From: Chris Wilson <dead.fets@gmail.com>
Date: Tue, 6 Jun 2017 16:39:52 +0100
Message-ID: <953388818.20170606163952@gmail.com>
To: rsgb_lf_group@blacksheep.org
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Subject: LF: Decoupling linear PSU
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Status: RO

Hello LF'ers,

 I have had a few issues with my lovely old Farnell H60/50 linear
 bench power supply. It'll do 60V @ 50A but I suspect it's last couple
 of uncontrolled output voltage failures may have been caused by RF
 getting into it, maybe up the output leads, maybe elsewhere. The
 manual makes mention of using caps of "a suitable value" across the
 output, or each output pin to ground, when used to power "transient
 loads" ; it's far from clear what's meant. The -ve floats relative to
 chassis ground. What do people recommend as a means of stopping RF
 getting in via the + and - output leads please?

 It has SCR control on the transformers primary to keep the voltage
 drop across the huge pass transistor tunnel down to around 8V, this
 seems to go haywire at random times when powering my TX, and the
 2N3055's don't like 103V into them. Worst case scenario should be
 73V, but I am pretty sure SCR control fails and the secondary rises
 to its full potential. Thanks.

-- 
Best regards,
 Chris                          mailto:dead_fets@gmail.com