Software for the SoftRock SDR
This post takes a look at some of the software that can be used with the SoftRock SDR hardware that is designed for amateur radio use.
A previous post explored the steps involved in building a simple SoftRock receiver for the 40M amateur radio band (7-7.3MHz), that works by downconverting and quadrature sampling a 48KHz wide slice of spectrum and uses software running on a PC for further processing.
The centre frequency of the receiver is determined by a crystal-controlled oscillator and the SoftRock output comprises I (in-phase) and Q (quadrature, or 90° phase shifted) signals, each of 48KHz bandwidth and which are simply fed into the stereo microphone input on a PC.
The Quisk SDR software is available as a Python package and the most convenient way of installing it is to use the easy_install command provided by Python setuptools.
Quisk is extremely simple to use and on starting up it defaults to displaying a spectrum graph along with familiar receiver controls for band, modulation type and bandwidth etc.
A number of other display options are available and the waterfall mode, which displays a spectrogram that shows spectral density, is perhaps the most useful.
There is little in the way of configuration for Quisk, it doesn't take very long at all to figure out its controls,and as such it makes for an excellent application for novice users.
In contrast to Quisk the Linrad software is far more complex, requiring more of an understanding of the operation of SDR systems and an initial configuration to be manually created upon first use.
The user interface also suggests that this software is aimed more at power users, as the controls are less intuitive and the screen presents more information.
There appears to be no shortage of software for amateur radio use, and the great thing about SDR which simply uses a PC sound interface is that if you don't like the feature set or look and feel of one application you can just swap it for another. No need for device drivers and for applications to support a range of different hardware.
Alternative applications include:
SDR-Shell – a GUI application built on the classic DttSP software
ghpsdr3-alex – a modular system with support for remote Android clients
PowerSDR-sr40 – a fork of the popular PowerSDR software for Windows