain 18ht? Witch has been done since the 50's 60's?
Multiband dual feed / phased? I have no idea.
@@DXCommanderHQ static.dxengineering.com/global/images/instructions/hgn-av-18ht.pdf. here is the rf reports in the directions
@@Dwasham04 First line of instruction manusl.. "The "Hy-Tower" is an omnidirectional.." - this is phased.
PS - And it's also a TRAPPED vertical, not resonant antenna lengths.
@DXCommanderHQ on the big hytoweronly 160m is trapped I do believe 80 down is resonate. I thought the rf reports might help you. Ps not the 18ht jr that is trapped yes.
Hi all, I’m hoping in all this great content and information I can work out how to or get some advice on how to make a 2 end radio system hopefully both ends to send and receive 9 miles apart in london. From what I’ve researched so far HF would be best but I’m 100% unsure how to implement this. I Need this to work if a certain country starting in R and ending in ussia send out their new space missiles to EMP parts of the planet meaning relays and satellites are down in this scenario. Faraday pouches and boxes already considered, more in need of what radio technology to use and how.
I know I know I sound crazy but it’s for good reason, I’m not just out of my mind on conspiracy theories lol. my girlfriend has major anxiety and previous for carrying a bag full of daily items and clothes due to a parent breakup when she was young, she required therapy for this and I’m worried she would absolutely loose all rational and calm if anything were to happen.
Is there any way I could get some advice on this.
Thanks and keep it up
OK.. it all depoends on whether this is transmitting data or voice.. In the main, VHF can work fine with outside antennas up on a roof., From inside a building more difficult.. Actually, even CB would work but you would have all sorts chiming in. If you have a ham license, the 2m band (145MHz) with 25W both ends would work, again ideally with an outside antenna. If one end is completely hidden behind a hill, then we're screwed slightly because we could use HF at say 50-miles due to the skip zone on perhaps 40m band or 80m band - but 10 miles is normally catered for via line-of-site.. Email me with specific requirement. Sounds an interesting problem.
Why are two extremely experienced antenna professionals measuring at 5 degrees? Crazy. Oh, hang on….. I’ve been watching the wrong channel. 😊
HAHA Tom!!
Fantastic work...
Alchemists… excellent… reminds me of the amateur radio operators of long time ago, doing their experiments then sharing the proof with others…or the government…
I told my missis about getting a DX Commander for the garden and she started skrykin about it and pulling her face… then when I looked at what I want… it’s not a practical development 🥲😡 no space. Wifey doesn’t want to look out the window and see an “ugly DX Commander antenna”… I told her “it’s a thing or great beauty’” but she wouldn’t have it 😁 🤣 😆 🥹.
S O ,,, doing this will need some decent garden or land in my opinion, but, for those who can and want to… get it done… it would be a great project.
Some really nice research by Roly and John… 👌💎 although it’s far too clever for myself.
It will be interesting what the Grand Alchemists do in the future development of this…🧐 🤔
Best wishes to everyone… 73 💙
Tell her we can do a custom pink Signature 9!
@@DXCommanderHQ hahaha Great Cal I’ll ask her 😁
Mine did the same and she still hates looking out into the back garden and seeing the dxc next to the shed and fish pound. But a nice LV handbag did the trick she took the payment so now i have a quiet life. You just have to get them trained or buy them off strange people women.