HF and Software Defined Radio: HDSDR + USRP + GNU Radio + RFMap

This is a tour through using SDR to receive HF: wiki.spench.net...
spench.net @spenchdotnet / spenchdotnet
HF with ultra-cheap-SDR RTL2832U-based DVB-T USB dongle: • Ultra-cheap SDR: HF wi...
Files are now available on BitTorrent: spench.net/down... Please keep seeding!
To use the recordings in GNU Radio, please apply this patch to your WAV File Source first: wiki.spench.net...
Otherwise you will encounter a 'runtime error' as the original code doesn't like HDSDR recordings.
Transmission types covered:
Whistlers
Ionosondes
Weather fax (WEFAX)
Flight Information Service
Link 11 (TADIL A)
RTTY
Over-the-Horizon RADAR
STANAG 4285
Sweepers
Unknown sweeping 'blocks'
ACORN (Ocean RADAR)
ALE (Automatic Link Establishment)
OFDM (Orthogonal Frequency Division Multiplexing)
DRM (Digital Radio Mondiale)
Resources:
maps.spench.net...
wiki.spench.net...
wiki.spench.net...
wiki.spench.net...
www.lucabarbi.i...
www.wavecom.ch/...
imos.org.au/aco...
www.codar.com
en.wikipedia.or...
en.wikipedia.or...)
-----------------------------------------------------------------------------------------------------
Links to SDR software packages:
You can use the cross-platform GNU Radio (used to do the pop-up analyses). It's a very powerful signal processing framework, so you can do almost anything in it: gnuradio.org/
HDSDR (the main one) runs on Windows: www.hdsdr.de/
Sigmira (used for STANAG, but also does all the standard analog modes+some other digital ones) is cross-platform: www.saharlow.co...
There are other Linux/cross-platform ones like:
napan.ca/ghpsdr3/
www.sm5bsz.com/...
-----------------------------------------------------------------------------------------------------

[@chadmspooner]

I've successfully downloaded the recordings from BT, and taken a first look at all ten files. It looks like you placed inphase samples in one channel of the wav file, and quadrature in the other. The spectra look good! Thanks very much to you and Matt for doing this.

[@batterseapowered]

This is a very well produced video. Thanks for taking the time to put in all those split screens, zooms and annotations. I don't know much about radio but I found it very interesting and informative to watch.

[@davekeck]

I understood maybe 25% of what you're talking about, but wow that was an awesome video. It's incredible how you can see and listen to all the signals occurring all around you. So freaking cool, and you really seem to know what you're doing =)

[@TheCanesVenatici]

I've been decoding digital mode transmissions since 1995 using an AEA PX232 MBX TNC. Not a whole lot good today since most RTTY/TDM/BAUDOT from commercial sites is encrypted. I now use an Alinco SR8T and SDR software for rig control but it would be very cool to have software that could do signal identification and decode the more sophisticated digital modes. Very good video.

[@N0SSC]

Great vid! Those "whistlers" are definately ionosondes; they're easily identitied by their constant slope over a wide band. Some amateurs have ionosondes, so they may stop and go; the wider ones are also ionosondes, just with a different sound which draw differnent graphs. The quicker sweepers are definitely radars like codar like you mentioned. The whistlers on VLF are somewhat related to lightning bursts; they are quite anomalistic and enigmatic and are natural earth sounds like sferics.

[@FirstToken]

Going to have to break my comments into several pieces here: The “sweepers” at about the 01:15 mark in the video (and at several other points) are indeed Ionosondes, also called Chirpsounders. You might want to research the AN/TRQ-35 or TRQ-35 sounder for details. Sweep rates of 100 kHz / sec are common. If you plot the time of the sounder at any frequency you can even correlate it back to the source. There used to be, not sure how active it still is, a Chirpsounder Yahoo group.

[@TheHubblethebubble]

Very nice and well produced informative video! Thanks for having taken the time to share it.

[@balint256]

You've hit it on the head: that's the magic of RF, why I love it so - it's an invisible world that's full of signals to explore, analyse and decode. A fascinating natural resource (when you think about it).

[@balint256]

Thanks for watching it and giving such detailed feedback! I'm sure other viewers will appreciate it too.

[@smidgedy]

boom, exactly the resource I was looking for. Cheers for that, and let the experimenting begin!

[@JK360noscope]

I will have to second the first comment, as this is by far one of the most enjoyable videos I've watched in the past year. No searching around for definitions of things, as it's already explained in the video. This should be an archetype for a good educational youtube video.

[@balint256]

No worries! Glad you enjoyed it. Could probably tap their IF outputs and sample that using a simpler SDR (quadrature receiver) ;)

[@roccotanto]

this is a fascinating video, thank you for sharing it! i really have to get an SDR, seems like a very powerful tool for a SWL'er......things sure have improved since my old Hallicrafters :-)

[@balint256]

This set up is using a USRP, so YMMV with the RTL2832 dongle. The recordings are only 1 MHz wide, which the dongle can do - but it's only 8 bits so you'll have reduced dynamic range. The transverter just puts the HF signal into a 60 MHz mixer, so you just add 60 MHz to the frequency you really want to listen to when setting the tuning. Unfortunately I don't know what's available on the market now - I have an old Kuranishi Instruments FC-965DX-T.

[@brianwalker9816]

There is an instrument which sends out a repeating swept RF signal. Signals are scattered back from the ionosphere and and also back from the ground when the signal bounces. The backscatter is measured and the distance is calculated. This way one can know where on the earth a certain signal will hit after bouncing off the ionosphere once or twice. Some people leave these devices running all the time just to annoy those of us with more serious uses of the spectrum. :p

[@FirstToken]

The slow rate sweeper at 11:25 in the video is a sounder, it might be associated with JORN. If you pay close attention after it leaves one freq it steps up or down (one direction or the other, a given one always travels in one direction only) 1 to 2 MHz and sounds again. And then another 1 or 2 MHz and again, etc. The steps are not always even 1 or 2 MHz steps, but are often close to that size.

[@balint256]

Yes, other people have also mentioned CODAR too. That night signals were booming in - it hasn't really been repeated since.

[@balint256]

I know you know now ;) But for everyone else: the bandwidth is dependant on the input sampling rate, which can be adjusted in the ExtIO's Device Control dialog. The range is above 900 ksps to 3.2 Msps (i.e. above 900 kHz to 3.2 MHz).

[@balint256]

I haven't used Excalibur/Perseus myself, but I imagine they're both pretty good. First place would be to check their specs on sensitivity, etc. Then read about what other users have reported regarding performance. That said, the USRP is in a class of its own because (as you say) it's just so flexible. Apart from the transverter+WBX, you could also build your own pre-amp (e.g. using the one in the Genesis radio kit), and use it in front of the LFRX - I think that could work really well too!

[@lui_gough]

band. 4:13 - Sweeper - I've occured some that are continuous and others which are cycling frequencies and some have told me it may have something to do with SuperDARN or CODAR sensors. 4:58 - The blocks you mention tend to be the ones which are cycling - the pulse repetition frequencies of these are often different and are usually radar of some sort. You have very good reception! These are real signals though! 5:50 - Maybe you can see if Sigmira could lock the STANAG signal?

[@balint256]

Thanks - it's great having the extra bandwidth (or the widened perspective as you say ;).

[@balint256]

Thank you! Of course: HFDL - seen it in screenshots, but never received it before. Will have to tune to 10 MHz next time and watch...

[@balint256]

All that was done with various blocks in GNU Radio Companion, so I would start experimenting with that firstly (and perhaps finding sample flowgraphs on the net). Once you feel more comfortable, get gr-baz (and possibly my GNU Radio patches) from my wiki, compile/install, and you can use the Fast Auto-correlation sink and other combinations that use other new blocks (e.g. Variable Delay). See the gr-baz wiki page for screenshots of block combinations that do that sort of analysis.

[@FirstToken]

The multi speed sweeper at 15:40 is another sounder. Quite possibly associated with the same source as the one at 11:25, again, it might be related to JORN. Note that this sounder generally does 64 sweeps at each rate before stepping down to the next rate, it also often has 16 speed steps. And again it is common for this one to step up or down 1 MHz and sound again.

[@balint256]

Consider this video the inspiration to get into SDR then! :) You could just jump in by getting a cheap SDR receiver ($20 Realtek RTL2832 dongle - originally a DVB-T receiver - or a FUNcube Dongle) and using HDSDR, and then later read about GNU Radio (they have a huge site with lots of resources), what it can do, and how you can begin experimenting with it (e.g. it has a nice block-based graphical programming tool called "GNU Radio Companion").

[@FirstToken]

Both radar KZbin videos you pull up at 03:00 are mine ;) The sweep at 04:40 is indeed CODAR. The “blocks” at 04:53 are a sounder. The exact location and designation for this one has not been confirmed. The sweeps at 06:25 are CODAR, under one of the channels of Chinese OTHR (I have seen up to 12 simultaneous channels of Chinese OTHR, in channel “pairs”). The CW is unrelated to either.

[@balint256]

Camtasia Studio (they have a free trial) - a great package. It's split-screen as they're actually just two monitors and the recording area extends across both.

[@DK8OK]

Fascinating, and full of helpful information! I really do like the combination of GNU Radio and RFMap. 73 Nils, DK8OK

[@drspastic]

thanks for identing the stanag. i was wondering what that was for years

[@balint256]

No worries - have fun & good luck!

[@martin1698]

the sweeps are chirp transponders they go from 4hz up to 30mhz they show on a display the f1 f2 f3 layers for good propergation for tx rx ccts

[@Ulterior1980]

I bought all needed parts for SDR just after seeing this vid :)

[@balint256]

You can certainly try! However, you will need a transverter to bring HF up to the frequency range that the dongle accepts (e.g. I use a Kuranishi Instruments FC-965DX-T for +60 MHz to use HF with the WBX in my USRP).

[@lui_gough]

I've had a few locks but since it's all encrypted, it's pretty useless. Sorry, I'm writing this as I watch - I see you've mentioned CODAR. I've also seen sweepers with discontinuities as well - and sweepers which isn't very linear either towards the higher bands usually sweeping downward. Very nice constellation plot on that Stanag signal - and now I see you used Sigmira too. Great video! Really enjoyed watching this :D Been a bit busy myself, but unfortunately not with radio ...

[@lui_gough]

Whistlers - I tend to get them around here, and it's almost certainly man-made. Ionosondes maybe, someone suggested that I reference the time it crosses WWV/WWVH's 10Mhz signal and I will find that they are supposedly very regular! 1:43 - that's HFDL aka HF-ACARS used by long haul aircraft. The single "alignment" tone before the data burst is a giveaway - you're tuned a bit too low so it might not have been that easy to spot by ear. The fact they're clustered is because they are in the aviation

[@balint256]

No, but it works with the USRP (that is what is used in the video), which is what OpenBTS also uses to transmit/receive (i.e. it's the common hardware).

[@AlbertMilliron]

Very informative video, nice to actually learn something

[@alexcazaux]

Verrrrry instructive !

[@balint256]

Yes! That is most definitely one of my favourite films (even though it differs from the book in some respects).

[@FirstToken]

The radar at 08:50 is a bit more iffy. It might be the radar you quote, it also might be, probably is in fact, the PLUTO II radar out of Akrotiri. The specs are all correct for PLUTO. Of course, these are common techniques, so it could be any one of several radars. If it is always on that freq you noted it is probably the radar you have associated to it. But, PLUTO jumps in freq from time to time. It also has several second of dead carrier before the sweeps start.

[@balint256]

Thanks for your lovely comment!

[@atomikrobot300099]

Great Video! After watching this video I feel a bit.... ALL GLORY TO THE HYPNOTOAD

[@nominalvelocity]

Just an unedcuated guess, the relatively weak stepped signals you pointed out at 5:17 might be a reflection from some sort of AESA / low probablity of intercept militarty radar.

[@w9zsj]

Terrific job! I'll rerun to study this again. W9ZSJ

[@balint256]

I wouldn't think so. Such continuous and 'linear' signals are usually caused by ionosondes sweeping the ionosphere. Frequency-hopping radios would likely jump through a series of discrete frequencies as opposed to changing continuously like that. Although you never know! (Nevertheless, there's no modulation on them...) That's the mysterious beauty of HF.

[@TM-cb2te]

This is fantastic

[@balint256]

Please refer to my GNU Radio 'patches' wiki page (in video description) where you will find the appropriate patch to apply to the GNU Radio WAV Source block. There is a problem with the original code that prevents it from playing HDSDR recordings. Once you apply the patch, it will work fine!

[@balint256]

Yes, you certainly can! Please have a look at my latest video: "Ultra-cheap SDR: HF with RTL2832 and transverter" (link in video description).

[@tjhowse]

What are you using to record your screen? The zooming and split-screen stuff is very nice, I'd like to use it to show off a project of mine.

[@PauloCSantosGarcia]

I also agree with your opinion, its a signal from ionosondes

[@IAMVIBRATIONMUSIC]

the blocks that move across the spectum at a different rate seem to be in morse code staggered with a delay to either separate, or break down the message into intervals. like a binary code.

[@balint256]

So sorry, I haven't had a chance to upload them yet. I'm in a bit of a pickle because I just launched Aviation Mapper publicly, and my upstream is saturated. I need to keep it as free as possible to handle the incoming requests (perhaps I could throttle but then it would take forever). I might try to ask a friend to upload/torrent it for me... Will post back here when I do!

[@alienhybrid]

great video! a couple of questions... how do you identify the signals? software or personal knowledge? How did you get HDSDR to display the correct frequency with the transverter? Thanks! Just getting started in SDR and very interested... bought an EzCap after watching one of your videos.

[@rgc4684]

I've just ordered a P160 tuner from ebay.com.au and I'd like a little more info on your setup. You mention a transverter that "adds 60MHz" to the signal coming in to the USRP. Is there some transverter you could recommend that I could use with my P160? I understand that the Unikoo UK001T (I understand the P160 is like the UK001T) has a somewhat limited bandwidth, though, so a +60MHz up conversion may not be enough for me.

[@balint256]

I have put the recordings on BitTorrent - see the video info for the torrent's URL. Thank you to my SDR mate Matt Robert for the initial seed while my net connection is hammered by Aviation Mapper visitors!

[@flyingfrancisco]

Good morning I I thought that the RTL2832U was tunable from 60MHz to 170MHz. I see you are in the ham band at 7MHz. How are you able to do that. I bought one of these and most of the radio waves I can see or listen to is in the FM band 88MHz to 107MHz. Thx in advance

[@Malvineous0]

Very interesting! Any chance you'd be willing to make one of those capture files available so we can try this all out without owning an SDR device?

[@udovdh]

Very interesting application. What Linux software enables the user to browse a very wide spectrum visually and maybe also in audio? (AM, FM, WFM, etc)

[@chadmspooner]

Thanks very much for the video. Like Malvineous0, I would very much like to obtain I/Q samples corresponding to your collected HF data. Did you end up placing any data in a dropbox or other accessible location?

[@todkapuz]

Very cool ... sdr really looks like the way to go... just got back into scanning and ham radio... last night i was in the 5-6mhz area and found some of these.. always wondered what they might be... but i also was changing modes and switched to wide-fm and actually was able to hear a spanish broadcast in widefm that i couldnt make out in am/ssb/ or any other mode. i can't find anyone on such a signal, any thoughts?

[@balint256]

That could be a 'sounder' for RADAR (as suggested by someone else).

[@nxxxxzn]

Lovely vid!

[@Malvineous0]

Great, thanks! Otherwise a bittorrent link on your web site would be fine for me, I'm happy to seed it for a while.

[@balint256]

Have a look at the bottom of this video's description for some options.

[@jeroen1205]

It all looks and sounds so cool in this vid, but I have no clue what you are doing :-) Where can I learn more about this stuff?

[@r00t3d]

hi, please help me, how do you set the bandwith range? can t find any info about that .thx for helping

[@definty]

Could you do a tutorial on decoding the different signals to get the data/voice in them?

[@balint256]

The main one I use in the video is HDSDR, which is Windows only - but GNU Radio, Sigmira and many others run on Linux and/or are cross-platform! Please see my updated video description for links to the various packages you can use...

[@smidgedy]

G'day, are there any resources out there on basic gnu radio usage like you did with the STANAG signal?

[@GROOVETECHSETS]

I have RTL2832, I can tune the same transmissions what you show in your video if I live in Spain? srry for my english, thank you! =)

[@hotforit]

Ran across this video while researching SDR software. I have not had the opportunity to use SDR before and found this very informative. Thank You balint256. KB1ZYI

[@r2kordmaa]

i tried to use the recordings but i get RuntimeError: is not a valid wav file from wav file source block, how do i replay these for GNURadio?

[@ruawhitepaw]

How do you record "raw airwaves" like this? Wouldn't it create really big files because you need such a high sampling rate to capture a decent sized frequency range?

[@TheReconPrepper]

What's the widest bandwidth you can see at one time. You mention that what u r showing is 1mhz. Can it do wider scans? If so what? Thanks just found your channel and subscribed.

[@fatimahanif1364]

is it possible to use HDRSDR for files other than audio files? i want to read the signals coming from GPR (ground penetration radar) which are obviously not audio waves. how do i input such files in this software?

[@Kevin_KC0SHO]

Where can I get the file for GNU Radio that you used for the analysis with the tabs at the top? I love the video, sdr really fun. I'm currrently using sdr-console and HDSDR mostly. I've got a HAM it Up coming and plan to use it with my HackRF.

[@christopherdenize2450]

Could the large sweeping signals be coming from a doppler weather radar?

[@balint256]

That's a great idea! Compressed it's about 1.7 GB in total though - any hints on where I should have it hosted?

[@balint256]

I just put them on BT - please see video info for link.

[@steveambrose1734]

Hi when I run DSD with HDSdR I change my sound card to VAC1 I can decode DMR but I cannot listen to analog signals without changing the sound card setting back to the speakers how can I change this so I can hear all signals please

[@SignalsEverywhere]

Unfortunately when you are streaming your audio data into DSD you are only going to get decoded digital audio. The only real option to hear both would be to go into your sound card settings and click the 'listen to this device' option. However you would then hear digital noise at the same time you heard the decoded audio. Realistically this isn't very convenient. Most SDR applications tend to require you to stop the client in order to change the audio sources. I'd recommend giving CubicSDR a try as it allows you to change where you send your audio while continuing to monitor your SDR.

[@erniehollingsworth1601]

What software do you use to make recordings?

[@Ixquick979]

Can someone explain to me what is a sweeper?

[@balint256]

I might put it in my public Dropbox folder...

[@GROOVETECHSETS]

Can i do this with rtl8187?

[@PhrackTheLord]

I'm running Ubuntu, can I use the same software as you are?

[@LeeLee-lt8tp]

I can not find the torrent file,i get a usrp1 recently,would you seed this file again ? Many thanks!

[@aaronmiller112]

Very very good video. I am going to get SDR to talk to aliens

[@thetarget]

11:23 Can you tell me what is this?

[@r00t3d]

yep thxx a lot, weird i can t set it more than 1.800 mhz :'(

[@yoyis-898]

does this work with OpenBTS?

[@jcims]

Nice presentation! Just getting started into amateur radio and sdr, and i'd see several of these artifacts/anomalies at w4ax.com (especially whistlers). This is the first attempt i've seen at looking at these things from the perspective that SDR provides.

[@AndrewMurphy8383]

Those are normally signal

[@balint256]

I believe that's a WiFi chip, so my guess is probably not :(

[@DrStacked]

You could upload it as a torrent

[@duke222222]

Why is he talking over the song?

[@jcims]

Also, the TADIL-A/Link 11 stuff reminds me of the signal in Contact /watch?v=5vFwTJ44lFw#t=45s

[@radiosification]

haha I thought those lines going diagonally were radar

[@MAlEssa96]

Sounds like Chase from House

[@SC2Wins]

Interesting...NOT!!