I am considering using a full-passive radiator. Is the heat release measured? Thank you
No, there is no measurement of this.
Nevertheless, you have created a case with ribs of a certain size for better heat dissipation.
Can I consider total heat release = 5 x (RTL-SDR Heat release equivalent)? Or am I missing something?
The cooling fins were introduced by @krakenrf_carl, based on various research papers he had come across, as well as practical testing. I’m sure he can provide more context regarding this.
Kraken is dissipating 5v * ~2.2A = ~11W. So design your fins accordingly. There are some calculators online, but I can’t remember which ones I looked at before.
You actually don’t need a fan on the enclosure to have the Kraken electronics work fine. It’s just that the enclosure gets too hot to the touch, which is bad for humans handling it. The airflow from the fan cools it down enough to be touchable.
What’s most important is the consideration of thermal mass. You’ll need some decent thermal mass (aka a chunk of metal without fins) to keep the temperature stable across tuners. If you have very little thermal mass the temperature between tuners can oscillate, resulting in the phase drifting.