John Mills recently wrote in to us at RTL-SDR.com to show us how he cools his RTL-SDR by using a thermal gap pad stuck to the entire bottom of the RTL-SDR PCB. A thermal gap pad is a soft pliable material that is often used to interface between electronic chips and heatsinks. The gap pad forms into tight hard to reach spaces and conducts heat towards the heatsink. It is not electrically conductive, so the entire bottom of the RTL-SDR can be stuck to the thermal gap pad, which is then stuck to a metal heat sink.
John uses a thermal gap pad made by Bergquist, with part number GP5000S35-0.100-02. This gap pad is 0.1 inches thick, is easily cut with a craft knife and is tacky so it easily sticks to the heatsink and RTL-SDR PCB. It has a thermal conductivity of 5W/m.k. John uses the pad to help to cool the R820T, RTL2832U and voltage regulator chips. It has been shown in some previous posts that by cooling the R820T chip increased sensitivity can be obtained, especially at frequencies above 1.2 GHz.
He writes that if there is sufficient interest then he may consider selling strips of it on eBay. You can contact him at sdr_AT_milairuk.co.uk.
Below we’ve posted images of Johns thermal pad cooled RTL-SDR’s, along with his comments on them in the captions.