====== RTL-SDR TCXO mod ======

  * Buy [[http://www.ebay.com/itm/400943404059|TCXO 28.8MHz 28.800M Ultra precision Crystal Oscillators DIP 0.5ppm]]
  * Desolder RTL-SDR xtal

<code>
 /-----------\
 | 1       3 |
 | 2       4 |
 +-----------/
(top view)
</code>

  * Solder:
    * 1 ... +3.3V (can be found e.g. on the IR receiver)
    * 2 ... not connected
    * For rtl-sdr that used the small rectangular oscillator:
      * 3 ... R820T pin 8 (the second in the second row)
    * For rtl-sdr that used the 2-pin THT xtal
      * 3 ... the other pin than pin 8 that was connected to the xtal
    * 4 ... GND
  * Enjoy your 0.5ppm experience!

  * When used in constant temperature, the original oscillator and TCXO provide comparable performance (+/- 0.1 ppm over several hours).
  * However, increasing the temperature from 28 to 48 °C means 0.14 ppm drift of the TCXO, but 3 ppm drift of the original oscillator.