Re: Parallel and Series LCR Circuit Qs

[FutureT-at-aol-dot-com (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

In a message dated 8/20/00 9:44:53 AM Pacific Daylight Time, tesla-at-pupman-dot-com 
writes:

> Original poster: "Richard Kircher" <richard.kircher-at-worldnet.att-dot-net> 
>  
>  Hi All,
>   It sure sounds like a lot of things are important in TC design.  Maybe the
>  prime question is "what's most important". 

Dick, all,

I have been intriqued for many years by the question of what is most
important in TC design.  Some of the things that seem to be most
important from my work are:  Low bps operation (around 120 bps),
large toroid relative to the secondary, many turns in the secondary,
which will permit many turns to be used in the primary for a high
surge impedance, (1000 to 1500 turns depending (?) on the width 
of the secondary), and of course low losses in the transformer, etc. 
Using these methods, I was able to obtain 42" sparks using 570
watts, but using any other design method, I got shorter sparks.

> and match the reactive component.  

I think the reactive component is readily "cancelled" out during the
tuning process, of course it's a compromise adjustment because
streamer Xc changes during operation.

> it would seem that the streamer de-tunes the coil and
>  lowers the secondary resonate frequency.  So, I guess the primary should be
>  tuned lower in frequency than the secondary to start with (?).  I wonder
>  how much lower?  Maybe the answer is to just tune the coil by trial and
>  error until the maximum streamer length is reached and forget about the
>  grid dip meter.  

I think there's no doubt that the best way to tune the coil is by trial
and error until max streamer length is reached, or until the desired
streamer appearance is obtained.  Tuning inward will tend to create
a greater number of shorter streamers in many cases.

Cheers,
John Freau

Any ideas about this (or any ramblings) would be welcome.
>  
>  Dick (K2YZ)
>