From:  L.Robertson [SMTP:LWRobertson-at-email.msn-dot-com]
Sent:  Friday, April 03, 1998 12:29 AM
To:  Tesla Builders
Subject:  Inductance

For you folks contemplating length to radius,
and Q to length to radius there are an interesting
set of curves in American Journal of Physics,
Vol. 65, No. 8, Aug. 1997 on page 749 in the
middle of an article on building a Tesla coil.

It has length/radius on one axis, Q on the other,
and four curves representing different wire
size. For very small wire (0.4 mm) there is almost
no difference in Q. As wire size increases ( to a
maximum of 1.6 mm in the graph) Q maximizes
strongly at a L/R just over 2. 

Malcolm's contention that Q is maximum at L/R
of exactly 2 is probably true for very thick wire,
at least according to this.

Two more cents.