Capacity hat - Revision history

LDighera: Added top hat photograph, but it needs to be re-sized

2013-08-20T13:41:19Z

Added top hat photograph, but it needs to be re-sized

← Older revision		Revision as of 06:41, 20 August 2013
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	~~Related Wiki pages: [[Antennas]], [[Electronic Theory]]~~

	'''Capacity Hats'''		'''Capacity Hats'''
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	Although it is true that the input impedance of antennas using Capacity Hats is higher than coil loaded antennas this is not an indication of an increase in radiation resistance, for the same reason that a folded dipole with 300 ohms impedance has the same radiation resistance as a standard 73 ohm dipole.		Although it is true that the input impedance of antennas using Capacity Hats is higher than coil loaded antennas this is not an indication of an increase in radiation resistance, for the same reason that a folded dipole with 300 ohms impedance has the same radiation resistance as a standard 73 ohm dipole.


			[[File:15m_tophat_P1020593.JPG \| frame \| Figure 1: Capacitive hat added to 40-meter wire dipole elements lower resonant frequency so that it lies within the 15-meter band. Source: KJ6YVT ]]Related Wiki pages: [[Antennas]], [[Electronic Theory]]


	{{antennas}}		{{antennas}}

Carlb: Capacity Hats moved to Capacity hat

2009-06-05T21:36:22Z

Capacity Hats moved to Capacity hat

← Older revision	Revision as of 14:36, 5 June 2009
(No difference)

Carlb at 21:33, 5 June 2009

2009-06-05T21:33:32Z

← Older revision		Revision as of 14:33, 5 June 2009
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	It is true if you put a Capacity hat on top of a short mobile antenna it will change the antennas efficiency but what happens is the current on the radiating element moves further up to the top.		It is true if you put a Capacity hat on top of a short mobile antenna it will change the antennas efficiency but what happens is the current on the radiating element moves further up to the top.

	Because the current is now further away from ground this lowers ground ~~lost~~. So the ratio of radiation resistance to ground ~~lost,~~ and Omni Loss resistance, which is the reduction in the amount of inductance needed for the loading coil, goes down.		Because the current is now further away from ground this lowers ground loss. So the ratio of radiation resistance to ground loss and Omni Loss resistance, which is the reduction in the amount of inductance needed for the loading coil, goes down.

	Although it is true that the input impedance of antennas using Capacity Hats is higher than coil loaded antennas this is not an indication of an increase in radiation resistance, for the same reason that a folded dipole with 300 ohms impedance has the same radiation resistance as a standard 73 ohm dipole .		Although it is true that the input impedance of antennas using Capacity Hats is higher than coil loaded antennas this is not an indication of an increase in radiation resistance, for the same reason that a folded dipole with 300 ohms impedance has the same radiation resistance as a standard 73 ohm dipole.


	{{antennas}}		{{antennas}}

Carlb at 00:56, 9 April 2009

2009-04-09T00:56:59Z

← Older revision		Revision as of 17:56, 8 April 2009
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	Although it is true that the input impedance of antennas using Capacity Hats is higher than coil loaded antennas this is not an indication of an increase in radiation resistance, for the same reason that a folded dipole with 300 ohms impedance has the same radiation resistance as a standard 73 ohm dipole .		Although it is true that the input impedance of antennas using Capacity Hats is higher than coil loaded antennas this is not an indication of an increase in radiation resistance, for the same reason that a folded dipole with 300 ohms impedance has the same radiation resistance as a standard 73 ohm dipole .


			{{antennas}}

G7VRD: Antenna -> Antennas

2008-07-12T16:16:03Z

Antenna -> Antennas

← Older revision		Revision as of 09:16, 12 July 2008
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	Related ~~wiki~~ pages: [[~~Antenna~~]], [[Electronic Theory]]		Related Wiki pages: [[Antennas]], [[Electronic Theory]]

	'''Capacity Hats'''		'''Capacity Hats'''

TimVK4YEH: internal links

2008-07-03T07:17:23Z

internal links

← Older revision		Revision as of 00:17, 3 July 2008
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			Related wiki pages: [[Antenna]], [[Electronic Theory]]

	'''Capacity Hats'''		'''Capacity Hats'''

Ke4uyp at 13:07, 8 February 2008

2008-02-08T13:07:14Z

← Older revision	Revision as of 06:07, 8 February 2008
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		'''Capacity Hats'''

		by Lou Rummel KE4UYP

		Capacity hats will reduce the amount of inductance necessary to resonate the antenna, and increase bandwidth. But contrary to popular belief they add nothing to the radiation resistance. For a component of an antenna to increase radiation resistance it must itself radiate.

		It is true if you put a Capacity hat on top of a short mobile antenna it will change the antennas efficiency but what happens is the current on the radiating element moves further up to the top.

		Because the current is now further away from ground this lowers ground lost. So the ratio of radiation resistance to ground lost, and Omni Loss resistance, which is the reduction in the amount of inductance needed for the loading coil, goes down.

		Although it is true that the input impedance of antennas using Capacity Hats is higher than coil loaded antennas this is not an indication of an increase in radiation resistance, for the same reason that a folded dipole with 300 ohms impedance has the same radiation resistance as a standard 73 ohm dipole .

Ke4uyp: Removing all content from page

2008-02-08T13:03:59Z

Removing all content from page

← Older revision		Revision as of 06:03, 8 February 2008
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	~~'''Capacity Hats'''~~

	~~by Lou Rummel KE4UYP~~

	Capacity hats will reduce the amount of inductance necessary to resonate the antenna, and increase bandwidth. But contrary to popular belief they add nothing to the radiation resistance. For a component of an antenna to increase radiation resistance it must itself radiate.

	~~It is true if you put a Capacity hat on top of a short mobile antenna it will change the antennas efficiency but what happens is the current on the radiating element moves further up to the top.~~

	Because the current is now further away from ground this lowers ground lost. So the ratio of radiation resistance to ground lost, and Omni Loss resistance, which is the reduction in the amount of inductance needed for the loading coil, goes down.

	Although it is true that the input impedance of antennas using Capacity Hats is higher than coil loaded antennas this is not an indication of an increase in radiation resistance, for the same reason that a folded dipole with 300 ohms impedance has the same radiation resistance as a standard 73 ohm dipole .

Ke4uyp at 12:57, 8 February 2008

2008-02-08T12:57:35Z

← Older revision		Revision as of 05:57, 8 February 2008
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	by Lou Rummel KE4UYP		by Lou Rummel KE4UYP

	Capacity hats will reduce the amount of inductance necessary to resonate the antenna, and increase bandwidth. But contrary to popular belief they add nothing to the radiation resistance. For a component of an antenna to increase radiation resistance it must itself radiate~~. It is true if you put a Capacity hat on top of a short mobile antenna it will change the antennas efficiency~~.		Capacity hats will reduce the amount of inductance necessary to resonate the antenna, and increase bandwidth. But contrary to popular belief they add nothing to the radiation resistance. For a component of an antenna to increase radiation resistance it must itself radiate.

	~~What~~ happens is the current on the radiating element moves further up to the top. Because the current is now further away from ground this lowers ground lost. So the ratio of radiation resistance to ground lost, and Omni Loss resistance, which is the reduction in the amount of inductance needed for the loading coil, goes down.		It is true if you put a Capacity hat on top of a short mobile antenna it will change the antennas efficiency but what happens is the current on the radiating element moves further up to the top.

			Because the current is now further away from ground this lowers ground lost. So the ratio of radiation resistance to ground lost, and Omni Loss resistance, which is the reduction in the amount of inductance needed for the loading coil, goes down.

	Although it is true that the input impedance of antennas using Capacity Hats is higher than coil loaded antennas this is not an indication of an increase in radiation resistance, for the same reason that a folded dipole with 300 ohms impedance has the same radiation resistance as a standard 73 ohm dipole .		Although it is true that the input impedance of antennas using Capacity Hats is higher than coil loaded antennas this is not an indication of an increase in radiation resistance, for the same reason that a folded dipole with 300 ohms impedance has the same radiation resistance as a standard 73 ohm dipole .

Ke4uyp: Mobile moved to Capacity Hats

2008-02-08T12:18:35Z

Mobile moved to Capacity Hats

← Older revision	Revision as of 05:18, 8 February 2008
(No difference)