From: Chris Wilson <dead.fets@gmail.com>
Date: Sat, 10 Jun 2017 14:22:58 +0100
Message-ID: <251639453.20170610142258@gmail.com>
To: DK7FC <rsgb_lf_group@blacksheep.org>
In-Reply-To: <59385FE1.50405@posteo.de>
References: <953388818.20170606163952@gmail.com> <CAFDVXLkiP+bL2eV4uRog4UG6cwVzqvmnfqXmFr1bQsqETqi=oA@mail.gmail.com> <59385FE1.50405@posteo.de>
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Subject: Re: LF: Decoupling linear PSU
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Hello Stefan,

Thanks  for  the  reply, with regard to the current transformer, where
does  the  1  Ohm  resistot  go??  In your drawing of the chokes can I
assume  the  six  turns each you drew is accurate and you intend me to
wind six turns on each core? Thanks!

Wednesday, June 7, 2017, 9:19:45 PM, you wrote:

> Hi Chris,

> Yes, maybe try a homemade filter. I would try something like in the 
> attachment...

> Build yourselfe a current transformer and measure RF common mode 
> currents in the supply line of the power supply. This can be done with a
> clamp ferrite which has a secondary winding and a 1 Ohm resistor. You 
> can then measure the current with the scope, of course it is decoupled
> then. The common mode chokes may already help to lower such currents. 
> Maybe even simple clamp ferrites on the supply cable can help if these
> is no other ground connection.

> Of course the ripple voltage of the DC voltage should be as small as 
> possible. A few 1000 uF near the load may help too...

> 73, Stefan


> Am 07.06.2017 21:12, schrieb Lawrence Galea:
>> Hi Chris,
>> Did you Try capacitors across the supply lines right at the output
>> connectors and also from both + and - to earth?
>> Did you try the same at the mains input with suitable voltage rating?
>> Regards
>> Lawrence


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