Please check the license details you will need to purchase this unit
Icasa will have to issue you with the necessary license to use this unit (It will depend on the use of the device)
See section in G14 in this document http://www.zs6wr.co.za/live/wp-content/uploads/2010/10/RadioRegs-Act-No.-103-of-1996-Amentment-2005-2007-1.pdf
What is the difference between the RTL dongles
The DVB-T dongles is based on the Realtek RTL2832U and can be used as a cheap SDR, since the chip allows transferring the raw I/Q samples to the host, which is officially used for DAB/DAB+/FM demodulation. The possibility of this has been discovered by Eric Fry (History and Discovery of RTLSDR). (With the nessary software and antenna you could listen to the following frequensies 48.25-863.25 Mhz.
Officially the RTL dongle documentation only specify the frequency range "48.25-863.25 Mhz" but the one's I have tested do work from about 24MHz to 1766MHz with a dead spot just above 1.2Ghz
To see this RTL dongle in action go to my webSDR at http://zr6aic.giga.co.za:8901 the 2m band is using RTL dongle.
It has an MCX antenna connector, which is not really popular so you will need adapter if you want to connect to external antenna.
Windows SDR# software is available here
This image show the difference in sensitivity and filter.
Linux Quisk software.
Quisk is available here
Click on Youtube video below to see the RTL dongle in action
Gqrx On Linux
Installation instructions here