[hpsdr] Mercury questions

[Håkan Andersson]

Hi!

I modified the LPU with LT1083 and two serial resistors 1.2 ohm 10w on a cooler.
That works great for me!

73 SM7GEP Hakan 

Skickat från min iPhone

> 7 jan. 2017 kl. 18:02 skrev George Byrkit <ghbyrkit at chartermi.net>:
> 
> ***** High Performance Software Defined Radio Discussion List *****
> 
> Jim,
> This wasn't in the BOM because it wasn't done by the manufacturing process.
> There are some who may have added a heatsink (like the small, stick-on RAM
> heatsinks, maybe), based on some old discussions on this list, to reduce the
> temperature at U5, which is the ADC chip.  I'd try asking the person from
> whom the board came initially.  Or it may be a Mercury EU?
> 
> There were similar discussions about changing the resistor values and such
> on the LPU so that it could put out more current than originally, and often
> had you replace the large resistors with 2 in series, standing up in the
> air, to improve the heat dissipation there.  It is a Linear power regulator,
> after all.
> 
> 73,
> George K9TRV
> 
> -----Original Message-----
> From: Hpsdr [mailto:hpsdr-bounces at lists.openhpsdr.org] On Behalf Of Jim
> Sanford
> Sent: Saturday, January 7, 2017 10:16 AM
> To: hpsdr at lists.openhpsdr.org
> Subject: [hpsdr] Mercury questions
> 
> ***** High Performance Software Defined Radio Discussion List *****
> 
> All:
> 
> I am helping a friend get an HPSDR going.  In comparing his Mercury 
> board with my two boards, I see that one of mine has a heatsink on U5.  
> My other board (purchased from TAPR years ago) and my friend's board do 
> not have a heatsink on U-5.
> 
> I do not see a reference to a heatsink in the BOM.  Thermal imaging 
> predictably shows higher temperatures on the devices without a 
> heatsink.  (161F versus 150F or so on the heatsink.)
> 
> This was obviously added to my one board somewhere along the way.  Does 
> anybody know when/why?
> 
> Specifically, should I be looking for heatsinks for the two boards?  If 
> so, does anybody have/remember part number and source?
> 
> Or is this "nice to have" but not necessary?
> 
> Thanks & 73,
> 
> Jim
> 
> wb4gcs at amsat.org
> 
> 
> 
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