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Construcción de una antena de radio - Contenido educativo

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Subido el 17 de enero de 2022 por Innovacion

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Howdy folks, welcome back to the shop. Today we are going to be building a Yagi antenna. A quick note from future me 00:00:00
This is going to be a long video 00:00:05
But we're gonna go through step by step every action and discuss why we're doing that 00:00:07
To get to the end product and some design things that may change so that you can understand why and how this antenna is built 00:00:12
This way so stick around let's build a Yagi 00:00:18
This is the first prototype that I made which has some problems 00:00:21
most of which is it is way too fragile as you can tell when the antenna blades kind of go back and 00:00:25
forth too many times they become work hardened and they snap right off like that which makes them 00:00:30
not optimal for an antenna there's definitely a you know balancing act between rigidity and 00:00:36
usability this is definitely not rigid enough so we are going to be using copper pipe and that is 00:00:43
of course significantly more rigid with some new 3d printed brackets that will grab onto this pipe 00:00:51
and uh hold it in a very strong way so 3d print design for this will be down in the comments 00:00:58
below and we'll be right back with all the things that you'll need to do to follow along 00:01:06
to make this antenna all right folks we are going to need soldering iron some solder a tape some 00:01:10
form of marker, a 3D printer, or you can get this from someplace, lots of retailers online that will 00:01:19
print and ship. We're going to need a drill of some kind to poke some holes into the aluminum 00:01:25
channel. We have the copper pipe, of course, your favorite RF connector, and some 50 ohm coax wire. 00:01:31
Since this is going to be a handheld antenna and relatively short, we're going to be using this 00:01:39
really thin stuff. It's going to be used with handhelds. And then, of course, the half inch 00:01:43
aluminum square rod, which is going to be the beam holding all of this together. So that should 00:01:47
do it. If there's anything I have forgotten, it will be on screen now. Normally antennas have two 00:01:56
tricky parts. One tricky part is the measuring and the other tricky part is the soldering and 00:02:04
getting all of that put together. But this antenna is going to have a third tricky part 00:02:10
and we're going to focus on that one first. We'll put the measuring off for a moment. We'll put the 00:02:13
soldering off for a moment. Let's just focus on these copper coils. All right, before we step 00:02:18
outside though, we need to know some measurements. Go to the online calculator that's on the screen 00:02:23
right now. There's a link to it down in the description. This thing's been around for at 00:02:28
least half of my life, I think. Hopefully it doesn't go anywhere. If it does, there will 00:02:32
probably be newer, better, or similar calculators around. Plug in the frequency target range that 00:02:36
you're going for. This is really only going to be happy in the two meter, you know, several hundred 00:02:42
megahertz range. As soon as you get below that, the size is just going to be not practical for 00:02:49
this size of, uh, you know, 3d printing and copper. So for a 430 ish megahertz, 440 ish megahertz 00:02:53
antenna, which is what we are going to be going for. This one is tuned to 435 megahertz. We're 00:03:02
going to need a reflector, a dipole, and several directors. The reflector is unique in the fact 00:03:08
that it also needs to be grounded. So it needs to be grounded to the ground side of the dipole 00:03:14
where the director elements out here in the front are 100% passive. So they do not touch or, you 00:03:23
know, do anything to what is going on with the wiring that we have to do back here. We need to 00:03:30
go punch into the calculator and figure out how wide these need to be. For our 435 megahertz, 00:03:36
the reflector needs to be about 13 inches or so, and then they get smaller the further out they go. 00:03:44
But that means that we now have a length that we need to hit just a little over 13 inches. Let's 00:03:52
add about two inches to each side, so we'll get up to about 17, 18 inches. Go outside and straighten 00:03:56
up some pipes we've got all of the copper pits cut down to roughly about 18 inches this is for 00:04:02
433 megahertz of course if you have your own make sure you double check your measurements 00:04:08
measure twice cut once all that fun business but we're going to uh take this uh put it in the vice 00:04:12
and then uh basically you just crush the end so the end of this is you know in the vice and then 00:04:18
bent down 90 degrees down to a pair of vice grips which are attached to the end here and we're going 00:04:23
to take Mr. Hammer here and give that thing a good smack. And this thing will become pretty 00:04:29
straight after a couple of smacks. Let's, uh, let's give that a go. This vice grip is on here 00:04:33
pretty tight. So just a tap, tap and a tap. Wow. It's already significantly straighter. I don't 00:04:37
know if you can see that. Let's just do a couple more. We don't want to elongate this too much. 00:04:44
You can kind of hear how it goes boom afterwards. And, uh, this is pretty much straight. So I'll 00:04:51
you up there we'll take this one apart and we'll do it to the next one so we take this one down 00:04:57
and we have now a reasonably straight 00:05:04
i mean you know nothing's perfect but uh significantly straighter than say 00:05:09
one of these which we can see has major bends in it so let's uh open the vice jaws back up get it 00:05:16
it about a half inch in we don't want it coming out of the vice and get this thing down until it 00:05:24
pretty much doesn't move i'm going to bend this then grab onto the end with the vice grips 00:05:29
crush that copper then we're going to hold it from here and give it a couple good taps 00:05:37
there we go i was about to say and there we go but i knocked my phone down so here we go 00:05:43
this one is reasonably straight as well. Again, not perfect, but we're talking maybe a millimeter 00:05:53
or two across an 18 inch span. Pretty good. I'm just going to knock the rest of these out 00:06:01
and I'll see you back inside. All right, welcome back inside. I actually made it inside this time. 00:06:08
Here are our raw elements that we are going to be cutting to their final dimension. 00:06:14
so these need to be pretty accurate the higher in frequency you go the easier it is for smaller 00:06:19
changes to throw off the performance of the antenna greatly this is a reasonably small antenna 00:06:26
especially for a yagi we're under you know 20 inches or so in in total length so you know this 00:06:31
this isn't going to be a unwieldy device but uh in doing so that means that our cuts here need to be 00:06:39
extremely precise. And you can see in the conversions to inches here, I left two decimal 00:06:46
places. Hopefully, I'll be able to get pretty close to that, and I want to leave very small 00:06:52
marks. So let's just mark each of these, and we'll go through them. So some of these are 00:06:58
significantly shorter. I'm going to just arrange them in a biggest to smallest orientation, 00:07:06
And then effectively, I'm just going to mark on here what each of these are going to be. 00:07:13
So this guy is going to be the reflector. 00:07:18
This is the dipole. 00:07:21
And then this is just going to be one, two, and three for the passives. 00:07:23
And that will give us what we need for each of these. 00:07:28
Now, we're going to mark their lengths and then cut them off. 00:07:32
So I find this easiest to just put the tape down. 00:07:39
then bottom this out on the end of the tape and now we have our length that we 00:07:41
need so the reflector needs to be thirteen point zero seven so you come to 00:07:48
thirteen and zero seven is a little less than a sixteenth so we're gonna just put 00:07:55
the mark right in the middle there between the sixteenth and that one is 00:08:01
good don't forget that your dipole is actually gonna need to be cut twice 00:08:06
because each element needs to be isolated from itself so make sure to put 00:08:17
your mark in there for that then the passives absolutely nothing special with 00:08:23
them we're just gonna knock them down all right so one last comment on the 00:08:28
dipole here is that we've got here's our dipole we want the final length to be 00:08:39
this and we want a little bit of space between these two so what I'm gonna do 00:08:45
is I'm going to add a quarter inch gap in here and then we're going to mirror that quarter inch gap 00:08:49
when we affix these. So here is the two and there is the quarter right there. So we're going to 00:08:55
leave that gap and that's where our coax is going to come up and split to go one way and split to 00:09:03
go the other. Don't worry too much about that. Follow basic dipole or it will make more sense 00:09:10
when we do it. I'm going to go cut these on the bandsaw and I'll be right back. 00:09:16
Let us get the dimensions down on our actual beam here. And this is just a little piece of 00:09:21
extruded aluminum, nothing too fancy going on here. I'm going to leave a section here on the 00:09:28
back where I'm going to put a handle on it so that I can hold it a little bit easier. You don't need 00:09:35
to do that if you don't want to, or you can come up with some sort of a fixment strategy. Whatever 00:09:41
Whatever the affixment strategy is, though, would be best if it was left or made in some 00:09:45
material that's not going to interfere with the RF signals. 00:09:52
Keep it simple, wood, plastic, PLA maybe, and go from there. 00:09:57
Let's get the tape laid back out. 00:10:04
This is a pretty small antenna, as I said a while ago. 00:10:06
We're under 20 inches for the whole thing, so we're going to put the tape up to about 00:10:09
26 inches. 00:10:13
just going to add six inches to all of these so our our reflector is going to be right at six 00:10:15
inches and then our dipole is going to be six and a half inches up from that so that's going to be 00:10:22
twelve and a half and then we've got eight point five four so plus six is fourteen five four so 00:10:28
So there's 14, 5, 4, and then we've got 13.42 plus 6 is going to be 19, 4, 2, which is just 00:10:41
right here, and then we've got 19, 2, 9 plus 6 is going to be 25.29, so 25 and a third 00:10:55
is right there and then uh we'll just cut the material after that 00:11:06
awesome sauce let's start putting things together 00:11:12
yeah i think that's a good idea no we can't do that yet this needs to get cut down we need to 00:11:18
do a couple of things we need to talk about the 3d parts let's do that next so all of these 3d 00:11:27
parts have a hole printed in them. There are actually two parts. Let's take one of these 00:11:35
apart real quick. Let's see what we're talking about. So this 3D print was designed by me to 00:11:42
basically be as extremely functional as possible. And that means that everything kind of serves a 00:11:54
purpose. And in here, the main thing that this has to do is just hold the copper pipe, you know, 00:12:02
in a specific position on this tube and what we're going to do um there are a couple things to help 00:12:08
with that and for the passive elements which are the uh the directors one two and three up in the 00:12:15
front uh they're completely isolated so basically all we have to do is find the the midpoint and 00:12:22
then just kind of give it a little push and it'll actually stick into the 3d print just a little bit 00:12:29
because there's there's a smidge undersize uh for for how this was printed out which means when we 00:12:35
put the uh the one on the other side and get the uh the bolts in there to clamp this thing 00:12:43
is not going to move at all it'd be cool if i could get that all in the frame so here they are 00:12:51
and they are not moving. We also have a couple little notches here and some raised notches here 00:12:58
which allow these to get locked into the same plane and the tube holds it along the other axes. 00:13:06
So that is the design. There is also a hole in here which allows us to get our coax in and out. 00:13:15
It is a significantly oversized hole. There's plenty of room to get coax in and out of here. 00:13:22
It does have to go through the tube though. So what I'm going to do now is we're going to have 00:13:29
to go cut this tube and drill the holes that we need in it, but we need to figure out where those 00:13:34
holes are. So I'm going to turn the tube sideways so that all of our marks are now pointed towards 00:13:39
the camera and then i'm going to drop this down onto it and uh it's a tight fit but it will go 00:13:46
down onto it make sure that it's right centered up and then we're going to transfer two little 00:13:54
black dots onto there and that will be where we're going to want to drill so we're just going to need 00:13:59
to get some black marks on here for each and every one of these so i'm just gonna go through and do 00:14:04
that real quick and i will see you on the other side so all right we have a bit of a problem here 00:14:10
Unfortunately, because of the design of how wide these are, we effectively need 00:14:38
two to be intersecting each other. So what we're gonna have to do is cut these 00:14:44
down a little bit, probably out on the bandsaw, so that we make them as short as 00:14:48
possible along the same kind of position here. So I'm gonna make a mark here that 00:14:54
we want to get rid of pretty much that and as much as reasonable for this. And that will hopefully 00:15:01
allow us to get these two still in. I think there's enough space there to have enough meat 00:15:15
on either side. So here are all of our knots. Here are where they are centered up. We're going to go 00:15:22
a center punch and then drill these with clearance for a quarter inch bolt then when i put the last 00:15:27
one down i took a little sharpie mark and just created the arc i'm gonna go on the bandsaw and 00:15:33
cut that out as well and that will pretty much make this occur i'm gonna go outside it's really 00:15:36
dark cold and windy outside right now and you know just the joys of washington winters and uh 00:15:42
then i will be back here on the bench and we can start talking about actually building this thing 00:15:49
our tube has holes in it now, I could have done a little bit better job centering them up, but 00:15:55
don't worry about that, uh, that's why I chose a drill size two sizes, two fractional sizes larger 00:16:00
than the quarter inch bolt, so there's a little bit of play that can, uh, 00:16:06
assist in my shoddy workmanship all right so let's uh let's work on the wiring first so 00:16:13
we're going to work on the dipole and then we'll go back to the reflector and that means that we're 00:16:26
going to need one of the ones that we cut i will make a 433 megahertz or 430 440 megahertz specific 00:16:34
design that has one of these coupled together like this with that first element spacing baked in 00:16:42
so instead of there being two bolt holes here effectively there's just going to be 00:16:50
one bolt hole here because this is i don't know man i don't think we have a space for this 00:16:54
regardless you will not have to worry about this moving on oh if you have a larger 00:17:03
say a 2 meter 00:17:12
Yagi that you want to build 00:17:14
you can use all of these components 00:17:16
they will be separated far enough 00:17:18
you don't have to worry about it, it's only if you're making 00:17:20
a really tiny one in the 00:17:22
higher frequencies, I guess 00:17:24
this really isn't going to work well up in the 00:17:26
gigahertz range either, it's just way too 00:17:28
big, but 00:17:30
yeah, let's get on 00:17:32
making on, the dipole 00:17:34
remember we're going to put a quarter inch between them 00:17:36
so the dipole is 00:17:38
gonna be the one that we cut here and I'm just gonna put this down where it 00:17:40
needs to be and then I'm gonna make a mark because we have to make another 00:17:48
hole in here and this hole is not a mechanical device this hole is going to 00:17:51
be specifically for managing our wires because we want our coax to go through 00:17:59
here and we're gonna we're gonna have it pop out the end you could if you wanted drill all the way 00:18:08
through and then have the wire come down right here um i'm just gonna route it out the back 00:18:16
because that's kind of i don't know where i want it to be there we go that's a good reason so right 00:18:21
in here i'm going to say we're going to want another hole right in the middle of this we're 00:18:28
also going to need another hole right in the middle of here but that is for grounding and 00:18:35
we're going to use a tech screw to mechanically attach to this aluminum. Aluminum is pretty 00:18:43
difficult to solder to because of its rapid oxidization and you know it's very hard to 00:18:52
break through that. I have tried a couple different solutions mainly some people saying that you can 00:18:58
put like cooking oil on it and give it a good scratch and uh you know solder should stick to it 00:19:03
that has not been the case in in my experiments um i'm actually going to try and deposit some 00:19:10
copper onto uh some aluminum in a future video so stay tuned for that one for now we are going to 00:19:18
get a tech screw and put uh probably about an eighth inch hole in here and we're going to put 00:19:25
another big hole in here so we can get our coax to come up. I'll be back when these holes are in 00:19:31
here. Hi folks, welcome back. We have the hole right here in the middle. We have the tiny hole 00:19:39
for the tech screw, which of course I forgot to add to the list in the front, so it'll be there. 00:19:43
Here's a little Phillips screwdriver, and here's the tech screw we're talking about. So 00:19:49
with that, let's get the soldering iron hooked together because we're about to need to put some 00:19:54
solder on some copper ye all right let's get to it all right all these hot iron 00:20:01
heats up here we are going to get pretty much everything situated in the way that 00:20:09
we do that we need to do there's some English words in here somewhere I 00:20:15
promise all right here's a coax this coax is really tiny so I'm going to 00:20:21
actually feed it up the back the coax data you have if it's uh thicker stuff like this i believe 00:20:28
this is uh rd58 you know uh it it might have a little bit more trouble getting by the uh 00:20:34
the quarter inch bolts here so you might have to drill all the way through 00:20:41
and uh you know if you do you know that that's perfectly okay uh and then you're just gonna 00:20:46
feed it straight up through me though i want it coming out the back so we're gonna shove it down 00:20:53
here and uh hopefully we'll be able to pick it up through that center hole and since i cut it all 00:20:59
the way through i can poke from the back so now i pulled it back a little bit and it's getting caught 00:21:10
All right, there we go, uh, no, no, no, yes, good, good, good, there we go, okay, I got 00:21:21
it to work, whew, that was close, I, uh, twisted the tube around until the, the wire kind of 00:21:40
fell, uh, down, and then I smashed it real hard into the edge and poked it with the, 00:21:45
uh, screwdriver, and now it popped through, so make this go through here, and we have 00:21:50
with a little bit of effort there we go we can line this up with the holes that we have 00:21:57
and then we know that our antenna is going to come out here and we need a quarter inch gap between 00:22:05
these two so it's going to be just a little less than the width of the hole that we cut down there 00:22:10
um just be about that or so we're going to make uh one of these negative and one of these positive 00:22:19
And we're also going to bridge this back down to the beam here. 00:22:25
So the entire beam is going to be grounded. 00:22:32
And that's required because the tech screw back here is using the tube here as its grounding element. 00:22:35
So we need to make that happen as well. 00:22:43
Generally what I do to do that is when I split this coating, I loop one around here. 00:22:46
so it gets crushed underneath this plastic. 00:22:53
So we're actually gonna take this back quite a ways 00:22:56
because we need a bit of this on 00:22:57
for both the dipole and to connect to here. 00:23:02
And that stops things from being way too messy in here, 00:23:06
also not putting another screw down 00:23:08
that can affect this cable. 00:23:10
So let's get a decent amount back here. 00:23:13
And strip the coax. 00:23:19
if I can actually just strip the outer jacket. 00:23:23
There we go. 00:23:26
And then everyone's favorite part, 00:23:28
we gotta separate the shielding wire here 00:23:30
from the center conductor. 00:23:33
I'll just back it off a little bit at a time, 00:23:36
kinda just get it to untwist. 00:23:41
And remember, we're gonna wanna keep this 00:23:47
into kinda two somewhat major groups, 00:23:49
cause one is gonna be going to ground the beam 00:23:52
and the other is going to ground the dipole. 00:23:56
To be clear, when I say beam, I do not mean like a beam antenna. 00:23:59
I mean like a rigid structural beam, which is just our half-inch aluminum pipe. 00:24:03
We're about halfway there. 00:24:14
As it gets longer, it gets harder to get them to kind of pull through 00:24:16
because there's more resistance with a with a bit of luck though you can always kind of pull them in 00:24:22
different directions you know and then if you can try and pinch and then pull out right from the 00:24:30
base it tends to work pretty well so all right so we got this back down pretty much the edge of the 00:24:36
shielding that we stripped off and we're going to kind of group this into two bunches we want one 00:24:56
bunch and another bunch kind of like that about 180 degrees apart and then we're going to twist 00:25:00
so that we don't have any stray squigglies because if we do and they go touch the positive side of 00:25:05
the antenna bad things happen e.g. the antenna stops working you might damage part of your radio 00:25:13
too so we'll we'll make sure that there's no stray you know angries before we connect it up to a radio 00:25:22
or anything so don't got to worry about blowing things up as long as you make sure to uh you know 00:25:28
isolate everything so we're going to tuck this down a little bit and then effectively i'm going 00:25:34
to put one end like that up uh under the plastic and the other end is going to get soldered there 00:25:40
and then the other other end is going to get bent that way and go there so to before we get down 00:25:45
there, I am going to strip off a pretty long section of this, probably about 10 millimeters 00:25:53
or so, just under a quarter of an inch. Well, I guess a little more than a quarter of an inch, 00:26:00
probably right around a half. We want to make sure that we have enough material here to actually 00:26:05
grab onto the copper. There should be no real torque applied to this other than its own weight 00:26:11
because all of the mechanical holding of the 3d printed parts so we're not relying on the 00:26:18
solder joint to be both electrical and mechanical it's only going to be mechanical so there we go 00:26:27
let's get the plastic piece lifted up and then we'll pull this down and get it tucked under 00:26:33
And that is, of course, going to ground out our aluminum as well. 00:26:42
And you can see it tucks down in there right next to the through hole. 00:26:51
I'm going to push that down real good, and we'll try not to make that move. 00:26:56
And then these guys are going to go that way and that way right here. 00:27:03
and before we get any further I'm going to tin both of these because again we don't want these 00:27:10
two touching each other at all and wow that tip is dry so let's clean that up a little bit 00:27:18
all right now we are also going to put just a little bit of solder onto our our dipoles here 00:27:25
and basically I'm just going to push down onto it put a little bit of solder down so that there's 00:27:35
heat getting into the pipe and now we pretty much just have to wait because we're waiting for the 00:27:40
pipe to get up to temperature to actually start flowing and if you put just a little bit of solder 00:27:45
right next to the soldering iron and it doesn't melt we know we're not up to temperature yet 00:27:51
so just keep pushing on it and give it a little bit of extra every once in a while just 00:27:55
when you see the flux start to to burn off and uh after a moment or two 00:27:59
we should get some solder to be deposited here on the end of the pipe 00:28:06
there we go that looks pretty good now we're going to do the same thing over on the other side 00:28:13
and once we have solder basically on both of the connections all we have to do is kind of get it to 00:28:20
reflow and it will grab right onto itself so this is probably the most difficult and fickle part of 00:28:24
this entire assembly. I guess the measuring could be pretty fickle as well. So, you know, just 00:28:32
stop, be slow, take your time, make sure everything is, you know, accurate when once cut. And you 00:28:39
know, things should work out pretty well. The math is pretty darn good. Like physics doesn't 00:28:47
generally get things wrong. And RF energy is pretty well understood. I just saw this entire 00:28:54
thing kind of float down onto the tube which means if I pull away we should have a nice little blob 00:28:59
here now one thing that we do want to make sure that does not happen is what's occurred right here 00:29:06
and we have a little edge any spurious edge like that we we don't want in our system it creates 00:29:12
little areas for the RF energy to come to a point and then get shot out so you know try to not do 00:29:21
that when soldering all of these things together. We're going to let these copper tubes cool down 00:29:28
a little bit because they are both toasty. And we're going to take a step back just for a second 00:29:34
and prep a couple of these. I will bring you back when these copper pipes are cool to the touch. 00:29:41
All right, our pipes are cool to the touch, which is good. And that means it is time to get these 00:29:49
guys aligned up and I'm going to put these upright so when we uh we'll be able to see them 00:29:55
before we clamp things down though I'm going to take both of the tubes and I'm going to rotate 00:30:02
them forward like this so that we remove as much tension as we can off of the the joint so what 00:30:06
I'm going to do is push these down and they should remain reasonably snug up against the uh the PLA 00:30:13
or abs if you chose to print it in that and then we're going to put a little bit of tension down 00:30:21
onto the wire i have my uh flathead here to help because these little guys get really hot 00:30:26
and then uh all we're gonna do is wait for both of those uh bits of solder to flow together 00:30:33
and we should be good there we go i just watched the uh the solder flow through so that one should 00:30:41
should be good and then we're gonna do the same thing to our second one, our 00:30:52
positive side of the dipole. Just gonna give a little bit of solder on to the 00:30:58
soldering iron here and then don't forget to kind of push the wire into a 00:31:04
way that it will preload. You don't really want to be fighting the wire 00:31:09
to get it where it wants to be. Looking at this it's actually a little bit 00:31:15
longer than I think it needs to be. 00:31:19
So we're just gonna cut that little tip off the end. 00:31:22
Now let's push it down and get soldering. 00:31:26
All right, so I just watched it flow over 00:31:34
and it should pull off pretty quick. 00:31:37
We have everything we need here pretty much done. 00:31:40
What I'm gonna do is grab both of these 00:31:44
and kind of push them together. 00:31:49
and then, I don't know, let's see, I said I was going to rotate them that way, but it actually 00:31:52
looks like it would be best to kind of pull them in this direction, and then we're just going to 00:31:57
give a little bit of a snug push, and then we'll take the top plate and put them on. Now, I know 00:32:04
that this needs to be about a quarter inch, and I'm just using the width of the hole we've got 00:32:12
down there to give us that dimension. So now it's a pretty good idea to get this bolt punched 00:32:17
all the way through, which of course is a little bit tricky because we now have a coax wire in 00:32:26
there. So if you've got something small and pokey laying around, you might be able to push it far 00:32:33
enough out of the way. I said push it far enough out of the way. Come on, don't make me re-solder 00:32:41
everything. You fit, I have faith. Right over to the side. Yeah, there we go. I knew it would work 00:32:55
out. So then let's get this pinched down. And then on this side, we want this one to be, you know, 00:33:04
very secure so because this is the side that has the wire contacting down to the uh the beam 00:33:20
i want it to have the washer because out of the two if you know if i had to choose 00:33:29
i want the extra right here now we'll just get this one a little bit snugged up 00:33:36
and then i'm going to push down and get this one snugged up as best we can and we'll get those 00:33:45
fully done up later but here we go there is our active element now let's uh go back towards the 00:33:52
the backside here and we are going to use a a little bit of wire here to go from our screw 00:33:59
up into our our reflector so let's get another one of these and we're going to need a small piece of 00:34:06
wire here's the tiny little piece of wire i put a little end that we're going to put on to solder 00:34:17
the tube and then i've got another end over here that we're going to put under the screw so this 00:34:24
guy i'm going to wrap around into a half hoop then somewhere around here somewhere around here 00:34:31
there it is we have a screw and we're just gonna get the screw in 00:34:39
and then we put the hoop if we put the hoop around this way with the screw turning 00:34:45
i need to eat with a screw turning to the right it's going to cause this hoop to open because 00:34:55
it's gonna put pressure on it like this. 00:35:01
We don't want that. 00:35:04
So if we put the hoop the other way around, 00:35:05
as this gets tightened, it's gonna bite and pull it in, 00:35:08
which is what we do want. 00:35:11
So let's put this hoop through. 00:35:13
Then I'm gonna get it as tight as I can 00:35:17
just kinda by pushing it. 00:35:19
Then we're gonna pull this towards the back 00:35:22
just so that it's nice and taut. 00:35:24
And then we're gonna tighten this down nice and slowly. 00:35:26
And then as soon as you see it bite, 00:35:30
just give it a little bit of an extra, 00:35:32
and that should do it. 00:35:34
Now, we're gonna raise this a little bit up, 00:35:36
and we're gonna tin it. 00:35:40
Now the rest of these are going to be 00:35:43
a little bit more tricky, 00:35:46
because the dipole, we knew where the center mark is. 00:35:48
And you guys, it's cut in half. 00:35:53
But each of these guys, we don't have a center point for. 00:35:56
Alright, we've got all of our center points marked, and we've still got the 1, 2, 3 in 00:36:00
the reflector. 00:36:07
So let's continue down the path of the reflector here, right in the middle, which is effectively 00:36:08
where this is going to be. 00:36:14
We're going to want to put together our holder. 00:36:15
Then for me, because I routed things, let's say, uniquely, we're going to have to make 00:36:24
sure that the coax stays out of the way when we put the bolts down. 00:36:30
So now that we kind of know roughly where this is going to be, we know where this wire 00:36:34
can live. 00:36:37
And this wire really kind of has to get out of the way, so make sure that it lays down 00:36:38
in that pocket. 00:36:42
We don't want it to be affecting the clamping force here. 00:36:43
So effectively, I'm just going to pick that up a little bit, and we're just going to solder 00:36:48
it right down onto there. 00:36:55
Now, when soldering this tube, it is going to get pretty hot. 00:36:56
When doing it on this one, you want to leave it as little time as you can on the 3D print. 00:37:01
But what I'm going to try to do here is lift it off of the 3D print using just a couple pieces of metal here, bolts. 00:37:08
And then when we get this to heat up enough to actually flow the solder, we won't melt the PLA. 00:37:16
all right now it's centered up and the wires soldered on so we can move to putting the top 00:37:25
plate on and then we just got to push the uh the wire out of the way and get our bolts pushed 00:37:33
through all right that was a little bit of a snug fit but uh we got all of the bolts to go through 00:37:41
and then we'll just make these nice and snug because we don't want these center points moving 00:37:58
at all as it will throw off the geometry of the antenna there we go the hardest and trickiest part 00:38:04
is now done we only have the passive elements left there's no soldering left to do and you know 00:38:10
that means we're within minutes of finishing this job thanks for sticking with me through here so 00:38:17
effectively you do the same thing just minus the soldering and we're going to start with 00:38:23
the number one reflector here which is going to be the biggest which should be this guy 00:38:29
and then for me this is the one that I cut you will not have to worry about that 00:38:37
so we'll just pop this plastic apart and then as we have before we just push this down and then 00:38:42
just slide it back into the position that it needs to be. There we go. Then we take our number 00:38:54
one, and we want to make sure that that is centered up as accurately as we can. Then we'll 00:39:00
take the top plate, make sure that we put it on the right way, and then it should push right into 00:39:08
there. Now, that's one of the passives, so let's just move right along. Make sure you pick up 00:39:16
number two. That looks like number two. Then we'll, remember, just give it a little push to 00:39:27
seat it, and then we'll come over here and set this down, and then put the bolts through. 00:39:35
same thing pop this over that 3d print was a little snug push it down make sure it's aligned 00:39:44
appropriately then get the third reflector push it down so that it is nice and snug 00:40:00
and then these will sit on top push down again we've got everything aligned that we need 00:40:09
we've got the entire antenna assembled there is only two things that we really have to do 00:40:18
and uh you know my my rf connectors are already attached here so if you still have to do that 00:40:29
uh you know choose your favorite rf connector and get that uh assembled and whatnot there's 00:40:35
so many different kinds and flavors and shapes and sizes and whatnot we're just not going to 00:40:40
dig into that right now the litmus test to make sure that this is roughly right is you want to 00:40:44
hold it on end and if you let it rest on its smallest element you should notice that there is 00:40:50
a an even gap pretty much through most of these if you find that it does not rest on its last 00:40:58
element like say that it's resting on this reflector um there's something very wrong it's 00:41:07
either to do with the alignment or to do with the overall length of one of these but you should 00:41:12
always even in both directions always have you know a really good you know slope across so you 00:41:18
know pretty much this this looks pretty good all right so let's not fret too much about that the 00:41:28
last thing that we need to do to make sure that you're not going to fry your radio or cause any 00:41:34
issues is we're going to grab our multimeter we're going to move it over into the resistance mode 00:41:37
and then what we're going to do is take our connector here we're going to put one pin on 00:41:42
the positive and one on the negative here and we want to see zero or you know open lead which is 00:41:49
what i've got right now just to check that everything is connected appropriately if i 00:41:56
push these together it shows 0.000 resistance. Now to be doubly sure of everything we're going 00:42:01
to just make sure that everything's connected as we'd expect. So if I go ground and then I touch 00:42:08
the aluminum chassis here we have you know no resistance. If I hit the back element here which 00:42:13
is our reflector I have looks like a couple ohms probably due to this yeah there you go so almost 00:42:20
no resistance there. Let's go figure out which side of this is the negative. Obviously, it's 00:42:29
going to be yep, I'm getting open lead over here. And then over here, we've got 0.000. So if we go 00:42:36
to the positive in our connector, and then over to our other element, we have 0.000. Let's make 00:42:43
sure that we don't have positive on our ground, we have open lead, we don't have positive on the 00:42:52
chassis which is open lead and one last sanity check let's just connect the meter and we have 00:42:57
zero ohms of resistance which is what we pretty much expect cool well thanks for sticking with 00:43:03
us again this was the 433 430 430 440 megahertz uh yagi we're going to take it outside in a little 00:43:10
bit and we'll do a couple directional tests for this see if we can poke a repeater or two with 00:43:20
the little bow thing handheld and then uh you know that's pretty much all that uh that it has 00:43:25
for this project of course give me scale up scale down to pretty much whatever you want um you know 00:43:31
if you're gonna make this twice as bigger or you know so far you know i'd recommend scaling the uh 00:43:36
the plastic bits up and down especially to match the size of the tubing that you're going for 00:43:42
And yeah, this, this is really cool. I'm, I am significantly happier with that compared to 00:43:48
where we started earlier today. So this, uh, this was a great learning experience, 00:43:58
but obviously not very stable. This is significantly better and I'm very happy 00:44:05
with how it turned out so all right folks that does it for this as always get out there make 00:44:12
something in your shop right now on screen there's a video that's a youtube algorithm has decided 00:44:20
you might like to watch so feel free to give it a look 00:44:27
Idioma/s:
en
Subido por:
Innovacion
Licencia:
Reconocimiento - No comercial - Compartir igual
Visualizaciones:
479
Fecha:
17 de enero de 2022 - 13:26
Visibilidad:
Público
Centro:
C RECURSOS INNOVACIÓN
Duración:
44′ 34″
Relación de aspecto:
2.35:1
Resolución:
1280x544 píxeles
Tamaño:
364.83 MBytes

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