[Elecraft] K3 power down problem

[Robert Mccormack]

Ian wrote:

Date: Tue, 10 Nov 2009 15:18:00 +0000
From: Ian Maude <ian at gb7mbc.net>
Subject: Re: [Elecraft] K3 power down problem
To: Elecraft List <elecraft at mailman.qth.net>
Message-ID:
    <d74929a00911100718y4a54b756lb4e9800851985f0 at mail.gmail.com>
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Yep as per my thread, I did it but still the same issue.  I cannot imagine
that was the issue though on #455 after all this time.

73 Ian

2009/11/10 Greg - AB7R <ab7r at cablespeed.com>

> This is the mod description from the website:
>
> This modification adds a diode to the KPA3 12V sense circuit to hold the
> voltage to no
> more than 0.6V when the K3 is turned off. Without it, some K3s refuse to
> turn off when
> the POWER button is tapped because the 12V sense circuit does not drop to a
> low enough
> level to shut down the K3???s MCU.
>
> The diode is a common leaded part. No work with SMDs is required. A minimum
> of
> disassembly is required and no boards need be removed to perform this
> modification.
>

You're not alone Ian - we have two K3s #320 and #321 in a Multi-Single or Multi-Two arrangement for CW contesting.   #321 developed the power down problem so I did the mod.
 
No effect at all.

#320 has never had the problem, even though they run off the same 12v power supply.

Not a show-stopper - I just disconnect #321 until contest time.<G>

73, Ken ZL1AIH (ZM1A in contests)