Antenna placement examples. What are we doing here Steven? Alright so
I've been talking to quite a few folks about some of the wireless issues
they've been having you know just questions and concerns and and many of
them have mentioned some advice on antenna placement okay and really there
could be so many ways to to express this and then make diagrams but I figured
we'd pick you know maybe three examples they could really help us out they're
pretty general but give you a good idea of just the baseline of where to put a
tennis okay so these are some common things that you have done wrong or you
see other people do wrong and we can kind of show here with graphics both yes
I have done them wrong and I see it done wrong call me okay so my hope is that an
infographic should be fairly self-explanatory so if you have the
patience for it I would love to see what I already understand and then maybe ask
questions about what I don't understand so far yeah let's deport okay
so I don't know what all these shapes are but I know that these are two
antennas and the the title here says I am TX and Mike rx so I understand that
to being in your monitor transmitter and microphone receiver is that correct so
far absolutely correct okay so what is this crazy-looking antenna on the left
here that's the IEM transmitter so that is a very common antenna type that we
use for IMS it's called a helical and that little squirly a little spiral
there you see is actually what is it's basically shifting the wave to make
something called well 360-degree polarization that create
what's called circular polarization which means that if we have a pack and
should have had this ready here we go this is my in-ear pack that means if
this if I bend over and the antenna turns sideways or it straight up it
doesn't matter that antenna is basically shifting the way if you're in 60 degrees
where it's gonna reach it at 80 point so we like these antennas a lot for in ears
because of that that characteristic now they also are I gain which is important
when you have just a tiny little antenna that's trying to get a lot of signal
that's buried maybe under your skin signal is important so we have circular
polarization to hit the antenna action and we have a lot of for game to
try and push through clothing and skin effect and okay okay so helical antenna
makes it so that I can mount the receiver any way I want for the in-ear
monitor and it has lots of forward gain and so I'm understanding from this big
red X here in this big green check mark here that this here is wrong here on the
left and this is right on the right correct yeah absolutely
and so let's think about that for a second so we mentioned a lot of for game
which means we have a lot of power coming from this guy and so then we
don't think about our microphones that are pretty sensitive because they're
trying to pick up small signals and far away again so if we take and I have the
helical here something with a lot of power pointed in this direction going
that way and I put something here trying to pick up small power we're going to
overload this quite heavily okay and that's going to cause a lot of problems
and even though that antenna is directional and it's supposed to have a
null behind it it's still having some pick up it's not no pick up
yeah there is no such thing is an infinite no think about your 58
microphone with heads booth has you know a little bit of a knoll on the back it
still gets sound in the back but not as much as from the front so as much as we
haven't whole in that back we're still when we're blasting with high-powered RF
from behind it's still gonna be getting into that antenna got it okay so this is
making sense to me if I set these up I should have the I am transmitter behind
the receiver so I shouldn't have the imtranslator behind the receiver so I
don't blast my receiver with unwanted transmissions yes okay and some of you
and a lot of our comes down to some people might say well I've done it
before it worked then it depends on a lot of things you could have had your
frequency band was far enough out or it's filtered but again we're always
going to general practice because the minute one thing breaks in the system
that could be all it takes just destroy your signal so we want to just follow
good practice from start to finish cool all right so so far this makes
sense to me so I can kind of remember this setup for the antennas and it looks
like since we're looking at the side here and this is like a section view
we're just looking at these two dimensional representation
the antennas then this maybe is the same thing down here in the middle but a
planned view from the top so now I'm looking at something similar but from
the top is that correct yeah and so this is kind of what we're
looking at here is we kind of want to get more than six feet away from any
transmitting antenna it's something where to get into a little bit when we
get to the bottom example with corporate a via something called the reactive
near-field which right around the antenna we want to keep things away from
it but when you get farther away we're trying to do just avoid the power coming
out of that incentive again like we talked about the null there is a knoll
and there's a lot of direct forward direction that it's very focused and
helical but it's also radiating out the sides as well so we want to keep
transmitting antennas a minimum of six a lot of people say ten but a six you can
get away with it a lot of times there's you know you can say I want this twenty
feet that way but in practical situation that has always happened so I feel like
six is a very good very good compromise you'll be safe that way so Stephen one
thing I just noticed here in the middle though is that these I am sorry is that
these LPB a shark fin antennas are not all the way behind the helical antenna
like they are up here in the section view so why aren't they pushed farther
backwards like up here that's a very good point
and so the example we have up here is more for close proximity though if
they're not six feet apart yes if you have to be quite close together that's
come away one it you want to have this this rx antenna the receive antenna in
the null now if you have some room to spread out which always welcome kept
talking about is a very good thing then we can actually come in we can play it
around a little bit with it not being directly behind that because you're far
enough away to or in a sense you almost need space to filter that out of the
antenna so this this is all good so far so now what about this bottom part this
looks like the big red X is telling me antenna farm bad having me trim you know
receiver is also close to each other and we need to space them apart and I'm
guessing at least six inches right yes absolutely and I like I mentioned very
briefly before something called the reactive near-field so we asked me
Goldman 10 o'clock 2 o'clock what incentive Farms so we have these
antennas close to each other even if they're on the receive what's this
starts getting energy and starts resonating they can actually transfer
some of the energy back and forth so we lose that energy between different
incentives now if you have frequencies very spaced very close together that
could get some unwanted signal this intent of the cause their appearance
we're also losing some energy so if we space it out about 6 inches 6 inches
tiny round 5 inches is a is the reactive Muirfield about four Missoni megahertz
so 6 inches again more is better but because of constraints in an actual
environment that we operate in you can't you know can't have a corporate a/v
table with your microphone with receivers sherry I mean that's that's
why we stack them up normally right as I'm trying to save space because it the
same space and it looks pretty but it's not always the best for RF so again 6
inches it's compromised but uh it should be seen a pretty safe area and the only
way to not have to do this kind of spacing would be to have an antenna
splitter right so then we could just have 2 antennas a splitter and those all
go out to each of the receivers yes and that works well because there's
isolation these one of those ports so everything I mean essentially you can
put isolated another incentive with it and a hole in the top being quite
expensive but yes so the other way to do this is with and it's in the district or
multi couple and two incidents awesome well this has been really helpful for me
this is something that I feel like I would print out and take with me because
although I understand it right now now that we've had this conversation I feel
like I could pretty easily forget about this you know in a couple of weeks when
I might need to use it so if you're watching right now and you have some
questions about this please comment below this video if you have any other
suggestions about antenna placement and how it's done best and how you do it I
would also love to hear those you know my whole goal in doing this kind of
stuff is not only for myself to learn more but for us to sort of share all
this information so Steven thank you much thank you much
so Steven thank you so much for putting this together
and I think you're working on some more that we're gonna be talking about in the
future right absolutely I'm quite excited about it and I hope everyone
watching this sticks in for that part as well.