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#1
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The capacity hat?
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? |
#2
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The capacity hat?
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 |
#3
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The capacity hat?
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. :/ |
#4
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The capacity hat?
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 |
#5
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The 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 |
#6
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The capacity hat?
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 |
#7
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The capacity hat?
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 |
#8
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The capacity hat?
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 |
#9
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The capacity hat?
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 |
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