Show off any of your RTL-SDR or cheap SDR related projects.
2 posts • Page 1 of 1
SDRs with Rafael 820T2 tuner chip are mostly supplied by the Chinese dongle assemblers with the exposed pad un-soldered at the center of the chip's QFN package. Whereas Rafael recommends the E-pad soldered to ground. It aids heat dissipation, as well as RF functioning. The chip consumes around 180mA at 3V; which is more than 500mW of heat. There had been concerns over this IC's overheating. Soldering the 4 vias beneath the IC's E-pad to get the vias soldered to the E-pad is a good idea, but needs some care. To further improve cooling, some unnecessary components, namely, the photodiode and the white LED were removed to make way for a junked laptop cooling fan which runs on 5V, 90mA. A trial connection to the USB 5V dc supply points is shown in the pictures. There is a makeshift pastel sheet dome. The cooling is considerable. At the present room temperature of 23 degrees Celsius, the tuner chip does not show any signs of heating when touched. (Also, a standard SMA connector replaces the usual snap on SMA originally fitted in the dongle.)
Last edited by anadish on Mon Mar 05, 2018 3:46 pm, edited 2 times in total.