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Noise level between two ant types
jawod wrote:
. . . Seems to me, that Joules per unit time is precisely the measure that's needed in this "analysis". Is this Voltage, or am I mistaken? Joules (energy) per unit time is power, not voltage. Compare the density of the dust cloud with the charge collected. There should be a correlation. What about velocity of the cloud: more charges transferred per unit time. Charge per unit time is current. If your rug was scorched, some "work" was done. My college physiscs is only a nightmare away: what is the relation of Joules to work? The joule is a unit of energy. Work is energy, so it can also be expressed in joules. . . . If a given volume of dust particles moves through the field of an antenna (it would have a field, wouldn't it? ... even if grounded? An antenna creates an electrostatic field if charged, but an electromagnetic field only if that charge is being accelerated, that is, if it carries current which changes with time. perhaps field is the wrong word), increasing velocity of the volume would mean more particles per unit time passing the antenna. Hence more charge transferred: more charge per unit time. Again, is this Voltage? No, charge per unit time is current. . . . It's impossible to contribute much to the understanding of complex phenomena without first gaining an understanding of the most basic principles. Roy Lewallen, W7EL |
Noise level between two ant types
Tom Donaly wrote:
Whether it's dust, snow, or the atmospheric electric field charging the antenna, the noise is still corona discharge. At least that's what most of the sources say. It is my understanding that the air around a conductor must ionize for it to be defined as corona. Obviously, there is a time when charge is transferred to the antenna before ionization (corona) occurs. Corona is defined as a discharge function. The charging function must necessarily occur before corona. If the charge is not allowed to accumulate up to the ionization level, corona will not occur, by definition. Precipitation static occurs before the corona threshold is reached. For what it's worth, here's what the 2000 ARRL Handbook says: "Precipitation Static and Corona Discharge" "Precipitation static is an almost continuous hash-type noise that often accompanies various kinds of precipitation, including snowfall. Precipitation static is caused by rain drops, snowflakes or even *wind-blown dust*, transferring a small electrical charge on contact with an antenna." "Electrical fields under thunderstorms are sufficient to place many objects such as trees, hair and antennas, into corona discharge." Although not stated explicitly, seems to me there is a strong implication that precipitation static is not strong enough to ionize the air, i.e. not strong enough to cause corona to exist. Indeed, the arcing at a coax connector or the DC grounding of an antenna may be enough to prevent ionization and corona during a precipitation static episode. -- 73, Cecil http://www.qsl.net/w5dxp |
Noise level between two ant types
jawod wrote:
Cecil Moore wrote: Tom Donaly wrote: Whether it's dust, snow, or the atmospheric electric field charging the antenna, the noise is still corona discharge. At least that's what most of the sources say. The argument is not what it is called. The argument is whether charged dry-air dust particles can transfer charge to bare-wire antennas. Man, you guys really crack me up. I must admit I kinda enjoy reading your posts, though. \There must be some source citing experimental evidence of charged particles in a dust storm transferring their charges to a collector of some sort (antenna). I alluded earlier to a practical use of such collection... Cecil, you said you have no idea how many Joules were represented (or something along those lines). Seems to me, that Joules per unit time is precisely the measure that's needed in this "analysis". Is this Voltage, or am I mistaken? Compare the density of the dust cloud with the charge collected. There should be a correlation. What about velocity of the cloud: more charges transferred per unit time. If your rug was scorched, some "work" was done. My college physiscs is only a nightmare away: what is the relation of Joules to work? What was the other issue: number of particles versus the charge per particle? Got me. As the particles are swept off the surface of the desert, would their charge (per particle) be distributed (as Gauss or some other )? I would think the # particles would be more important. If a given volume of dust particles moves through the field of an antenna (it would have a field, wouldn't it? ... even if grounded? perhaps field is the wrong word), increasing velocity of the volume would mean more particles per unit time passing the antenna. Hence more charge transferred: more charge per unit time. Again, is this Voltage? I guess I can't part with my trickle charger idea. You guys have at it. Thanks for letting me butt in. John There was once an article in the old Scientific American Amateur Scientist section about using the earth's electric field to power various static electric motors. Just build a motor from one of the simple designs on the web; using a weather balloon, run a wire up 300 feet or so (should give you 9000 volts or so on a clear day); attach your motor between the wire and ground, and, once the wire charges up, the motor turns. You won't get much work out of it, but it'll run a long time. 73, Tom Donaly, KA6RUH |
Noise level between two ant types
Cecil Moore wrote:
Tom Donaly wrote: Whether it's dust, snow, or the atmospheric electric field charging the antenna, the noise is still corona discharge. At least that's what most of the sources say. It is my understanding that the air around a conductor must ionize for it to be defined as corona. Obviously, there is a time when charge is transferred to the antenna before ionization (corona) occurs. Corona is defined as a discharge function. The charging function must necessarily occur before corona. If the charge is not allowed to accumulate up to the ionization level, corona will not occur, by definition. Precipitation static occurs before the corona threshold is reached. For what it's worth, here's what the 2000 ARRL Handbook says: "Precipitation Static and Corona Discharge" "Precipitation static is an almost continuous hash-type noise that often accompanies various kinds of precipitation, including snowfall. Precipitation static is caused by rain drops, snowflakes or even *wind-blown dust*, transferring a small electrical charge on contact with an antenna." "Electrical fields under thunderstorms are sufficient to place many objects such as trees, hair and antennas, into corona discharge." Although not stated explicitly, seems to me there is a strong implication that precipitation static is not strong enough to ionize the air, i.e. not strong enough to cause corona to exist. Indeed, the arcing at a coax connector or the DC grounding of an antenna may be enough to prevent ionization and corona during a precipitation static episode. Cecil, you can do a web search for "precipitation static," and "Saint Elmo's fire," to find out what most people think precipitation static is. Before I'd believe that each little raindrop makes a noise as it strikes the antenna, I'd want to see an experiment showing this. Most of the sources on the web, at least, don't mention it, but generally agree with Tom about the cause of the problem. You can read all that for yourself. 73, Tom Donaly, KA6RUH |
Noise level between two ant types
Tom Donaly wrote:
Cecil, you can do a web search for "precipitation static," and "Saint Elmo's fire," to find out what most people think precipitation static is. Before I'd believe that each little raindrop makes a noise as it strikes the antenna, I'd want to see an experiment showing this. It's only raindrops having a charge different from the antenna that make the noise and I have previously explained the mechanism of charge equalization between the two dipole elements through the link. Seems to me only magical thinking would result in each and every raindrop having a charge exactly equal to the antenna upon which it is falling. I'd like to see you come up with a proof for such an assertion. Most of the sources on the web, at least, don't mention it, but generally agree with Tom about the cause of the problem. You can read all that for yourself. I have read it for myself and *nothing* I have read agrees with W8JI. Corona doesn't exist until ionization takes place. Precipitation static and even arcing do not require any corona to exist. Here's a web page that explains the difference between arcing and corona discharge including a gray area called "brush discharges". http://www.ce-mag.com/archive/1999/novdec/mrstatic.html Please notice that arcing at a coax connector doesn't require corona at all. -- 73, Cecil, http://www.qsl.net/w5dxp |
Noise level between two ant types
Cecil Moore wrote:
Tom Donaly wrote: Cecil, you can do a web search for "precipitation static," and "Saint Elmo's fire," to find out what most people think precipitation static is. Before I'd believe that each little raindrop makes a noise as it strikes the antenna, I'd want to see an experiment showing this. It's only raindrops having a charge different from the antenna that make the noise and I have previously explained the mechanism of charge equalization between the two dipole elements through the link. Seems to me only magical thinking would result in each and every raindrop having a charge exactly equal to the antenna upon which it is falling. I'd like to see you come up with a proof for such an assertion. Most of the sources on the web, at least, don't mention it, but generally agree with Tom about the cause of the problem. You can read all that for yourself. I have read it for myself and *nothing* I have read agrees with W8JI. Corona doesn't exist until ionization takes place. Precipitation static and even arcing do not require any corona to exist. Here's a web page that explains the difference between arcing and corona discharge including a gray area called "brush discharges". http://www.ce-mag.com/archive/1999/novdec/mrstatic.html Please notice that arcing at a coax connector doesn't require corona at all. Cecil, show me your experiments. You can ratiocinate your head off and you still won't be any closer to the truth. Tell me how I can spray water drops on my antenna and make a noise in my receiver as each drop hits the antenna. Can you do it? 73, Tom Donaly, KA6RUH |
Noise level between two ant types
On Thu, 15 Jun 2006 17:42:40 GMT, "Tom Donaly"
wrote: You can ratiocinate your head off and you still won't be any closer to the truth. Hi Tom, As Judge Judy would say, "Don't discharge on my leg and tell me its corona even if you've been drinking beer." 73's Richard Clark, KB7QHC |
Noise level between two ant types
Tom Donaly wrote:
show me your experiments. You can ratiocinate your head off and you still won't be any closer to the truth. Tell me how I can spray water drops on my antenna and make a noise in my receiver as each drop hits the antenna. Can you do it? No, I think it is up to you to prove that each and every raindrop that falls has exactly the same charge as any antenna upon which it might fall. Which means that you must prove that all antennas being rained upon have identical unchanging charges. That is what would have to be true for you to be correct. Sorry Tom, please peddle your magical thinking to someone else. What do you think about the 2000 ARRL Handbook quote? "Precipitation static is an almost continuous hash-type noise that often accompanies various kinds of precipitation, including snowfall. Precipitation static is caused by rain drops, snowflakes or even wind-blown dust, transferring a small electrical charge on contact with an antenna." The physics of charged particles has been understood for a century or so. I am not going to waste my time proving those known and accepted facts of physics. It is up to you and W8JI to prove a century of physics knowledge to be wrong. Good luck on proving that all static is caused by corona discharge even in the absence of the necessary ionization that defines the word "corona". -- 73, Cecil, http://www.qsl.net/w5dxp |
Noise level between two ant types
Richard Clark wrote:
On Thu, 15 Jun 2006 17:42:40 GMT, "Tom Donaly" wrote: You can ratiocinate your head off and you still won't be any closer to the truth. Hi Tom, As Judge Judy would say, "Don't discharge on my leg and tell me its corona even if you've been drinking beer." 73's Richard Clark, KB7QHC In Cecil's case he'd claim it was Corona Extra. 73, Tom Donaly, KA6RUH |
Noise level between two ant types
Cecil Moore wrote:
Tom Donaly wrote: show me your experiments. You can ratiocinate your head off and you still won't be any closer to the truth. Tell me how I can spray water drops on my antenna and make a noise in my receiver as each drop hits the antenna. Can you do it? No, I think it is up to you to prove that each and every raindrop that falls has exactly the same charge as any antenna upon which it might fall. Which means that you must prove that all antennas being rained upon have identical unchanging charges. That is what would have to be true for you to be correct. Sorry Tom, please peddle your magical thinking to someone else. What do you think about the 2000 ARRL Handbook quote? "Precipitation static is an almost continuous hash-type noise that often accompanies various kinds of precipitation, including snowfall. Precipitation static is caused by rain drops, snowflakes or even wind-blown dust, transferring a small electrical charge on contact with an antenna." The physics of charged particles has been understood for a century or so. I am not going to waste my time proving those known and accepted facts of physics. It is up to you and W8JI to prove a century of physics knowledge to be wrong. Good luck on proving that all static is caused by corona discharge even in the absence of the necessary ionization that defines the word "corona". You're the one who made the statements, Cecil, so you're the one who has to prove them. Just tell me how you sprayed charged water drops on your antenna and recorded the noise from your receiver when each one of them hit. If you can't do that, all appeals to a higher authority are meaningless. 73, Tom Donaly, KA6RUH |
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