For accurate frequency tuning even amongst large temperature in an SDR, a Temperature Compensated Crystal Oscillator (TCXO) should be used as the main oscillator.
Standard RTL-SDR dongles used a frequency of 28.8 MHz and do not come with a TCXO, but for some time now we have been selling our own branded dongles that come with a TCXO built in (out of stock at the moment sorry – back in the first half of April!).
If you have an older or other dongle that does not have a TCXO it can be an interesting exercise to hack one in yourself.
The biggest problem though, is that 28.8MHz TCXO oscillators are not commonly found for sale in low quantities.
La suite est à lire Building a 28.8 MHz TCXO for the RTL-SDR de : RTL SDR