Cecil Moore wrote in message ...
Art Unwin KB9MZ wrote:
No I have not, but I have made one using hardline coax
for use on the antenna when the weather gets better.
we have ice up here !.
What is the basis of your suspicioun regarding 'Q' ?

The flux from each loop flows across all the other
loops. A web search for "pancake coil" turns up some
interesting stuff including one company's claim that
their coil-on-chip process turns out coils with double
the 'Q' of pancake coils.

Cecil
I suspect that the 'Q' of a pancake coil would be higher than
the single layer solenoid coil.
!. Modeling shows that for a given length the inductance supplied
is about equal with the edge going to the pancake coil.
2 I believe it is well established that the'Q' of the standard coil
increases as the former radius increases.
Based on the above one could roughly equate the relative inductances
as somewhat proportional with the mean diameter of coils.
3 Since the first pancake coil would have a diaameter more than zero
I think one could say that the pancake coil would tend to have a
higher "Q'
and not the lower "Q" that you suspect.
If a whip coil was made pancake style would this not present less wind
resistance when going mobile ?
Cheers
Art





Incidentally, a pancake coil doesn't solve the magnitude
difference problem between current in and current out in
a standing wave antenna. It may not radiate but it certainly
has a delay through the coil which is what causes the current
in to be different from the current out in standing wave
antennas. This is explained on my web page at the bottom
of the page.
--
73, Cecil, http://www.qsl.net/w5dxp/current.htm