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Noise level between two ant types
wrote:
Cecil then proposed, if I am not mistaken, that P-static was caused by particles striking the antenna, each one making a noise as it discharged into the antenna, and that noise could be reduced by grounding the element at DC. That is really the only point I disageed with. I'm glad you now agree with it. Grounding the feedline obviously reduces everything, including noise. -- 73, Cecil http://www.qsl.net/w5dxp |
Noise level between two ant types
Cecil Moore wrote: You just admitted above that shorting the transmission line to ground changes the noise level, i.e. indeed does make a difference. You have agreed with every leading question that I have asked you so it seems we are in agreement. Cecil, When you short ANY transmission line center to ground and the shield is grounded, which is what you asked, ALL signal levels will decrease. They will all go to zero if it is a pefect short. You have a very strange way of defining noise decreases! If I unplug the receiver or place it on standby, noise will decrease also. So will turning off the RF amplifier. So will adding an attenuator. If shorting the center to shield making noise go away and ignoring the fact it also makes the signal go away makes you feel like you have proven something, then I can't go further. That's about the silliest thing I've ever heard as a logical arguement! 73 Tom |
Noise level between two ant types
wrote:
When you short ANY transmission line center to ground and the shield is grounded, which is what you asked, ALL signal levels will decrease. They will all go to zero if it is a perfect short. Glad you agree. Now would you agree that in a system with arcing, anything that eliminates the arcing and preserves the signal has reduced the noise? A path to ground will do exactly that. -- 73, Cecil http://www.qsl.net/w5dxp |
Noise level between two ant types
Cecil Moore wrote: wrote: When you short ANY transmission line center to ground and the shield is grounded, which is what you asked, ALL signal levels will decrease. They will all go to zero if it is a perfect short. Glad you agree. Now would you agree that in a system with arcing, anything that eliminates the arcing and preserves the signal has reduced the noise? A path to ground will do exactly that. Of course I agree when someone shorts the RF input connector of their radio the noise will decrease! Better yet, they should just unplug it and throw it in the closet! Then the noise will be zero! 73 Tom |
Noise level between two ant types
wrote:
Of course I agree when someone shorts the RF input connector of their radio the noise will decrease! W8JI previously wrote: So when you provide a DC path that does not short the antenna at radio frequencies, it does nothing. In AZ, I provided a DC path (choke) that eliminated arcing and allowed me to make contacts. The elimination of arcing obviously improved my signal to noise ratio. You have stopped asserting that folding doesn't make for a quieter antenna system. Do you now understand why a folded dipole is less noisy than a non-folded dipole in a charged particle environment? Do you understand that the probable cause for high antennas having more particle noise is that the higher you go, the faster the wind blows? -- 73, Cecil http://www.qsl.net/w5dxp |
Noise level between two ant types
Cecil Moore wrote:
wrote: Of course I agree when someone shorts the RF input connector of their radio the noise will decrease! W8JI previously wrote: So when you provide a DC path that does not short the antenna at radio frequencies, it does nothing. In AZ, I provided a DC path (choke) that eliminated arcing and allowed me to make contacts. The elimination of arcing obviously improved my signal to noise ratio. You have stopped asserting that folding doesn't make for a quieter antenna system. Do you now understand why a folded dipole is less noisy than a non-folded dipole in a charged particle environment? Do you understand that the probable cause for high antennas having more particle noise is that the higher you go, the faster the wind blows? Yes, but there are fewer particles. What, in Yahweh's name, is particle noise? Is it somehow related to the triboelectric effect? What about the effect of the earth's electric field (100 volts/meter)? This is beginning to sound like the Forrest Mims III creation science school of explaining natural phenomena. There are a few articles on what's called "precipitation static" on the web. Generally,it's supposed to be the noise made by corona discharge on objects that have been charged up to high voltages by natural means. You might want to read the articles, Cecil, before you speculate. It could only improve your mind. 73, Tom Donaly, KA6RUH |
Noise level between two ant types
Tom Donaly wrote: have been charged up to high voltages by natural means. You might want to read the articles, Cecil, before you speculate. It could only improve your mind. 73, Tom Donaly, KA6RUH ......or doing some actual experiments like I have done. 73 Tom |
Noise level between two ant types
Tom Donaly wrote:
Yes, but there are fewer particles. I don't think that is true. Dust is sucked high into the air during the formation of a dust storm. I have seen a wall of dust hundreds of feet high in Arizona. It didn't look any denser closer to the ground. In any case, it is not the number of particles that matter but the average charge per particle which increases with wind speed. -- 73, Cecil http://www.qsl.net/w5dxp |
Noise level between two ant types
wrote:
.....or doing some actual experiments like I have done. I have been reporting actual experiences from when I lived in the Arizona desert and I can guarantee you that charged particles exist in the dry-air desert wind. Where does the charge on an antenna come from if not from charged particles? -- 73, Cecil http://www.qsl.net/w5dxp |
Noise level between two ant types
Cecil Moore wrote:
Tom Donaly wrote: Yes, but there are fewer particles. I don't think that is true. Dust is sucked high into the air during the formation of a dust storm. I have seen a wall of dust hundreds of feet high in Arizona. It didn't look any denser closer to the ground. In any case, it is not the number of particles that matter but the average charge per particle which increases with wind speed. How do you know that? 73, Tom Donaly, KA6RUH |
Noise level between two ant types
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Noise level between two ant types
Cecil Moore wrote:
wrote: .....or doing some actual experiments like I have done. I have been reporting actual experiences from when I lived in the Arizona desert and I can guarantee you that charged particles exist in the dry-air desert wind. Where does the charge on an antenna come from if not from charged particles? It probably comes from charged particles and the earth's electric field, but you won't know anything for sure unless you can come up with a mechanism for showing how dust particles get their charge in the first place. Then you have to measure it. In some old issue of Scientific American there's an article showing how to make a simple gadget to measure the electric charge on a raindrop (about .3 volt, average). I expect you could use the same idea to measure the charge on a dust particle during a dust storm. Then you'd have to calculate. That shouldn't be too hard for you to do, Cecil, you're an engineer. 73, Tom Donaly, KA6RUH |
Noise level between two ant types
Tom Donaly wrote: It probably comes from charged particles and the earth's electric field, but you won't know anything for sure unless you can come up with a mechanism for showing how dust particles get their charge in the first place. When I was working on repeater systems trying to figure out how to make an omnidirectional antenna (mounted ABOVE the tower or mounted above other things on a roof) not get wiped out by p-static I talked to an person at NASA who delt with problems NASA had. I've forgotten most of the numbers he quoted for electric field intensity as height increased and the effects of things that modified the impedance of that voltage, but I left those conversations and the experiences with an entirely different view than when I entered. Moving the antenna just a few feet lower than other objects made a large difference in p-static, and that was at heights between 200 and 800 feet above ground. It's a nice guess by Cecil that there is less wind or less particles at 180 feet rather than 200, or 780 feet rather than 800 AGL, but in real life there probably isn't much difference. When people spend a few thousand bucks changing to dc grounded antennas, antennas in radomes (Super Stationmasters) with only a metal tip exposed, and folded dipoles... only to find the only thing that helps is making the antenna NOT the tallest or most protruding point....it's tough to accept something that didn't ever make a difference. Of course if I viewed the world through a 80 meter dipole at 50 feet with only dust to worry about and never talked to the fellow at NASA, or if I never had multiple antennas on multiple tall towers or worked on all those commercial systems, I might agree with Cecil. All the problems I saw related to corona. 73 Tom |
Noise level between two ant types
Tom Donaly wrote:
How do you know that? Simple physics. I don't believe in magic. -- 73, Cecil http://www.qsl.net/w5dxp |
Noise level between two ant types
wrote:
Of course if I viewed the world through a 80 meter dipole at 50 feet with only dust to worry about and never talked to the fellow at NASA, or if I never had multiple antennas on multiple tall towers or worked on all those commercial systems, I might agree with Cecil. When the only tool one has is a corona hammer, all problems look like corona nails. Fortunately, I am familiar with both corona problems and dry-air wind-driven charged particle problems. All the problems I saw related to corona. At least that's what you assumed. Just because all the cars parked in your driveway are white doesn't mean all the cars in the world are white. -- 73, Cecil http://www.qsl.net/w5dxp |
Noise level between two ant types
Cecil Moore wrote:
Tom Donaly wrote: How do you know that? Simple physics. I don't believe in magic. I thought simple physics was magic. 73, Tom Donaly, KA6RUH |
Noise level between two ant types
Cecil Moore wrote:
wrote: Of course if I viewed the world through a 80 meter dipole at 50 feet with only dust to worry about and never talked to the fellow at NASA, or if I never had multiple antennas on multiple tall towers or worked on all those commercial systems, I might agree with Cecil. When the only tool one has is a corona hammer, all problems look like corona nails. Fortunately, I am familiar with both corona problems and dry-air wind-driven charged particle problems. All the problems I saw related to corona. At least that's what you assumed. Just because all the cars parked in your driveway are white doesn't mean all the cars in the world are white. 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. Tom says height makes all the difference. That would make a lot of sense given the way the earth's electric field is structured. 73, Tom Donaly, KA6RUH |
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. The argument is not what it is called. The argument is whether charged dry-air dust particles can transfer charge to bare-wire antennas. -- 73, Cecil http://www.qsl.net/w5dxp |
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. 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 |
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 |
Noise level between two ant types
Tom Donaly wrote:
You're the one who made the statements, Cecil, so you're the one who has to prove them. Sorry, I'm just agreeing with the 2000 ARRL Handbook and all other references I can find on the subject. It is you who has to prove all those references wrong. -- 73, Cecil, http://www.qsl.net/w5dxp |
Noise level between two ant types
wrote:
1.) It isn't the noise made by the actual contact of particle to the antenna that makes what is commonly called p-static noise. Assuming that "p-static" is precipitation static, you already agreed with the laws of physics that make your statement false. Any particle with a charge different from the antenna wire will cause particle noise even when the corona threshold is not even close. There's no way to stop a charged particle from transferring its charge to a bare-wire antenna. There's no way to keep that charge from equalizing through the link coupling in a non-folded dipole. This is all easily proved using very small charges nowhere near the corona threshold. I agree that some cars are white. I just disagree with your assertion that all cars are white. I agree with the 2000 ARRL Handbook about precipitation static Vs corona static. The 2000 ARRL Handbook says: "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." I also agree with what they say about corona static which certainly exists and is what you are talking about. But corona static is not the only thing that exists, as you are asserting. -- 73, Cecil, http://www.qsl.net/w5dxp |
Noise level between two ant types
On Thu, 15 Jun 2006 20:05:08 GMT, "Tom Donaly"
wrote: 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. BAILIFF! Whack his pee-pee! |
Noise level between two ant types
Cecil Moore wrote:
Tom Donaly wrote: You're the one who made the statements, Cecil, so you're the one who has to prove them. Sorry, I'm just agreeing with the 2000 ARRL Handbook and all other references I can find on the subject. It is you who has to prove all those references wrong. Ha, ha! Nice joke, Cecil. I'll tell you what: if you can show that a group of students can tell whether it's raining or not solely by listening to the static on a radio with an outside antenna, I might begin to believe part of what you say. Otherwise, all your talk about carefully selected references is little more than a pathetically hollow attempt at self justification. 73, Tom Donaly, KA6RUH (P.S. You'll have to figure out a way to get rid of any charge buildup in order to keep the corona noise at bay.) |
Noise level between two ant types
Cecil Moore wrote:
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". It especially shows up in the 300 inches a year lake effect snowfalls in northern NY. You can hear it on 6 and 2 quite well. These were DC grounded yagi antennas on all elements, so no corona available here, thank you. Also, K1RQG, who is net control of the EMENet on 14345 Sat and Sun mornings, had it so bad from rain last weekend that he couldn't copy most of the participants for a few minutes. And in a heavy rainstorm, I have doubts that it had much to do with corona. tom K0TAR |
Noise level between two ant types
Roy Lewallen wrote:
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. Welcome to my nightmare. How many joules does it take to scorch a carpet? . . . 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. If the antenna is at ground potential and charged particles move across it, does it not induce a current inthe antenna? 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. OK, current. You just saved me the trouble of digging out my old physics book, thanks. . . . It's impossible to contribute much to the understanding of complex phenomena without first gaining an understanding of the most basic principles. I couldn't care less about "contributing" to the diatribes on this ng that pretend to address "understanding" Like, I said, I just wanted to butt in. I'll continue to read the posts (for some strange reason). If I post, I trust that someone will always be there to correct my errors. |
Noise level between two ant types
Tom Donaly wrote:
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 Thanks, Tom, for your reasonable response. So, I guess we're talking lots of voltage and very little current...makes sense. Wasn't Ben Franklin involved in working all this out? I'll ask another question that no doubt is off the mark: The Santa Ana winds in California are supposed to blow for long periods of time. Are there any measures of voltage, current, joules or cole slaw on antennas in this area? Do they experience the "noise"? Couldn't one connect a large capacitor circuit to store the charge and trickle it to a battery? (I just won't give up, eh?) |
Noise level between two ant types
It especially shows up in the 300 inches a year lake effect snowfalls in
northern NY. You can hear it on 6 and 2 quite well. These were DC grounded yagi antennas on all elements, so no corona available here, thank you. What makes you think the charge gradient and corona goes away with a grounded element? Because there is never lightning and lightning never hits a grounded object? Where dod you get that idea? The earth is one terminal, the air and things in the air (like clouds) have a charge difference. Since the "sky" is one terminal and the earth the other with large charge differential, why would you think connecting a tall sructure to earth REDUCES the charge differential? Also, K1RQG, who is net control of the EMENet on 14345 Sat and Sun mornings, had it so bad from rain last weekend that he couldn't copy most of the participants for a few minutes. And in a heavy rainstorm, I have doubts that it had much to do with corona. Why? Maybe you can answer this..... Do we have more lightning, which is caused by a charge difference between clouds and earth so severe it actually arcs for thousands of feet, in heavy rain or on clear dry days? Do the leaders and streamers form on clear dry days, or when the weather is nasty? You have it exactly backwards Tom. Grounding the element doesn't reduce corna or reduce the charge difference between air and things in air around the element and the element, it INCREASES the difference. If we could float the element and allow the element to charge to the potential of things around the element, the voltage gradient between the element and things around the element would be reduced. Why do you think the element, if we float the feedline, arcs to earth? It does that because the air around the element is greatly different in potential than the earth. As for moisture, you also might do another test. Blow gently on a CRT anode lead. See if your hot humid breath increases corona or decreases it. Now go get a Windex bottle full of water and spray a mist on the anode lead and see if the corna goes away, or gets worse. I wonder how many people really understand there is a huge potential difference between the air and earth even on a calm clear day, and nasty weather can just make it worse. 73 Tom |
Noise level between two ant types
jawod wrote:
Tom Donaly wrote: 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 Thanks, Tom, for your reasonable response. So, I guess we're talking lots of voltage and very little current...makes sense. Wasn't Ben Franklin involved in working all this out? I'll ask another question that no doubt is off the mark: The Santa Ana winds in California are supposed to blow for long periods of time. Are there any measures of voltage, current, joules or cole slaw on antennas in this area? Do they experience the "noise"? Couldn't one connect a large capacitor circuit to store the charge and trickle it to a battery? (I just won't give up, eh?) You'll get a lot more energy out of the wind by just putting up a wind generator. There are many wind farms in California. 73, Tom Donaly, KA6RUH |
Noise level between two ant types
Tom Ring wrote:
Cecil Moore wrote: 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". It especially shows up in the 300 inches a year lake effect snowfalls in northern NY. You can hear it on 6 and 2 quite well. These were DC grounded yagi antennas on all elements, so no corona available here, thank you. Also, K1RQG, who is net control of the EMENet on 14345 Sat and Sun mornings, had it so bad from rain last weekend that he couldn't copy most of the participants for a few minutes. And in a heavy rainstorm, I have doubts that it had much to do with corona. tom K0TAR Grounding might make it worse. Can you see why? 73, Tom Donaly, KA6RUH |
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