Tuning Observations

From: 	Julian Green[SMTP:julian-at-kbss.bt.co.uk]
Sent: 	Tuesday, July 22, 1997 11:51 AM
To: 	tesla-at-pupman-dot-com
Subject: 	Tuning Observations

Has anyone noticed that the tune a coil is affected by spark length?

I noticed this effect when tuning my coil at very low power where adjustments
on the primary tap are extreemly sensetive.   (By low power I mean output 
spark of 2".)

Has the power of the coil is increased and output spark length increases to a
point where the coil goes out of tune and spark length does not increase as 
power increases.   Adding an extra turn of primary corrects the problem.

I also notice that this effect is greater with a small toroid.

The conclusion I have drawn from my observation is that as a streamer emits
from the toroid it is in effect adding to the conductive surface area of the
toroid and hence increases capacitance of the toroid.   Perhaps the ion cloud
also effects the capacitance of the toroid and hence tuning.

Therefore use a larger toroid so these effects are minimized.

Julian Green