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The earth
On Sun, 15 Apr 2012 18:49:08 +0200, "Szczepan Bialek"
wrote: And what do you do with the static build up? Best Regards, S* Use a static electricity dissipator: https://www.google.com/search?q=static+dissipator&tbm=isch Commonly found on airplane wing tips, fiberglass hull vessels, and ungrounded towers prone to lightning hits. A 1M resistor to ground will discharge any static build up across a base insulated tower. http://www.lbagroup.com/international/tower-lightning-protection.php http://www.lpsnet.com/ALS.asp I'm not sure why you're arguing about grounding antennas. There are plenty of examples of antennas that operate without a ground. If low frequencies are your immediate concern, may I point out that DF loop antennas are very popular on the beacon bands (200-400KHz). They also work nicely in airplanes, where there's no available earth ground. BCB is no different. There were plenty of antique home receivers that used either an internal or external loop (or loopstick) antenna, that didn't require a ground connection. If BCB stations decided to use horizontal dipoles instead of vertical monopoles, a ground would not be needed. The only reason they need a ground is to act as the counterpoise for the monopole. This provides the missing 1/4 wave element of the dipole. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
The earth
On 4/15/2012 11:28 AM, Channel Jumper wrote:
Well I am going to be unusually kind today, since it is Sunday and also because I am going to show some intelligence here. So everyone listen up - because I am only going to do this one time. How kind of you. I am not going to fight over who invented radio, or the different types of modulation scheme's - since the days of spark gap transmitters. I tried to post some relevant information - but it seemed to get lost in the jumble. The info you posted dealt with mostly mobile applications. Only vaguely relevant to the statement at hand, which was a quote from a long dead radio buoy, stating that no practical wireless system exists, which is not connected to earth. Most of the irrelevant blabber-gab deleted to save bandwidth, except for this one.. There is nothing in outer space for the signals to bounce off of - so they travel millions of miles in just a couple of seconds. That I would like to see, being as it takes light from the sun over eight minutes to travel from the sun, to the earth.. Try about 372,564 miles in two seconds.. Hardly millions.. Or that some ham would be willing to spend 10's of thousands of dollars to buy a transceiver that does the same basic thing as a AM radio you can buy in any Walmart or Goodwill for a couple of bucks. That's about one silly statement, unless the ham plans to do nothing but listen to KTRH all day long. Most use them in other ways, which most all of which the typical Wallace World special could only dream of. I only wish Wallace World sold usable amateur radios for a couple of bucks. I'd have several hundred more radios than I already have. :| When you crank up the power, it allows the person on the other end to use a smaller antenna - hence the people who buys or builds the big towers and the big beam antenna's would think that their investment would allow them global communications on a daily basis - and still we have not gotten past the fact that all reliable communicatiosn is LOS - even 100 years later... Does that mean they are all SOL? The OP wanted to debate the fact that some antenna's works best when we include some type of ground. Yes a good vertical transmitting antenna includes some type of ground to keep the signal from warming the clouds and being wasted. Not all verticals require ground systems, and how did the clouds ever get involved? Seems you may be confusing the benefits of feed line decoupling with the benefits of a radial system under a ground mounted monopole. :/ A beam antenna does not have a physical ground, yet still works - maybe the ground reflections helps the signals to travel further. Then maybe they don't.. Also, some directional arrays do use ground systems, if they are ground mounted. But this statement does not mean Marconi's statement is correct. But we all know that effective communications requires the antenna to be as high as possible. In some cases, it may make no difference how high the antennas are. In others, it may mean a great deal. Only once you get to what is it 38,000 miles one antenna will transmit to one hemisphere - or is it what ever part of the earth you can see and will transmit no further. That is the point of diminishing returns. Maybe so, but there are no structures that high for me to attach an antenna to. And I can't jump that high. :( |
The earth
In the statement about AM Broadcasters you state about the ideal ground
system & describe about the Radials but then ask why, That goes to show you don't know anything about Antennas, Transmitters. Feedlines, Matching, Efficiency, If you read farther you would have possibly learned something but you don't want to learn just bother the group. Nowhere in what you wrote does it state it is for static or what it is for except if you would read farther it would have told you...What about a balanced antenna, It has no earth connection & doesn't need one per your earth definition. If Maxwell was alive today & had read about all the improvements & discoveries that have been made & are still being made He would say He was wrong & that the answer to your question is NO.....I see you have started a new thread called Electron Gun but keep referring back to this thread for the answer. I'm very sure you know nothing about a electron gun, or a vacuum tube....To bad you don't know how to read or study & especially learn about anything... "Szczepan Bialek" wrote in message .. . "Jeff" napisal w wiadomosci ... On 15/04/2012 10:33, Szczepan Bialek wrote: Uzytkownik napisal w wiadomosci ... On 15/04/2012 09:58, Szczepan Bialek wrote: But you wrote that your radio have the earth/chassis. The point that you are missing is that the earth connection has NOTHING to do with transmitting or receiving a signal. If is merely there for safety in the event of a lightening strike or build up or static. So the radio have the earth/chassis. Ian's equipment will work no differently is the earth connection is disconnected. Marconi was WRONG!!!! And what about your equipment? Is the earth connection disconnected? S* I have no earth connection, so it cannot be connected or disconnected. Why than: "The ideal ground system forAM broadcasters comprises at least 120 buried copper or phosphor bronze radial wires at least one-quarter wavelength long and a ground-screen in the immediate vicinity of the tower. All the ground system components are bonded together, usually by welding, brazing or using coin silversolder to help reduce corrosion". From: http://en.wikipedia.org/wiki/Monopole_antenna Tell them that they are WRONG. S* |
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"Ian" napisał w wiadomości ... "Szczepan Bialek" wrote in message ... Real dipole needs: "In the lower half of the mast, there was a vertical steel tube, attached to the mast's outer structure with large insulators. This tube was grounded at the bottom, and connected electrically to the mast structure by an adjustable metal bar at 328 metres.[2] This technique allowed adjusting the impedance of the mast for the transmitter and worked by applying a DC ground at a point of low radiofrequency voltage, to conduct static charge to ground without diminishing the radio energy. Static electrical charge can build up to high values, even at times of no thunderstorm activity, when such tall structures are insulated from ground. Use of this technique provides better lightning protection than using just a spark gap at the mast feed, as is standard at most mast radiators insulated against ground." From: http://en.wikipedia.org/wiki/Warsaw_radio_tower End of discussion. S* Good evening Szczepan. The Warsaw radio mast was not a dipole. "Large constructed half-wavelength dipole towers include the Warsaw radio mast - the only half-wave dipole for longwave ever built." May I remind you that I would appreciate an answer to my question "Are you discussing resonant or non-resonant aerials, please?". It would help to clarify what you have in mind, It seems to me that you do not know what the word "resonans" means. We are discusing the earth/chassis/ counterpoise and the field electron emission. Best Regards, S* |
The earth
"Szczepan Bialek" wrote in message
... " "Large constructed half-wavelength dipole towers include the Warsaw radio mast - the only half-wave dipole for longwave ever built." May I remind you that I would appreciate an answer to my question "Are you discussing resonant or non-resonant aerials, please?". It would help to clarify what you have in mind, It seems to me that you do not know what the word "resonans" means. We are discusing the earth/chassis/ counterpoise and the field electron emission. Best Regards, S* Hello Szczepan. If you mean the Warsaw radio mast ( http://en.wikipedia.org/wiki/Warsaw_radio_mast ) then you are incorrect. It was not a dipole. Do you mean another tower which supported a dipole aerial? I assure you that I do know the meaning of "resonant". I need to know and understand it in order to match my radio to my aerials. Kindest regards, Ian. |
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"Jeff Liebermann" napisal w wiadomosci ... On Sun, 15 Apr 2012 18:49:08 +0200, "Szczepan Bialek" wrote: And what do you do with the static build up? Best Regards, S* Use a static electricity dissipator: https://www.google.com/search?q=static+dissipator&tbm=isch Commonly found on airplane wing tips, fiberglass hull vessels, and ungrounded towers prone to lightning hits. A 1M resistor to ground will discharge any static build up across a base insulated tower. http://www.lbagroup.com/international/tower-lightning-protection.php http://www.lpsnet.com/ALS.asp I'm not sure why you're arguing about grounding antennas. There are plenty of examples of antennas that operate without a ground. If low frequencies are your immediate concern, may I point out that DF loop antennas are very popular on the beacon bands (200-400KHz). They also work nicely in airplanes, where there's no available earth ground. BCB is no different. There were plenty of antique home receivers that used either an internal or external loop (or loopstick) antenna, that didn't require a ground connection. If BCB stations decided to use horizontal dipoles instead of vertical monopoles, a ground would not be needed. The only reason they need a ground is to act as the counterpoise for the monopole. This provides the missing 1/4 wave element of the dipole. I am not arguing. I agree with you that " they need a ground is to act as the counterpoise for the monopole." I hope that you agree with me that monopole on the plane/satellite has the counterpoise in form of chassis. S* |
The earth
Użytkownik "Howard K0ACF" napisał w wiadomości ... In the statement about AM Broadcasters you state about the ideal ground system & describe about the Radials but then ask why, That goes to show you don't know anything about Antennas, Transmitters. Feedlines, Matching, Efficiency, If you read farther you would have possibly learned something but you don't want to learn just bother the group. Nowhere in what you wrote does it state it is for static or what it is for except if you would read farther it would have told you...What about a balanced antenna, It has no earth connection & doesn't need one per your earth definition. If Maxwell was alive today & had read about all the improvements & discoveries that have been made & are still being made He would say He was wrong & that the answer to your question is NO.....I see you have started a new thread called Electron Gun but keep referring back to this thread for the answer. I'm very sure you know nothing about a electron gun, or a vacuum tube....To bad you don't know how to read or study & especially learn about anything... Is the field electron emission from the tip top of antenna or not? I "do not know anything about Antennas, Transmitters. Feedlines, Matching, Efficiency," S* |
The earth
Szczepan Bialek wrote:
I am not arguing. I agree with you that " they need a ground is to act as the counterpoise for the monopole." I hope that you agree with me that monopole on the plane/satellite has the counterpoise in form of chassis. S* You claimed that ANY transmitter with ANY antenna ALWAYS needs an earth connection. That is incorrect. If Marconi claimed that, Marconi was wrong. Now you are more and more restricting the playing field by talking about AM transmitters, monopoles, etc. And by extending your definition of "an earth connection" to a chassis. This of course leads to nothing. The original claim is still wrong. |
The earth
Szczepan Bialek wrote:
UÂżytkownik "Howard K0ACF" napisaÂł w wiadomoÂści ... In the statement about AM Broadcasters you state about the ideal ground system & describe about the Radials but then ask why, That goes to show you don't know anything about Antennas, Transmitters. Feedlines, Matching, Efficiency, If you read farther you would have possibly learned something but you don't want to learn just bother the group. Nowhere in what you wrote does it state it is for static or what it is for except if you would read farther it would have told you...What about a balanced antenna, It has no earth connection & doesn't need one per your earth definition. If Maxwell was alive today & had read about all the improvements & discoveries that have been made & are still being made He would say He was wrong & that the answer to your question is NO.....I see you have started a new thread called Electron Gun but keep referring back to this thread for the answer. I'm very sure you know nothing about a electron gun, or a vacuum tube....To bad you don't know how to read or study & especially learn about anything... Is the field electron emission from the tip top of antenna or not? I "do not know anything about Antennas, Transmitters. Feedlines, Matching, Efficiency," S* Not. There is no electron emission from an antenna when operated without arcing, something that everyone except Tesla wants to avoid at all times. |
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"Jeff" napisal w wiadomosci ... And what about your equipment? Is the earth connection disconnected? S* I have no earth connection, so it cannot be connected or disconnected. Why than: "The ideal ground system forAM broadcasters comprises at least 120 buried copper or phosphor bronze radial wires at least one-quarter wavelength long and a ground-screen in the immediate vicinity of the tower. All the ground system components are bonded together, usually by welding, brazing or using coin silversolder to help reduce corrosion". From: http://en.wikipedia.org/wiki/Monopole_antenna Tell them that they are WRONG. S* They are not wrong a such; your quote is about "AM broadcasters", which is normally (and incorrectly) meant to mean 'long & medium Wave' broadcasters. Because for the long wavelengths involved many such broadcasters choose to use vertical monopoles for antennas, and for those monopoles to work efficiently they do indeed require a good ground system. (These were the systems that Marconi was referring to). If there is sufficient space a dipole could be used which would *NOT* require the ground system. That in Warsaw required the ground system: ""Large constructed half-wavelength dipole towers include the Warsaw radio mast - the only half-wave dipole for longwave ever built." S* |
The earth
"Rob" napisal w wiadomosci ... Szczepan Bialek wrote: I am not arguing. I agree with you that " they need a ground is to act as the counterpoise for the monopole." I hope that you agree with me that monopole on the plane/satellite has the counterpoise in form of chassis. S* You claimed that ANY transmitter with ANY antenna ALWAYS needs an earth connection. That is incorrect. If Marconi claimed that, Marconi was wrong. Now you are more and more restricting the playing field by talking about AM transmitters, monopoles, etc. And by extending your definition of "an earth connection" to a chassis. This of course leads to nothing. The original claim is still wrong. The original Marconi's claim was: In 1909 Marconi wrote: http://www.nobelprize.org/nobel_priz...ni-lecture.pdf "The necessity or utility of the earth connection has been sometimes questioned, but in my opinion no practical system of wireless telegraphy exists where the instruments are not connected to earth.""By "connected to earth" I do not necessarily mean an ordinary metallicconnection as used for ordinary wire telegraphs.The earth wire may have a condenser in series with it, or it may beconnected to what is really equivalent, a capacity area placed close to thesurfaceof the ground (Fig. 4).It is now perfectly well known that a condenser, if large enough, does notprevent the passage of high frequency oscillations, and therefore in thesecasesthe earth is for all practical purposes connected to the antennae."Is the original claim wrong?S* |
The earth
Szczepan Bialek wrote:
"Rob" napisal w wiadomosci ... Szczepan Bialek wrote: I am not arguing. I agree with you that " they need a ground is to act as the counterpoise for the monopole." I hope that you agree with me that monopole on the plane/satellite has the counterpoise in form of chassis. S* You claimed that ANY transmitter with ANY antenna ALWAYS needs an earth connection. That is incorrect. If Marconi claimed that, Marconi was wrong. Now you are more and more restricting the playing field by talking about AM transmitters, monopoles, etc. And by extending your definition of "an earth connection" to a chassis. This of course leads to nothing. The original claim is still wrong. The original Marconi's claim was: In 1909 Marconi wrote: http://www.nobelprize.org/nobel_priz...ni-lecture.pdf "The necessity or utility of the earth connection has been sometimes questioned, but in my opinion no practical system of wireless telegraphy exists where the instruments are not connected to earth.""By "connected to earth" I do not necessarily mean an ordinary metallicconnection as used for ordinary wire telegraphs.The earth wire may have a condenser in series with it, or it may beconnected to what is really equivalent, a capacity area placed close to thesurfaceof the ground (Fig. 4).It is now perfectly well known that a condenser, if large enough, does notprevent the passage of high frequency oscillations, and therefore in thesecasesthe earth is for all practical purposes connected to the antennae."Is the original claim wrong?S* Yes, the original claim is wrong. It is wrong. Wrong. But you are not prepared to accept that. Please stop arguing. |
The earth
On 4/16/2012 3:40 AM, Szczepan Bialek wrote:
"Is the original claim wrong?S* Let me try this again in a repeating manner you might possibly be able to understand. I'm surely not going to hold my breath waiting for viable indications of comprehension, but here goes.. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. 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Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes, the man was wrong! wrong! wrong! wrong! wrong! wrong! wrong!!!! wrong! wrong! wrong! wrong! wrong! wrong! wrong! wrong! wrong! wrong! wrong! wrong! wrong! wrong! wrong! wrong! wrong! wrong! wrong! wrong! wrong! wrong! wrong! wrong! wrong! wrong! wrong! wrong! wrong! wrong! wrong! wrong! wrong! wrong! wrong! wrong! wrong! wrong! wrong! wrong! But he had an excuse.. It was 1909. Good grief... It does boggle the mind.. :| |
The earth
In message , NM5K writes
On 4/16/2012 3:40 AM, Szczepan Bialek wrote: "Is the original claim wrong?S* Let me try this again in a repeating manner you might possibly be able to understand. I'm surely not going to hold my breath waiting for viable indications of comprehension, but here goes.. Yes. Yes, the man was wrong! But he had an excuse.. It was 1909. Good grief... It does boggle the mind.. :| In the early days of radio, most experimenters tended to think of antennas as working by RF alternating currents charging (and discharging) a big capacitor in the sky via a long, vertical wire (or multiple wires, to increase the capacity, and to minimise losses). To push and pull the current in and out of the capacitor, it was necessary to have a good, solid, zero-potential reference point, and the best one available was ground/earth (or, at sea, the hull of the ship). So, for the types of antennas being experimented with (and used) at the time, Marconi was absolutely correct. Also, it wouldn't have taken them long to appreciate the benefits of bringing the antenna system to resonance on the frequency the operators wanted (rather than it simply being an act-of-God and hope-for-the-best affair). But note that with Marconi's famous crossing the Atlantic experiment, I believe there is no documentation of exactly what frequency was used. Instead of it being something extremely low (which is what they expected), it is now thought that the signal which travelled 3000 miles would have been one of the many harmonic resonances of the antenna, as this would have been excited by the extremely wide band of frequencies created by the spark transmitter. Knowing now what frequencies cross the Atlantic in daylight, the signal might have been as high as 10 or 15MHz (frequencies which Marconi only dreamt about using!). -- Ian |
The earth
On Mon, 16 Apr 2012 10:15:29 +0200, "Szczepan Bialek"
wrote: I am not arguing. Very well. You are debating. I agree with you that " they need a ground is to act as the counterpoise for the monopole." Not true. At higher frequencies, one can use the grounded coax cable feed to act as a crude counterpoise. I hope that you agree with me that monopole on the plane/satellite has the counterpoise in form of chassis. No. You claim that because the monopole requires a ground, therefore all antennas require a ground. That's too general a claim and is not true, even for a monopole. For example, a very common antenna type at 2.4GHz is a "meandering 1/4 wave" antenna, which uses no ground: http://802.11junk.com/jeffl/antennas/laptops/slides/compaq-2120us.html Another example is the metal rim of the iPhone 4G. It's an untuned, ungrounded, end-fed, monopole in the form of parts of a metal frame. There's also a large distinction between a "ground" and a counterpoise. A counterpoise is a part of the antenna system and may be earth ground in some situations. In RF, a ground is a connection to the earth. While there is some overlap in these definitions, your claim, that all antennas require a ground, was presumably referring to the earth ground, as described by your examples of broadcast towers and static buildups. For a satellite, there's may be a counterpoise, but no (earth) ground. The counterpoise is unlikely because most satellites use circular polarization (to eliminate sensitivity to orientation), using spiral wound or pyramid shaped antenna structures that are matched to whatever the coax cable provides. The skin of the satellite is crammed with other antennas, solar cells, and sensors, that finding an area sufficiently large to be considered a metal counterpoise, is impossible. The only thing really necessary for an antenna to function is the radiating element. Everything else is optional and depends on what you're trying to accomplish. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
The earth
"Jeff" napisal w wiadomosci ... They are not wrong a such; your quote is about "AM broadcasters", which is normally (and incorrectly) meant to mean 'long& medium Wave' broadcasters. Because for the long wavelengths involved many such broadcasters choose to use vertical monopoles for antennas, and for those monopoles to work efficiently they do indeed require a good ground system. (These were the systems that Marconi was referring to). If there is sufficient space a dipole could be used which would *NOT* require the ground system. That in Warsaw required the ground system: ""Large constructed half-wavelength dipole towers include the Warsaw radio mast - the only half-wave dipole for longwave ever built." S* As I said in one of my other posts: That does not describe a 'normal' balanced dipole, which is fed at the centre. It is the description of a very special case where a 1/2 wave length radiator is 'end-fed'. It is not what people normally mean when the refer to a dipole, although it is a 1/2 wavelength radiator fed against ground "Physic Principle An End Fed Half Wave Length Antenna is a variation of the much more common half wave length dipole antenna. When an antenna that is one half wave length long has RF energy applied to it at its resonant frequency a standing wave develops on it." The earth is connected at the node. "A node is a point along a standing wave where the wave has minimal amplitude." Does ""Large constructed half-wavelength dipole towers include the Warsaw radio mast - the only half-wave dipole for longwave ever built." needs the ground? S* |
The earth
Szczepan Bialek wrote:
Does ""Large constructed half-wavelength dipole towers include the Warsaw radio mast - the only half-wave dipole for longwave ever built." needs the ground? S* It does NOT require a ground to be functioning, assuming the energy is coupled into the radiator using some other way than an end-feed. Of course it would be stupid to erect an over 600m high mast and not connect it to ground, but that is for reasons entirely unrelated to its use as a transmitter antenna. |
The earth
"Rob" napisal w wiadomosci ... Szczepan Bialek wrote: Does ""Large constructed half-wavelength dipole towers include the Warsaw radio mast - the only half-wave dipole for longwave ever built." needs the ground? S* It does NOT require a ground to be functioning, assuming the energy is coupled into the radiator using some other way than an end-feed. Of course it would be stupid to erect an over 600m high mast and not connect it to ground, but that is for reasons entirely unrelated to its use as a transmitter antenna. So Marconi was not stupid. S* |
The earth
Szczepan Bialek wrote:
"Rob" napisal w wiadomosci ... Szczepan Bialek wrote: Does ""Large constructed half-wavelength dipole towers include the Warsaw radio mast - the only half-wave dipole for longwave ever built." needs the ground? S* It does NOT require a ground to be functioning, assuming the energy is coupled into the radiator using some other way than an end-feed. Of course it would be stupid to erect an over 600m high mast and not connect it to ground, but that is for reasons entirely unrelated to its use as a transmitter antenna. So Marconi was not stupid. S* Marconi was wrong. You are stupid. You cannot even grasp basic logic and reasoning. When you read that a cow is an animal, you think that every animal is a cow. |
The earth
"Jeff" napisal w wiadomosci ... As I said in one of my other posts: That does not describe a 'normal' balanced dipole, which is fed at the centre. It is the description of a very special case where a 1/2 wave length radiator is 'end-fed'. It is not what people normally mean when the refer to a dipole, although it is a 1/2 wavelength radiator fed against ground "Physic Principle An End Fed Half Wave Length Antenna is a variation of the much more common half wave length dipole antenna. When an antenna that is one half wave length long has RF energy applied to it at its resonant frequency a standing wave develops on it." The earth is connected at the node. "A node is a point along a standing wave where the wave has minimal amplitude." Does ""Large constructed half-wavelength dipole towers include the Warsaw radio mast - the only half-wave dipole for longwave ever built." needs the ground? S* No, the 1/2 wave radiator does not need a ground, however, because of the way they chose to feed the 1/2 wave, the feed system does. If they had chosen the insulate the tower half way up and feed it there no earth would have been required at all. The tower insulated half way up and feed there are the two monoples. It is the array. But such are in form of the two monopole mast 1/4 wave apart. Will be better to end the discussion. S* |
The earth
Szczepan Bialek wrote:
Is the field electron emission from the tip top of antenna or not? No. Read this: http://en.wikipedia.org/wiki/Field_electron_emission Read all of it. Then read it again until you understand it. After you have mastered that, read this: http://en.wikipedia.org/wiki/Corona_discharge Read all of it. Then read it again until you understand it. After you have mastered that, read this: http://en.wikipedia.org/wiki/Electric_arc Read all of it. Then read it again until you understand it. If you can get this far, your question has been answered fully. I "do not know anything about Antennas, Transmitters. Feedlines, Matching, Efficiency," Obviously. |
The earth
Szczepan Bialek wrote:
So Marconi was not stupid. No, Marconi was not stupid, but he was wrong about some things because he did not have all the information we now have 100 years later. You, however, are very stupid. |
The earth
Szczepan Bialek wrote:
Will be better to end the discussion. S* Would be even better when you did not start the discussion. Remember that for next time. |
The earth
On 4/16/2012 5:16 AM, Ian Jackson wrote:
To push and pull the current in and out of the capacitor, it was necessary to have a good, solid, zero-potential reference point, and the best one available was ground/earth (or, at sea, the hull of the ship). So, for the types of antennas being experimented with (and used) at the time, Marconi was absolutely correct. Yep.. I think the frustration tends to be difficulty in understanding that it's just one type of system, and others that do not require any ground connection do exist. Which means you would have to classify his statement as incorrect in the overall larger picture. I believe most have already stated that while some antennas do require such a connection, any "complete" antenna does not require one. The vast majority of my antennas do not require any ground connection for proper operation. Fer instance, I'm sitting out in the woods up at my recreational living center.. I have dipoles strung up in the trees which I leave there, and I roll the rg-58 coax up and hang it on a tree branch when I leave. Not a ground wire, or ground connection in sight.. And works perfectly well. Of course, you can't really see the wires here, but "S" can trust me, there is no ground connection. The radio is sitting on that stone bench, and the only connections are 12v to my car battery, and rg-58 coax feeding the dipoles. "I have 80 and 40 meter dipoles fed parallel with a single coax, and can slap a tuner on it, if I want to use some other band. " I have videos of this radio session using almost every band from 80m to 10m.. I went through each one seeing if they were active. They all were, up through 10m, on that day. If one wants to hear another band, just change the "80" in the url to "40", 20", "17", etc.. I think they should be on the server.. I think I missed 12m though for some reason.. Maybe no one was talking when I tuned it.. But it was open to somewhere, as I recorded Rarotonga Islands on 10m. http://home.comcast.net/~disk200/80.wmv Also, it wouldn't have taken them long to appreciate the benefits of bringing the antenna system to resonance on the frequency the operators wanted (rather than it simply being an act-of-God and hope-for-the-best affair). But note that with Marconi's famous crossing the Atlantic experiment, I believe there is no documentation of exactly what frequency was used. Instead of it being something extremely low (which is what they expected), it is now thought that the signal which travelled 3000 miles would have been one of the many harmonic resonances of the antenna, as this would have been excited by the extremely wide band of frequencies created by the spark transmitter. Knowing now what frequencies cross the Atlantic in daylight, the signal might have been as high as 10 or 15MHz (frequencies which Marconi only dreamt about using!). It wouldn't surprise me too much. Heck, I've been faked out more than once when using cheap receivers, and picking up something that was actually not on the frequency that I thought it was. :| |
The earth
In article , NM5K wrote:
Yep.. I think the frustration tends to be difficulty in understanding that it's just one type of system, and others that do not require any ground connection do exist. Which means you would have to classify his statement as incorrect in the overall larger picture. I believe most have already stated that while some antennas do require such a connection, any "complete" antenna does not require one. Correct. One interesting counter-example, would be the simple one of a full-wavelength loop of wire, which is fed with a balanced feedline (twinlead or open-wire or ladder line), which is fed from a fully-balanced transmitter output stage (e.g. with transformer coupling from the driver transistors). To be extreme about it, let's say that the transmitter is itself based on a fully-balanced (differential) circuit, all the way back to the crystal oscillator. It's powered by a single battery, and is installed in a plastic chassic. This sort of antenna would have no galvanic connection to "earth" at all. Measure the resistance or RF impedance between any part of the antenna or feedline structure, and *anything* not part of the antenna, and the result will be "huge". Since it's a loop antenna, it has no "ends"... no points at which electrons could "fly off". The net current flow going up the feedline to the antenna will be zero, at all points - a positive current on one side of the feedline will be exactly balanced by a negative current on the other side of the feedline. There are no "excess" electrons or charge flowing in either direction. You can even insulate the antenna wires, if you wish. It will transmit just fine, with no connection at all to "ground". Disconnect the transmitter, install a receiver of a similar "balanced and isolated" design, and it'll receive just as well... again, with no connection to "ground". -- Dave Platt AE6EO Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior I do _not_ wish to receive unsolicited commercial email, and I will boycott any company which has the gall to send me such ads! |
The earth
On 4/16/2012 3:51 AM, Rob wrote:
Szczepan wrote: The original Marconi's claim was: In 1909 Marconi wrote: http://www.nobelprize.org/nobel_priz...ni-lecture.pdf "The necessity or utility of the earth connection has been sometimes questioned, but in my opinion no practical system of wireless telegraphy exists where the instruments are not connected to earth.""By "connected to earth" I do not necessarily mean an ordinary metallicconnection as used for ordinary wire telegraphs.The earth wire may have a condenser in series with it, or it may beconnected to what is really equivalent, a capacity area placed close to thesurfaceof the ground (Fig. 4).It is now perfectly well known that a condenser, if large enough, does notprevent the passage of high frequency oscillations, and therefore in thesecasesthe earth is for all practical purposes connected to the antennae."Is the original claim wrong?S* Yes, the original claim is wrong. It is wrong. Wrong. But you are not prepared to accept that. Please stop arguing. He is a troll. Stopping feeding him would be the best idea. Google "PLONK". K0TAR |
The earth
Użytkownik napisał w wiadomości ... Szczepan Bialek wrote: Is the field electron emission from the tip top of antenna or not? No. Read this: http://en.wikipedia.org/wiki/Field_electron_emission Read all of it. Then read it again until you understand it. After you have mastered that, read this: http://en.wikipedia.org/wiki/Corona_discharge Read all of it. Then read it again until you understand it. After you have mastered that, read this: http://en.wikipedia.org/wiki/Electric_arc Read all of it. Then read it again until you understand it. If you can get this far, your question has been answered fully. I "do not know anything about Antennas, Transmitters. Feedlines, Matching, Efficiency," Obviously. You are ordering me to read the above. Why you do not read it. There is wrote: "A further feature of the structure of negative coronas is that as the electrons drift outwards, they encounter neutral molecules and, withelectronegative molecules (such as oxygen and water vapor), combine to produce negative ions. These negative ions are then attracted to the positive uncurved electrode, completing the 'circuit'.". From: Negative coronas. Mechanism. http://en.wikipedia.org/wiki/Corona_...gative_coronas "The difference, then, between positive and negative coronas, in the matter of the generation of secondary electron avalanches, is that in a positive corona they are generated by the gas surrounding the plasma region, the new secondary electrons travelling inward, whereas in a negative corona they are generated by the curved electrode itself, the new secondary electrons travelling outward." "in a negative corona the electrons are generated by the curved electrode itself". Is the field electron emission from the tip top of antenna or not? S* |
The earth
"NM5K" napisal w wiadomosci ... Fer instance, I'm sitting out in the woods up at my recreational living center.. I have dipoles strung up in the trees which I leave there, and I roll the rg-58 coax up and hang it on a tree branch when I leave. Not a ground wire, or ground connection in sight.. And works perfectly well. Of course, you can't really see the wires here, but "S" can trust me, there is no ground connection. The radio is sitting on that stone bench, and the only connections are 12v to my car battery, Where is the car battery? On the stone bench or in the car? S* |
The earth
"Dave Platt" napisał w wiadomości ... Since it's a loop antenna, it has no "ends"... no points at which electrons could "fly off". A loop antena have the antinodes. The points at which electrons could "fly off". See Fig. 2: http://www.antiquewireless.org/otb/lodge1102.htm The net current flow going up the feedline to the antenna will be zero, at all points - a positive current on one side of the feedline will be exactly balanced by a negative current on the other side of the feedline. There are no "excess" electrons or charge flowing in either direction. ""A further feature of the structure of negative coronas is that as the electrons drift outwards, they encounter neutral molecules and, withelectronegative molecules (such as oxygen and water vapor), combine to produce negative ions. These negative ions are then attracted to the positive uncurved electrode, completing the 'circuit'.". From: Negative coronas. Mechanism. http://en.wikipedia.org/wiki/Corona_...gative_coronas In the each antenna is the excess/deficit of electrons and "charge flowing in either direction." But the negative corona and the positive corona are not simmetrical. At transmitting you have the deficit and at receiving the excess. Without the earth the static build up and radio stop working. You can even insulate the antenna wires, if you wish. Can you measure the static electricity? It will transmit just fine, with no connection at all to "ground". Disconnect the transmitter, install a receiver of a similar "balanced and isolated" design, and it'll receive just as well... again, with no connection to "ground". You will transmit just fine if you have the ground/chassis/counterpoise. S* |
The earth
Szczepan Bialek wrote:
At transmitting you have the deficit and at receiving the excess. Without the earth the static build up and radio stop working. How would you know that when you don't even have a transmitter? You will transmit just fine if you have the ground/chassis/counterpoise. S* And without it, fine as well. |
The earth
"Jeff" napisal w wiadomosci ... You are ordering me to read the above. Why you do not read it. There is wrote: "A further feature of the structure of negative coronas is that as the electrons drift outwards, they encounter neutral molecules and, withelectronegative molecules (such as oxygen and water vapor), combine to produce negative ions. These negative ions are then attracted to the positive uncurved electrode, completing the 'circuit'.". From: Negative coronas. Mechanism. http://en.wikipedia.org/wiki/Corona_...gative_coronas "The difference, then, between positive and negative coronas, in the matter of the generation of secondary electron avalanches, is that in a positive corona they are generated by the gas surrounding the plasma region, the new secondary electrons travelling inward, whereas in a negative corona they are generated by the curved electrode itself, the new secondary electrons travelling outward." "in a negative corona the electrons are generated by the curved electrode itself". Is the field electron emission from the tip top of antenna or not? S* Yes it is, but the effect being talked about is corona discharge, and has nothing to do with the wanted radiation of radio waves. It is an *unwanted* effect on normal antennas, and occurs when the voltage at certain points gets high enough to cause ionization of the air. I repeat it is normally an *UNWANTED* condition on a normal radio antenna used for communication. And the "normal" remedy for it is the earth/chassis/couterpoise. S* |
The earth
On Apr 17, 3:41*am, Jeff wrote:
Corona discharge has nothing to do with grounding, it is purely due to the peak voltages seen at, (usually), the tips of the elements. To what are those peak voltages referenced? -- 73, Cecil, w5dxp.com |
The earth
I doubt that he is a troll. Trolls usually show some intelligence in
adapting their responses, so as to keep the fun going. This one simply fixates on a few sentences and appears unable to focus on anything out of the immediate context of the original sentence. This inability to shift focus to process new information is more a symptom of a cerebral handicap, something like Alzhheimer's or Asperger's diseases or even early-stage dementia. Unfortunately, there is not a great deal that medicine can do for these problems. Perhaps his keepers give him a computer to occupy his attention. Internet newsgroups are wonderful (IMO), but there are not good mechanisms to prevent one or two people from destroying an otherwise excellent group. One can plonk the offender(s), but that still leaves all the responses visible. I wish people would simply cease responding to him, since it is a pointless exercise. Bill |
The earth
"Bill Ogden" wrote in message
... I doubt that he is a troll. Trolls usually show some intelligence in adapting their responses, so as to keep the fun going. This one simply fixates on a few sentences and appears unable to focus on anything out of the immediate context of the original sentence. This inability to shift focus to process new information is more a symptom of a cerebral handicap, something like Alzhheimer's or Asperger's diseases or even early-stage dementia. Unfortunately, there is not a great deal that medicine can do for these problems. Perhaps his keepers give him a computer to occupy his attention. Internet newsgroups are wonderful (IMO), but there are not good mechanisms to prevent one or two people from destroying an otherwise excellent group. One can plonk the offender(s), but that still leaves all the responses visible. I wish people would simply cease responding to him, since it is a pointless exercise. Bill Hello Bill. Thanks - you said it and I thought it. He seems to copy phrases and paste them without understanding what they mean. I still reckon we had a good discussion about aerials. Regards, Ian. |
The earth
"Rob" napisal w wiadomosci ... Szczepan Bialek wrote: At transmitting you have the deficit and at receiving the excess. Without the earth the static build up and radio stop working. How would you know that when you don't even have a transmitter? But my "friend" Marconi had a lot. He wrote: "but in my opinion no practical system of wireless telegraphy exists where the instruments are not connected to earth." You will transmit just fine if you have the ground/chassis/counterpoise. S* And without it, fine as well. It is not true. You know that. S* |
The earth
Szczepan Bialek wrote:
You are ordering me to read the above. Why you do not read it. I did read all that and more when I went to school and took electromagnetics classes. snip quotes from Wiki Is the field electron emission from the tip top of antenna or not? No. You obviously did not read the information or did not understand it. |
The earth
Jeff wrote:
Is the field electron emission from the tip top of antenna or not? Yes it is, but the effect being talked about is corona discharge, and has nothing to do with the wanted radiation of radio waves. It is an *unwanted* effect on normal antennas, and occurs when the voltage at certain points gets high enough to cause ionization of the air. I repeat it is normally an *UNWANTED* condition on a normal radio antenna used for communication. Jeff What happens on antennas is NOT "field electron emission" by the modern definition of the term. Corona discharge is something else, related, but something else. |
The earth
Szczepan Bialek wrote:
And the "normal" remedy for it is the earth/chassis/couterpoise. S* No, it is not. |
The earth
"Szczepan Bialek" wrote in message ... "Rob" napisal w wiadomosci ... Szczepan Bialek wrote: At transmitting you have the deficit and at receiving the excess. Without the earth the static build up and radio stop working. How would you know that when you don't even have a transmitter? But my "friend" Marconi had a lot. He wrote: "but in my opinion no practical system of wireless telegraphy exists where the instruments are not connected to earth." You will transmit just fine if you have the ground/chassis/counterpoise. S* And without it, fine as well. It is not true. You know that. S* Hello chaps. Several of you have said that Szczepan seems unable to accept new ideas. I see that he persists in believing Marconi's comment that an earth connection is necessary. Those of us who use Yagi , loop or dipole aerials know, through experience, that an earth connection is not necessary. I am undecided why he prefers to believe the opinion of someone who worked in the early days of radio rather than those of us who use radio in modern times. I feel it is awkward to say that Marconi was wrong even though we now know this is the case. Personally, I'd say that Marconi's opinion that "no practical system of wireless telegraphy exists where the instruments are not connected to earth" obviously related to his own use of wireless. As I understand it, Marconi's aerials were not resonant at the frequency he was using. They would therefore be a mis-match to his radios and this situation was alleviated by using connections to earth. I find it puzzling that Szczepan feels happy to ignore our comments and continue to accept Marconi's opinion given that he (Szczepan) said that a transmitter is a "black box" to him. I've speculated that his English may not be very good but I shall be amused if we find out that his first language is English despite his non-English name. He never answered my question about resonant / non-resonant aerials so I guess his technical knowledge is limited. Kindest regards to all, Ian. ps: If Szczepan is happy to constrain his knowledge to the days of Marconi then I wonder how come he is using a computer. Didn't have those in the days of Marconi. |
The earth
Szczepan Bialek wrote:
A loop antena have the antinodes. The points at which electrons could "fly off". Yet they do not. See Fig. 2: http://www.antiquewireless.org/otb/lodge1102.htm Why? A lot more has been learned since 1887. snip Can you measure the static electricity? Sure, with a static meter. Yet another device that didn't exist in 1887. You will transmit just fine if you have the ground/chassis/counterpoise. It depends on the type of antenna. If it is a dipole, yagi, log-periodic, sturba curtain, rhombic, parabolic, helix, loop, cubical quad, on any of many, many more types of antennas that have no place or need to connect a ground, it would not. |
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