3 Sep
2025
3 Sep
'25
10:25 a.m.
On Wed, Sep 03, 2025 at 05:18:44PM +0100, Rob Jarratt wrote:
One test I do is put the probe and ground clip both on ground. If you still
get a good amount of noise you know its not real. Works best when ground and
where you are probing are close together so you aren't moving probe much to
do the test.
-----Original Message-----
From: Jon Elson via cctalk <cctalk(a)classiccmp.org>
Sent: 03 September 2025 15:39
To: cctalk(a)classiccmp.org
Cc: Jon Elson <elson(a)pico-systems.com>
Subject: [cctalk] Re: Repairing an Olivetti M24 PSU
Those are not real. They are conducted
interference from the switching
supply getting into the scope preamp via the ground lead.
I have seen this MANY times, ignore it.
Jon
Thanks Jon, obviously I don't have enough experience to know this. How can I
recognise this in the future?