From: "Clemens Paul" <cpaul@gmx.net>
To: <rsgb_lf_group@blacksheep.org>
References: <1456380282.20170524154713@gmail.com> <5925A16B.7050100@posteo.de> <4F1550D1E41F4437969FE559D083515C@Clemens0811> <1214966465.20170525122451@gmail.com>
In-Reply-To: <1214966465.20170525122451@gmail.com>
Date: Thu, 25 May 2017 14:04:44 +0200
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Subject: RE: LF: Iron dust toroids and heating
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Hello Chris,

>So  in simple terms, does this mean that it is to be expected that the
>G3YXM  LPF  will  NOT  work correctly on the W1VD amp? If so, again in
>simple terms please ;) , why?

Markus (DF6NM) has given an excellent expanation in his posting from 7/14/2007:

"...the PI-type combiner per se is not the problem. All I was trying to say is that you have to prevent it from short-circuiting the
harmonics directly at the output of a (voltage-mode) class-D PA. In that case, I would recommend a T-type low-pass filter between
each PA and combiner input, starting with a series inductor rather than a shunt capacitor. 
Note that the desired harmonic load impedance depends on the type of Class-D PA: Voltage-mode class D with rectangular voltage and
sinusoidal current should see a high impedance termination for harmonics, i.e. an inductor or series resonant circuit. On the other
hand, current-mode class D designs would have sinusoidal voltage and rectangular current, and require a low-impedance shunt for
harmonics..."

73
Clemens
DL4RAJ 


>-----Original Message-----
>From: owner-rsgb_lf_group@blacksheep.org 
>[mailto:owner-rsgb_lf_group@blacksheep.org] On Behalf Of Chris Wilson
>Sent: Thursday, May 25, 2017 1:25 PM
>To: Clemens Paul
>Subject: Re: LF: Iron dust toroids and heating
>
>Hello Clemens,