Re: Tube Type Tesla Coils

To: tesla-at-poodle.pupman-dot-com
Subject: Re: Tube Type Tesla Coils
From: Tesla List <tesla-at-stic-dot-net>
Date: Wed, 19 Mar 1997 19:01:40 -0600
Approved: tesla-at-stic-dot-net
Subject: 
        Re: Tube Type Tesla Coils
  Date: 
        Wed, 19 Mar 1997 16:15:01 +0000
  From: 
        "John H. Couture" <couturejh-at-worldnet.att-dot-net>
    To: 
        Tesla List <tesla-at-pupman-dot-com>


At 08:20 AM 3/15/97 +0000, you wrote:
>Subject: 
>        Re: Tube Type Tesla Coils
>  Date: 
>        Sat, 15 Mar 1997 00:28:28 -0500 (EST)
>  From: 
>        FutureT-at-aol-dot-com
>    To: 
>        tesla-at-pupman-dot-com
>
>
><<snip >>no transmission line with a Tesla coil. One way to make the
>test is
>to
>>set
>> up a robust oscillator and connect it to the TC secondary coil via a
>> calibrated transmission line and a bridge type VSWR meter. This test
>> would
>>not be static and would be at low voltage. 
>
>John,     I seem to remember hearing that the Corum's (or maybe their
>students), did this with a tube coil.  If I remember correctly, they
>were
>able to acheive a quite low, maybe 1.5 or so VSWR, and they said the
>coil did
>perform best at lowest VSWR.  I don't remember where I heard this story.
>
>>  The Corum's said they measured a TC at 1000 VSWR but did not say how
>> it was done.
>
>It was my impression that these high VSWR's were acheived using some
>form of
>actual cavity, but I have no "hard" info on the matter.  I don't really
>know.
>
>>. Dr. Gary Johnson of Kansas State University measured a TC at
>> 200
>> VSWR. He gave some details on this test at the 1992 Tesla Symposium in
>> Colorado Springs.
> 
>>  The advantage of knowing the VSWR of the TC is to determine if the TC
>> is
>> properly tuned for maximum output. The Q factor can also be found with
>> this
>> test. This Q factor should then be coordinated with the operating spark
>> gap duration.
>
>I thought that k factor would much outweigh Q factor regarding firing
>duration requirements.
> 
>>  Has any coiler researched this parameter? This test is also related to
>> the
>> Smith Chart but I have not found that very helpful. The Smith Chart was
>> designed for radio work.
> 
>>   John Couture
>  >>
>John Freau
>
------------------------------------------------------

  John F. -

  The 1.5 VSWR would have to be for a radio test by the Corum's. The
only
Tesla coil VSWR test I have read about by the Corum's was for a Tesla
coil
that they had built and tested and found  a VSWR of 1000.

  A VSWR graph for Tesla coils is shown in my Tesla Coil Notebook. This
is a
typical radio VSWR graph that has been extended to include Tesla coils
and
illustrates how radios differ from Tesla coils. Radio transmitters feed
antenna resistive loads and Tesla coils feed secondary terminal reactive
loads.

  Note that a high Tesla coil VSWR refers to the secondary terminal
charging
and not the spark length. For example, a high Tesla coil VSWR in the
vacuum
of space would indicate a highly charged secondary terminal and large
forces. The forces would indicate the ability to do work. There are no
sparks in space.

  In my Tesla Coil Construction Guide there are definitions for sparks,
arcs, streamers, etc.

  John Couture