In the textbooks, a capacity hat is shown as having a capacity down
to ground (in the case of a marconi antenna), but if you do the calculations
based on the physical dimensions, the resulting capacitance is so small
as to be meaningless.

So, .... what is the real picture here?

In rec.radio.amateur.antenna gareth wrote:
In the textbooks, a capacity hat is shown as having a capacity down
to ground (in the case of a marconi antenna), but if you do the calculations
based on the physical dimensions, the resulting capacitance is so small
as to be meaningless.

Then obviously that is not the way to calculate the effect.


--
Jim Pennino

On Wednesday, December 31, 2014 2:48:18 PM UTC-6, gareth wrote:
In the textbooks, a capacity hat is shown as having a capacity down
to ground (in the case of a marconi antenna), but if you do the calculations
based on the physical dimensions, the resulting capacitance is so small
as to be meaningless.

So, .... what is the real picture here?

Abraham Lincoln often wore a large capacity hat. :/

In message ,
writes
On Wednesday, December 31, 2014 2:48:18 PM UTC-6, gareth wrote:
In the textbooks, a capacity hat is shown as having a capacity down
to ground (in the case of a marconi antenna), but if you do the calculations
based on the physical dimensions, the resulting capacitance is so small
as to be meaningless.

So, .... what is the real picture here?

Abraham Lincoln often wore a large capacity hat. :/


This one ?

http://cdnimg.visualizeus.com/thumbs...-c6c9e070c37bd
bce15f32993245d99d0_h.jpg?ts=93246

I once made an Abe Lincoln for 23cm as prototype for a beacon
antenna.

Http://www.agder.net/la8ak/images/alford.jpg

Brian



--
Brian Howie

On Wed, 31 Dec 2014 20:48:15 -0000, "gareth"
wrote:

In the textbooks, a capacity hat is shown as having a capacity down
to ground (in the case of a marconi antenna), but if you do the calculations
based on the physical dimensions, the resulting capacitance is so small
as to be meaningless.

So, .... what is the real picture here?

http://www.k0bg.com/caphats.html
http://en.wikipedia.org/wiki/T-Antenna
http://www.buzzbar.com/w8uzzch.html
http://www.smeter.net/antennas/short-top-hat-loaded.php
http://www.dxengineering.com/techarticles/hotrodzandmobileinstall/dx-engineering-hot-rodz-antenna-capacity-hats

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Nice links Jeff! Thanks!
The W8UZZ has quite the collection!

Irv VE6BP

Jeff Liebermann wrote:
On Wed, 31 Dec 2014 20:48:15 -0000, "gareth"
wrote:

In the textbooks, a capacity hat is shown as having a capacity down
to ground (in the case of a marconi antenna), but if you do the calculations
based on the physical dimensions, the resulting capacitance is so small
as to be meaningless.

So, .... what is the real picture here?

http://www.k0bg.com/caphats.html
http://en.wikipedia.org/wiki/T-Antenna
http://www.buzzbar.com/w8uzzch.html
http://www.smeter.net/antennas/short-top-hat-loaded.php
http://www.dxengineering.com/techarticles/hotrodzandmobileinstall/dx-engineering-hot-rodz-antenna-capacity-hats

On Fri, 02 Jan 2015 11:17:07 -0700, Irv Finkleman VE6BP
wrote:

Nice links Jeff! Thanks!
The W8UZZ has quite the collection!

Irv VE6BP

Google turned up quite a few hits, but most of them were useless for
describing how a capactive hat works. So, I picked out what I
considered to be the better pages. I also looked at Google Images for
decent photos, which is where I found the W8UZZ collection.

Incidentally, I'm only 5ft 5in tall, so I wear a capacitive hat on my
head so that I can act like the big guys.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Jeff Liebermann wrote:
On Fri, 02 Jan 2015 11:17:07 -0700, Irv Finkleman VE6BP
wrote:

Nice links Jeff! Thanks!
The W8UZZ has quite the collection!

Irv VE6BP

Google turned up quite a few hits, but most of them were useless for
describing how a capactive hat works. So, I picked out what I
considered to be the better pages. I also looked at Google Images for
decent photos, which is where I found the W8UZZ collection.

Incidentally, I'm only 5ft 5in tall, so I wear a capacitive hat on my
head so that I can act like the big guys.


Have you considered an aluminum pyramid? :-)

Irv

On Fri, 02 Jan 2015 12:59:39 -0700, Irv Finkleman VE6BP
wrote:

Jeff Liebermann wrote:
Incidentally, I'm only 5ft 5in tall, so I wear a capacitive hat on my
head so that I can act like the big guys.

Have you considered an aluminum pyramid? :-)
Irv

Yeah, but they are too big to wear:
http://www.setileague.org/photos/wghorn/pyramid.jpg
http://www.setileague.org/photos/wghorn/horn0302.jpg
http://www.setileague.org/photos/wghorn/ewenhorn.jpg
Although they haven't heard any alien broadcasts, they do quite well
at sharpening razor blades.
http://pyramidrazorsharpener.wordpress.com

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558