This is a multi-part message in MIME format.
------=_NextPart_000_006E_01C1878D.D44AE0A0
Content-Type: text/plain;
charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable
We run a simulation today... Tomorrow we will try to test real life with =
our
induction oven (25KW at 13.8MHz) power generator.
Simulation says that if the coil is 4 Inch in diameter it will start to =
ark
between threads at a level of 5.8KW combined, forward and reflected.
However there is a solution as the simulator suggests. Not to isolate =
the wire (i.e. use bare wire) and make the spring with a progressives =
thread.
This implies that some of the coil will short circuit some of the =
windings during compression not allowing build up of high RF potential =
between threads.
However this will actually decrease the inductance also, so we are back =
to square one. I guess that an interim solution is to keep the power =
handled by the coil under the isolation (air) break down potential or =
make it a VACUUM variable coil, much as the capacitors :) or, inspite =
the simulator, use a _heavy_ isolation wire. 0.5mm of Teflon isolate =
wire should keep sparking from occurring. This has an other draw back =
namely the maximum inductance now is limited to the closest spacing =
between the threads which is limited by the 2 times the thickness of the =
wire isolator.
It seems that there is a lot of work to be put into a simple spring :)
Alex
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
If we can accept the notion that GUNS are
the killers and not the people, why is it that
we can not accept the idea that CARS are
the speeders and not the drivers?
Alex, trying to understand the world around.
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D.
----- Original Message -----=20
From: JimMoci@aol.com=20
To: amps@contesting.com=20
Sent: Monday, December 17, 2001 6:06 PM
Subject: [AMPS] Another novel variable inductor
How about a large slug tuned inductor? I have an old RCA broadcast =
transmitter form the 50's that has one. It is a large inductor =
(4"diameter, 9" long) with what looks like a tin can in it that moves =
back and forth. I dont know what kind of range it has but it seems to =
work well. I really like the idea of compressing the coil like Alex =
mentioned but I guess there are power limitations when the turns get =
close.=20
Have fun and Happy Holidays!=20
Jim=20
------=_NextPart_000_006E_01C1878D.D44AE0A0
Content-Type: text/html;
charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META http-equiv=3DContent-Type content=3D"text/html; =
charset=3Diso-8859-1">
<META content=3D"MSHTML 5.50.4134.100" name=3DGENERATOR>
<STYLE></STYLE>
</HEAD>
<BODY bgColor=3D#ffffff>
<DIV><FONT face=3DArial>We run a simulation today... Tomorrow we will =
try to test=20
real life with our</FONT></DIV>
<DIV><FONT face=3DArial>induction oven (25KW at 13.8MHz) power=20
generator.</FONT></DIV>
<DIV><FONT face=3DArial></FONT> </DIV>
<DIV><FONT face=3DArial>Simulation says that if the coil is 4 Inch in =
diameter it=20
will start to ark</FONT></DIV>
<DIV><FONT face=3DArial>between threads at a level of 5.8KW combined, =
forward and=20
reflected.</FONT></DIV>
<DIV><FONT face=3DArial></FONT> </DIV>
<DIV><FONT face=3DArial>However there is a solution as the simulator =
suggests. Not=20
to isolate the wire (i.e. use bare wire) and make the spring with a =
progressives=20
thread.</FONT></DIV>
<DIV><FONT face=3DArial></FONT> </DIV>
<DIV><FONT face=3DArial>This implies that some of the coil will short =
circuit some=20
of the windings during compression </FONT><FONT face=3DArial>not =
allowing=20
build up of high RF potential between threads.</FONT></DIV>
<DIV><FONT face=3DArial>However </FONT><FONT face=3DArial>this will =
actually=20
decrease the inductance also, so we are back to square one. I guess that =
an=20
interim solution is to keep the power handled by the coil under the =
isolation=20
(air) break down potential or make it a VACUUM variable coil, much =
as the=20
capacitors :) or, inspite the simulator, use a _heavy_ isolation wire. =
0.5mm of=20
Teflon isolate wire should keep sparking from occurring. This has an =
other draw=20
back namely the maximum inductance now is limited to the closest spacing =
between=20
the threads which is limited by the 2 times the thickness of the wire=20
isolator.</FONT></DIV>
<DIV><FONT face=3DArial></FONT> </DIV>
<DIV><FONT face=3DArial>It seems that there is a lot of work to be =
put into a=20
simple spring :)</FONT></DIV>
<DIV><FONT face=3DArial></FONT> </DIV>
<DIV><FONT face=3DArial></FONT> </DIV>
<DIV><FONT face=3DArial>Alex</FONT></DIV>
<DIV><FONT face=3DArial></FONT> </DIV>
<DIV>=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D<BR>If we can accept the notion that =
GUNS are<BR>the killers and not the people, why is it that<BR>we can not =
accept=20
the idea that CARS are<BR>the speeders and not the drivers?</DIV>
<DIV> </DIV>
<DIV>Alex, trying to understand the world around.</DIV>
<DIV> </DIV>
<DIV>=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D.<BR></DIV>
<BLOCKQUOTE=20
style=3D"PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; =
BORDER-LEFT: #000000 2px solid; MARGIN-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 title=3DJimMoci@aol.com =
href=3D"mailto:JimMoci@aol.com";>JimMoci@aol.com</A>=20
</DIV>
<DIV style=3D"FONT: 10pt arial"><B>To:</B> <A =
title=3Damps@contesting.com=20
href=3D"mailto:amps@contesting.com";>amps@contesting.com</A> </DIV>
<DIV style=3D"FONT: 10pt arial"><B>Sent:</B> Monday, December 17, 2001 =
6:06=20
PM</DIV>
<DIV style=3D"FONT: 10pt arial"><B>Subject:</B> [AMPS] Another novel =
variable=20
inductor</DIV>
<DIV><BR></DIV><FONT face=3Darial,helvetica><FONT size=3D2>How about a =
large slug=20
tuned inductor? I have an old RCA broadcast transmitter form the 50's =
that has=20
one. It is a large inductor (4"diameter, 9" long) with what looks like =
a tin=20
can in it that moves back and forth. I dont know what kind of range it =
has but=20
it seems to work well. I really like the idea of compressing the coil =
like=20
Alex mentioned but I guess there are power limitations when the turns =
get=20
close. <BR>Have fun and Happy Holidays! <BR>Jim</FONT>=20
</FONT></BLOCKQUOTE></BODY></HTML>
------=_NextPart_000_006E_01C1878D.D44AE0A0--
--
FAQ on WWW: http://www.contesting.com/FAQ/amps
Submissions: amps@contesting.com
Administrative requests: amps-REQUEST@contesting.com
Problems: owner-amps@contesting.com
|