 Where is Digikey? The highly anticipated Great Search brought to you every single week by Digikey and Ada Fruit. It's so exciting even sitting here. I knew it was going to happen. I have a full seat but I only need the edge. Okay, so what is this week's Great Search where Lady Ada helps you find all the things you need on digikey.com. Okay, well let's go to the overhead and I'm going to show, I'm going to re-intro this and get right to it. So on this design for a 900 megahertz radio module we have a low-cost antenna option where you just solder a piece of wire. We have these spring antennas that they're like a couple cents. You solder them into a through-hole port but let's say you want a really big antenna like you want something panel mounted that you can connect to the outside box. It can be waterproof then and then just the antenna sticking out. For these you'll want to connect an SMA antenna. That's the most common like 400 to 800 to 900 megahertz antennas. Almost all use SMA for the connector. They look like this and you need something that takes this and lets you plug it into this micro-UFL. Now you might wonder well why not just have an SMA connector on your boards. You can. People definitely do. I have dev boards that have an SMA connector on them. You can plug the antenna directly in but that sort of means first off you need a lot more space. They have to be hand soldered or wave soldered. They're physically large. They can't be pick and placed whereas UFL can. The trade-off is you know if you use UFL they're a little delicate. They only are really meant for about 10 to 50 plugs and unplugged so you do have to be careful with them because they're so tiny and delicate. They are good for up to 6 gigahertz you know but you need to have this adapter. You need to have a little adapter cable that'll take you from UFL to SMA. One thing I want to mention because this has tripped everybody up so many times I've seen. So you can have you see how this has a little slot in the middle. There's a hole and this antenna here this like huge antenna here has the little pokey part. So the pokey part has to go in and matches up with the whole part. This screws in the outside is ground it makes a nice solid connection. The RF signal is actually gone goes through the center bit the little coaxial bit but if you are doing 2.4 gigahertz Wi-Fi or BLE or ZigBee or anything that uses 2.4 gigahertz the antennas are RP SMA reverse polarity which means if you notice there's a hole there. So if you plug this in to an SMA notice that there's nothing connected it won't connect through and you'll be like my antenna is broken my SMA adapter is broken my board is broken my radio signal is really bad. You need a different one called an RP SMA. I'll probably be able to show you that they have UFL to RP SMA reverse polarity. So just watch out 2.4 gigahertz and only 2.4 gigahertz maybe 5 gigahertz also these days because 5 gigahertz is used for Wi-Fi they'll have RP SMA connections see hole in the middle whereas what we're going to talk about is 900 megahertz which is SMA which has the the pokey part on the antenna not the adapter. I don't want to talk about days that I've lost being like what's wrong with my design until I finally realized opening it up I'm like oh my god it's not connected through because I had 2.4 gigahertz with the wrong connector. Okay everyone's bumped into this so I'm going to try to save you some time. So we want is a little cable that takes UFL here and this is the UFL connector and again on an earlier great search we covered the UFL connector it's pick in place they're almost completely universal basically if it's not SMA it's almost always UFL it plugs in like this and it actually has a little bit of rotation so just be aware of that if you need to you can mechanically stabilize this but you know it can rotate a little bit and then this part you'll notice is bulkhead panel mountable so you can unscrew this and you have a very wide panel mount that you can connect to you've got some locking nuts as well and then a nice plated hex nut and you you know you screw it in you attach it then you have make sure you have plenty of thread for your not rpsma your SMA you can then plug this in to make a nice solid connection you'll note I mean maybe if we have time we'll show it but uh basically the the db rssi goes to like you know negative 20s of negative 60 okay so let's go to let's go to the computer let's go to the computer we're finally ready okay so what we're looking for and again there's SMA and rpsma I don't want to talk about how many times I messed that up and also UFL there's WFL um and sometimes it's like UFL 2 or UFL 3 there's a lot of different versions so just just be aware um you might want to check data sheets use your calipers to make sure what you're looking at is the right width of what you're you think it is so UFL it's um uh hiroshi is the original makers of the parts and maybe it's prance hyros uh hiroshi is the original maker of the UFL but it's now universal you'll see it everywhere UFL to SMA um and so you can get the individual connectors also you can get um these adapters so just to show the difference between the cables and the adapters um here's where you would go if by chance you have to connect an rpsma thing to an SMA thing you have to like you know switch which side is the pokey part which is the plug in which is the socket you can get adapters that do the change over for you so that that's available but let's just try to get the right thing the first time um so coaxial cables so first off let's get uh active only and then um let's make sure i mean in my case where happened to be using um 900 megahertz but you know uh let's just make sure we can do at least 2.4 gigahertz and then uh in stock let's apply okay um so we're gonna have at the end uh free mount sorry uh panel mount not free hanging free hanging would mean you know maybe it's an adapter and then goes to another cable or something but we want what i showed you where it has the the screw you know goes through the panel and you hex mount it on so panel mount uh and then you can check different lengths you know um they go up basically from two inches which is a little bit too short and three inches to maybe uh you know 19 or 17 or so so let's do that let's just make sure it's a little longer than two um so ufl sometimes called umcc uh note that they do have uh rpsma which we don't want we want sma and then and also sometimes they have right angle or or not but uh and you can see there's like tons of these apply all you know and then it's just a matter of like um you know there's different makers different lengths um you know honestly this one looks like pretty good and it's only you know three bucks uh sometimes i look at uh you know what they have the most in stock of and final you know they make a version um you can see here it's got you know the right ufl connector this one from tau glass is good to te um they're all good i mean all of them are going to do what you want they just have sometimes different cabling um different height you know highest frequency this one comes with an o-ring you know um this one from tau glass is perfectly fine so i'd say you know you want just a short cable um goes down to a couple bucks a piece when you get them in quantity this one is uh a good option i'm going to pick some of these up and then um you know then you can just attach whatever uh antenna you want on the other side maybe next next great search will uh search for a uh nice lora antenna pair with this feather that's a great search