My radio monitoring began as the son of a volunteer fireman, but quickly turned to aviation when I bought my first scanner at around 10 years old. My love of airplanes has led to a career in flying. Strange as it may seem I still am interested in listening to the chatter of airplanes as they pass overhead even though I hear ATC all day at work.
As an addition to my ATC voice monitoring, I was interested in getting a virtual radar receiver that can plot aircraft location and/or altitude using Mode-S and ADS-B data. For a year I tried a AirNav RadarBox receiver. I enjoyed its ease of use out of the box and the ability to combine outside FAA data in one program. However, the RadarBox is limited in its ability to pass raw data to 3rd party programs such as Planeplotter.
Last month I traded in my RadarBox for a Kinetic Avionics SBS-3 Virtual Radar Receiver (http://www.kinetic.co.uk/sbs-3.php). In addition to the Mode-S reception, the SBS-3 has a couple of other features that are really great! The box has 2 SDR tuners that have a bandwidth of 8 MHz that can be divided into 6 receivers. Additionally, there is built-in ACARS decoding and for those near the coast a built-in AIS decoder as well.
The box can be connected to a PC via USB, or used stand-alone via ethernet. Kinetic provides their Basestation software to interface with the SBS-3. I've found it very robust. The main difference here between the SBS-3 and RadarBox is the lack of online data updates built into Basestation. When an aircraft is received, Basestation displays all the data that it receives, but unlike RadarBox, it doesn't go out on the web and download additional aircraft information.
The good thing is there is add-on software that interfaces with Basestation which will download the aircraft information and populate your database. I use ActiveDisplay (http://www.gatwickaviationsociety.org.uk/AD_home.asp) and decided to purchase a subscription for one year to access the Gatwick Aviation Society aircraft database. There is a lite version which is free.
My next project is to set up Planeplotter and interface the SBS-3 with it. One feature I'm interested in is Multilateration. This gives the ability to approximate the location of non-ADS-B aircraft by using data from other users in the area that can see the aircraft.
Seeing Mode-S and ADS-B data is a fascinating way to enhance aircraft monitoring and add to the awareness of who's flying around.