[Elecraft] A fluke may have fried my KX3 and KXPA100 I need advice

[hawley, charles j jr]

Those exposed nuts are supposed to have plastic covers over them...

Chuck Hawley
 c-hawley at illinois.edu

 Amateur Radio, KE9UW
 aka Jack, BMW Motorcycles

________________________________
From: elecraft-bounces at mailman.qth.net <elecraft-bounces at mailman.qth.net> on behalf of Andy Durbin <a.durbin at msn.com>
Sent: Friday, May 22, 2020 8:24 AM
To: elecraft at mailman.qth.net <elecraft at mailman.qth.net>
Subject: Re: [Elecraft] A fluke may have fried my KX3 and KXPA100 I need advice

"The most likely contact scenario would seem to be that the shell of the USB connector made contact with a grounded nut on the power supply. "

I received an email that said Astron power supplies have exposed transistors that are not at ground potential.  That prompted me to investigate the Astron design.  Page 13 of this paper http://www.wb1gof.org/files/AstronPDF.pdf  shows the bottom of the case has an exposed stud/nut with 13.8 VDC.

It may be interesting to find out (by analysis) what the PSU does if this stud is grounded.  If the output voltage goes high it could explain the KXPA100 and KX3 failures.  Maybe someone already knows the answer.

Andy, k3wyc


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