History.The information on this page was moved from the SM5BSZ home page in November 2012. The number of tested hardware is growing and this section deserves its own URL now.
Digital hardware may not behave like oldfashioned analog receivers. Conventional measurements of the intermodulation-free dynamic range, the intercept point, the point of 1 dB compression and other figures of merit may be grossly misleading. This link practical performance observations for the SDR-14 shows that contrary to a conventional receiver that should be operated with low signal levels, a VHF-sampling receiver should be operated at high signal levels.
In 2007 the Perseus appeared. This unit has excellent dynamic range and behaves nearly like an analog receiver although performance figures are much better as compared to normal receivers like IC-7800, Orion and others. Linrad-02.45 and later support the Perseus hardware. Click here Perseus with Linrad for more information on this excellent receiver.
There is now a rapidly increasing number of very good digital receivers. Linrad supports some of them natively. Hardwares for which ExtIO libraries exist can be used with those libraries in Linrad.
There is an internal signal generator in Linrad that can be used to test Linrad itself and to generate test files to test other SDR software. This link Bits and Dynamic Range shows the effects of truncation on the noise floor.
There are lower cost hardware in the form of USB dongles. The FUNcube Dongle can be used with the EXtIO_FCD_G0MJW.dll file with Linrad under Windows. The FUNcube dynamic range suffers from a low noise amplifier that is added in front of the E4000 chip.
In 2012 the rtl-sdr appeared. A low cost USB dongle that can be used as a general purpose SDR for VHF and microwaves. These units can be obtained for USD 20 or less. They can be used with an ExtIO dll under Windows. Under Linux performance is much better with a modified software for the dongle (linrad-03.40 and later, July 2012. Hopefully the ExtIO dll will improve soon.) RTL-SDR with Linrad
Links to tests of different hardware.SDR-14 The significance of digital feedback in direct sampling.
SDR-14 Two-tone test.
Perseus Tests for IM2 and IM3.
FUNcube Dynamic range testing.
RTL-SDR Dynamic range testing.
SDR-14, Perseus, SDR-IP, Excalibur and WSE Direct comparison of different SDR hardware.
Softrock Ensemble Many soundcards tested with two Softrock Ensemble units. One of them modified for better dynamic range.
Softrock Dynamic range testing.
Soundcards Dynamic range.
ELAD Dynamic range with two-tone test.
IQ+ Dynamic range with two-tone test.
bladeRF Dynamic range, sensitivity and stability on 432 MHz.
bladeRF Dynamic range and sensitivity on HF using the direct input.
Mirics MSi001 This tuner is used in Funcube PRO+, Logitec and Mirics USB sticks. This link has several sub-pages discussing frequency stability, sensitivity and dynamic range.