The tuning range depends on the hardware. See the first table at http://sdr.osmocom.org/trac/wiki/rtl-sdr http://sdr.osmocom.org/trac/wiki/rtl-sdr for details.

The tuning range depends on the hardware. See the first table at http://sdr.osmocom.org/trac/wiki/rtl-sdr http://sdr.osmocom.org/trac/wiki/rtl-sdr for details. All have 2.8MHz bandwidth. A (relatively) simple hardware mod lets you bypass the tuner and pick up 0Hz to 28MHz. Noise and sensitivity vary. I know at least one person ran a bunch of tests with a spectrum analyzer. (Can't find that link though.) Performance generally seems to be limited by the poor shielding/filtering and the low quality timing crystal. If you fix the worst flaws, they are rather capable. For example, they've been used for GPS and radio astronomy. Biggest differences with a more traditional setup is the lack of a transmitter and the questionable build quality.