How hot is hot?

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m0roj
Posts: 1
Joined: Tue Apr 27, 2021 4:20 pm

How hot is hot?

Post by m0roj » Tue Apr 27, 2021 4:55 pm

My rtl-sdr v3 runs so hot that it cannot be held by hand; even during casual, short-term duties.
I am now wanting to run it in a continuous mode for satellite tracking work and I'm concerned about its stability, and even whether it will survive.
There are a number of mentions when searching "hot" or "very hot" but with no real reference to stability or shortened EOL.
There are also some glancing mentions of cooling, but nothing particularly constructive.
  • So, my question is "how hot is hot" and will it survive when its too hot to touch?
  • Or is it faulty?
  • Has anyone carried out tests along these lines?
  • Is there any recommended cooling method?
Many thanks in advance to responders.

Arkanic
Posts: 1
Joined: Wed Apr 28, 2021 12:53 am

Re: How hot is hot?

Post by Arkanic » Wed Apr 28, 2021 1:02 am

I don't know about RTL-SDRs in particular, but the maximum cap before cooling is required to prevent long-term degradation in most electronic devices is about 80 degrees Celsius. Of course depending on device design and environment, this can go up and down, but 80 is a good rule of thumb.

From the reviews on Aliexpress, I think hot temperatures are normal for the device

I've seen some people stick heatsinks onto the cases of theirs, but I have no clue if they are effective or not. I suppose if you really wanted to get it cool you could add heatsinks to the larger chips internally and cut a space for a small cooling fan and air holes in the case... It really is just up to you.

rtlsdrblog
Site Admin
Posts: 2913
Joined: Mon Nov 19, 2012 11:54 pm

Re: How hot is hot?

Post by rtlsdrblog » Thu Apr 29, 2021 11:23 am

The metal case is thermally interfaced with the PCB via a thermal pad, so the case acts as a heat sink. It can feel hot to the touch because of this, but that's normal. The R820T2 tuner is fairly power hungry for a tuner, but that just means it has good performance.

Unless you're keeping the dongle in a location with continuous direct sunlight, or a box without any airflow, there is no need to worry about cooling. I will note that if the ambient environment is very hot, L-band reception can begin to fail about around above ~1.5 GHz, but that's mostly fixed with the thermal pad, and rtlsdrblog driver branch on Github.

Kenn
Posts: 54
Joined: Fri Apr 08, 2016 8:43 pm

Re: How hot is hot?

Post by Kenn » Thu Apr 29, 2021 5:51 pm

My version 3 dongle runs about 95-98 degrees for most operations. Definitely not too hot to hold. It sits on a wire rack shelf with ample air flow all around it.

-K

lmantuano
Posts: 3
Joined: Thu Aug 14, 2014 11:02 pm

Re: How hot is hot?s

Post by lmantuano » Fri Apr 30, 2021 12:59 am

@Kenn,
Wow, 2 more degrees and you can boil water for a cuppa-tea! ;)
lm

Kenn
Posts: 54
Joined: Fri Apr 08, 2016 8:43 pm

Re: How hot is hot?

Post by Kenn » Fri Apr 30, 2021 2:28 am

lmantuano wrote:
Fri Apr 30, 2021 12:59 am
@Kenn,
Wow, 2 more degrees and you can boil water for a cuppa-tea! ;)
lm
Hah! Guess I forgot to specify Fahrenheit. Also that room temp was 75 degrees during the test.

:)

Mayo
Posts: 2
Joined: Thu Jun 17, 2021 1:53 am

Re: How hot is hot?

Post by Mayo » Thu Jun 17, 2021 2:15 am

I have my v3 running 24/7 as a county wide p25 dedicated streamer on a 1.4ghz clocked pi 3b+. It use to get very hot. To cool it I ended up using silicone based thermal paste and applied it to the inside circuit rail as well as the inside thermal pad since the thermal pad isn't to well placed. I then placed a 25mmx50mmx5mm heatsink on top with 2 25mm fans. It runs extremely cool now.
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alanzfq
Posts: 204
Joined: Thu Oct 04, 2018 11:18 am

Re: How hot is hot?

Post by alanzfq » Thu Jun 17, 2021 7:26 am

I hope you have now covered the joints in your fan power leads with hot-melt?
When I do something like that they quickly twist together and short:-)
Alan

Mayo
Posts: 2
Joined: Thu Jun 17, 2021 1:53 am

Re: How hot is hot?

Post by Mayo » Thu Jun 17, 2021 10:21 am

alanzfq wrote:
Thu Jun 17, 2021 7:26 am
I hope you have now covered the joints in your fan power leads with hot-melt?
When I do something like that they quickly twist together and short:-)
Alan
Been there done that throughout the years.. :)
They got the shrink tube treatment when it went back to the its permanent location.

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