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loop antennas and noise suppresion
"Sal M. O'Nella" 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* |
#2
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loop antennas and noise suppresion
Szczepan Bialek wrote:
"Sal M. O'Nella" napisa? w wiadomo?ci ... (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: Marconi was wrong, idiot. And the topic of discussion is prevention of static build up on antennas which requires a particular set of circumstances to occur and does NOT happen all the time and everywhere. You are an idiot. |
#3
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Quote:
Friendless and alone. IN THEORY - Marconi was correct. IF wind blows directly across a loop antenna, it stands to reason that the wind would create a static, and when connected to a transceiver it would look for a ground to travel to - like lightning in a storm cloud - and even saying static discharge is incorrect. Antenna's by nature is electrically charged - this is why they receive. I could cite some irrevelant information that no one would listen to, but no one would know what I was talking about / or care. I can tell you of one man who lives across the street from a low power AM commercial radio station -= daylighter station with about 4K transmit / that gets shocked everytime he touches his loop antenna. It stands to reason that if it was electrostatically charged, just like shuffling your feet across the carpet floor and then touching a old water tap with copper pipe - that an arc would jump and a spark would be produced and you would get jolted. Some good sloper antenna's also uses a discharge mech to dampen the static on the line. A club I belong to - but did not participate with - in field days this year, built a matching network for their 240' repeater tower and loaded up the entire tower and tried to make contacts on 160 meters one year. Someone acted ignorant and told them to get off of 160 meters - that it was for bullchitting and not for contesting =- when the club broke into their QSO - and they disconnected the matching network and threw it away. A bunch of CB'rs in my opinion. ONe other thing to note - and I am suprised that no one produces it, is a loop antenna for 11 meters. If the manufacturers would get together and make a 11 meter loop and sell it to the trailer manufactuers - tuned, and would install it on the enclosed truck trailers - these 11 meter / CB radio nets would dissappear almost overnight. Someone told them that they needed a half wavelength of coax to have a balanced feed line - no one told them that it had to be electrically a half wavelength. Hence every other post includes how they bought 18' of coax, reguardless of make or model and how they have high swr's because their antenna will not tune up = 3 or 4 foot long - double sticks - with no ground plane and a fiberglass body. If I had a nickle for every time I told them they would be better off with a walkie talkie - they get mad and throw me off their forums. You could probably hold a 4' long whip antenna in your hand and do more good then mounting it on the side of a fiberglass door with no ground plane! As far as me building a loop and worrying about static discharge or noise - a NVIS antenna is only a couple of feet off the ground and it works - it does not talk very far, maybe 1500 miles max, but it listens and is real quiet - because it does not receive as much. Good for doing close up local work, not good for skip. I even heard tell of a guy who buried his antenna 1 foot below ground and made some contacts, but couldn't stand the electrical burns he got every time he touched something metallic while holding or talking into the mic. RF needs some place to go and the best path it found was out of the mic. Marconi was a theif and a cheat, because his first across Atlantic contact never happened, he just needed something to be of proof so he could get a license to do what he wanted to do and he needed government approval to do it before he invested his own money into it. Even Heimlic Hertz knew more about radio then Marconi did and he dismissed it as a novelty. KHZ MHZ or KILLO CYCLES MEGGA CYCLES YOU BE THE JUDGE! Last edited by Channel Jumper : June 25th 12 at 03:18 PM |
#5
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loop antennas and noise suppresion
"Szczepan Bialek" wrote in message
... "Sal M. O'Nella" 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* What is your point is (other than demonstrating copy-and-paste)? If it is that "all aerials require an earth" then you're clearly ignoring previous postings which have said that this is not the case. The Wiki item doesn't seem to appreciate the difference between a return path on a circuit board and a connection to earth. Regards, Ian. |
#6
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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 |
#7
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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* |
#8
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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. |
#9
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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* |
#10
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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. |
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