Bart,
I agree with the above because you left out the stipulation that I included
that the coil in question must have an LTR cap, and be powered by an
NST. I agree that there are many things that we can't yet conclude
about coil operation, yet there are things that we can conclude at least
on a practical basis. For example if I'm speaking to a newbie coiler
who has no familiarity with coil behavior, he might wonder when he
can get a stronger spark using a 120 bps rotary or if he can get
an equally strong spark using a static gap. If he has an NST, LTR
system, I'd feel pretty confident telling him that he'd get longer sparks
by switching over to a 120 bps rotary gap system. In fact this has
happened many times on this list. I consider this to be practical
information that a newbie coiler can use and benefit from right now,
"before" spark gap physics is better understood. Certainly all static
gaps are not the same, but I'm suggesting that even the best ones
cannot outperform the rotary in the situation I describe. I consider
this to be a rule of thumb of coiling. I suppose it's possible that
there might be some rare "outlier" type situation where what I'm
saying might not be true, but most newbies probably want to know
what works in nearly all cases. Much would be depend on the type
of newbie. If a particular newbie wishes to begin their coiling
experience by learning the most intricate details of arc-dynamics,
and the physics of coiling, then they might approach things in a
certain way. Others want practical information about coiling.
Many of the newbie questions that I see on this list are of that
type. And that is the type of question which I was responding to
with my comments. If I can offer rules of thumb which tend to
work well, that's something that can benefit a newbie.
I can understand your cautious view of not
wanting to jump to any conclusions about the behavior of coils
before things are fully understood. I also think it's important to
address what type of behavior a newbie might see in a particular
design of coil. For this purpose I divide coils in the various
"styles". For example there's the NST, LTR coil which has
certain characteristics, then there's the NST, STR coil which
has other characteristics. Then there's the ballasted pig coil
which has still different characteristics. If the newbie can get
a grip on the expected behaviors of these various types of coils,
then he's ahead of the game at least as a starting point. As he
progresses in his coiling over time, he may or may not decide to
study the underlying physics, or subtleties of coil and gap
behavior, etc. The ideas I'm offering offer a starting point for
understanding for the newbie as he's approaching coil design
questions.