Gary is absolutely correct, I would like to point out that Bill Wysocks
13M coil ( a true monster if ever there was one) uses a propeller gap of
sorts. I can't find the link to the page that details of it but you can
see here from the back of the gray spark gap the tip of the propeller in
an acrylic box.
http://www.teslauniverse.com/photos/wysock-13m#id=album-17&num=content-622
The only difference between this and the ones us amateurs make is the
surface area of the point of contact, there is nothing stopping someone
from making an arbor capable of holding several tungsten rods in parallel
and electrically binding them together so dwell time is tiny but
conducting area is huge. It might be difficult to machine but it would
perform superbly, and still be lighter than a disk. I'm going to say it,
carefully built propellers are better in every way, I think there is room
for improvement in the design of the "prop," making something special
instead of just a rod in some PE, to correct issues like electrode spacing
and as argued current handling capability, but I doubt I'll ever build a
disk type. Just putting this out there.
Scott Bogard.
I'm not sure it's fair or useful to suggest that a propeller gap isn't up
to
the task of a 10KW or whatever, coil. I don't see how a disk holding
short
tungsten segments is inherently more capable than a propeller geometry.
I
think what matters is only the diameter of the tungsten rods. If the
same
diameter tungsten were used in a propeller gap, wouldn't it be equally
capable as a disk-based geometry? I was going to suggest that maybe
propeller gaps are limited because long welding rods don't normally come
over 1/4" diameter, but just noticed that McMaster-Carr has lengths up to
12" and diameters up to 2". Wowza!
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla