so i wanted to run past the idea of a huge triangle now james and i built one at the scout
hut and we called it the the mega loop as it so happens in fact there's going to be some pictures
on the internet the scout hut was bottom right of this corner here this was the original loop
so this is 80 meters in total so that is just under 30 meters aside but we made we made we'd
the idea is we're going to make this one as well this is a hyperloop so this is actually twice the
size so this is a twice a 160 meter loop what we ended up with is halfway between the two
we ended up with about 55 56 meters on average per leg huge triangle held up with um
paracord now i've got some pictures of this i'll just quickly let you see hang on a minute
oh well this is a a snowy a snowy snowy scout heart we can't i can't even
i wonder if we could see the wire oh my goodness i can see it
just coming along here and down it might be a better one actually let's just have a look
okay so this this this is the the tree and this is a 80 meter one corner of the 80 meter loop and it
comes down bit of paracord and all the way down so i mean that's i mean it's big okay that's a 60 65
feet there's a four to one balance sitting there and you could see the coax wandering down to the
scout hut in fact that's probably it coming over the top and in through a hole i probably drilled
and that's another view of the the four to one balance so this was actually quite
it was tuned for coax all right you can easier to put balance line with a big fat tuner on one end
and then it will just be every band you want but we didn't want the expense of a balanced tuna we
just wanted a coax fed and what we did is we tuned this and get rid of this we tuned this for the 40
meter band and once it's tuned for 40 as you'll see in a minute it'll kind of work everywhere so
let's set this up for um roughly i don't know 7.15 it could be 7.2 i mean the difference is you know
not a lot let's just see where this actually plots to just hold on a minute i might cut this bit out
okay so currently this is tuned at 7.2 something all right so 7.2
then this is a big triangle so we look at the big triangle there it is there we've got coax fed in
one corner it just happens on the right hand side at the moment and we got it working at roughly
7.2 what's i think it was 715. all right which is giving us an impedance down this line here it says
um 196 about 200 ohms therefore if we go to the optimization tab and click advanced
and go to the environment you can see i've said mark this for 200 ohms in other words
give me a four to one ballon put a four to one ballon in there and this is what we've
got and then that gives us a far field plot so this is based on what height at the moment
let's bring it up if you're going to put something this big in let's bring it up to 20 meters on
average there'll be quite a lot of sag all right forget the fact that it says no loss there you'll
see it makes next to no impact you will find as cswr goes up and down as you change frequencies
things like the impedance will change a lot of people will say oh the impedance of a loop is x
uh just like the impedance of a dipole is why but that's in free space there's no such thing as free
space you're always somewhere near the ground all right near within a few wavelengths anyway
so let's look at the far field plot on 40 meters and this is what it was giving us
and if you watch the video what's best a vertical or a dipole you'll know that
at 20 degrees off the horizon achieving let's say you know zero dbi or better is is great so if i
just go tell this to go that ding was me by the way if i tell this just show me what this is going
to do at 20 degrees off horizon which is anywhere between and 1500 miles up to a couple of thousand
kilometers in the evening we can then spin around here and find out what's happening so 5.4 so very
very nice antenna not so hot right in the middle so if we say what's this doing at 65 degrees
off the horizon okay so with that real short stuff we can see not as quite as good not quite as good
but in the main they'll still hear you it doesn't really matter so let's go now as
you know a lot of people love the idea of five degrees of horizon that's quite hard to get to
a lot of real dx is between sort of that three to eight degrees of horizon rising to maybe 10
12 some of it's coming in at 15 and 80 meters so it's even coming in at 20 right
so this is at five degrees of horizon where a straight vertical will be giving us not by
the c now but just in your average potato field right be giving us about minus five so what's this
giving us this is giving us minus two look minus 2 there minus 3.7 minus 3.9 yes there's some dips
all right but in the main it's slightly better than a vertical on 40 meters does this work
on 80 as well well it will do but further down because 80 meters and 40 meters aren't perfectly
harmonically related so i'm telling this show me what it's like at 3.6 please it's giving us an
sw ic of 1.04 and there's my plot now i use this antenna um and won the irish counties dx category
right because ireland was literally there okay and i had the best signal from anywhere outside
ireland into ireland because islands just to hop literally over the corner so yeah i won
that in about 10 years ago was it it was two hour contest or four hour contest or something
so 80 is doing fine a little bit where it's a multi-band antenna my problem is if you try
and run that at 3.8 it's not harmonically related so the swr is getting a bit high
now swr 5-1 is no big deal you can easily dial that out either with a big fat tune or
if you had a balanced tuner and that's what we considered at one point in time going down there
but triangles have got a very specific particular characteristic so you could tune this a little bit
all right to get it up to 7.25 7.3 in which case 80 meters would come up a bit better
to three because you'd need to take i don't know about a meter off it something like that
but again if you're coax fed you'd need to be up and down the ladder and
sorting out to get the best tune overall if you tuned it at 40 though
what would happen is that 7.2 would become 14.4 because it's all harmonic
related so 14.4 by the way we can't transmit above 14.35 but anyway let's just have a look
got a bit of an swr here wonder what it's like at 14.3
okay worse so it might you might want to make this a whisker bigger and then you'd get a
perfect tune on 14.4 in fact i'm just going to do that now i'm going to say take me from 7.2
to 7.1 by the time you've got to run a coax in you'd never notice a little bit of swr 1.87 to
1 whatever else but we've still got the height we're a wavelength off the ground and this huge
160 meter effectively loop going all the way around three you know whatever
and this is why i was running a pileup to the us and holding the pile up at 10 watts people going
you still five and eight okay so five degrees off the horizon and this is what i was getting so i'm
now getting a gain of nearly nine dbi compared to my vertical which is minus five so if we get
my little book out if i can find a spare page we'll just work out oh there's a spare page
we'll just work out what that is so let's say my vertical's minus six you know a bit
of crappy ground i've got minus three and this is doubling the power every time that gives us
zero that gives us plus three that gives us plus six this is giving us plus nine nearly
so if that's my hundred watt station if i converted if i switched from my
loop from my vertical to this okay which is 160 meter james and i called it a mega loop
it would be the equivalent of putting this much power into the vertical 100 200 400 800
1600 watts 3200 so by switching to this if or i could do the same as going from 100 watts to 3200
watts on the vertical i think you'd find it'd be better to do this however there's nulls as well
i mean look at down here where's that null minus seven you know there's three point four all this
is great and what we found is that uh you keyed a microphone with a couple of hundred watts cool cq
somebody somewhere answers not so fantastic for a contest antenna where you need some front to back
but you just want to get through to somebody and it just so happens that was about 290 to us 290
degrees which came right over the top of new york all the way down to florida and then a bit of it
would still go to as far as kind of vancouver seattle and that sort of thing uh because that's
just the way it was orientated fantastic isn't it if we go up a little bit higher to 21.3 ish ignore
the swr we played around with this to get the right compromise across all the bands
it says 3.9 there but what's it doing here i mean look you see how there's very little up
here and it's all pancaked out flat elevation five degrees so look at this 11.6 11.6
11 so it's nearly 12 isn't it so that's that's me running the same as running 6400 watts
on a vertical by running 100 watts on that can you hear me now yeah so if you've if
you ever get the opportunity 28.5 there i'll let this run it might take a while
if you ever get the opportunity or you have a look around you go oh look that's three trees here
any reasonable triangle would do it and the height doesn't really matter we'll take some
height off this and see what it does in a minute same here we are look at this five degrees
look at this yeah it's it's it's all up there someone is going to hear you in the
world this is all roughly the same as running several kilowatts on a vertical all right
what's the best antenna what's the best antenna people keep asking me what's the best antenna this
was my best antenna the mega loop every time if i could only have one antenna i'd have a mega loop
i just would it's just so obscene it's better what happens if we just reduce the height so 10
meters now 10 meters is fairly achievable you know an old apple tree or something
uh i'll tell you what i'm on the wrong can we hit the stop button no let it run let's come
down to 20 meters with a half wavelength all right so it's come down to 14 ish or whatever
let's have a look on 20 meter band just what it does to us you know elevation 5 average dx
we're still achieving 2 3 db all right now in fairness who remembers who remembers what the
hex beam was at 30 or 40 feet uh that was that was about the same as a hex beam isn't it in fairness
but nice you're everywhere though you see it's a really lovely antenna of course this will hello
not quite sure whether to do this 145 megahertz this might take quite a while okay because it's a
huge thing but we ran it on vhf as well two meters and 70 centimeters because the thing is it's so
high right then and it does it pancakes this low bout and it does work i'll show you the plot at
the end of this video because it's going to take forever you know this is that many calculations
to do right while that's running i just got to say that it doesn't matter if you feed it on a corner
or a flat okay so just because you've got this this big dragon but your shack is here
all right can you feed it there yes you can right and it still behaves the way we behaved there not
quite as obscene right but it still works and in fact as you move that feed point around this this
the clock thing twists a little bit which is fascinating so you don't have to feed it there
put your four to one ballon in the middle doesn't have to be in a corner that's what i'm saying okay
right i've been running this for a couple of minutes just uh to show you what it's like on the
145 well the two meter band okay now we ran this quite successfully on two meters ignore the swr
we had it five but this was absolutely hilarious uh say two well i'll do five degrees of horizon uh
but it it's it is obscene elevation one degree off the horizon yeah people people were hearing us and
it was it was doing this on the 77s as well so if you've got a big oh there it is there look at that
fantastic so if you've got a couple of big trees have a go it's good fun that's it for
the time being let's do uh we'll do some square loops uh hang around if you want more of these
loops big wires things you can do when you've got a few trees knocking around
all right that's it for today all the best thanks for tuning in bye for now