Over on the 3D printing sharing site Thingiverse, user “Way” has uploaded a 3D printer design for an RTL-SDR cooler block. The block works by allowing a PC cooling fan to blow air efficiently over the dongle body, removing any heat generated.
Cooling a dongle helps to avoid the L-Band problem, which is when R820T/2 units get hot and stop working about ~1.3-1.5 GHz. Generally passive cooling is enough (like with the thermal pad and metal cases used on our V3 dongles), but further cooling can apparently help increase sensitivity slightly although we are unsure if there is any statistically significant difference.
“Way” has made two designs, one to fit a 40 x 40 mm fan, and another to fit a 50 x 50 mm fan. The fan simply screws to the top of the block, and the dongle is placed at the bottom. Air is ducted over the dongle body and escapes out the back.