Video intro to receiving HF with Software Defined Radio

[VK2FUNK]

Hi folks,
I'd like to share this video I recently put together that demonstrates how one can use Software Defined Radio to receive HF. I analyse a number of interesting/unusual signals (e.g. STANAG, DRM, OTH RADAR) by putting them through various pieces of software (e.g. HDSDR, GNU Radio, Sigmira).

If you have any thoughts on the mystery signals I mention, please comment! (Some have already been revealed on the YouTube page...)
Hope you find it interesting!
73 Balint VK2FUNK @spenchdotnet



PS: The important thing to note is that SDR and this sort of analysis can be applied to any frequency/signal - I just happened to use a long wire here. If you'd like to see it done for other signals (VHF/UHK/Ku) then check out the "Blind signal analysis of satellite transmissions" thread I started here: viewtopic.php?f=46&t=10530

[VK2GOM]

Most interesting... and well put together.

Pine Gap are looking for people like you! How do you like Alice Springs?

73 - Rob VK2GOM / G0MOH

[VK2FUNK]

Pine Gap are looking for people like you! How do you like Alice Springs?

Thank you for checking it out!

I would certainly be amenable to applying such skills there Not sure whether I ought to wait for an invitiation though...

[I2NDT]

very interesting indeed!
can you describe also your "Ettus Resarch" receiver?

i2NDT Claudio

[VK2FUNK]

can you describe also your "Ettus Resarch" receiver?

I have the USRP 1 with WBX daughterboard (50 MHz - 2.2 GHz), which does 16-bit I/Q at 8 MSps, or 8-bit at 16 MSps, over USB 2. It can be found here: https://www.ettus.com/product/category/USRP_Bus_Series

If you're thinking about getting one, it's probably worth getting a newer model (e.g. B100) - unless you want to have two daughterboards in the one SDR unit.

[I2NDT]

ty!
it looks really very interesting and, if I am not wrong, that B100 can work with a TX daughterboard.
but I am afraid it's too complicated for me!
the website is meant for professionals and not simple hams like me!!! hahaha

i2NDT Claudio

[I2NDT]

ty!
it looks really very interesting and, if I am not wrong, that B100 can work with a TX daughterboard.
but I am afraid it's too complicated for me!
the website is meant for professionals and not simple hams like me!!! hahaha

i2NDT Claudio

[VK2DDS]

I have the USRP 1 with WBX daughterboard (50 MHz - 2.2 GHz), which does 16-bit I/Q at 8 MSps, or 8-bit at 16 MSps, over USB 2. It can be found here: https://www.ettus.com/product/category/USRP_Bus_Series

Is that the sample rate is uses when viewing 1MHz on the waterfall? With IQ sampling you can get a "waterfall bandwidth" almost equal to the sample rate, what's stopping the SDR software from having a 16Mhz wide waterfall?

I haven't had time to watch all the way through, but the first ~5mins looked great!

[VK4APN]

Hi folks,
I'd like to share this video I recently put together that demonstrates how one can use Software Defined Radio to receive HF. I analyse a number of interesting/unusual signals (e.g. STANAG, DRM, OTH RADAR) by putting them through various pieces of software (e.g. HDSDR, GNU Radio, Sigmira).

If you have any thoughts on the mystery signals I mention, please comment! (Some have already been revealed on the YouTube page...)
Hope you find it interesting!
73 Balint VK2FUNK @spenchdotnet

PS: The important thing to note is that SDR and this sort of analysis can be applied to any frequency/signal - I just happened to use a long wire here. If you'd like to see it done for other signals (VHF/UHK/Ku) then check out the "Blind signal analysis of satellite transmissions" thread I started here: viewtopic.php?f=46&t=10530

Congratulations on a well produced and very informative video.
Paul vk4apn

[VK2FUNK]

Is that the sample rate it uses when viewing 1MHz on the waterfall? With IQ sampling you can get a "waterfall bandwidth" almost equal to the sample rate, what's stopping the SDR software from having a 16Mhz wide waterfall?

The full bandwidth (including the waterfall) of the digitised signal will equal quadrature sampling rate. For HF, because the signals are usually so narrow, it doesn't make sense to go so wide because you can't visually resolve anything on a display of limited resolution. For broadband signals (e.g. DAB, DVB) then a faster sampling rate helps.

Also, calculating the real-time FFT of a 16-bit complex baseband signal at 16MHz will require a bit of CPU grunt! A USRP 1 with GNU Radio can render a waterfall nicely at 8MHz 16-bit and 16MHz 8-bit. I've been able to do 4MHz well with HDSDR and BorIP http://wiki.spench.net/wiki/BorIP (so the USRP 1's output is streamed across gigabit LAN). 8MHz might be possible there, but the machine running the BorIP server currently isn't up to it.

[VK2FUNK]

@VK4APN: Thanks Paul - glad you found it informative!

[VK2FUNK]

Wow! How was that for a burst of techno babble bullcrap???

That was fantastic!!! Really happy to see you getting into it there.

GNU Radio is the way to go. Only try setting up on Windows with MinGW-x86 (I've done this - some difficult-to-follow notes here: http://wiki.spench.net/wiki/GNU_Radio_MinGW) if you're really familiar with the Linux development/compilation workflow (i.e. Automake, Make, pkg-config, etc). Otherwise you'll get bogged down pretty quickly (unfortunately).

The alternative is to install a distro (e.g. Linux Mint) under VMware/VirtualBox/etc, and do it all emulated (if you have a modern PC it will still work well), OR - and this may be a better option but I haven't tried it - use the CMake port for Windows: http://www.joshknows.com/gnuradio_port (reduced functionality, but not by much IIRC).

Good luck! Keep in touch - let me know how you go.

PS: You must download the latest/newer features.dat for Sigmira, otherwise it'll crash. I got it working on Win 7 and XP, but not Vista (just crashes). I got away without it, but you might also want to try running it under Compatibility mode.

[VK5PJ]

Edited

[VK2FUNK]

a wave form that you could not identify some where around 6 to 7 MHz

Thanks for that Peter! Just to clarify, you're talking about the weak sweeper I mention in the first recording (LO = 7.023MHz) and it's just on the right of the HAM band (with plenty of AM broadcast on the right), so it sweeps between 7.150-7.180 MHz? Unless I've identified the wrong one, I'm just confused about the 150kHz bandwidth you mention - where does that come into play?

[VK2FUNK]

So as per usual there will be one really important step missing so I can spend a few days pulling out my hair

Hopefully this won't happen! GNU Radio is a hugely popular project and so is refined on a regular basis (plenty of docs too as you've found). Installation takes some time, but is straight forward assuming your build environment is pretty vanilla. Good luck! (Also don't be alarmed that certain components won't be built at the end of ./configure)

[VK2AVR]

Very interesting vid!

[VK5PJ]

Edited

[VK2FUNK]

@ Peter VK5PJ: No worries at all! If/when you do, would be great to discuss again...

[VK5PJ]

Edited

[VK2FUNK]

Thanks for the analysis! Righto - the first sweeper at 04:04 you mention was the one I referred to.

Very interesting to hear the variable WRF is known as 'agile mode'! Pretty amazing you can see such slow-moving vehicles too.