How to Build a 4:1 Balun Start to Finish with Mike and Callum
so we're in the workshop today with mike and uh my goodness we're building a fort well mike is building a four to one balance because he's good at doing things like that we've decided to use three of these one again ft 240 43s and what's that wire let's think it's a 1.8 millimeter shellac or enamel coated copper wire so we're going to make a four to one ballon so we're doing 200 ohms down to 50 yeah or a thousand ohms down to 250 exactly whatever all right that's funny photographs you've got on there are you going to tell them what the difference is between a current ball and the voltage balance yeah one does current the oven does voltage this is a serious channel you can do this in a different in a number of different ways okay we can literally double them up like so and put the the turns through them or we can use them like so and you make two multiples i see um so i can show you that's a single way of doing it where you put them on top of each other or a single core um where you would you would literally just um put the cores through both sides of the toroite if you like and yeah and join join a pair together yes or we can use multiple versions where this is the more than one i think we just uh stack them on top of each other i think it's a simpler way of doing it and if i wanted to be a bit paranoid on the qro could we just do could we yeah yeah you can do some more and more i i i think it would be fun to make a monster and then i've got um we've got a box here i found in my junk box which obviously bought for a project good boy one of the common myths about um shellac or enamel coated wire is it does not need to be put inside additional plastic or pvc coated wire to isolate it or insulate it from the cores and that's because the cores themselves don't conduct this is our center line we're going to turn cores on this side cause on this side and then you'll see how they're wired together afterwards all right so this is your measuring tape isn't it this is a measuring tape quite literally that because i'm going to do what we've got now we've got one two three and i think we're going to do four turns side yeah i think four turns aside would be nice and so what happens is i'm gonna do the first one with a single piece of copper because that's gonna join again and then literally come back on itself to here right okay um then do we have to wind another one rewind another one on this side okay and then another one on this side going in the opposite direction right and that gives us the pair correct is the diameter of the wire important for the current capability then the obviously the the the thicker the cable uh or the thicker the wire the more um capacity the more current it can handle right i think it might become difficult evident in a minute hopefully okay it's more like metal work isn't it yeah and it must admit it hurts the fingers with this size of wire i haven't seen live without will hold the ferrites together i gotta leave enough gap because i gotta wind another one beside it yeah what's it like having a cameraman it's a lot easier than doing it balancing it on the shelf to work today all the time make sure you're in frame oh so is this do you buy that by like like 100 meters yeah yeah 100 meters of that you actually buy it in weight rather than in length okay so that's a kilogram or 1.5 kilograms that's a kilogram a kilogram of copper yeah as a commodity of course you have to buy it where did you get it from um that one's from uh bro cot dot co dot uk okay um it's i believe the companies based in the north of the united kingdom yeah um and i must admit they've always been really good i've always bought my copper wire from them and it's normally at my premises within a day or two of purchasing it and this coating you were talking about shellac or something shellac or enamel yeah enamel yeah so are all in our enamels the same um pretty much um it's basically a varnish yeah for one of a better way of putting let's put on the cable but in fact i mean that acts as an insulator then yeah yeah literally that one two three four five one two three four five primaries so that's the one that goes to the center core and then to the shield and then we're gonna wind the second one that goes from the shield to the center core but the same one also comes off here fine for the other side of the just literally a transformer square root and all of that right so i've lost my wire but it's on the floor sir behind you wear you through it all right i need to measure it again but i'm gonna have to guesstimate it should have cut it i know oh don't guesstimate it that's a shame that's all it's only right right so we start basically the other end same coil turns and if you notice that hopefully anyone's noticed but they're going in the opposite directions to each other yeah see oh my goodness yes all right it's kind of like a puzzle yeah now if i have um gone one too many turns which is a possibility we can always undo this one and join the nice one and join it back up okay i think we should be all right yeah so just to show them so it's that's where you started isn't it yeah so you're going to do the same here only this one's going to be it's got to go all the way around does it yeah this one's got to go just the half so this these have to couple yeah so i literally have to follow the other one and because they're coated obviously insulated yes got it have we got enough we'll find out when we get there if if if not i should be cutting another length for fire slightly longer sir oh this just got to get to one end yeah okay metal work yeah by mike yeah i haven't cut enough i've got pillock i'm too short by that much oh no ah so so i needed that much more what do you want to do soldier a bit on no no take it off and start again oh jeez it will look awful i mean i have done it in the past well i've just sewed it a bit on the end yeah and then i've got loads and loads of people moaning on the stream or on the uh on the chat saying no you can't do that it'll get hot and de-melt or desolder itself okay so so it's safer to just put a new piece in all right i mean we're talking what pencil yeah well i don't know i thought it was like ten thousand meters yeah yes i'm talking about a half a thousand pounds right so back to you've cut another piece a bit longer this time just to start the ball rolling yeah yeah yeah it's quite a long piece here isn't it drop that through we're tidy all up at towards the end so is it important the amount of gap between each yeah now we need to try to make the gaps constant all the way around the around the cores yes um so we're just feeding it through for now and then pulling it through as tightly as we can so that we don't have any you know spare yeah and then we can do the wiggles then we can wiggle it into play afterwards into place okay so you've got a nice tight winding then yeah and chances are you can move and then do to glue it or tape it or you can do literally that you could put some um some hot melt glue on it if you want to keep them in place you should find that once you've positioned them and you've stuck it inside the box they won't move anyway okay fine so this should only get hot if it's over saturated like for instance i like top band too much power or something literally so i'll just show them back home then so the original winding was was this one yep and you've gone round and round and round and come out there yep on this one and then what you're saying is once we're all done we can then fiddle around and we can close the coat yeah okay fine um you know if we have a 200 ohm resistor somewhere um we can put that across the one end and literally um then connect it up to an swr meter on the back of your radio and then you'd key up on perhaps one watt or something yeah just to see and then you literally just close the uh open in the gaps to tune the uh oh two okay fine if you really want it exactly a four to one yeah if you don't mind if it's four and a half to one or three point seven five to one then nobody cares effectively right okay all right right do you remember how much we cut because i gotta do it again no good job i got that bit then oh it was a bit longer than this wasn't it okay same trick i make a little jiggery poker at the end doing your metal work focus mike focus did you say focus yeah hang on yeah don't cross the streams cool honestly i feel like bloody popeye come on olive looks really tough is this the last one yeah oh but got a finger now look at that it's done that look oh my goodness right that looks pretty doesn't it it does let's hope i've got it right okay so i've just got the cup of tea on catalon you're putting cable ties around now just to hold i want to hold the ins and outs yeah i want to hold the windings in the in the right places yeah um i managed to miss that one completely but i did good job of holding it holding the toroids it's all right yeah uh no it's okay it's uh it's caught up on the inside of them if you can see that okay oh yeah well that's all right which is important so that's good i don't need to put another one on the other side to hold that in play and you can admire that for a few seconds if you wish yes i think we should i'm just tidying up mike and i are halfway through building a four to one balloon and i just realized i haven't really explained what it's for so you would use a four to one balance normally um to reduce yeah reduce your impedance so for instance like um a one wavelength loop yeah yeah uh that very often it's 200 ohms yeah yeah yeah so you'd use a lot of these are 200 ohms so you would connect your at the feed point you might put something like this and then you put your coax to it so you've got 200 ohms one end you've got 50 ohms at the other end or if it was 400 ohms there you would have 100 ohms here correct right so that's fine now i'm using this because sorry about this you have to go on instagram to catch the rest of that if you want to see my if you want to see mike singing he does a good singing all about window panes i'm using this because i'm going to put some sort of random doublet up on the trees outside and we just want to get the impedance down so let's say i don't know what the impedance is going to be if it's going to be like a thousand ohms this will bring it down to the end of the ladder line down to that'll be 250 ohms then i'm going to run some really fat coax to it and we'll just tune the nuts off it in here so that's that's why we're building this so what do you want these long nose pliers for oh i see you are pinch up the middles the middle so that they sit closer together if you can if i can i might not be able to in which case i might have to tape them or something so now we need to identify these two are the um the 200 ohm end or the 400 ohm end yeah okay whatever end yeah and this is the 50 ohm end yes so right this is the original turning these two okay okay and and this goes from um if my memory size me well from the center core and this one then connects to the shield all right okay yes um this one connects to the center core as well actually it might be the other way around that might be the shield i'll have to identify them yeah okay well that's fine well we've got to test it so we'll do that in a minute basically the idea is that yeah the um the center core goes all the way around the coil and comes back on the opposite coil and then connects up to the shield yes okay um and the the center core on this side goes straight out right and the um the shield on this side goes straight out right does that make sense yes okay good because it probably makes a lot more sense to you than it did to me perhaps put different colored tape on the end so that we know what's hot and what's not okay yeah what colors would you like sir i've got some red and black red and black we can do because that's hot and not very nice so of course there's two ways of taking the enamel off you could scrape it with a a blade yep or that's got a little sort of sandpapery thing isn't it yeah on the dremel don't know can you once it doesn't need to be that long that that that connection does it no i mean depending on where the so239 is and where you place it in and it can be really uh okay but you might as well yeah but i'm leave a tail as well yeah so i just want it all to be really nice and neat okay so you can like leave the longer one here and snip that short one off um so yeah that's easy to get to the two three it depends on how big the orifice is in the 239 i suppose well i was hoping to be able to put it put the whole thing in the middle of it but we'll have a look in a minute or perhaps yeah i'd wage i will yeah for now i'm just going to straighten it out yeah okay um now this one i'm going to do slightly differently this is the um the shield connection yes i'll make it all pretty obvious again in a minute yeah um and we didn't need that in the end okay um and what i'm going to do here i'm just going to place it there and i'm going to actually going to turn this on that one around you take this out of the way actually on on this one okay and then we drop some solder on there in a minute we'll drop some soda on it as you say and that'll make it all nice and wonderful yeah i've done this once or twice nice nicely done okay okay so this is so239 land yep this is the shield yeah which i should bear some more back up and and if the case is here you can see yeah connect up to the bottom yeah we don't know where it's going to be and this one will go indeed lovely all right yeah excellent stuff let's hope i got it right yeah really fine business as they say in the ham radio world uh time for a cup of tea yes indeed yeah let's hope i got that right yep good right do you think everybody understands this circuit now i'm not sure so let's shall we go through it okay because we we untangled it to double check didn't we so anyway so we'll we'll bring the photograph up behind it so that we can and let's hope i've got it right if not i'm gonna look like an idiot oh you'll be fine which is normal for me okay so hopefully this one is the beginning yeah of this one yeah but it won't be working here no or here or ear yes correct okay so this one is what we would term as being this hot one here okay all right because it's not connected to anything apart from the center core but it will be in a minute yeah all right this one it goes all the way from the earth here all right and then connects back to this one yeah but we didn't need to connect it because we wrapped it all the way around is that right that's correct all right okay so we've already connected that return path to here yeah right and it's difficult to to so am i right and saying this bit here that's the one that's just turn it around so yeah show them yeah oops so the long one yeah yeah indeed is the bit that comes up yeah so i just want to show them the speed so this bit here we didn't need to connect it because we just put a thing in there continued the same continue that's fine yeah good right and this is the one that comes all the way back and is this cable right so this cable in this cable is the same cable yeah okay that's fine then this one right same bloody cable as this one is this end if that makes sense yeah okay fine all right right i think that makes uh absolutely no sense whatsoever it doesn't matter as long as it works it works right i think it's a good idea so now what we need to do is just do final happiness together yeah all right wind them together which i've already done once i've taken it apart so that i could show you where the cable is fine right this connects to the center core this connects up to the to the shield and that's it it's as simple as fine so it's just a bit of engineering now yeah i can do that it says all right we'll come back to them and i'll start preparing a box yes please okay the s239 is down at your work blank one down at your body just a little just the section yeah they're down there right so get one of them a couple of washers oh thank you okay now then how are we going to connect inside here sorry that's right ring ring connector the mic's all set up now to connect to that i just wanted to blank that off for and get that ready excellent okay you happy with that looks good yeah i think so do we need to get a soldering iron out now yeah i'm gonna get that out of my box and turn it on oh i've got this one here oh even better i think what we should do is plug it in mate it's normally a really good idea if i can find the lead you plug it in yeah i'm plugging it in you plug it in i'm plugging it in and plugging it in yeah yeah it's going in now 400 and 400 and somewhat million degrees 470 that's good nice and hot so this is like a test fit then mike yep i'll just place it all in without soldering obviously yeah and so what would i think what would do will be clever clevers could yeah a little bit clever oh i see you get you're making a an up and over is that an up and under one of a minute when i run up yeah we'll have to bend those down a bit further i've got them a little bit too high as you can see but uh general idea all right well yeah i can cope with that all right okay mike so we've had a bit of a break you have tindy ends now yep both sides yeah bend it all into shape bent shape so these four connectors you're thinking we'll put these on before we put it in the box yeah we can kind of measure where they're going to go yeah and uh finally i'm gonna watch you make a [ __ ] up then yep please do yeah i'll enjoy it so i want to first and foremost solder apparently it's got an l in it yeah soda as they say in america yeah i'm gonna solder these onto here first okay so i'm doing it this way so that i can oh i see told me to come around the other side yeah it might be a good idea yeah i like the idea of having tools that help you rather than hinder yeah do you read that's in the right place well we'll find out when i put it in the box okay yeah you're just waiting for it to go right i like it but i want to put more solder in the middle in in there okay that's going to fall off if i try it yeah it is so we need to prop it up we could use the metric adjustables would you want something underneath the core now i should be fine come on come on baby there we go i'll do the same on the other one right trying to get you in focus here mate yeah come on heat and you're starting to go in though excellent that one that's got a center i reckon that's pretty successful okay right fun time i'll come back around this way this looks so easy on the map it does isn't it like all these things and just simply slip the bolts through the holes like so captain and then we've just said then simply sold the transformer to the so2 39. right okay this
is looking good what have we gotten that i'll just have a nice little picture there for the people back home showing the bolts obviously we haven't done them up tight yet the bolts secure them so i'll just stick yeah nuts and bolts lovely he says i can't even get the thread in my hand tell you what he's done it he's done it yeah it's gonna be difficult for me to film this so what i might have to do is so well we'll see what you can see what he's trying to do is that this tail at the bottom he's going to try and put on that earth lug there we are and this did you notice i used the word try yeah yes and then the centers we're going to try and get on the center try just like that all right so uh just make that a bit more oh nice right do you want me to hold that if you like i wanna i'm just gonna tin them first but uh i'm gonna tin them a little bit first okay gobson soda exactly how do they say the word solder in america because in the uk we definitely say solder don't we yes but in america they they leave the l out solder so it's almost a silent l jump major well you can poke that instead how about that oh okay so i'm the solder man you you play with the solder right you're gonna we're in the center for a center push away that's it yeah but i'm running out of weak fingers okay away i'm just waiting for it to melty it's frozen again hang on that's where yeah we are okay take it away i'm trying to take away take away that's a lot of solder on that but it'll be fine same down here yes please come it's a nice how much was your soldier it looks expensive this i don't think i said if you if you're watching in black and white yeah the red one it's there behind the red one we are evil to ourselves right here we go this is a hot glue land hot glue and what we do is we'll melt it into that corner down there if there's such a thing as a corner on a circle like that it's hot enough yeah you just want to let it set now yep that's it and that's it that's it he's in done yeah i go with that goodness gracious me that is hot that glue in it is it yeah so when that hit that seals up that will just stop it it's done rattling around don't it's done happy as larry my goodness what a ballon you see i would consider that to be handmade how do we test it that's a good point though do we test it we haven't got any gear here you've got your analyzer yes so if we put it on a 50 ohm feed yes it should in theory be 12. yes 12 and a half yeah where do we get 50 ohms from antenna oh okay yeah i see what you mean or a dummy load i have got a tummy load but i don't know where it is we'll use the anterior oh i've got another four to one ballon that's confused wasn't it i didn't say i don't want this balance we're only doing this to make a video no i wanted a dog's nuts good boy django what is that i think i think i've got four to one balance coming out my ears here i've told you i've got adhd and lose everything i literally lose everything are we gonna tell them what we're doing we're trying to create a 200 ohm load by stringing up a 10 meter loop inside the factory battery that should be fun i'm gonna need the end of that loop in a minute yeah certainly what you do for a hobby what are you doing up there come down here so we've got about there we are goes along to there down to the 200 iron the 4 to 1 band we should get if we get anything between about 60 and 80 ohms out of this where did i put the stick there's your stick so about 30 megahertz give or take this should be now i actually can't remember how this works okay well how do i do auto ah good question exactly oh i should have bought mine ham there we are we're at 31 megahertz i'm at 30 ohms so it probably works it's probably a hundred and sitting at 120 ohms i'd agree with that give or take right it's definitely transforming i'll tell you what every time i use this i feel like dave castler the dx kavanagh okay well it's doing something then i mean until we do a formal test outside you know with the right gear yeah so what do we do put the gasket on top seal it up should we drill a drain hole uh do you know what i'm not a fan of that oh you're not right no why it's supposedly well i'm just going to swap sides with you because there's better lighting from here yeah i know it's not um hermatically sealed because we've obviously drilled a hose oh good point yeah but you know what when it's connected if you just stick a load of silicon over the joints yeah but what i've heard it happens is it cools down it sucks air in and then when it heats up it condenses yeah i hear you but then there's nothing inside there anyway that's going to be have adversely affected by a little bit of condensation or water i don't think okay um i mean i i might be wrong and i'm sure some of the guys out there in youtube land will correct me or will know better yeah um the last three or four um 64 to ones that i've made i've not bothered putting a drain hole in the bottom of them and they've been up for four or five uh years now hours hours four or five days yeah they've had no problems all right you know you're gonna snip that now aren't you yeah slightly long oh white out there right slightly long so that i can push it in okay and make a better seal at the base yeah doesn't it right thank you the screws are here now if you really are gonna be worried about the um the hose should be sort of their-ish anyway um not in the sunlight it should be at the very very bottom yeah because you're mounting it that way up so if any water is going to regress it's going to aggress or condensation yeah and i would seriously just cover the base of it with a bit of silicon stopping okay maybe but each one to their own right yeah you're going to need that many that many screws just in case you hadn't realized when callum and i get together to play it's actually 90 percent stupidity jokes 10 real wonder we ever get anything done or made well we don't this is quite unusual by the way if you want a little bit more of mike go and see his channel as well or just search mike dash m0msn that right that's your channel isn't it mike it certainly is and if you want any more of callum you just keep watching this one go to the internet and put in m0msn now this has got to be one of the biggest four to one balance ever made isn't it surely i mean he weighs about five pounds it's got three three two three kilos um and uh someone's gonna tell us we've used the wrong mix yeah they're 43 aren't they these 43s yeah that'd be fine three of them probably better off with a 31 mix but these would be fine yeah it's only to give my tuna an easier time coming down from this fake doublet you know we need the crowning piece of glory on the front of this now oh a dance commander sticker we certainly do right i think they only need one sticker then we you'd be a bit ridiculous having more than one should be on the top of the lid yes central yes mike thank you very much for making this ladies and gentlemen round of applause for young mike here remember to go see his channel m0msn in the meantime it's good night from me and it's a good night from him a very good night where's the next video coming oh it's there there it's in the middle okay there just so makes videos in the middle all the best bye-bye who was that the two ronnies that's it we both
2022-04-08 01:30
