Re: Latest QCX-mini pcb rev.2 and C38 mod #manual #mods #pcbversion #qcxmini #c38


Hans Summers
 

Hi John

There is no need for the capacitor in Rev 2. No additional 10uF capacitor in Rev 2 (with the 78M05 regulator). I have not yet been able to update the manual.

The only changes to the Rev 2 PCB are the change of voltage regulator to 78M05; and moving some components in the immediate area to make space for it (as 78M05 is larger than AMS1117). 

73 Hans G0UPL
http://qrp-labs.com

On Fri, Feb 19, 2021 at 2:48 PM <john@...> wrote:
Hello all,
I've almost completed the build of a latest batch QCX-mini.
I've followed the assembly instructions v1.05 (latest rev?) to the point where I should add the additional capacitor C38, but realised the new pcb layout v2 has a new regulator chip, and fitting the additional electrolytic as detailed would now achieve nothing, because the regulator pinout has changed and the lead of the diode and adjacent regulator pin pad are actually the same node electrically.  I could find an alternative point to earth the capacitor, e.g. the heatsink tab of the regulator, but since the regulator is now different, is it still necessary to perform the modification?
Has anyone else got this far with the latest batch of rev.2 pcbs?
It's gone well so far, I haven't spotted any other changes on the rev.2 board until now.
John G3ZTU

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