Message-ID: <50CD1F7A.3040304@iup.uni-heidelberg.de>
Date: Sun, 16 Dec 2012 02:10:18 +0100
From: =?ISO-8859-1?Q?Stefan_Sch=E4fer?= <Stefan.Schaefer@iup.uni-heidelberg.de>
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References: <CAMFjj723AN8YQa1yKot=6QTTBkaXH_0e-8u3O+O-u_=t1BU2dw@mail.gmail.com> <A5AC7825ED8A4E66BAA0582EB736B87D@GaryAsus> <001f01cddb10$64a50b30$0501a8c0@xphd97xgq27nyf>
In-Reply-To: <001f01cddb10$64a50b30$0501a8c0@xphd97xgq27nyf>
Subject: Re: LF: Re: Re: M0BMU mods to the G0MRF PA
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Mal,

Am 15.12.2012 23:06, schrieb mal hamilton:
> Gary
> I see you only wind on half the ferrite core whereas I spread the 
> turns symetrically around the whole circumference.
> In my case I need 8 turns on Prim es 24 on Sec.
> I first wind the 24 turns around the circumference evenly then the 8 
> tunrns on top also evenly. This works for me.
> I wonder if there is any real difference in efficiency

Yes, using the whole circumference is better, especially when the core 
is driven close to saturation. Also the AL value from the datasheet for 
a certain core assumes a homogen spread of the turns.


Warren,

Yes, of course you can make taps on the secondary side. I'm doing this 
in my MF matchbox, using a 6 pole switch. This allows to rise the power 
in 3 dB steps...

73, Stefan/DK7FC



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Mal, <br>
<br>
Am 15.12.2012 23:06, schrieb mal hamilton:
<blockquote cite="mid:001f01cddb10$64a50b30$0501a8c0@xphd97xgq27nyf"
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  <div><font face="Arial">Gary</font></div>
  <div><font face="Arial">I see you only wind on half the ferrite core
whereas I spread the turns symetrically around the whole circumference.</font></div>
  <div><font face="Arial">In my case I need 8 turns on Prim es 24 on
Sec. </font></div>
  <div><font face="Arial">I first wind the 24 turns around the
circumference&nbsp;evenly then the 8 tunrns on top also evenly. This works
for me.</font></div>
  <div><font face="Arial">I wonder if there is any real difference in
efficiency</font></div>
</blockquote>
<br>
Yes, using the whole circumference is better, especially when the core
is driven close to saturation. Also the AL value from the datasheet for
a certain core assumes a homogen spread of the turns.<br>
<br>
<br>
Warren, <br>
<br>
Yes, of course you can make taps on the secondary side. I'm doing this
in my MF matchbox, using a 6 pole switch. This allows to rise the power
in 3 dB steps...<br>
<br>
73, Stefan/DK7FC<br>
<br>
<br>
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