Re: Why the primary is a flat spiral?

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>" <FutureT-at-aol-dot-com>

In a message dated 4/9/02 10:17:22 AM Eastern Daylight Time, tesla-at-pupman-dot-com
writes:


>
> the primary is in its flat form to
> 1.   keep coupling to a minimum value



Scot, all,

The coupling can be kept just as low by using a wide diameter
cylinder primary.  Instead I would say that using a flat primary,
the coupling usually just "happens" to work out closer to a
correct value, without using a computer program to pre-calc
the k value.  With a cylinder pri,  the secondary may need to
be raised a lot, which may not give as nice an appearance.
I suspect that much of the appeal of flat primaries is in
the appearance too.

>
> 2.   to reduce the height to minimize strikes to it



In some sense, the wider diameter of a flat primary makes
strikes more likely rather than less likely.  Although I agree
in a way.

>
> 3.   to make adjustments a bit easier when tuning



cylinder primaries are easy to tap and tune.

>
> 4.   and its a bit easier to mount a primary in this configuration...



I agree.

The answer I would have given the group, is that the primary
doesn't have to be flat, but flat is better in certain ways, but
other shapes are valuable too, and will work fine.

cheers
John