RTL SDR

Based around a RTL2382U-R820T board this is my first sdr setup.

Is has been built inside a metal box for shieldig purposes; for the same purposes the following steps have been performed:

-power lines have been filtered using a toroidal ferrite core

-data lines have been twisted toghter

-to suppress noise the grounding of the usb cable has been connected to the metal case via a rc network

-sma connectors, antenna switcher and upconverter have been grounded directly

-the upconverter uses a separate power supply

-the LO uses a 125MHz frequency in order to avoid spurious reception on the commercial fm band

-the sdr board has been wrapped around adhesive aluminium foil for grounding purposes

Once the lid is closed and the SMA disconnected the unit behaves very well: even with the gain set up to the maximum the received spectrum is almost a flat, even zero. The upconverter and integrated amplifier behave well too, and with the right antenna, i could hear shortwaves very well (even the famous UVB-76) down to a few thousand kHz.