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[AMPS] Q:Rf chokes

To: <amps@contesting.com>
Subject: [AMPS] Q:Rf chokes
From: johnf@futurenet.co.za (John Fielding)
Date: Thu, 29 Oct 1998 18:31:58 +0200
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It depends a lot on how the chokes are wound.  Ferrite chokes aren't much
different from conventional ones.  If the winding technique is poor the
performance will be also.  Saturation causes bad harmonics to be formed. 
Most ferrites have a "hard saturation" characteristic, giving a "snap-on &
snap-off" mode which causes terrible harmonic generation.  Some baluns
wound on ferrite have similar problems, the amp may be clean but the balun
screws things up!

John    ZS5JF


----------
> From: Jon Ogden <jono@enteract.com>
> To: Peter Chadwick <Peter_Chadwick@mitel.com>; 'amps'
<amps@contesting.com>
> Subject: Re: [AMPS] Q:Rf chokes
To: <amps@contesting.com>
> Date: Thursday, October 29, 1998 5:22 PM
> 
> 
> >I have seen some Kw + chokes using ferrite for HF. In that particular
case,
> >there was a lot of playing about to get around resonance problems, and
as
> >Carl said, using the right ferrite
> 
> I gotta believe that ferrites that will not saturate under KW of power 
> are either large or expensive or both.
> 
> 73,
> 
> Jon
> KE9NA
> 
> 
>
--------------------------------------------------------------------------
> Jon Ogden
> 
> jono@enteract.com
> www.qsl.net/ke9na
> 
> "A life lived in fear is a life half lived."
> 
> 
> --
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<html><head></head><BODY bgcolor=3D"#FFFFFF"><p><font size=3D2 =
color=3D"#000000" face=3D"Arial">It depends a lot on how the chokes are =
wound. &nbsp;Ferrite chokes aren't much different from conventional =
ones. &nbsp;If the winding technique is poor the performance will be =
also. &nbsp;Saturation causes bad harmonics to be formed. &nbsp;Most =
ferrites have a &quot;hard saturation&quot; characteristic, giving a =
&quot;snap-on &amp; snap-off&quot; mode which causes terrible harmonic =
generation. &nbsp;Some baluns wound on ferrite have similar problems, =
the amp may be clean but the balun screws things =
up!<br><br>John&#009;ZS5JF<br><br><br>----------<br>&gt; From: Jon Ogden =
&lt;<font color=3D"#0000FF"><u>jono@enteract.com</u><font =
color=3D"#000000">&gt;<br>&gt; To: Peter Chadwick &lt;<font =
color=3D"#0000FF"><u>Peter_Chadwick@mitel.com</u><font =
color=3D"#000000">&gt;; 'amps' &lt;<font =
color=3D"#0000FF"><u>amps@contesting.com</u><font =
color=3D"#000000">&gt;<br>&gt; Subject: Re: [AMPS] Q:Rf chokes<br>&gt; =
To: <amps@contesting.com>
Date: Thursday, October 29, 1998 5:22 PM<br>&gt; <br>&gt; <br>&gt; &gt;I =
have seen some Kw + chokes using ferrite for HF. In that particular =
case,<br>&gt; &gt;there was a lot of playing about to get around =
resonance problems, and as<br>&gt; &gt;Carl said, using the right =
ferrite<br>&gt; <br>&gt; I gotta believe that ferrites that will not =
saturate under KW of power <br>&gt; are either large or expensive or =
both.<br>&gt; <br>&gt; 73,<br>&gt; <br>&gt; Jon<br>&gt; KE9NA<br>&gt; =
<br>&gt; <br>&gt; =
-------------------------------------------------------------------------=
-<br>&gt; Jon Ogden<br>&gt; <br>&gt; <font =
color=3D"#0000FF"><u>jono@enteract.com</u><font =
color=3D"#000000"><br>&gt; www.qsl.net/ke9na<br>&gt; <br>&gt; &quot;A =
life lived in fear is a life half lived.&quot;<br>&gt; <br>&gt; <br>&gt; =
--<br>&gt; FAQ on WWW: =
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</font></font></font></font></font></font></font></font></font></font></f=
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>
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