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#1
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loop antennas and noise suppresion
On 6/22/2012 10:20 AM, Szczepan Bialek wrote:
"Sal M. napisał w wiadomości ... (Last year, I used a 20m dipole at 30 feet, operating out of my van. Everything floated above ground without incident and many QSOs.) I value your opiniion. In Marconi opinion: http://www.nobelprize.org/nobel_priz...ni-lecture.pdf "By "connected to earth" I do not necessarily mean an ordinary metallic connection as used for ordinary wire telegraphs. The earth wire may have a condenser in series with it, or it may be connected to what is really equivalent, a capacity area placed close to the surface of the ground (Fig. 4). It is now perfectly well known that a condenser, if large enough, does not prevent the passage of high frequency oscillations, and therefore in these cases the earth is for all practical purposes connected to the antennae." And Wiki: "The use of the term ground (or earth) is so common in electrical and electronics applications that circuits in portable electronic devices such as cell phones and media players as well as circuits in vehicles such as ships, aircraft, and spacecraft may be spoken of as having a "ground" connection without any actual connection to the Earth. This is usually a large conductor attached to one side of the power supply (such as the "ground plane" on a printed circuit board) which serves as the common return path for current from many different components in the circuit." From: http://en.wikipedia.org/wiki/Ground_(electricity) S* And he changes his argument again. Because now the electrons cannot flow to ground. Which blows his whole "antennas radiate electrons" argument. Troll or moron? You decide. tom K0TAR |
#2
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loop antennas and noise suppresion
"tom" napisal w wiadomosci . net... On 6/22/2012 10:20 AM, Szczepan Bialek wrote: "Sal M. napisał w wiadomości ... (Last year, I used a 20m dipole at 30 feet, operating out of my van. Everything floated above ground without incident and many QSOs.) I value your opiniion. In Marconi opinion: http://www.nobelprize.org/nobel_priz...ni-lecture.pdf "By "connected to earth" I do not necessarily mean an ordinary metallic connection as used for ordinary wire telegraphs. The earth wire may have a condenser in series with it, or it may be connected to what is really equivalent, a capacity area placed close to the surface of the ground (Fig. 4). It is now perfectly well known that a condenser, if large enough, does not prevent the passage of high frequency oscillations, and therefore in these cases the earth is for all practical purposes connected to the antennae." And Wiki: "The use of the term ground (or earth) is so common in electrical and electronics applications that circuits in portable electronic devices such as cell phones and media players as well as circuits in vehicles such as ships, aircraft, and spacecraft may be spoken of as having a "ground" connection without any actual connection to the Earth. This is usually a large conductor attached to one side of the power supply (such as the "ground plane" on a printed circuit board) which serves as the common return path for current from many different components in the circuit." From: http://en.wikipedia.org/wiki/Ground_(electricity) S* And he changes his argument again. Because now the electrons cannot flow to ground. Which blows his whole "antennas radiate electrons" argument. All time the electrons flow to or from the ground. "Let me answer some of your questions. Capacitors loose their charge both through the insulation between the plates and through the air surrounding the capacitor. The charge is a surplus of electrons on one plate and a rarefaction of electrons on the other. Where the electrons are compacted (the negative plate) the electrons tend to push each other off. Where there is a deficit of electrons (the positive plate) electrons are attracted from other sources - air, the positive plate. Both of these actions tend to decrease the potential difference between the plates... to discharge the capacitor. From: http://www.newton.dep.anl.gov/askasc...0/phy00900.htm Troll or moron? You decide. " Variable capacitors with their plates open to the atmosphere were commonly used in radio tuning circuits." If you have such try to measure "the Capacitor charge holding" and decide. S* |
#3
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loop antennas and noise suppresion
"Szczepan Bialek" wrote in message
.. . All time the electrons flow to or from the ground. "Let me answer some of your questions. Capacitors loose their charge both through the insulation between the plates and through the air surrounding the capacitor. The charge is a surplus of electrons on one plate and a rarefaction of electrons on the other. Where the electrons are compacted (the negative plate) the electrons tend to push each other off. Where there is a deficit of electrons (the positive plate) electrons are attracted from other sources - air, the positive plate. Both of these actions tend to decrease the potential difference between the plates... to discharge the capacitor. From: http://www.newton.dep.anl.gov/askasc...0/phy00900.htm S* Let's disregard the spelling error ("loose" and "lose"). The article continues thus: "How can this be discouraged? There are a number of possibilities, but they are selectively employed due to practical and economic reasons. Two possible methods - Increase the distance between the plates or change the material separating the plates. For instance glass insulators are sometimes used on very large (tall as a house) capacitors or the capacitor may be packed in oil. " Anyone seen a capacitor that is as big as a house? snip "Often one wants a capacitor to have the largest possible capacitance. This is accomplished by making the plates large in area and close together and filling the space between the plates with an insulator which has a large dielectric constant. A parallel plate capacitor has a capacitance given by C = eA/d, where e is the dielectric constant, A is the area of the plates and d is the separation between the plates. Notice that making the area large and the separation small makes it easier for a current to flow between the plates, thereby discharging them. For many purposes the small leakage current is not a serious problem. Often a large value of capacitance is much more important than a slow discharge. Notice that even with air between the plates, cosmic rays will occasionally pass through the capacitor, ionizing the air and thereby discharging the capacitor slightly." Note the statement "makes it easier for a current to flow between the plates". That's "between the plates" and not "flow to earth". snip "It is true, most capacitors tend to self-discharge about 50% in something like 15 minutes." That's "self-discharge" and not "discharge to earth". For a detailed discussion of electrons, why not try posting on one of the Physics or Science newsgroups? Regards, Ian. |
#4
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loop antennas and noise suppresion
"Ian" napisał w wiadomości ... "Szczepan Bialek" wrote in message .. . All time the electrons flow to or from the ground. Note the statement "makes it easier for a current to flow between the plates". That's "between the plates" and not "flow to earth". The Earth surface works as the plate. snip "It is true, most capacitors tend to self-discharge about 50% in something like 15 minutes." That's "self-discharge" and not "discharge to earth". The Earth surface works as the plate. For a detailed discussion of electrons, why not try posting on one of the Physics or Science newsgroups? They know what the electrons are. S* |
#5
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loop antennas and noise suppresion
"Szczepan Bialek" wrote in message
... All time the electrons flow to or from the ground. Note the statement "makes it easier for a current to flow between the plates". That's "between the plates" and not "flow to earth". The Earth surface works as the plate. snip "It is true, most capacitors tend to self-discharge about 50% in something like 15 minutes." That's "self-discharge" and not "discharge to earth". The Earth surface works as the plate. For a detailed discussion of electrons, why not try posting on one of the Physics or Science newsgroups? They know what the electrons are. S* Hello Szczepan. No, the earth doesn't act as a surface of a capacitor. Capacitors will self-discharge even when they aren't connected to any circuit. |
#6
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loop antennas and noise suppresion
"Ian" napisał w wiadomości ... "Szczepan Bialek" wrote in message ... All time the electrons flow to or from the ground. Hello Szczepan. No, the earth doesn't act as a surface of a capacitor. Capacitors will self-discharge even when they aren't connected to any circuit. My answer was to Sal. He wrote: "(Last year, I used a 20m dipole at 30 feet, operating out of my van. Everything floated above ground without incident and many QSOs.)" The floor of the van is the plate and the surface of the Earth is the second plate. S* |
#7
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loop antennas and noise suppresion
"Szczepan Bialek" wrote in message
... No, the earth doesn't act as a surface of a capacitor. Capacitors will self-discharge even when they aren't connected to any circuit. My answer was to Sal. He wrote: "(Last year, I used a 20m dipole at 30 feet, operating out of my van. Everything floated above ground without incident and many QSOs.)" The floor of the van is the plate and the surface of the Earth is the second plate. S* Thanks, Szczepan . That made me smile. I'm sure you will find sites on the web that will help you to understand capacitors. Have a nice day. Ian. |
#8
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loop antennas and noise suppresion
On Monday, June 25, 2012 2:23:22 AM UTC-5, Szczepan Bialek wrote:
The floor of the van is the plate and the surface of the Earth is the second plate. How about the capacitors and antennas on Voyager I and II which are still operating at the edge of the solar system? -- 73, Cecil, w5dxp.com |
#9
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loop antennas and noise suppresion
"Szczepan Bialek" wrote in message ... "Ian" napisał w wiadomości ... "Szczepan Bialek" wrote in message ... All time the electrons flow to or from the ground. Hello Szczepan. No, the earth doesn't act as a surface of a capacitor. Capacitors will self-discharge even when they aren't connected to any circuit. # My answer was to Sal. He wrote: "(Last year, I used a 20m dipole at 30 # feet, operating out of my van. # Everything floated above ground without incident and many QSOs.)" # The floor of the van is the plate and the surface of the Earth is the second # plate. # S* Just as a mental exercise, assume that the entire setup...van and antenna, is transported to a place in space where there is negligible capacitance to the earth. Is it your contention that the setup would operate any differently? |
#10
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loop antennas and noise suppresion
"Szczepan Bialek" wrote in message
... Hello Szczepan. No, the earth doesn't act as a surface of a capacitor. Capacitors will self-discharge even when they aren't connected to any circuit. My answer was to Sal. He wrote: "(Last year, I used a 20m dipole at 30 feet, operating out of my van. Everything floated above ground without incident and many QSOs.)" The floor of the van is the plate and the surface of the Earth is the second plate. S* Hello Szczepan. Please try to take note of earlier postings. A dipole is a balanced aerial and works without reference to earth. Regards, Ian. |
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