People bang on about innovation but that's exactly what this is. This opens up a lot of options for those without space. You realise 50 years from now the books will talk about this internet dude Callum and his true multiband vertical.
When the day comes that I have a kid if it’s a boy I’m naming it Callum and hopes that he grows up and innovate and comes up with the ham radio antenna idea that makes me money
Hi Cal, Great that you can get 80 and 30 on the same element. Had some fun early yesterday morning by making a contact with Hayden VK7HH. Finally have him in my log on SSB. That put a smile on my face, considering everything else that has been happening. You and your family stay safe. 73 WJ3U
This is awesome Cal. So glad you worked this out. I'm a 30M junkie. I can't wait for mine to ship out. It's interesting that you are doing a slight helical wind for 80M, I'm building a helically wound vertical for 160M using 6 4 long fiberglass military masts and winding 256.5 feet of wire wrapped around the poles and putting a small capacitance hat on top.
It's WONDERFUL to see you so excited! I've ordered and I'm looking forward to bragging all about it when it's deployed as one of our Field Day antennas!
Nice work. I had some 90MPH + gusts over here. It took out about 70 feet of my fence! But, the DXC Classic is still up and working perfectly. I’m looking forward to the signature antenna. I’m thinking it will need all the guys I can get on it, and will be great!!
Hi Callum what a great video I know I said this before and it’s a repeat but that is one awesome looking antenna. And to have that type of an antenna 80 through 6 m is incredible. Congratulations and I’m sure you had fun on the research and development. Take care and have a great weekend. WD5ENH Steve
Wonderful Cal, yeah at first I was thinking a trap but you've explained that so no. Really be great to see what the difference is between the coil and inverted L. Keep up the great work buddy 73
Can't wait! If that's 50mph, definitely needs another set of guys for my install, 40mph is a couple times a week here. Bought some 2mm Mastrant. Should be light enough to keep the top from swaying around too much and not put a bunch of guy weight on the pole.
OK 2mm Mastrant is perfect! Top guys, do not tighten.. Leave them with a tiny little "droop" not actually tight. Actually, my guys are not actually tight either.
@@DXCommanderHQ Exactly my plan. Don't care if it moves around a foot or two. If it's not windy those upper guys shouldn't really be doing anything but hanging there. Thanks for the reply.
I love the way Cal explains things, then throws us a curve ball. Constant development is great. The trouble I have been having with mine is flop in the elements. This will take some of it out for sure. Cheers, Raymond 🙂
Hi Cal great to see you've cured the 80 metre problem. Just a couple of questions my noise floor is very bad at my qth would adding a ground spike in addition to the radials help. Also have you considered putting using the guy point for slopers for adding bands.
Unlikely.. Instead, just go and lay a loop on the ground. I have two. One at 90m diameter and one is 30m in diameter. Both work rather nicely. I did have wahat they call a "Loop On The Ground" (Google) but it wasn't quite loud enough for my taste - it worked though!
This is a great development. I'm wondering if this concept could work for your Expedition Antenna? Maybe not for 80m but just to add more of the bands above 40m to a more portable set-up 👍🏿👍🏿👍🏿👍🏿👋🏾🙏🏿🙏🏿🙋💯
Hi cal, great video, and congrats on your hard work. I did something similar with 3 wires, so I know the amount of work off camera you must have done. Coils are interesting wee devils. I have a 40m vertical with a 7.1meg trap on the top, and a extra length of wire going out to make a 80m inv L, and for what ever reason I don't know, with a bit of help from the tuner here and there, it will work on all bands from 80m to 6m. 30m being the odd one with a poor mismatch , but I still get through to eu with 200w. That's the good thing about ants, there can surprise us, and there don't always have be perfect to work dx. All in all I think after what you have achieved, you must have a wee smile on your face, well done. Zl3xdj
Hiya Brian. OK, so if you took your inverted L for 80m off same feedpoint, you won't need the trap.. For 40m, fold the top 1.5m over the top on so it's now 9.2m UP and about 1.5m DOWN (40m and now 15m perfect). Add a single 4.95m element for 20m and your inverted L should tune 30, 17 and 12/10m. Good idea :) Dare you!
Great work, Callum! If you could show in detail how you connect the Signature to the hinge I as well as others would really appreciate that. I recall you saying somewhere a metal pole mount would cause SWR problems. I'm wondering if that includes a short metal base stub mount for the Commander/hinge arrangement? Thanks!
Hi Callum, Congrats to you, love your work and vids, thank you, it inspires my interest in antennas. The coil height question?? We're the other elements installed during the testing of the 30m element? If yes, I wonder if the height change causing resonance change, could be due to paracitic capacitive/inductive connection to the other elements. I don't know the answer, but the fine adjustments required, would suggest to me, that 'height above ground', perhaps wasn't the influence, or the total influence. It could be a combination of these two influences. Brill Callum, keep up the great work Gon'nor. Mark Woodhouse.
Well done sir! I’m really impressed by the wind loading. Here on the prairies it’s not unusual to see that wind speed. Based on the recommendations from the gentleman from the US (that did the video how to wind up the elements like a roadie) I run a second set of guys to the top spreader on my Classic and it handled 80km no problem. If I only had the room in my back yard you would be shipping one of these to me today. Cheers from Moose Jaw Cal Tim VE5THF
Good comment.. I found that when using multiple guys, not to tighten the tops too much - but honestly you are probably ahead of the curve in that department!
I've got an unguyed S9 antenna which is 13 meter long. It's green and a single wire runs inside the pole, very low visual impact in our always green countryside. Matching requires an automatic antenna tuner at the feed point, or 4 to 1 balun and a very low loss half inch coaxial cable towards a wide range tuner in the shack. A galvanized tube is hammered into the ground sticking out a couple of feet with a rubber shrinking piece on the top, in order not to damage the fiber glass pole. Even in the slightest winds it bends more than a little, moderate winds make bending very evident like a fishing pole trying to catch a big fish, strongest winds make it look like if I had caught a huge whale but that's all!
Yes that’s good advice Cal. I have the lower guys tensioned to support the pole and the upper guys just enough that they don’t hang loose. That way they don’t have down force on the pole in normal conditions but provide additional support to the upper thin part of the pole when the wind comes up. Also, I’m going to put a couple wraps of electrical tape at each joint before I install the clamps to keep rain water from getting in between the pole segments. Water could tend to lubricate the joints, lessen the friction and allow a section to collapse. Cheers
Hey, Callum, hope all is well with you. I just watched your new antenna video @ 2:30 AM on 4/22/22, I have a question. if I mount (bolting it to one of the metal fence supports), your new Signature 12.4m DX Commander All Band Vertical 80m or the Classic DX Commander on a metal fence at about 1.5 meters off the ground, can I use the whole metal fence like a radial? I do not have a very big yard, I live in a mobile home park, but I own my home. I really cannot run many radials. As for me, I am doing okay but I still got a lot of heart & back problems. My cardiac doctors are still trying to find out why I am getting this shortness of breath every time I exert myself. I'm okay just sitting but just getting up to go in the kitchen, I have to sit down and rest. Medically the heart is working great but the back is causing major problems, like me falling when my legs give out and I crash to the floor, (which just happen on Wednesday night at our Ham Club meeting), it took 4 people to get me up. but I just got to deal with everything else. de Krisy N6KV, Klamath Falls Oregon.
it is called antenna theory. Theory being the key word. I have single element verticals fed with a 4:1 unun that are under 2:1 swr on all but 1 band. And cover the world. Love to play with theory.
30 meters is where I consider the "Low Bands" start & I look to verticals for my DX solution on these bands. Most hams will ha have a hard time getting horizontal antennas high enough for good DX performance above 14 MHz. When it comes to HF Yagis on towers, you can safely get on 20 meters on a modest budget, the longer wavelengths above 20 meters get really expensive.
Cal, How long of coax do you recommend to use with the the 12.4 and the Nebula? I have 50ft and 100ft of LMR 400. Worried about matching impedance to rig. Thanks!
Great video - love it when you take us along your thought/development process. My elmer told me to try and keep the diameter and length of antenna coils roughly the same to maximize bandwidth. At least to keep the length smaller than twice the diameter. So this makes me wonder if a pvc pipe with a larger diameter than the pole (and less windings to get the same inductance) slid over the pole would improve the Q? Downside is that the windings get closer to the elements - don't know... sounds like something I would like to try when I as soon as I set one of these up... 🙂
@@DXCommanderHQ Well, if it works it works... I am still racking my brain over your question why the harmonic frequency shifts with the position of the coil... interesting...
That's for minimising the loss of power in the coil, but it does not increase de bandwidth. Actually a high quality coil, with a length equal to one or two times de diameter, increases the efficiency at the expense of decreasing the bandwidth.
Hi Callum, quick question. I have a Classic 10M DXC, currently configured for 30M instead of the 80M inverted-L. Is there a reason that both wouldn’t work? I.e, say I have it set up with the 80M element, could I drill the extra holes & add the 30M element? I’m assuming not (element spacing, perhaps?), but I’m curious as to why? 73 Jack M0JMU
Jack, good point.. Never tried it.. You could start with a long cable tie instead of new holes and bring the inverted L out a foot or so from the spreader at the top..?
@@DXCommanderHQ Hey, thanks for the reply. That gives me a little confidence (that you haven’t tried it), meaning it should in principle work, versus “I tried it and it messed up X”. When works saps less of my time, I’ll give it a try and report back!
Better than expected.. I did some WSPR tests and frankly it was "too good". We *THINK* it's a bit like a q/wavw with another loaded q/wave on top.. I wish it was that on 20m actually.. I MAY do some experiments, lower the coil down a bit and see if I can get 20m running the same as 30m.. Then change the 30m element into a straight q/wave.
Ok so when is the video where you put another one behind it for 80 and do the plot. I believe you called it “ Flame Thrower” on one video a while back. Very nicely done. Can’t wait to build it.
Hi Callum... Great work. Have you tried using the next set (above your current coil position) as a point to connect hot guy wires? Remove the coil and electrically connect the next set of guys. With a few meters of them becoming hot. This would then be an Umbrella Design. Where the guys give top hat capacitive loading. As a person tinkering with short designs for 1611 kHz with 400 watts of AM... 24/7 key down ... with processed audio. The coil scares me.... As you would know if xxx micro henry's does the job up the top... less henry's are needed to get the same result at the base. What you are really trying to do is encourage your wiggles (others would say aerial current) to be encouraged up the mast. In broadcasting world the coil you have would be seen as a bad idea. As it limits the amount of current the aerial will take. Even though it does encourage more "wiggles" to run up the mast. Short version here is try your coil at the base. I'm also concerned how tight it is and it small diameter. I'd also suggest you look at proximity effect with the other wire elements. Hope this sparks the idea that fixes the problem. 73's from VK land.
@@DXCommanderHQ Not quite sure that is totally correct. The coil is there to lengthen the element for 80m isn't it? No coil and added top hat gets the job done without the down side of coil losses (and other bad stuff). I'm not across the rest of the way you get to 50 ohms for the over all aerial to go to coax. So I don't know what you need to see at the base to get this to all co habitate. Yes in the 1611khz game.... The rule is max vertical length you can before employing loading tricks. When you do in comes....... more wire in the air the better. I've often used the analogy. Think of the Vertical part like a mains extension cord... Then the Horizontal (some times slopped - like the umbrella design) as Festoon lightbulbs runs.... The more lots of festoon lamps hanging in the air plugged into the vertical extension cord. This pulls more current up the Vertical mains Extension cord..... It's current flowing in the "vertical cord" that works with the ground currents to make your signal. The fact current is flowing in the top hat wires at "broadcast frequencies" is not a big deal due to the wavelengths involved. Higher up it would come into play and mess with your pattern. But I'd say 80m you'de be ok if you watch the ratio of vertical to top hat lengths.... Say 15m vertical with about 3m guy wires hotted up.... Coil gone and hopefully the problem you mentioned too ;)
Callum, Like so many others, I've waited for the 12.4 to hit the streets. Unfortunately, I still can't make up my mind.... 12.4 or the Nebula (Neboola) :-) But, while I've been pondering my next move, I started thinking about something that I hope you can help me and others with. Its my understanding that due to the lower angle of radiation, the vertical is a better antenna for DX which, is my main interest. However, since 92% (my best guess) of the hams in the world are using dipoles and or horizontally configured beams, how much loss might a vertical suffer in a DX situation as opposed to having an antenna which is also in the horizontal configuration? Thanks for all that you do for the ham radio community.
OK, polarisation will NOT affect you because as soon as the RF comes back through the skip, it'll be twisted to hell.. Great fun to LISTEN on left ear Vertical / and right ear horizontal (if you have 2 x VFOs) and you can hear the drift between ears..
PS - Persnally, I would go with 12.4m It's easier to handle, less expensive and all that you are missing is 60m band. SWR Curve video and WSPR plot videos coming out soon on this antenna.
Clear PVC because the rubber stuff went through the ROOF price wise.. I would have to add another $30 to the price. Crazy. But clear works and has done for years.
Ive seen online that 64% height is optimal for the lowest takeoff angle for a vertical - just a little more than 5/8 ths. Was wondering if you made every element a 64% element how that would perform? So the 20m would be about 42' long (could come back down from the top about 12' like you do w the 40m currently) - this would become linear loaded 20m. The 40m would be about 83' long and would just be too big (especially for a 10m pole) however, now that you have discovered using the coil on the vertical, this could get you a coil loaded element. Just wondering where and how high the coils would need to be on a 10m pole to accommodate the 40 and 80 m bands
OK Pat.. Our issue will be that coild resonate at weird places.. And in any case, the gain is only a couple of dB which can be compensated for with a superb ground. For instance sea-water will give you an extra 10dB..
@@DXCommanderHQ I can't work anything after 8pm as get +20 of noise from neighbours garden lights.ofcom coming out before May 25th so hopefully gets sorted.ive just not got room for guy ropes :(
A good antenna can be a magic thing, all though the dxc is probably one of the best contemporary antenna systems in the world, the sheer fun of homebrewing should not be forgotten. Innovation, usability and sheer Callum style market placement is as serious as it is fun, learning all about antennas, modelling with mmana_gal helps a lot. Cheers and beers mate!
@@DXCommanderHQ Hi Callum :) How about a video which verifies identical antennas with and without a common choke? Afaik you can hear the difference ...
Hi Cal Has anyone anchored the 12.4 to a double chimney on a pitched roof. I see flat roof installs on the dx gallery. I would guy plates 2 and 4. Concerned about the radials. Would love to hear your or other hams thoughts. Cheers and 73 from KK4NKR
Does it work on the full bandwidth on 80 meters without a tuner or having the need to change the coil winding ort placement or is it only functional at a very narrow portion of the band?