Software Defined Radio
I've been playing round with some basic Software Defined Radio's since about 2010 when I purchased the SoftRock 9 and SoftRock TX/RX kits. The WA VHF Group purchased a heap of these as a kit based project for group members.

Both of these kits are SoundCard based SDR's which use the L/R channels to sample the I & Q signals from the SDR chip.  This is where it becomes quite apparent that not all soundcards are created equal, and the vast majority of soundcards will give limited results. For optimum use of the softrocks, you need a very high sampling rate and bitrate. 192Khz @ 24bit professional soundcars (studio recording) in my view are the minimum requirements.

Thankfully, given my interests in music composition and recording (I had my own recording studio in Canberra), I already had a couple of 'soundcards' suitable.

One of the best value 'Buget' units I've found which cover these minimum rates are the E-MU series.

I opted for all of the PA and filter modules to go with the SoftRock RX/TX, which gives me every HF band. Add a suitable PA and you have an all band, all mode 100W HF Transceiver from your PC. The beauty of this, is that using the likes of VNC, Skype, logmein etc, you can operate it remotely from any computer.

The beauty of the SDR world, is that there's a plethora of open source (and commercial) software out there which will work with a lot of the various hardware options.

Since then I've been playing with the el-cheapo USB Dongles you can pick up for as little as $10 from the likes of eBay etc. These dongles can typically receive from about 22MHz right up to as high as 2.2GHz on just about any computer with USB, even the likes of the Raspberri Pi boards. So for well under $100 you can have a VHF/UHF SDR receiver, and, coupled with the right software can RX/decode all kinds of Analogue/Digital signals.

There are now a number of block downconverters which you can put in the RX line, which will also allow you to receive in the HF region. If you DIY these converters with some old boards/components in your junk box, or purchasing a few of the key components (such as a NE602, SA602/612 or SBL1), you can have a very powerful HF/VHF/UHF receiver, still for under $100.

SDR Hardware
El-cheapo / Getting started hardware
Soundard Based SDR Hardware
Probably the most common soundcard based SDR's are the 'SoftRock' range. There is the SoftRock v9 which receives HF, and the SoftRock RXTX which is a HF Transceiver. The SoftRock Transceiver has several optional plug in PA and filter modules which allow you to us it to TX/RX on all of the HF range.

There are several other Soundcard Based SDR's.

Cheap USB Based SDR's
By far the cheapest and easiest way of starting in SDR's is with the Realtek RTL2832U based USB Dongles. These little things the size of a typical USB memory stick are actually made/sold as a TV/FM receiver (such as the EZCap, LifeView, VideoMate), but many of them can can receive all modes in the entire VHF spectrum right up to UHF @ 2GHz+. At a price as cheap as $10 (though typically around $25 at a computer shop), what they're capable of is simply astonishing!!!  To determine which model you might want in terms of size and frequency range, check out this site.  There's also a heap of other good SDR stuff here.

There are several others

Mid-Range (price wise)
An SDR trnsceiver which has really grabbed my attention (and ill probably buy) is the G11 Transceiver made by GenesisRadio. This $299USD hybrid kit is capable of up to 5 HF bands (depending on filter choices) at 10W. This SDR transceiver has been used to win a number of contests!

Professional range
Here are some of the rather expensive professional range of SDR's.

Australia's very own SDR which has been around since the early 90's, WinRadio. I was actually fortunate to meet the original founders of WinRadio back in the mid 90's at one of Melbourne's Hamfests. Little did I know at the time that I'd get hooked on Software based radios (I don't think SDR was even a term then).

Here is a great matrix list of a HEAP of different SDR's out there.

Here is another very extensive list of SDR PROJECTS.

Since building this site many years ago, other much better sites have shown up. For the best comparison of Software, check out the RTL-SDR site here.

SDR Software
WEBSDR is a site which which allows your to use other peoples Web-Enables SDR's via your own web browser. Many are dedicated to HF, however there are many other bands offered all around the world. Another one is

glSDR is an excellent Android app which allows you to access many Web-Enabled SDR's via your Android-based Smartphone or Tablet Computer.

USB Dongles:
By far the easiest/simplest software to get you started using the cheap USB SDR's is SDRSharp!  or SDR#.  This is a very simple program to get you using SDR at a basic level. It will let you receive in all modes, and easily vary your filter bandwidths etc, as well as a nice colourful waterfall.  I know of a few people who had some troubles getting their dongle to work with this software due to drivers. If you FOLLOW THE INSTRUCTIONS from the website, you shouldn't have any problems. I've sucessfully used multiple instances of SDRSharp to receive using multiple dongles at the same time.

HD-SDR IS a great program which is very easy to get started on, yet still featureful. It has a HEAP of integration options to other software packages such as CAT control, digital modes etc.

RTL-SDR contains the librtlsdr library which is used by most of the software backages out there. This is a very popular package to try if you're just starting out.  Don't be mistake this software for only being for the beginner, as this core library is used for a basis for some VERY complex receiving/decoding!!!

RTL-SDR-Scanner is a package which you can install to use your SDR Dongle as a Radio Scanner!

GNURadio Is an absolutely amazing piece of software which really allows you to explore the flexible possibilities of SDR.

LinRad is a multiplatform SDR package. is a very powerful package written by the original author of Ham Radio Deluxe (HRD).

SDRadio is another nice little program.

Since building this site many years ago, other much better sites have shown up. For the best comparison of Software, check out the RTL-SDR site here.

Some Specialised Projects

SDRDF (SDR-Direction Finder) is an SDR based Direction Finder for tracking of signals.

Accessories / Additional Hardware for your SDR

HF Converters
Many SDR's will happily do VHF/UHF, especially the USB dongles of various sorts. To anable these dongles to be able to go down to the HF region, you'll need a converter.  There is one designed specifically for the FunCubeDongle (FunCube-Conv) about the size of a matchbox though it's quite expensive at 83 Euro.  A new model is here.
Another nice and cheap one is the open source converter by opendous and available from NooElec for only $50 delivered.

The DIY FunCube Upconverter allows this to be done for next to nothing if you can source your own parts.  Another nice one is here.

SDR Information Sources has a lot of information related to the RTL Dongles.

DXZone's list of SDR Software.