Re: More maggie Q & A

In a message dated 99-08-07 19:08:47 EDT, you write:

<< Next qustion.
> With regards to the primary/driver how close should the two coils be.
> I thought 2" or so.(This should give me room to add insulation around
> the driver)  
> Cheers Mike Tucknott  
 ** >>


this depends on the ratio of secondary to extra coil inductances;
if the ratio is high, a closer driver coupling can (and should) be used. 
also depends on the diameter of your driver, and the power level,
quenching, etc.  With a 11" dia secondary, and 1:4 ratio, I used 
about a 2 " spacing.  Closer spacings reduced the spark (or didn't
help), due to overcoupling.  It may be a good idea to arrange the 
secondary so it can be raised or lowered to adjust the coupling.
This is helpful also if you decide to compare various extra coils
with various L ratios.

The larger the topload, the smaller the L ratio can be, since the
voltage will be reduced at the top of the driver.  This permits the
distance between pri and sec to be increased (while still keeping
the same effective coupling), and may reduce corona.  Richard 
Hull's refers to this loading effect on one of his tapes.

John Freau