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: Fri, 14 Mar 1997 09:06:43 -0600
Approved: tesla-at-stic-dot-net
Subject: 
        Re: Tube Type Tesla Coils
  Date: 
        Fri, 14 Mar 1997 07:38:32 +0000
  From: 
        "John H. Couture" <couturejh-at-worldnet.att-dot-net>
    To: 
        Tesla List <tesla-at-pupman-dot-com>


At 03:57 PM 3/12/97 +0000, you wrote:
>To: Tesla List <tesla-at-pupman-dot-com>
>From: richard hull <rhull-at-richmond.infi-dot-net>
>Subject: Re:Tube Type Tesla Coils


>       charset="us-ascii"
>
>snip
>>
>>In fact I would be interested in hearing from anyone who has tried to
>>measure the VSCR of a classical or tube type Tesla coil. As I said before I
>>did not have much success with these measurements. This surprised me because
>>Ham operators make these tests on radio transmitters all the time.
>>
>>John C.
>>
>>
>John,
>
>The hams can make the active VSWR measurements because they aren't tapped
>into a 10 foot arcing output coil.  They are also looking to hit unity VSWR
>and their output voltage is low.  We are at the opposite end (looking for
>infinite VSWR) and instrumentalities for these potentials are not common.  A
>static or low power VSWR measurement is like a static Q measurement...rather
>valueless.
>
>Richard Hull, TCBOR
>
>----------------------------------------

  Richard -

  One of the problems I ran into in trying to measure the VSWR of a
Tesla
coil was to decide where to connect the VSWR meter. Hams connect the
meter
in the transmission line between the transmitter and antenna. But there
is
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. 

  The Corum's said they measured a TC at 1000 VSWR but did not say how
it
was done. 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.

 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