Off Grid Receive-Only JS8Call

hello again everyone and welcome back to the underground today we're going to be taking a look at how to receive js8 call messages without a license and without relying on any sort of internet connection as we've already learned there is a very very easy way to receive js8 call messages using an online softwar defined radio or SDR this is a great way to learn how to use some of the features of js8 call and kind of get more familiar with how HF radio works however when it comes to emergency preparedness you using an internet-based source is probably not the best option so today let's take a look at how we can do the exact same thing with a little bit more effort using offline sources there are two main options to receive js8 call messages or really any kind of Digital Data mode offline depending on what kind of Hardware that you have already on hand and depending on how much money you're willing to spend and depending on your personal preference you can use either one of these methods the choice is up to you the first option is to use use an SDR dongle like the RTL SDR V3 in conjunction with an HF radio antenna and some software the second option is to use a shortwave listening radio such as a CR crane radio or in this case a gp7 SSB radio from cycom pretty much any short W of listening radio will work this is kind of a backwards way of doing it but I did want to show this method because it one helps illustrate how all of this stuff works and two if you don't have time to get an SDR or if you already have a shortwave listening radio and you want to try this out before buying an SDR you can do that as well all right everyone I understand that this can be a little bit confusing for those of you who are maybe new to radio so I thought I would start with actually option two when demonstrating how some of this stuff can work in a last ditch extremely contingent situation a lot of people might find themselves with this exact setup right here with nothing else they may have a simple shortwave listening radio and a Windows computer with no internet access at all so let's start by doing a very quick and dirty example of how this might actually work with nothing else other than what you see right here again there are many ways to skin the cat when it comes to working with js8 call but at the end of the day all we are doing is piping in audio that we receive over the airwaves through a radio into this program to decode how we do that can vary and let me show you the most basic way of doing this the absolute simplest way of doing this with arguable success is to Simply turn on your radio and let the audio from the speaker of this radio go into the microphone of your computer so over here on jsh call we can open up file settings audio and select the input method as your microphone array then we can exit out of that open up your radio over here and on your radio depending on what your yours may look different of course but we're just going to tune this to 7078 mahz in SSB mode in Upper sideband mode once we have our our radio programmed uh to the right frequency and the right mode we can extend the whip antenna and hopefully get something these stock whip antennas for HF frequencies for digital modes like JSA call are not the best they're not the greatest um but you might want to try this before you move on to something else or before you buy a dedicated antenna again this is the last ditch method using the equipment that you might have on hand if you didn't really prepare too much ahead of time so we've got our whip antenna extended here our js8 call is programmed to listen to the microphone uh of this Windows tablet here so let's go ahead and turn up our radio and I know you might have a hard time I'm hearing me just a little bit over that but basically we're going to again take the audio from the speaker of this and pump it into JSA call turning off our radio here for just a moment to conclude this example this is again a quick and dirty method you're probably not going to hear too many signals coming in through this particular method but it does work again using very little infrastructure moving up in terms of Effectiveness uh what we might want to do the very first thing is stop using this small aerial and go ahead and go with a uh wire antenna so this is just a simple wire antenna that I've got strung up through the room here and this particular one is just a simple real antenna uh it uh comes with a little adapter so that you can plug in the antenna to a little clip here which can then clip directly to the aerial on the radio so now we're actually able to get pretty effective uh reception on this little radio pumping it into JSA call now again you can stick with the whole speaker into the microphone of your computer but again moving on up the line there are more effective ways of doing things and the next most effective way of doing this is with a USB sound card interface and a 3.5 mm aux cable so this is again a very simple device it's just a simple uh USB sound card interface they're about I don't know 5 to 10 bucks online uh I usually keep one or two these with all of my radio stuff especially if you have a shortwave receiver I would very strongly recommend keeping one of these and an auxiliary cable with it so that you can plug it into your computer like so then on this end we can plug in the auxiliary cable into the microphone Jack like that and plug the other end of the auxiliary cable into the headphone jack of the radio now we can turn up the volume on the radio and we shouldn't be able to hear anything because this is now going uh into our computer once we have all of this plugged in we've got our radio set to the right frequency the volume's turned up and we've got our real antenna stretched out across the room we can o open up js8 call again go to file settings audio instead of choosing the microphone we can choose the one that says microphone USB audio and clicking okay now our jsh call program is decoding the audio that it is hearing from this radio and as we can see we already have messages coming in being decoded some heartbeats here and there uh from all the way across the country so that's a pretty cool way of actually using a shortwave radio which you may already have on hand if you're uh into sort of emergency preparedness uh you've got your shortwave radio plug it into js8 call and see what you hear it's a pretty cool way of doing that so this is a pretty cool setup if you just wanted to use a shortwave listening radio to pipe audio into JSA call this is a great way to do that but again moving on up the ladder there's another thing you can do if you don't like all these wires and you just want to kind of you know use this tablet sitting on your couch at home or something like that and you want the radio to be in a an ideal position for listening what you can do is actually use a Bluetooth transmitter uh that plugs into the audio jack from your radio so this exact setup here is a cycom gp7 SSB radio it's a nice little compact radio people kind of like it a lot cuz it's got good battery life and there's some other features that make it a pretty good uh choice for a small shortwave radio but one of the things I like about it is that it's decently Compact and you can buy one of these aftermarket uh Bluetooth devices and using some double-sided tape just kind of stick it to the side and as we can see here the audio is coming from the headphone jack on the uh radio here it's going along this auxiliary cable to the Bluetooth transmitter and here on my computer my computer is actually synced uh with the Bluetooth device so now I can put this radio using a real antenna or whatever I wanted to do I can put this somewhere you know outside of my reach uh where it's a little bit more effective to receive and wirelessly do the same thing because now the audio is coming from this Bluetooth device into JSA call I don't know if this is going to be useful for every user but I think it's pretty cool I found it to be kind of Handy again experiences may vary but I thought this was kind of a cool option this nice compact uh and is a great way to get a little bit more everyday use out of a shortwave radio all right everyone as we can see the concepts that we're dealing with here are fairly simple even if it seems kind of complicated as we demonstrated with our shortwave listening radio really all we're doing is listening to signals that are whizzing through the air and we're decoding that as audio we're piping that audio into a program called js8 call that decodes it if we want to do exactly the same thing with a softwar defined radio or SDR there's a couple of other steps that we need and a little bit more software that we need to actually make this all work so here's what we need to get started we need to download four pieces of software to make all of this work the first is sdrsharp we need to download sdrsharp from this web page here just click download and extract that zip file to whatever folder you want to work out of next we need js8 call which we can download here by clicking the download tab and downloading whatever version that we have up next we need VB audio cable this is a virtual audio cable that we can download here and we also need a program called bkt time sync which we can download here by clicking this download button all of the software is free and you can download it very easily once we have everything downloaded and extracted we can open up SDR sharp first first uh so before we get started with the actual program we need to install the right drivers now this is a step that a lot of people tend to forget so I'll mention it right here right up front uh and that is to click this uh install dlstr dobat uh it's a simple bat file that all it does is when you when you double click it it installs the correct drivers for sdrsharp to actually work uh so this is something that you're going to need to do uh really before you get started with sdrsharp now I of course have this already installed uh but you simply just press any key and it will automatically uh run this for you once we have that driver installed we can open up sdrsharp if you want doesn't really matter uh you can do some of this stuff out of order I'm just going to uh minimize it for now and kind of uh get it out of the way so that we can work with the next thing which is our virtual audio cable now again very simple once we have installed a VB audio cable this is the kind of interface you're going to get and you'll have a big giant button right here that says install driver I've already done it it's already working on my computer so now I have the remove driver button but again simple one click to install the driver and we're done with VB audio cable to make sure that VB audio cable is installed and working what you can do is go down here to the bottom right and click your speaker button on your uh PC and see if you have an option to select the playback device as cable input if you have the option to select cable input as your playback device that means you're working everything's good to go so you can leave that next is to replace the driver that Windows erroneously installs for your SDR device now again Windows is kind of stupid when it comes to SDR devices you get the device you plug it into your USB port and windows installs the incorrect driver every single time because it it thinks that it's just some kind of gener generic USB device because this is such a problem an entire third-party piece of software exists to correct windows's mistake and that program is called zodic once we plug in our SDR dongle to our computer we can open up device manager and see which device it comes in as almost always it's going to be bulk in interface zero so in Zig here what I can do is Select options list all devices and from this drop- down menu select bulk in interface interface zero that's the one you want uh in this case I already have the correct driver installed but again if you were just doing this for the first time you would click this button here to install the right driver once we've installed this driver with Zig uh we're done with that we can move on to the next step which is bkt time sync now if you're not familiar with this program what it does is it changes your PC's clock to be super super accurate js8 call in order to decode messages needs for everybody's time to be kind of copasetic right because jsh call operates in Windows of 15 seconds everyone on jsh call needs to have really accurate time this program allows you to set that time in a few different ways primarily it can use the internet to sync your time with the atomic clock it can also use a GPS dongle so if you're off grid it will allow you to use a GPS satellite's time to sync your clock so that everything works and you're able to decode me messages in js8 call if you are connected to the internet you can run this software and click sync now and you'll get a little message here that says time was successfully synchronized using ntp server but again we're trying to do this a little bit off grid right and using the internet is not exactly a a great plan in an emergency so you can also come up here and configure your GPS I have a USB GPS dongle installed into this computer and it is using comp port three I don't have a GPS lock right now because I'm recording this inside but this software is smart enough to realize hey let me go ahead and use the GPS instead of the internet so if I disconnect my computer from the internet and click sync now it will sync using a GPS clock these are the two primary ways you want to be using js8 call because it's the easiest there is a way which I will show you in a moment inside js8 call to use to do this completely off grid with no satellites and no internet uh but it's a little wonky that's why we're covering this method now because it's probably the least frustrating method to work with at the moment usually I like to run bkt time sync every time I I start up js8 call it's just kind of a habit to get into launch the program sync your clock and it's a little easier to work with that way okay now that we've gotten all of our drivers installed and we've plugged in our SDR and everything's working we can open up SDR sharp and finish up the configuration before moving to js8 call opening up sdrsharp we have a few settings that we need to make sure that we change remember sdrsharp is the software program that's going to be controlling our software defined radio this is the control center for the whole thing so the first thing we need to do is open the menu up and go to source and make sure rtlsdr USB is selected this is going to tell this software to listen for signals coming through the SDR plugged into our USB port we need to do the same thing down here underneath this uh Source menu and we need to make sure that the device is selected as generic RTL whatever as long as there's something here that's probably going to be your SDR usually if you have a problem with setup or your SDR isn't working this will be blank but in my case uh the only thing I have here is just a generic RTL device we also need to go down to sampling mode and make sure that we choose direct sampling Q Branch this setting here highlights why most sdrs are not created equal there are some devices that cannot do this this is also a pretty big debate in the SDR World which I won't bore you with right now but needless to say the RTL SDR V3 is physically capable of direct sampling down at the HF frequencies if you were using a different device that does not allow this uh option you might find that you go up here to tune your frequency and you can't tune below a certain frequency because that SD R is not meant to go this low in frequency so the RTL SDR we have to do a little bit of um cheating the system so to speak by direct sampling the uh signals that are coming into the device so we're giving up a lot of efficiency that's normally used but this allows us to use an RTL SDR V3 without purchasing any kind of special Hardware which we may talk about at a later date for now if you're using the RTL SDR V3 this will work we also need to make sure that under the radio uh tab USB is selected remember we're going for upper side band because we're dealing with Digital Data modes also need to make one final change before we head over to js8 call and that is to change the output to our sound card so if I expand this a little bit you can see uh that we want the one that says usually like Windows Direct sound cable input VB audio vers virtual cable that's the one you generally want um you can try a few of the others uh they're they're depending on your installation and what other devices you have you may see multiple virtual audio cables uh but really you want to choose one that just says cable input and now we can click the play button and start listening to our frequencies so as we can see we've got the main js8 call calling frequency 7.78 right here and we are piping the audio that we're hearing on this frequency through through our SDR we're we're piping that audio into js8 call so let's go ahead and minimize this leave it running in the background and bring up js8 call now as we can see here I can immediately tell what's going on with jsh call this is wrong you should never see in jsh call these vertical lines this means one of two things one you've got a heck of a lot of interference or you've got the wrong audio setting set so let's open up file settings audio and there we go there's our problem we need to change the input to Cable output this is sort of like plugging in the other end of that virtual audio cable like okay our waterfall should clean up quite a bit and we should start seeing after a while some messages start rolling in now one can see here I've already started getting some heartbeats coming in which is impressive considering I'm just using a very tiny little whip antenna with this SDR and these guys are not even close to me so this does prove and show that the whip antenna that you can use with an SDR it does work just not very well not as well as you might expect there's one thing that I do want to note though on this page and that is this giant red bar over here this is the handy little volume meter basically to let you know that your volume is too high so what we want to do is bring this red bar down into around 70 or so as we can see right now we are at about 87 DB so to change that we pull up our handy dandy SDR sharp and arranging it so that you can see what I'm talking about here we've got our volume up here way too high so let's back it down a little bit into something that's a little bit more reasonable so that it doesn't sort of blow out the speakers so to speak in js8 call so round 70 as long as the bar is green you're good to go if you have it too low like that you might have a hard time decoding some signals uh but around 70 or so is good to go so now we can start see that we're getting some heartbeat messages coming in now before it goes away on my waterfall let me go ahead and grab this image so we can talk about it for just a second so this right here is what a standard message in JSA call looks like this one's extremely faint but as we can see the uh the actual message itself is coming in between the Green lines it's coming in between all of these green lines moving down the screen these green lines delineate time slots of 15 seconds so what I was saying earlier about the whole uh time sync thing you need to make sure that your messages are between the Green lines if they're in the green you're good to go if they are not in the green either one of two things has happened either one your time sync is off meaning your clock is inaccurate or the other guy that's transmitting has an inaccurate CL so if you ever see messages that are coming in like this and they're splitting the green line like that that means either you or they is is in the wrong so uh just you just want to make sure that your time is accurate now again there is a feature within js8 call to handle this just in case you don't have any third party software and in case you don't have an internet connection again I'm guessing that if you're watching this video you're probably wanting to know how to do this completely off grid right that's the whole purpose of learning how to do this so there is a way within js8 call to make these messages uh basically sync up so that if you're seeing a bunch of messages that are split like so you can basically shift your time you can drift your time so that basically you're all wrong together in a total apocalyptic collapse where there is no uh time server there's no way of sinking your clock with like a radio Source there's no way of syncing your clock with a GPS and there's certainly no internet what you can do is use the time drift within js8 call to basically be all on the same page so here's basically how the time drift function works if you click Start automatic time drift and you can set it to stop after two or 3 decodes it doesn't matter what js8 call is going to do is it's going to listen for messages and after a while of listening to messages however long you do you define it js8 call is going to assume that everybody else that it can hear is right and your computer is wrong so it will change this time drift Factor here this number to match up with everybody else so that's a pretty cool feature right you don't have to have a GPS lock you can do this solely by radio now you do need to have the ability to receive traffic right if you can't hear anybody else your time is not going to be accurate but if you're in a again if we're playing the wh if game and going down the total apocalypse route anytime you can you can visually see traffic here on the waterfall and as soon as you see someone transmitting you can start the automatic time drift and as they transmit your clock will sink with theirs and you can communicate with them so even in a total Hollywood style apocalypse scenario where you have nothing but an HF radio in the woods you can still communicate with someone else using js8 call that makes this this platform a very powerful tool now the problems with using automatic time drift all the time is that it's a little bit buggy um by that I mean sometimes it tries to average out uh all of the times so basically if you've got 10 messages here on your waterfall and one person is off it's going to throw off your time sync so that you still don't hear anybody but if you give it enough time js8 call is smart enough to where it will it'll sync up with everybody so that you're all on the same page I personally don't like to use automatic time drift except in like you know a training situation where I'm trying to not use a GPS receiver or something like that because it just takes a little bit of time and you tend to lose like the first part of a message because you know you have to rely on someone constantly transmitting so that you can start your automatic time drift but that's just me uh either way um it's not a perfect solution but it does work and it's what you would use if you did not have a GPS and if you did not have an internet connection this is how you would sync your time so that's basically it for the software side of things now like I mentioned I have been intentionally neglecting what is arguably the most important part of this whole thing and that is your antenna so let's jump back to the tabletop and we'll talk about what antennas you can use all right everyone when it comes to antennas you have quite a few options so I'll start with what I prefer to use for a receive only setup for most people who are not interested in going down the whole HF radio route and they're not really interested in radio as a hobby and they're not really interested in continuing uh to learn about radio the bare minimum I would recommend for most people is a simple pre-made commercially available shortwave real antenna these normally come with an adapter so that you can uh either plug them directly into a radio to receive and if you don't have a radio with an antenna Jack on it you can plug this into itself like I showed earlier and clip this directly to the aerial on a shortwave radio now again I prefer these because uh they're only about 10 to 15 bucks and it comes with the adapter usually uh so by the time that you've went ahead and built a homemade option you could have just bought this because the bare wire in here is you is sometimes more expensive to just uh to make it's easier to just buy something plus the rugged cases that these come in uh really makes it easy to kind of reel these back up and put away and store so this is what I would recommend for most people who want to use a shortwave listening radio or an SDR this is what I would recommend again there are other options though speaking of the shortwave radios themselves uh if you were to pick up a shortwave listing radio it's always going to have have a uh whip antenna now uh if you like using whip antennas that's cool uh I use them a lot uh even though they're not ideal for listening to js8 call sometimes it's easier to throw this and this alone in a bag and go one thing that I would very strongly recommend is purchasing a radio that has a replaceable whip antenna because I tend to snap these off quite a lot they're a pretty delicate piece of Hardware even though they're included in all radios you know it's just not really a rugged piece of gear so this one the cycom gp7 SSB has a user replaceable antenna and you can buy these uh you can buy several of these and keep them in your bag so that when or if you snap one of these off you can easily replace it there are a million different kinds of short listing radios but again you might want to make sure that you choose the right version for instance this version of the C crane skywave SSB uh this particular line of radios is probably one of the more feature Rich radios that you can buy uh because it has all of the traditional stuff plus the airband but this is a model from a couple of years ago and as we can see here it does not have an external antenna Jack like uh the cycom one does so this one has an actual antenna Jack so that we can plug in we don't have to use the adapter we can plug this antenna directly into the radio like so and run that uh that works on all of the the modes on this radio as far as I know it's marked as just being a longwave and medium wave antenna but it works on the short wave as far as I've been able to tell uh so that's that might be something you want to consider uh because when it comes to this you know somewhat expensive radio I still have to potentially introduce a moment of failure when I clip this uh Antenna adapter in so that's something you might want to keep in mind uh if you're trying to shop for a shortwave listening radio now when it comes to using an SDR uh you have quite a few options so most sdrs or the one that we have used so far is the RTL SDR model V3 now this one almost all sdrs are going to come with an SMA uh adapter here so the first thing you might want to pick up is a simple SMA to BNC adapter this will allow you to use a lot of the accessories and antennas that are made for HF radio so if you screw this together like so you can now use uh your HF antenna that you might be using for transmitting I like to use gear that is a bit redundant sometimes so I end up taking multiple HF radio antennas but it's nice to be able to use one antenna for everything so uh if you wanted to purchase an antenna or if you wanted to make an antenna uh this is going to allow you to easily attach your SDR to whatever HF antenna you build something else I would recommend that is probably a little bit uh controversial is buying one of these uh whip antennas for your SDR sometimes the older versions of this uh used to come with these uh or at least when I bought mine they it came with them but the newer versions come with a different kind of antenna array you might want to pick up one of these simple SMA uh whip antennas you can find them all over the Internet for just a couple of dollars a piece and you can buy buy them in multi packs the reason I would recommend this is because one it's very small very lightweight it takes up no space uh again it is a whip antenna so it's very uh very fragile but it allows you to have something quickly in your bag so that you can use your s strr with some level of Effectiveness also it allows you to have a more easy uh time of attaching your shortwave reel antenna like so if you wanted to do something like this you could yes it's not ideal it's a little weird and it's a little you know unnecessary perhaps uh but this is a good setup it's it's multi-functional you can use it in a bunch of different ways uh and this is probably what again the lowest common denominator would use which is people who are not exactly interested in radio they're interested in information so they're not really interested in the hobby of radio that's perfectly fine most people are like that that I am exactly like that as well I I don't necessarily enjoy radio as a hobby I like to use it for information exchange so for those people uh who aren't interested in building your own antennas or anything like that this is probably what you want to go with for now buying a real antenna and one of these with your SDR and going from there for those of you who are interested in uh going down the rabbit hole of HF radio and and improving your skills you might want to try one of these this is a BNC binding post adapter sometimes you'll see them called Cobra heads and basically this allows you to uh hook up your SDR here using again our binding post adapter now we can hook in uh two wires a wire here and a wire here and uh depending on what band you're on you can make a very simple quick and dirty dipole uh an unbalanced dipole uh for receiving traffic it can be very very effective if you wanted to just use this as well and and uh have a random wire going from here and a random wire of the same length going that direction you might find that you get decent reception as well again when it comes to receiving signals uh we have to differentiate between receiving and transmitting transmitting on something like this is going to be very hard to do uh because an unbalanced antenna it has a lot of potential for error but when it comes to receiving don't get caught up in a lot of the stuff that hams talk about when we're talking about balanced antennas and uh standing wave ratio and all this complicated stuff transmitting on an antenna is hard to do uh it's a it's it's a lot more complicated than just receiving uh so please keep that in mind is that you you don't necessarily have to go out and purchase a a very expensive sometimes HF antenna you can just use a piece of wire and that's exactly what I would recommend for the last ditch method in a last ditch extremely cont tangent circumstance where you didn't prepare not one bit you might be able to have a whip antenna or let's say a whip antenna on our shortwave listing radio and really all you need to do is get a random piece of wire this is a random unmeasured piece of wire that I've stripped the end off here and all we need to do is literally wrap that wire around the aerial antenna of the shortwave listening radio hopefully we can get a a decently tight connection there P it up a little bit make it look decently okay and string this wire here out across the room and uh get it up as high as you possibly can and that's what you might be able to do this will increase the range basically just turns this whip antenna into one of these uh one of these real antennas so uh it's not something it's not ideal obviously your connection here is not going to be as solid as you might want but in a again if you didn't prepare if this is all you have uh this will work uh just to receive message traffic obviously you couldn't use this to transmit off of unless you did some serious modification but again receiving signals is very very easy on HF frequencies now the whole random wire thing wrapped around the aerial uh the whip the Whip aerial here uh is probably not something you want to do every day um again if we're trying to use receive only radio message Network stuff like that if we're trying to use this on a daily basis you might want to have a little bit more uh dedicated system so um something like using just random lengths of wire is fine but really what we're trying to do is reduce a lot of the barriers when it comes to radio dragging out you know your your HF uh or your short wave listening radio here and stringing up an antenna and stuff like that it gets a little tedious for those people who don't like the hobby how however what is far more easy to do is for me to grab this out of my bag set it in the set it in you know my living room or something like that pop this antenna in like so string it out across the room and connect to it via Bluetooth sit on my couch and listen to signals coming in that is the easiest thing to do and it's even though it's not the most efficient sometimes we have to account for the human factor right you have to make this stuff to be where you want to use it if I have to use my SDR here and fire up four different pieces of software to get this to work well you know I can do that but a lot of times I'm not going to want to do that the choice is really up to you I just wanted to offer two different options for those people who might not be super interested in the software radio side of things they may already have a dedicated shortwave radio that they like to listen to or they've they've bought uh you know over the past couple years of craziness and um they've got this sitting in their emergency kit well here's a way you can actually put it to some good use you can get yourself a Bluetooth dongle or a sound card interface and an auxiliary cable and plug this in and and you're good to go so yeah hopefully this is helpful for all of you who wanted to have a more listen only receive only totally off-grid js8 call setup you can use this not just with js8 call but other data modes as well you can receive and decode Morse code you can do r you can do all kinds of other uh data modes with this setup it just the only thing that changes is the software uh on your computer that listens to the signal but as long as you can pipe in audio from either one of these or one of these as long as you can pipe that into your computer you're good to go so thanks again for watching everyone hopefully this has been helpful and we will see you next time and as always fight in the shade