Upright V antenna

Does anyone use / has anyone used an upright V antenna for 10/11/12m? If you have, what are your thoughts on it?

It seems so few people use an upright V compared to an inverted V that it is difficult to deduce from anything I have found on the net to how well they do perform. Obviously it's still a dipole, so not expecting magic.

The main stated benefit of using an inverted V over a flat dipole is that only one support pole is required for the feed point, the legs then come down at angles and can be fixed in place closer to the ground. For frequencies around the CB band though it is not difficult to make a self-supporting flat dipole or even an upright V still only using one support pole. So why so few upright Vs being used?

I read one report, and I wish I bookmarked it because I can't find it again now, that an upright has a slightly higher take off angle than an inverted. That might be a reason people do not use? But.. I computer modelled a 10m upright and an inverted tonight (something I do rarely as virtual modelling bores me) with the feed point of both at the same height above ground, 5m, and found that the upright actually had a lower take off.. 26.5° for the upright compared to 33° for the inverted. Strange. It does even out between them when feed point elevation is raised above half a wave length though.

Going to have a play with an upright V this Spring/Summer E time, as I know the only real way to find out is to try. At lunch today I made a V support that I can slip on top my telescopic flagpole mast. It's made out of strong but light, and very cheap, PVC. The couple of upright legs are half a metre long and will allow lightweight bamboo canes to slot into them to tape wire to. Could use for higher bands too one day with shorter bamboo, or none at all for 2m and higher.

Cost of all tubing parts (not including solvent weld, had that already), £3.52


The assembled V support..


Should be fine for temporary trials in my garden when the wind is calm. Be a couple of months I expect, if last year was to go by, before it's worth putting it up to try contacts via E's. Until then, as I started the post with, be interesting to hear other's thoughts and experiences of using an upright.

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Hi Neal,

I don't know if you've come across the following links but thought I'd post them here anyway in the spirit of helping :-

http://on5au.be/content/gup/gup37.html

Stupid 'white spaces' and being on a tablet means I can't paste the second link but search for "KK4OBI Centre fed V dipoles", it should show up as a qsl.net result.


I did try swapping my 10/11m Inverted V's back in the early days out of interest and although any 'tests' were quite subjective, (band conditions can often change by the second!), they did work. Unfortunately for my own circumstances this changed the antennas to a NNE, SSW RF direction to fit in the loft space and brought the centre of the dipoles closer to the house and upstairs wiring. I swapped back only because my loft installation meant that an Inverted V raised the centres away from the house and gave me a more desirable NNW, SSE directivity. I'm afraid that was as far as I got with that idea.

I can see the appeal with construction, a low feed point and also the fact that the high voltage ends will be raised away from prying hands but like you the take off angles threw some concerns. (Seems to depend on how you model 'ground' as ever.  )

As you say, you never 'really' know unless you build one for yourself and I'm sure from your past antenna exploits you enjoy the antenna experimentation/build as much as any final results.  


There always talk of 'compromise' antennas and I'm pretty sure that every antenna is just a compromise to fit what is available to you with budgets, materials and location. The compromise is simply just what works for you and let's face it, not many of us have the real estate to throw up a full size loop for 160m(!)

Wayne mentioned above 'magnetic loops' and I've built a couple which although amazing for their size wasn't as good as the fan array I have been using. I'm pretty sure that if I was in a flat/apartment though such an antenna would be a God send, the old 'any antenna is better than no antenna' phrase comes into play.


Keep at it mate and above all enjoy yourself.  

I'm sure that just as how often an unidentified voice screams, "This frequency is in use", or the old question, "Are you sure you're using your licensed 10 Watts?", wafts across the HF bands there'll be someone along to down play it all.


All the best,
Victor

Thank you for the links Victor. I think the first one is the one I came across previously that said about the higher take off angle for and upright V. Reading it fully now I see that the the model is done for the 40m band with a height of less than a half wave, and I think that will be contributing to shooting signals more skyward.

The models I made for inverted and upright are below, if anyone is interested. I tried to model it to as real life as I could, "real ground" at 0m and feed point at 5m.



You can see the pic for the upright looks good at that height. But we'll how it works when I try it.

Don't normally bother with modelling, it bores me as I said already, and also as you know am same as you for the permanent antennas being in the loft where the inverted fits much better to the roof line and the feed point (best radiating part) can be as higher. So much junk in the loft, plus house wiring and piping, that real world plots I am sure would look nothing like a computer model.. there's just no point modelling for anything fairly standard I put up there. But for a temporary pole in middle of garden held up with a garden table away from house a little, the model is a but more meaningful I think.

Have never tried a magnetic loop. Maybe one day. But something inside me just feels a bigger antenna is always going to be better, even if it is not.

Have been really lucky so far not to have been accused of using more power than I am allowed. I think I would be a little hurt if it did happen as I try to run less that 10w where I can and power is measured from the back of the radio even if I do possibly have some feedline losses, so maybe running a touch less into antennas than some people. Hopefully we'll catch each other on air one day and we can ask each other that question

I look forward to that day Neal and I'm sure we'd fill the airwaves with antenna chat and other nonsense.

Still mucking about with my DMR setup at the mo, getting wiped out by a local 2m repeater, (can pick up and transmit to the damn thing on a dummy load so must be on my doorstep somewhere!!) Just finished building a 70cm EDZ after a 2m cubical quad failed to eliminate said repeater and waiting on parts for a diplexer to hopefully fire up the 70cm DMR repeaters in my area. Spent the last year or so of my licence just trying to get setup! Hopefully this year I can relax and actually make some QSO's.


Glad you're enjoying yourself and I know like you there will always be that 'next project' we simply have to work on.   

73's mate.
Victor

Found some long enough canes, wired it up, fed it through a 1:1 current balun. Had it up and down a few times early this morning to trim/tune it. Didn't get to try it properly though as the winds got up. Anything over a slight breeze and the cheap campsite telescopic flagpole I use was bending it over. I thought it felt quite light for the size of it, but it's still a lot more weight than the random wire or t2lt I've been putting on it previously. Need to look for something stronger as a quick setup temporary mast.

Heard a station in Bracknell talking with a station in Saudi just before pulling it down, both sides clear, and Bracknell is 55 miles from me which is pretty good for line of sight/ground wave on 10m. So it pulls signals in ok it looks.

Not a word from the neighbours who were in their garden at the time. I guess they're learning anything odd I stick up in the air is only up for an a hour two and not permanent.

The Comet H422 is a multiband HF dipole for 10-40m which is configured like that. It does have a bit of directivity but it's less than a dipole. It basically works similar to an inverted V.

Great work there Neal and enjoy seeing your antenna experiments come to fruition.  

I may have to start playing again myself in the future as currently I have an 'awesome' Faraday cage surrounding the house ready for a new roof! Not sure if the fan array will survive or even if it'll fire through the new tiles either. 

Thanks Conor for the info. I have seen a couple of commercial ham antennas in that config. They always seem to have a huge price attached to them though, but I guess you're paying for design and construction of the traps for the other bands and the much better structural integrity. I feel this should do me fine for 10/11 in the field as I could guy it there with the cheap pole I have. For occasional use in the garden I am going to need a sturdier support pole though as guying space is very limited.

Oh no Victor! Will keep my fingers crossed for you that all will be ok. I think if I lost my wires in the loft I would first have a little cry, but would soon after set my mind in motion for coming up with alternative solutions. There's always a way to get some wire or metal up and I'm sure you'd work something out, and if got stuck there's lots here who could suggest ideas. When the wind got up yesterday I did have a play with my loft fan and made an amendment.. all is good but I do have an unanswered question I posed to myself, will do a new topic here later if I don't find an answer that satisfies me.

Maybe just add some guy ropes to keep it steady?

Yep Roger, I am going to give it a try next time I am left alone here. Out portable it's not so much of a problem to guy, but our back garden is tiny and the fences are our neighbours, but if I put the supporting garden table in the centre of the lawn I might just fit in tying to the ground with tent pegs.

I have a inverted v up in loft workes well using it at moment shack antenna down owing to storms

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Wireless wrote:

I've been watching this one, I like the idea as a single mounting point NVIS Antenna, I may have to build one for 40m.

Using a bit longer canes, or taping on a bit longer length and a bit more wire it should be easily usable for 12m and possibly even 15m with a bit of a bow to it. Would definitely need to be constructed of a stronger material once it gets to the lengths needed for 40 though, or have some kind of nonconductive support wire between the two. By the way you've been describing the kit being assembled in your NVIS thread, I have little doubt you'd be able to conjure something sturdy up

This experiment, like many others I have done have, apart from the PVC bits bought for the middle support, been assembled from what's laying around or what I have managed to "find" for free, literarily from rubbish sometimes (the wire from this is house electrical wire from a skip). In that continued cheap Peter Parker VK3YE fashion, the next time I put it up to play it will be guyed by attaching three lengths of string to the telescopic pole with a jubilee clip (hose clamp). That will not be for a couple of weeks with the forecast high winds and the back garden grass currently sodden like a swamp.

You could linearly load the dipole at longer wavelengths which dramatically reduces their overall length and is very simple to do. I was going to try it but bought the mobile whips instead.

As suggested by the last poster, and also from watching Tim G5TMs videos on the subject of linear loading (who also advised me the best way to tune the elements), I decided to build a linear loaded version of my upright V today. Trying to do a Victor.. a few bits were recycled from items found in the shed and loft (no skips involved though), but I did fork out a few pounds on some more PVC bends and an extra piece of pipe. The ladder line was also bought, but left overs from a previous project. No more than a fiver spent on top of the items I had already.

The linear loaded elements were made from 300Ω ladder line. Ladder line wires joined together with a bit of wire and mini choc block at one end of each element. A short section of the ladder line having one side removed at the other end of each element...



I strung the wires on the original V frame for tuning. I had to chop quite a bit down on my first tried lengths. It started out as resonant around 23.5MHz!

When a good SWR was achieved for a centre frequency of 28.450MHz I fitted the wires inside the pipes cut to just long enough to house the elements and made up another centre V section to hold it all together. Holes were bored in the bottom of the pipes for the single wire to exit out of to make the feed point, which was another old choc block.



A very shot section of coax was then fed into 1:1 balun pinched from the original V.

Typically, just like when I tried out the original V from the start of this topic, the winds were up quite a bit today. Although it's pretty light in weight for the size I couldn't get it safely up more than about 3m to try it. It did work though even it that height.. managed one into Russia and one into Turkey (1pt) for the 10m challenge. It's packed away under the trampoline now until a nice sunny summer day with no wind comes about.



Measurements if anyone wants to make something similar is 175cm for each element wire from the feed point choc bloc to the joining wire in choc block. The bit of ladder line that is cut back to just be a single wire is 17cm for each element. Overall it's about 1.5m shorter than a normal V. Bandwidth is not so good.. covers the most used SSB part of 10m and is just barely usable down on the 555, but not much lower. You'd need to add a cm or two for it to be used properly for 11m.

Absolutely awesome stuff there Neal!

A big thanks for sharing your antenna build and was really interesting to see you do a linear loaded antenna in such a fashion. Always fancied a go at a 'cobra' style antenna myself but that'll have to wait until the next skip in the neighbourhood.

Big thumbs up from me as ever for the use of 'choc block' - can't beat the stuff!

The proof of the pudding for your antenna concept wasn't in any modelling or other such but in the fact you achieved some great contacts using it. Always the best in my book mate.

A pleasure to read and see your work come to fruition.


All the best,
Victor

Here is one i made for my postage stamp garden , there has been flares galore and the band has been poor so not much testing with skip , the main test is if it interacts with the yagi which for the moment it looks like it doesnt, i made it from scrap parts i had mounted temp on a bit of wood , time will tell how good it works , 73 Jim

Looks like you've done a great job there Jim! Hope it works well for you when the E skip rolls in properly.. there haven't been many days of great short range E skip this year around my QTH yet.

I'd love to have 10/11m mono bander yagi like that up above my house... I'm soo jealous.

Awesome stuff there Jim and a pleasure to see.

Well done with the antenna work and thanks for sharing with us all.

Great stuff Jim, don't forget to let us know how you get on with it.

73's Gary.

Its picking up vertical signals that are way down on the yagi , { yagi is hombrew as well } also heard Brazil with it so its hearing well , my only concern is if its affecting the yagi , i had a 5/8th in front of it and then behind it and it made the swr go up , it doesnt seem to be doing it with the V , 73 Jim

Looks like a delta loop to me hehe

I have moved it as close to the yagi as i dare and i would say it has the normal figure 8 ish pattern of a dipole has but it receives vertical signals much better , worked a couple of 26 this morning on it on short Es , 73 Jim

Hello
My name is Russell, KB1UKU and I now only build V dipoles of the upright V design for the impedance is 50-52Ω perfectly. Plus the fact I can use antenna actually on the bench, porch, or anywhere near me. I got all my design plans from an old website of Hawaii.chem.edu but the page came down in the early 2000's. I luckily saved the HTML on my old laptop but can't get it off of it. So I printed it on printer.
I verified how go it works via  KK4OBI website.  Then finished proof thru HamUniverse horizontal V beams.  If anyone want to call me 24/7 or email me thru QRZ I'd be willing to send Pics GIFs, Jpeg, or what ever it is called. I experiment with V dipoles through Buddipole by experimenting with the different angles. My best choice is 90 degree but 112 degree also works great also.
I use AA-54 and the MFJ 259 to test antennae.
I can't find much info on Upright Vee style antenna/antennae.  If some one could help me resurrect the hawaii.chem.edu web site I can forward information but I am losing my vision fast.  My antenna works great on 6 Meter, 10 Meter,11 Meter, 12 Meter, 15 Meter and 20 Meters bare antenna whip / whips and works still really good on 40 Meter with Buddipole loading coils.  73 KB1UKU