A very good day from DX Commander my name is Callum M0MCX. Now I I first
discovered that a 40 meter vertical would resonate on a 15 meter band a few
years ago it's exactly the same as a 40 meter dipole resonating on 15 meters but
when you look at eham and all these forums there's a lot of very clever
people (yeah) who've read all the books but never experimented anything that's
the point who will tell you that a 40 meter vertical may well be resonant on
15 meters but it's a cloud warmer no good for DX really why is it my 40 meter DX Commander
all band vertical works so well on 15... Let's find out shall we
so I have modeled a DX commander is it might well so what is des commander Oh
move this around basically it's six elements 40 30 20 17 12 and 10 where's
15 well our interest 15 is this long one here so how does it work so let's go to
seven point one five and as we can probably tell we will get elevation five
degrees DX all right I'm probably gonna get somewhere about minus five apples or
D bi minus four point seven minus four point seven and if I go to fourteen
point two to five there abouts I'll get roughly the same probably a
whisker more five point two half a DB okay
um now then if our dipoles resonate on every odd harmonic so seven megahertz
will two sevens of 14 so it's not gonna resonate they're three seven two 21
ah right okay so if we go to twenty-one point three five well what am i doing
twenty-one point three five now there's a slight change here the DX command and
I can't model this on Mme a DX commander goes up to nine point two five nine
point three meters and it comes back down about 75 centimeters which is about
that lunch so a the physical length on 50 meters isn't three calls wave it's
slightly sure to get is kind of top loaded but the bandwidth is such on
forty meters so it operates exactly like a 40 meter vertical so I'm having two
tunas a bit higher because his software it thinks it's it's actually better than
this right that's all I'm saying and trying to justify myself as opposed
so this is where people go oh it's a cloud warmer don't use it and they don't
do is they don't dig into the numbers they don't actually understand so if you
remember my elevation at five degrees off the horizon for my DX what's it
doing is it better than five apples or is it worse minus two point seven so in
fact I've on 15 meters on a DX commander you will get twice the gain as all the
other bands but I find that quite interesting now that means that any 40
meter vertical should give you quite good DX gain on 50 meters so if you've
got something if you might have a 40 meter vertical B and have the confidence
to use it on 15 because you will be doing quite well and further up that's 5
degrees maybe you've got something it seven degrees it gets rapidly very good
so if we come up here it's as 20 degrees and if you do get some local conditions
you know that kind of quick hop you'll be doing fantastic 4.3 up here I mean
you you are into some super super super territory so have the confidence of
doing that now what's the time oh it's a nice short film that'll keep you
entertained so that's it for the time being my name is Kalin 50s commander
enjoy your verticals enjoy radio bye for now
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