[hpsdr] Fully enclosed Hermes cooling?

[John Marvin]

I have the TAPR version of Hermes and have put it into a fully enclosed 
cabinet, so I've been a little concerned about heat also. I decided to 
put the recommended heatsink on the bottom of the board below the 5V 
regulator, but I have my doubts about how helpful that is. It seems it 
would be better (if such a part existed) to put a miniature heatsink 
directly on the regulator. The A/D converter works equally as hard for 1 
receiver as it would for multiple receivers, so I don't see a reason to 
put a heat sink on that.

I've run the 4 receiver version of the firmware with all four receivers 
going for almost 90 hours straight without any issues, although the 
cabinet did get fairly warm (but I wouldn't call it hot).  I've also 
tried a 7 receiver experimental version of the firmware, but the longest 
I've gotten that to work is about 12 hours. That may be due to the 
higher heat, but I think it is more likely due to the common code it 
probably shared with the 1.8 (or earlier) version of the firmware that 
contained the "hang" bug (that has since been fixed). I haven't had a 
chance to try the new 2.1 firmware with all 5 receivers running for an 
extended period.

I don't know if the extra heat will have any significant long term 
effect or cause premature failure, but usually the kind of heat required 
to cause damage in the medium to long term causes flakey behavior in the 
short term.

Looking forward to testing the 13 receiver version of the firmware :). 
Probably not going to happen, but I can always dream!

John
AC0ZG


On 1/3/2013 9:34 AM, John wrote:
> ***** High Performance Software Defined Radio Discussion List *****
>
> My worries are probably unfounded since the ANAN-10 uses Hermes *and* a
> PA in a small box, but I am still worried that I might damage my Hermes.
>
> I mounted my Hermes in an older CDROM drive case by making aluminium end
> plates and carving up the plastic internal support of the original CDROM
> drive. With the top cover off I can feel a noticeable amount of heat
> with my hand about even with the top of the case. There must be about 8
> Watts of heat in that box... [(13.6 V * 0.6 A) - 500mW]
>
> Will I hurt the reliability of my Hermes by completely enclosing the
> CDROM drive case? Should I add cooling holes or a fan? My Hermes is a
> TAPR unit and I don't know if the components are rated the same as the
> ANAN-10.
>
> John, WoGN
>
>
>
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