Jumping in with both feet?

From:  Julian Green [SMTP:julian-at-kbss.bt.co.uk]
Sent:  Wednesday, January 28, 1998 8:24 AM
To:  tesla-at-pupman-dot-com
Subject:  Re: Jumping in with both feet?

> The secondary is wound with about #22 wire around a
> cylinder of 1/2" wide varnished wooden strips spaced about 1/2" apart.  It
> consists of two sections in series, each 2' long, about 3 inches between the
> two sections, for an overall winding length of 4'.  It is 16" in diameter
> with about 13 turns per inch.    

Moisture can be a problem with wood, if you get a spark that scorches the
wood then it will char the wood leaving a highly conductive path of carbon.
A devil of a job to get rid of as the carbon track can go very deep.

> Any opinions as to the capabilities of this rig?  Would it be meaningful to
> temporarily short the spark gap and attempt to grid-dip the primary tank and
> see where it resonates?   

Yes this is often done, but I've never done it.   I prefer to run the coil on 
very low power, with a very small spark gap.   I test my coil with only 5volts
input to the neon transformer.  I use a flourescent tube held near the output
terminal which glows brighter when the coil is in tune.

Does the secondary self-resonate with distributed
> capacitance?  

Yes, but you get better sparks if you have a big top load.  The bigger the better

> To what spacing should I set the gap when I start testing?

As small as you can make it, and work up from there.

Julian Green