The Realtek 2838 dongle I used to pick up 978 traffic ran warm from the start and finally died last week after a couple of months use. Disassembly didn’t reveal any heat damage and looks like the heat sink material was firm against the case and board. It was mated to a Pi 3B with stock power supply. The rig was kept indoors.
I’d like to get another one but am curious about how to extend its life if heat is an issue.
2832?
The cheap ‘generic’ dongles have no heatsinking to the point the chips heat spreader isn’t even soldered to the board. These last a surprisingly long time without appearing to fail from overheating.
That said, the RF frontend will run quieter the lower the temp, so cooling is certainly worthwhile.
A slow fan providing a gentle breeze will make a lot of difference.
Will look into a fan. Preference is for passive cooling since I have cats that occasionally “reconfigure” whatever I have in the network cabinet.
Is it practical to add a fan to your network cabinet?
I have some spare heatsinks from the two Pi3s that are now in a Flirc passive heatsink case. Also have some copper heat sinks which are larger and may not fit on the dongle board. Time to break out the dremel!
I wouldn’t remove the case to be honest.
Just attach the heatsinks to the casing.
Pre 1970 equivalent of RTL-SDR dongle.
No solid-state components/chips.
Instead used Vacuum Tubes (USA) / Valves (UK) which Generated a lot of heat.
Valves (Vacuum Tubes) used to burn out frequently (Like incandescent light bulbs) and needed frequent replacement
That’s a bit of a misconception - Valves are extremely reliable if you treat them correctly. The problem is that they are more likely to fail when being powered on, so power cycling them frequently leads to failures.The reconstructed Colossus computer has a specially designed power supply so that it brings the heater voltage up slowly in order to reduce thermal shock and extend the lifetime of its (very many) valves.
Saying an SDR is equivalent to an analogue valve radio is like saying a spaceship is equivalent to a pair of snow shoes.
My airspy mini is on a shelf in my unconditioned garage. Also there is a FlightFeeder.
Temperature at that shelf level is around 95F (35C), the airspy metalic case is hot to touch, measured at around 120F (49C). Those are measured with infrared/laser reader.
The FlightFeeder internal dongle died after a couple of years, so I got a replacement dongle from FA.
Also, the Pi3 power supply died, I have replaced the whole thing with an OrangePi One (it’s PS has a barrel connector, doesn’t fit to Pi3), and the CPU temperature is at 70C.
I’m using this 12 V fan on 5 V tapped from my RPi power supply, maybe something for you to improve longevity of your poor electronics? 
(good investment considering the Airspy isn’t cheap)
https://www.amazon.com/ARCTIC-F12-PWM-PWM-Signal-Configuration/dp/B002KTVFTE
My Airspies also get hot in my attic. I have heatsinks on them but the tape comes loose. I just received some heatsink adhesive so will look at changing to that.
I am tempted to disassembly mine to see if I can add a thermal pad or something inside, for better heat transfer. Those come in thickness of 1mm or 1.5mm…
I have also lots of CPU thermal goop, but that requires a clamping force.
Or should I look into a graphite thermal pad:
PS: I am glad that my finger is still “calibrated” from my young days of working with electronics. Back then I knew that hot to touch by finger, but still bearable, meant 50C 
Quick feel of unbearable burn meant over 70C.
The rtlsdr-blog dongle uses a several mm thick pad to transfer heat from the electronics to the case, their lna has the same.
I saw something similar in the base of a led light bulb I disassembled, filling out all available space. That is probably better at transferring heat than air?!
Definitely. Air is actually a good thermal isolation…
I found some at 3mm and even 5mm thick on Amazon: https://www.amazon.com/100x100x5-Heatsink-Conductive-Silicone-electronics/dp/B01A9SCLNG/
I have strapped my heatsinks (from discarded graphic cards) to the Airspy with zipties. Added som thermal compund before tightening the zipties with a plier. If room temperature exceeds 25C I also have a fan that can transfer the heat away.
The burned out dongle has heat transfer tape on the board’s bottom. Seems an odd place to put the stuff. Will cannibalize that tape for the next one I buy.
The underside of the two chip is mostly a large grounding/heat transfer pad. If this pad is soldered to the board, most of the heat generated in the chips is transferred into the PCB.
The result is that the underside of the PCB is the best place to transfer the heat out to somewhere else.
