Donuts

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

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

Tesla list wrote:
> 
> Original poster: "Ed Phillips by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<evp-at-pacbell-dot-net>
> 
> Tesla list wrote:

> > Original poster: "David Thomson by way of Terry Fritz
> <twftesla-at-qwest-dot-net>" <dave-at-volantis-dot-org>

> > Hi Steve,

> > >I've never seen any evidence that radiation becomes donut shaped.
> 
>         The radiation PATTERN of a short vertical antenna or loop does have a
> "donut shape", as does the radiation pattern of a TC.

	To expand a bit:
		a radiator which is a 1/4 wave, over a ground plane,
		at the operating freq, has a 'donut shaped pattern'.

	Similarly:
		A radiator which is a half wave in 'free space' has
		roughly the same.

	Similarly, many solenoids will do so, tho if they become
	large/long in terms if wave length, the pattern shifts to
	end fire.  (this case is more or less irrelevant to coiling
	work as the sizes are not encountered in coiling...
	
>  Don't know what "donut shaped radiation" means.
> David - explain?

	best
	dwp