Re: secondary coils for tube coils (fwd)

---------- Forwarded message ----------
Date: Wed, 20 May 1998 11:24:47 EDT
From: FutureT <FutureT-at-aol-dot-com>
To: tesla-at-pupman-dot-com
Subject: Re: secondary coils for tube coils

In a message dated 98-05-19 16:27:43 EDT, you write:

> I would be very grateful if someone can explain to me why a convensional
> coil uses a height to diameter ratio of 3:1 upto 5:1 and most vacuum
> tube coils I have seen use very long thin secondaries. I have a 3.5" x
> 10" secondary powered by three 812AW triods. I get a 4" "brush"
> discharge. Will I get better perfprmance if I went  to a secondary say
> 2" diameter by 36" long.
> Regards
> Pete >>

Pete, all,

The thin secondary design does not offer any advantages,
and has the disadvantage of low Q.  Perhaps the early designers of
these coils paid too much attention to the turns ratio.

The only way to substantially increase the output spark length
is to increase the input power, assuming the coil is well tuned, etc.

Vacuum tube TC's have been relatively ignored over the years, due
to their power-hungrey nature and flamelike sparks.  I use methods
of pulsing my tube coils for better "efficiency", and a more interesting
spark appearance and sound, IMO.

John Freau