Getting started with SDR# and an RTL SDR tuner

hi everyone this is Clayton V III IRR and today I'm going to show you how to use a piece of software called SDR sharp together with an RTL SDR TB 200 angle to receive signals I'll assume that you've already visited the RTL SDR comm web site where there is a QuickStart guide that gives you all the instructions you'll need to download and install the software and drivers for your tuner so we'll open up the SDR sharp folder where everything got downloaded to and double-click on SDR sharp and I'll just bring this up on the full screen here now the first thing you need to do when you open up this software is select what tuner you're using it with so in this drop-down box I will click on rtl-sdr USB and once that's done we can hit the play button and start receiving signals so well I tweaked a few settings here I'm just going to turn down the audio so that you can hear me and let's take a look at what we're seeing on the display here we've got two main pieces at the top here is what's called the FFT display and that's basically a signal analyzer it's showing you frequency along this axis and signal strength along this axis and this particular tuner picks up a range of 2.4 megahertz so you can see we're centered here at 105.5 megahertz and we can receive signals all the way down to 104 point 4 or so and all the way up to about 106 point five six megahertz and that's in the middle of the FM broadcast band and you can see I'm actually picking up 3 FM radio stations there's 106.1 there's 105.3 and there's 104.7 now down at the bottom of the display we're looking at a waterfall which is basically showing us the same information that's up here but over time and how this works is that the stronger the signal or the higher things are here the brighter the color will be so you can see where the signal is low it's kind of yellow right now and it gets redder as the signal gets stronger now one thing you'll notice with this particular tuner is that it's dynamic range is not that great and so you can see that the noise floor is down here somewhere between minus 60 and minus 70 dB and so there's not really much point in showing all this range here from minus 70 down to minus 130 so what we can do is scroll down here to the FFT display settings and take this range slider and just slide that to the left until our range of signal strengths is going from 0 down to minus 70 you can see that's a much more useful range it's made these Peaks a lot higher now and easier to spot and also the colors are a little more vivid in our waterfall display so you can see now when signals are really weak they're blue and the colors get get brighter as the signal strength goes up now the next thing you'll want to adjust is the gain of the rtl-sdr tuner so you do that by clicking the configure button and right down at the bottom of the settings for your rtl-sdr tuner is this RF gain slider by default it's way down at the bottom which is essentially zero gain and you can see that as I drag that slider to the right the signal levels go up the noise goes up but it looks like in this case the signal went up even more and so we can we can receive the signal better when that value is set higher you have to be you have to be careful not to set that too high though because you can see if I start to get up near the top of the range here we got a lot of strong signals and those signals will start mixing together and giving you internment giving you intermodulation products and so you can see here is a phantom signal that wasn't there before I increased the signal strength that's not an actual FM radio station that's just the signals from other radio stations mixing together and producing new new signals inside the receiver so that's obviously too high so we'll bring that back down so that those phantom signals disappear now where you want to set this will depend on the signal environment you're in if you're in if you're tuning in to a place where there's a lot of strong signals you might need to set that fairly low to avoid inter modulation and if you're tuned to somewhere where there's not any strong signals then you may be able to tune that all the way up to the right hand side and listen that way you can listen in to even the very faintest signals but we'll leave this a boat in the middle of the range for now so close that down now to actually demodulate these radio stations and start listening to them we go back up to the top here and select which demodulation we want to use in this case these are wideband FM stations so we select W FM and I'll just turn my audio back up so we can hear what's going on and if you want to tune in a station you can just click in the middle of it and there you go or receiving 103 point fm and you can see not only are we receiving the audio we're also receiving the RDS data so it's showing you the name of the song that's playing that's information that we're going to display it on your radio if it can receive RDS and if we want to retune I can click on the other station there's 104.7 no sigils of cyclic up here to listen to 106.1 another way you can read tune is by dragging the window left or right so you can see if i want to tune lower i can just drag over here and now we're going down the band there's 102.5 FM for example another way we can retune is by using the scroll wheel on the mouse so if I turn the wheel up I'm moving up the band and if I turn the wheel down I'm moving back down so let's just turn the audio back down again the next thing you'll want to do is correct for any inaccuracy in the oscillator in your rtl-sdr it's got a twenty eight point eight megahertz oscillator in it so it's supposed to be operating at exactly twenty eight point eight megahertz but the oscillator won't be perfect and so it'll be running a little bit faster or a little bit slower than twenty eight point eight megahertz which means that the frequencies that you see displayed in this program will be off by a little bit but fortunately almost all SDR software allows you to correct for that the way I like to do that is by tuning to a signal whose frequency I know and my favorite is to use the global TV television signal which starts at 470 megahertz and there is a pilot tone which is a nice narrow frequency that we can use to calibrate our our oscillator frequency so I'll just tune to 470 point 309 megahertz and press Enter you so you can see if you want to tune into different frequency you can just click on the digit that you want to change and then start typing it's on type 406 sorry 470 2309 hit enter and now we're tuned and you can see there's that there's that pilot tone that I was talking about that's exactly at for 7.30 megahertz so all the switch to CW for tuning in a narrowband signal and I can take the zoom bar if we want to zoom in and have a close look at that signal so you can see here's where here's where we're tuned to but the signal is actually over here so you we can see right away that my oscillator is not running at exactly the right speed so to correct for that we'll click configure again to bring up the settings for the tuner and you can see down here at the bottom of this frequency correction in parts-per-million and you just adjust that up or down until this signal comes right over to where it's supposed to be so in my case I need to move it up so you can see here in nineteen twenty twenty seven twenty eight twenty eight seems to be right on the mark so that's moved that 470 point 309 megahertz signal right into the right over top of the frequency that I'm tuned into so there we go now we should be getting accurate frequency readings so I'll just zoom back out and now let's tune in some other signals here as an example we could tune in the Environment Canada weather radio frequency for Ottawa that's one sixty two point five five so I'll just click here on the first digit here and type point six two five five enter and there we go now I'm still set to CW let's go back to narrowband FM or n FM click that and think I was valued upon Aditi Dinesh there we go wait a weather policy I don't know should you just turn that down a little bit once again you can see if I want to have a closer look at that signal I can bring the zoom bar up here and now I can see of course the signal is very strong in the center near where the carrier is and as the audio is modulated sometimes the carrier deviates out to the side when it's silent the carrier stays right there in the middle and you get a really strong signal so let's zoom back out another example here is we can tune to 315 megahertz that's where a lot of garage door openers and car keys operate at so we'll tune to 315 and I brought my car keys here let's see if we can see this signal show up here when I press the button just tuned down a little bit here yep it's just a little bit lower so it's just a bit below 314 megahertz so when I press the button you can see the signal show up there now if I turn turn this to an AM demodulator we should actually be able to hear it as well let me there you go there's my car keys and I have my garage door opener here as well this one I think is a little bit higher in frequency but I'll just press the button there it is over on the right-hand side of the screen you can see it popping up so it's tuned there there you go that's my garage door opening another interesting frequency band to listen to here in Ottawa is from about 866 up to eight sixty eight megahertz that's where the City of Ottawa has its drunk radio system that OC Transpo and Ottawa police are using so we'll just tune to the center of that at 867 megahertz and we'll go back to narrowband FM and you can see already there's signals popping up all over the place they use a number of different channels click there and we can start receiving there's another signal here's another another useful thing you can see I've tuned here to a station that's not our frequency that's not being used there's a swatch function so if I turn that up a little bit eventually the audio should cut out there we go so now we're not hearing anything but if I click on a active signal we should start hearing it there we go and once this station stops transmitting I guess it's gone on to a digital transmission if I tuned to a frequency where there's no transmission now it's good gets it gets welched out for us now for one last test let's see if we can receive some amateur radio beacons here in Ottawa the West Carleton amateur radio club operates a couple of beacons on 33 and 23 centimeters so let's see if we can pick those up so first we'll switch over to CW since they are CW beacons and the 33 centimeter beacon is operating at 9:03 point 360 megahertz now since it's a very weak signal we're going to need to increase the RF gain so let's crank that up just to vote to the top and of course we're in the middle of the 902 2 9 28 megahertz is M band and so all these crazy signals that you're seeing popping up here those are actually water meters and hydro meters this big one here is a hydrometer and all these little signals that are moving all over the place those are water meters and they're hopping around to all sorts of different frequencies so you can see they really move all over the place but the second we want to pick up should be somewhere around here now let's zoom in so we can see if we can spot it at all now one thing you'll notice is that if you zoom in really far the resolution here isn't great and you can improve that by going into your FFT settings and we'll just take the resolution from 4096 up to let's say 130 1000 now you can see a much sharper view of the signals that are there and what have we here that looks like the beacon right there so I'll just scroll down with my mouse wheel to get to that frequency so they are ve3 WCC now let's see if we can tune up and listen to the one on 23 centimeters the frequency for that is 1290 6.06 so we'll enter that in 1296 0.06 enter and there it is right there so I'll just click on that tune up a little bit let's just bring our game right up to the max here here there's no water meters or power meters to contend with so I can really get away with cranking that gain up to the very highest value so there you are the v3 WCC beacon on 23 centimeters and all the examples that I've shown you here I've just been receiving using the little whip antenna that the dongle comes with so as you can see it's doing a pretty good job even picking up weak signals I think this is only a few military as from downtown oddone I'm located out in in Canada so not bad that I'm able to pick that up so I think I'll leave it at that for now and leave you to explore the other capabilities of SDR sharp so have fun and enjoy your new hardware so 73 from V III IR are

Channel: Clayton Smith

Views: 329,797

Keywords: Amateur Radio (Hobby), Software-defined Radio

Id: IaKEYEyrRgk

Length: 17min 33sec (1053 seconds)

Published: Thu Dec 05 2013