On Thursday, February 13, 2014 4:44:04 AM UTC-6, gareth wrote:
wrote in message

...

On Thursday, February 13, 2014 4:09:53 AM UTC-6, gareth wrote:

My reasoning is that because the waves spread out in all directions

in the hat, then there is no, or very little, radiation from the hat

because

of field cancellation, but when the waves all return simultaneously to

the

main element, they have incurred a phase change that you'd get had there

been a capacitor in circuit?



(Always willing to learn more, and to be corrected if my thought

experiment has gone up a blind alley, or in this case, a capacity hat

alley!)



The use of the hat has two main purposes.

#1, it will reduce the number of turns needed with the loading

coil, assuming the whip is shorter than 1/4 wave including the

hat.

#2, and probably most important. It improves the current

distribution through the length of the whip and makes the current

distribution a good bit more linear from the base to the tip.

I don't use one myself, because they catch a lot of wind, and

they look ugly on a vehicle. :/

I compromise by mounting the loading coil as high as possible,

which also helps current distribution.



Yes, all very well, and not disputed, but I was interested in a

discussion of how it actually works at the physics level?

You are better off with the proper textbooks, than reading my
jibber jabber. That's what I use when I want to brush up on
how something works at the physics level. :|
I read the various books. I don't trust too many on the interweb,
as many will lead you astray with jibber jabber and gibberish.

Then, if you have a problem with something in the various textbooks,
you can come back and argue it on the interweb.