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Arne,
I know of several people that have used TEFLON for filament chokes =
and have not suffered any problems from them. Here is a simple test: =
Take whatever material you think may be suitable and place it in a =
microwave oven, (with a bowl of water), for about 1 minute. Pull it out =
(be careful! It may be hot!!). If it is warm or hot to the touch, or if =
it was rigid before going into the oven and it is now soft and pliable, =
chances are it will not be very good material to use.=20
Just keep in mind that there are exceptions to the rule but this =
will at least give you some degree of confidence.
Good luck,
Mike(y)
W3SLK
----- Original Message -----=20
From: Arne Gjerning=20
To: Amp Ref=20
Sent: Saturday, January 15, 2000 1:13 AM
Subject: [AMPS] RF Choke Forms
I have been advised NOT to use Teflon, Delryn, and a few other =
insulating materials for an RF choke. Instead only use ceramic. It was =
then stated the "D" factor was the reason.=20
OK, but why as I could not find info on this subject in the ARRL =
Handbook. Any help to point me in the direction of knowledge on this =
subject would be appreciated. May as well learn something while =
building my amp. And I want to do it RIGHT.=20
73 de Arne N7KA =20
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<DIV><FONT size=3D3>Arne,</FONT></DIV>
<DIV> I know of several people that have=20
<STRONG><EM>used</EM></STRONG> TEFLON for filament chokes and have not =
suffered=20
any problems from them. Here is a simple test: Take whatever material =
you think=20
may be suitable and place it in a microwave oven, (with a bowl of =
water),=20
for about 1 minute. Pull it out (be careful! It may be hot!!). If =
it is=20
warm or hot to the touch, or if it was rigid before going into the oven =
and it=20
is now soft and pliable, chances are it will not be very good material =
to use.=20
</DIV>
<DIV> Just keep in mind that there are exceptions to =
the rule=20
but this will at least give you some degree of confidence.</DIV>
<DIV>Good luck,</DIV>
<DIV>Mike(y)<BR>W3SLK</DIV>
<BLOCKQUOTE=20
style=3D"BORDER-LEFT: #000000 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: =
0px; PADDING-LEFT: 5px; PADDING-RIGHT: 0px">
<DIV style=3D"FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV=20
style=3D"BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: =
black"><B>From:</B>=20
<A href=3D"mailto:gjerning@flash.net"; title=3Dgjerning@flash.net>Arne =
Gjerning</A>=20
</DIV>
<DIV style=3D"FONT: 10pt arial"><B>To:</B> <A =
href=3D"mailto:amps@contesting.com"=20
title=3Damps@contesting.com>Amp Ref</A> </DIV>
<DIV style=3D"FONT: 10pt arial"><B>Sent:</B> Saturday, January 15, =
2000 1:13=20
AM</DIV>
<DIV style=3D"FONT: 10pt arial"><B>Subject:</B> [AMPS] RF Choke =
Forms</DIV>
<DIV><BR></DIV><FONT face=3DArial,Helvetica><FONT size=3D-1>I have =
been advised=20
NOT to use Teflon, Delryn, and a few other insulating materials for an =
RF=20
choke. Instead only use ceramic. It was then stated the "D" factor was =
the=20
reason.</FONT></FONT><FONT face=3DArial,Helvetica><FONT =
size=3D-1></FONT></FONT>=20
<P><FONT face=3DArial,Helvetica><FONT size=3D-1>OK, but why as I could =
not find=20
info on this subject in the ARRL Handbook. Any help to point me in the =
direction of knowledge on this subject would be appreciated. May =
as well=20
learn something while building my amp. And I want to do it=20
RIGHT.</FONT></FONT><FONT face=3DArial,Helvetica><FONT =
size=3D-1></FONT></FONT>=20
<P><FONT face=3DArial,Helvetica><FONT size=3D-1>73 de Arne=20
N7KA </FONT></FONT>=20
</P></BLOCKQUOTE></BODY></HTML>
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