E4000 & R820T Tuner Comparison.pdf

The author, HB9AJG, conducted tests on two DVB-T dongles, one with an E4000 tuner and the other with an R820T tuner, to measure their performance in terms of image rejection, internal signals, sensitivity, overload, 1dB compression, and intermodulation. The tests were carried out using HF signal generators and an AF voltmeter, with the software SDR# v1.0.0.135. The results show that the E4000 has a poor image rejection of 21dB without correction, but this can be improved to 50dB with correction. The R820T has better image rejection and is less prone to internal signals. The sensitivity of both dongles is high, with the E4000 being about 5dB more sensitive than the R820T between 50 and 500MHz, but the R820T is more sensitive at 1000MHz. The overload limit of both dongles is similar, with the E4000 being slightly better, and turning on RTL AGC or Tuner AGC can degrade the overload limit. The 1dB compression point is not explicitly stated, but the tests show that the preamplifier will saturate at some point, reducing the S/N ratio of a desired signal. Overall, the R820T seems to perform better than the E4000, especially in terms of image rejection and sensitivity at higher frequencies.