Pancake coils

To: tesla-at-pupman-dot-com
Subject: Pancake coils
From: peterB <zardoz-at-albany-dot-net> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)
Date: Mon, 07 Feb 2000 02:54:01 -0700
Approved: twftesla-at-uswest-dot-net
Delivered-To: fixup-tesla-at-pupman-dot-com-at-fixme

Hello,
This is my first post to this list.

I am planning to build a 'kicking coil' outfit based on plans in Stanley
Curtis's book
'Experimental High Frequency Apparatus..'.

I have read through many of the archived posts looking for answers to a
few questions
and have only found a partial answer for one question, (for a different
application,
however)

My first question concerns the winding of the secondary, which is 150
layers of 30 awg dcc
wire, each layer separated by 'oiled paper' .003" thick.
I am looking for a suitable substitute for 'oiled paper'. I am not sure
of heat buildup
inside the primary, so this may be an issue.
I have considered parafining regular paper for this, but this job may be
a bit much,
especially if there is an 'off the shelf' item available.
I was also considering 'empire cloth' (not available anymore) but I
believe it is simply
varnished cloth. If this is what it is, this may be a feasible option.

Question 2: I have about 10lbs of 26awg dcc wire (old) and for that
reason many of the coils
(including the above mentioned pancake that calls for 30awg) will be
using this.
I have seen some formulas for wire use, # of turns etc, but none that
would allow me
to plug in 26awg and spit out coil length, # of turns etc. Is there a
method of determining
secondary construction when I am limited to a certain awg?

Also, relating to the above two questions, certain dimensions for the
pancake are based on the
30awg wire. ex.-spacing of the turns, number of turns per inch etc.
I am wondering if I can use simple algebra to scale up all the
dimensions using 26 instead
of 30awg. for ex: using 30awg, the width of the layers shows as 1" turns
spaced 1/8"
apart(First 50 layers). so- 30/1=26/x, solve for x to get the new width.
Will this be ok to scale all
dimensions?

Q4: The plan calls for a 'hard rubber' cylinder drilled lengthwise
through the center to accept
a brass rod, the top of which suports the discharge ball. Any sources
for 'hard rubber' rods
(about 1 1/4" diameter) or substitutes?

Last question: The capacitor is 20 units of 10 plates each equiling
.1mfd. (I do not know what
the voltage should be, this coil uses ac that powers a kicking coil)
What would be a modern
equivelant?

Thanks for all your help.

-Peter B.