Osmocom Spectrum Browser & Signal Generator

There are a few basic software packages or SDR that can be exceptionally handy and they don’t require much work to install, here’s a couple from gr-osmocom that are likely installed already if you are up and running already.

The osmocom spectrum browser, osmocom_fft, is nice and quick to use and should have been installed already as part of the gr-osmosdr package:

Screenshot - 150814 - 09:51:53

Another handy one that should also be available already is a signal generator, osmocom_siggen, that will allow you to generate some basic signals. Take care to make sure you are transmitting on a frequency you are allowed to, the application starts transmitting straight away so set the frequency on the command line. If you don’t exit it properly it will stick on transmit.

Screenshot - 150814 - 10:47:04

The sweep generated above with the HackRF received on a rtl-sdr dongle:

Sweep

This was my first transmit test, so the HackRF transmits, yay 🙂

Another handy application is osmocom_spectrum_sense. This will give power readings for a frequency or within a range in the console so could be handy for quickly scanning or checking for a strong signal. It can be run over a range or on a single frequency with a 0 range. In the single example below we first get a reading of 15 from a broadcast fm station, the second reading of 2.7 is from 1mhz under the broadcast station where there is just noise.

2014-08-16 20:55:16.523750 center_freq 105650000.0 freq 101900000.0 power_db 15.5508674659 noise_floor_db -84.4425523316

2014-08-16 20:55:37.790722 center_freq 104650000.0 freq 100900000.0 power_db 2.76116236335 noise_floor_db -84.432340649

Pybombs GNURadio / GQRX / HackRF Install

Although I had a laptop set up with everything using the build-gnuradio script plus manual installs of applications, I also needed to have it up and running on a second laptop.

This time around I used the more up to date method of installation provided by the GNURadio developers, the PyBOMBS application. As described, this will build GNURadio, dependencies and out of tree projects. It also lets you keep on top of updates for projects so should be good going forward.

The install of GNURadio worked without a hitch as did installing the hackrf tools with “./pybombs install hackrf”.

Installing GQRX initially failed with an error as described here:

/usr/bin/ld: cannot find -lboost_system-mt
/usr/bin/ld: cannot find -lboost_program_options-mt
collect2: error: ld returned 1 exit status
make: *** [gqrx] Error 1
ERROR:root:PyBOMBS Make step failed for package (gqrx) please see bash output above for a reason (hint: look for the word Error)

And as in the solution there, removing BOOST_SUFFIX=-mt from recipes/gqrx.lwr allowed it to compile.

On starting the PyBOMBS installed GQRX I was pleasantly surprised to see there’s now a Bookmark function to store frequencies:

GQRX BookmarksAlso with the new install you don’t have to select “No limits” in GQRX to view under 30mhz as with my older GQRX/gr-osmosdr on the other laptop. The performance under 30Mhz isn’t going to be great but as described by Michael Ossmann in a talk at Defcon here it can go beyond it’s original specification which is nice 🙂

Toy Delivery – HackRF One

So after a long wait we finally receive the HackRF One plus its telescopic antenna in the post!

HackRF – Long time a coming!

Having played plenty with RTL-SDR dongles already, it was just a case of plug and play to see it working with GQRX.

We started off with gawking at 20Mhz being displayed instead of the 2Mhz of the TV dongle and briefly listening to broadcast FM which is like the “hello world” first step of SDR reception to see it was working as expected.

Opening the HackRF case required using a small screw driver to pop the holding clips in and working the way around after loosening the SMA nuts, it didn’t make too much of a mess thankfully.

HackRF with the lid off.

We also took delivery of the RF shield at the same time, it’s just a frame with a cover that needs to be soldered on to the square on the top right. The shield looks to be easy enough to solder on but I’m going to leave this for after the first 24 hours 🙂

Now to learn SDR..