right got confession on this one is that i haven't ever built a hex b i've spoken to
plenty of people that have got a hex beam and i'm about to sneeze oh no i didn't all right now it's
handy so what has your hex beam um we we go on the internet it's a lot easier than me drawing
it out actually but i mean we'll we'll use this in a movie or something else um hex beam antenna
just make sure everything is recording it is and we'll go to the images and that's the easiest one
there's a big x beam there now it looks funny but it doesn't look funny it's not like funny
hilarious but you can see pictures of this thing i mean because i i've modelled one as well maybe
i'll have a look at it too um so effectively what it is is you've got this center post we'll
look straight down on it like a bird's eye view you've got this center post and then we have these
um spreaders that are about 3.25 meters each side about six and a half meters in total length all
right i'm not quite sure how good i'm drawing this i need a bit of graph paper or something
okay that'll do so which way are we facing let's uh we'll it's going to face that way all right
and then these are fiberglass spreaders and they're they're they're held under tension
these these spreaders by all the wires because we can then put like there's one so239 connection
at the bottom i mean the original hex beam had little sections of coax but some manufacturers
have now got a tube and they've drilled it out and done really cool stuff but you don't buy
one or whatever else what i'm interested in is the basic construction and how well it works so that's
what we're going to do right just interrupt the flow because i'm editing this right now
obviously most hex beams are multi-band what they have is more than one element i'm just gonna draw
and describe one element and that's the 20 meter band but they'll work the same on all
of these all right let's get back to it now there's been a couple of iterations the very
first iteration of the hex beam had we'll use a light purple had something like i think it was
nothing like that at all uh there that's it not this bit so that m and there was a kind of a w
here all right that was the first one however uh i think it was g3 txq somebody did some
some research and and felt that actually it'd be better to bring make it a bit bigger and do
this and then bring that all the way around the back and then you get the separation you see
some separation between here and here xp right so get that away a minute because i've drawn one
in software i drew the wires out
and then deleted the effectively the struts and that's it's just drawn almost from memory if
you know what i mean i optimized it roughly to this and basically it kind of works x y
there's a couple of mistakes and the optimization is this should be down there and that should be
roughly there imagine it was just a piece of wire because you get one element if you
buy it from a manufacturer you shouldn't have to do anything you just string it up
clip it together and it's dying easy anyway just leave it as optimized at the minute because
i haven't drawn it that accurately i was just having some fun last night and thought oh that's
looks quite interesting i'll show the people back home you see so we can calculate at 14.2
and now is the height how high do you want this thing right so let's start off in my opinion if
you're going to go to the extent of having some sort of yagi i reckon 12 meters 40-ish feet is
great because it's more than half a wavelength on the 20 meter band now this is my optimized you
know a real hex speed might be slightly different if we look at the far field plot looks quite nice
and if you remember a single vertical just with a half decent ground at five degrees off the
horizon will give us about minus five ish dbi at five degrees so i've told this it's five degrees
and it says 1.5 dbi so that's six seven and a half db better at 40 feet 12 12 and a half meters
and that is worthwhile writing home about because not only have you got gain there
is you've got fantastic front to back so for us in the uk we've got the germans the italians and
the russians behind us and we're trying to make contact to the usa i can dial him back by minus
14 you know db tremendous all right however that's at 12 meters 40-ish feet now a lot of us can't do
that right we've got to come down a bit all right so if you just take two meters off that and do
10 meters now and we'll hit the start button and we'll go at five degrees off the horizon
how well is that going to be it's on 20 meters by the way only 20 meters
now we're at minus 0.5 so we're about four to five db better than a straight
vertical for instance and i'll do i've got um a comparison video uh what's best dipole versus
vertical and stuff if you watch all these you'll be able to piece together right because i'm not
gonna do a one-hour presentation for you about all these different things but anyway i mean i
would still say that would be worthwhile at 30 something feet or 10 meters now tom runs his i
know i think it's somewhere i think it's seven meters off the ground and he says sometimes the
dx commander is better sometimes the hex beams better so it's quite interesting actually because
at five degrees off the horizon it says minus three point eight who's absolutely right
because his dx commander will be giving him about minus four and a half so there's a negligible
difference between the two so that's quite interesting now then that's on 20 meters and the
reason i said that is that each time you you go up a band relatively speaking as a percentage of the
wavelength you've gone higher right so let's say you're on uh 20 meter band here but you flick up
to 10 meters all right you've effectively now doubled the height of your hex beam
off the floor all right you you just have because you're now a whole wavelength above the above the
ground whereas before you're a half a wavelength so rather than recalculating all this we just say
we'll just increase the height by double it put 28 megahertz and we'll start that and we will see
10 meter band we've got much better gain now 5.1 because it's a lot easier to get gain
when you're proportionately further off the deck all right because a hex beam won't just come with
one element you'll get at least three all right if not six it'll do all of them and it looks and
acts and feels like a two element yagi slightly maybe there's a half a db in it there's not a lot
you know a two element yagi like um an opti beam or or maybe a step ir two element step ir
there's not a lot in it actually a hex beam and this in fact i'll prove it to you let's go back to
um say 10 meters off the ground and this is for our hex isn't it yeah it's a funny old expert
whatever else and we'll do five degrees just roughly just so we're baselining everything
at five could be seven three the matter and i'll fire another instance uh um i can't spell
another instance of this stuff because i i also um got anywhere here's a two element yeah again
i just happen to remember it's at 14.05 real ground so we'll do 10 meters again the same stuff
make it out of wire you know just compare apples with apples ignore the swr i mean it's the far
field plot i'm after now i've got no i this looks funny plot to me
so this probably needs some optimization forward gains probably fairly accurate though
so let's have a look at the forward game point two and the hex beam says minus a half so it's
slightly more gain we could probably press some buttons here and actually tidy this yankee up
using the optimization button which i'm not going to do now that's the middle of the day but there
we are that's what a hex beam is what would i say if you can't do it if you can't get to 10 meters
and it's a hell of a lot of investment to put in right without getting to 10 million if you
get to 40 feet we get to 12 12 and a half meters i think you will be absolutely fly
tim m0u rx i think he runs his most the time on on 10 meters uh uh yeah about 10 meters high
because in the uk there's like 10 amasses a few companies that will do quite an economical 10
meter kit if you know what i mean you can bolt to the side of your house in america i know you can
go 60 foot you know fairly economically but then you've got to factor in um your tower your extra
coax and a half decent rotator and have a gang of people every now and then that you can rely on
every now and again come and see you to help you have a little maintenance party yeah once a year
or something all right so it's a big investment that's all i'm saying so make sure you know that's
what you want to do fantastic toy all right but if the wind blows and the storm comes up then
i can sleep at night because i don't have one of these all right good luck to you that's it for the
time being i think my dinner's ready i will see you on the next one all the best now bye for now