| Page 1 of 2 | 1 | 2 |
|
|
Reflector Vs Director
When modelling close spaced element antenma
assemblies it is possible that some elements are physically longer than the "driven" element. Is the length of a element sufficient enough to declare that element a " reflector" or are there other caveates involved.( i.e. phase) As background to this question I would point out that that it is possible to have two closed spaced (positioned) elements one of which is shorter and one of which is longer than the "driven " element, this combination being placed either forward or to the rear of the "driven " element. Regards Art |
the length itself relative to the driven element length is not sufficient to
apply any particular label to an element of a parasitic antenna. it should be noted that the terms 'director' and 'reflector' are not necessarily scientific terms, they are more of a vague word description of how an element apparently works based on the observation of the antenna pattern. the real effect of each element of an antenna must be described by describing the current magnitudes and phases and the physical location of each element. a good example of this is a 2 element parasitic array, at one frequency the parasitic element may be a 'director' and at another frequency it could be described as a 'reflector'... without changing the length of either the driven or parasitic element. " wrote in message news:u85ge.72716$c24.9252@attbi_s72... When modelling close spaced element antenma assemblies it is possible that some elements are physically longer than the "driven" element. Is the length of a element sufficient enough to declare that element a " reflector" or are there other caveates involved.( i.e. phase) As background to this question I would point out that that it is possible to have two closed spaced (positioned) elements one of which is shorter and one of which is longer than the "driven " element, this combination being placed either forward or to the rear of the "driven " element. Regards Art |
Dave
I was hoping that the IEEE would have a definition upon which I could hang my hat on. Hate to see another quabble like we had with TOA! In my particular case I have two elements coupled in such a way that even tho only one is driven the other is also of the same phase ie. additive, all other elements are longer than the driven element which suggests multiple reflectors, absent an accepted definition. Regards Art " wrote in message news:u85ge.72716$c24.9252@attbi_s72... When modelling close spaced element antenma assemblies it is possible that some elements are physically longer than the "driven" element. Is the length of a element sufficient enough to declare that element a " reflector" or are there other caveates involved.( i.e. phase) As background to this question I would point out that that it is possible to have two closed spaced (positioned) elements one of which is shorter and one of which is longer than the "driven " element, this combination being placed either forward or to the rear of the "driven " element. Regards Art |
Art Unwin wrote:
"When modeling close spaced element antenna assemblies it is possible that some elements are physically longer than the "driven" element. Is the length of an element sufficient to declare a "reflector" or are there other caveats involved (i.e. phase)?" Art answered his own question. The element doesn`t care how it gets a leading (capacitive) current, or a lagging (inductive) current. In our broadcast curtain antenna arrays, we used an RCA WM-30A phase monitor for the current angle in the ibnductive parasitic reflectors. Phase was adjusted to spec with a short-circuit stub connected to where the feedpoint would be if it were a driven element. Kraus is unequivocal on page 245 of edition no. 3 of "Antennas": "When the halfwave parasitic element is inductive (longer than its resonant length) it acts as a reflector. When it is capacitive (shorter than its resonant length) it acts as a director." Best regards, Richard Harrison, KB5WZI |
Interesting.
One respondent says position is a factor and the other says it is not according to Kraus ,who may well have been directing his comments at a Yagi model So I changed the feed point on my model, which is not a Yagi, to other elements to see if they lagging or leading. Surprise ! Some of the other elements were resonant also thus they could be fed in one or more places at the same time Since with the initial design they are not all directly fed these apparently do not fall into any catagory. I suppose literature in general can only apply definitions to that which is known by the author at the particular time Regards Art "Richard Harrison" wrote in message ... Art Unwin wrote: "When modeling close spaced element antenna assemblies it is possible that some elements are physically longer than the "driven" element. Is the length of an element sufficient to declare a "reflector" or are there other caveats involved (i.e. phase)?" Art answered his own question. The element doesn`t care how it gets a leading (capacitive) current, or a lagging (inductive) current. In our broadcast curtain antenna arrays, we used an RCA WM-30A phase monitor for the current angle in the ibnductive parasitic reflectors. Phase was adjusted to spec with a short-circuit stub connected to where the feedpoint would be if it were a driven element. Kraus is unequivocal on page 245 of edition no. 3 of "Antennas": "When the halfwave parasitic element is inductive (longer than its resonant length) it acts as a reflector. When it is capacitive (shorter than its resonant length) it acts as a director." Best regards, Richard Harrison, KB5WZI |
Well, everything stated may be true... but I have never seen a beam where
you would confuse the reflectors from the directors by physical size... if in doubt and you wish to confirm this--just look up! Warmest regards, John -- Sit down the six-pack!!! STEP AWAY!!! ...and go do something... " wrote in message news:u85ge.72716$c24.9252@attbi_s72... | When modelling close spaced element antenma | assemblies it is possible that some elements are | physically longer than the "driven" element. | Is the length of a element sufficient enough to | declare that element a " reflector" or are there | other caveates involved.( i.e. phase) | As background to this question I would point | out that that it is possible to have two closed | spaced (positioned) elements one of which is | shorter and one of which is longer than | the "driven " element, this combination being | placed either forward or to the rear of the | "driven " element. | Regards | Art | | |
John Smith wrote:
Well, everything stated may be true... but I have never seen a beam where you would confuse the reflectors from the directors by physical size... if in doubt and you wish to confirm this--just look up! Warmest regards, John Given a beam with two identical driven elements, which is the reflector and which is the director? :-) -- 73, Cecil http://www.qsl.net/w5dxp ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
Well Cecil:
You know me and my fondness for "tweaking" electrical lengths grin... I suspect it is more than possible to have 'em the same length, and indeed, you seen the folded 1 wave monopole I played with, it did exhibit side "nulls." Now, as to if the gain of the beam you point out is exactly equal or better, I doubt--as opposed to one being longer/shorter director/reflector (remember, I still ponder the ethers part in all of this--and NONE of our formulas take it into account)... but besides all of this... I JUST HAVEN'T SEEN ONE!!!! And, you know I am a hopeless "Assumer"--I dare to assume if it were such a great idea, I'd see a bunch---but then, I am open to a discovery here!!! Come on Cecil, with so many after my scalp--I can't afford losing any hair to you!!! grin I gotta get some work done here--I am turning off message notification... I will read/respond to your come-back later... grin Warmest regards, John -- Sit down the six-pack!!! STEP AWAY!!! ...and go do something... "Cecil Moore" wrote in message ... | John Smith wrote: | | Well, everything stated may be true... but I have never seen a beam where | you would confuse the reflectors from the directors by physical size... if | in doubt and you wish to confirm this--just look up! Warmest regards, John | | Given a beam with two identical driven elements, which is the | reflector and which is the director? :-) | -- | 73, Cecil http://www.qsl.net/w5dxp | | ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- | http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups | ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
Seems to me Cecil that the terms "Reflector" and
"Director" are very poor words to describe antenna elements for an HF array . I have oft times changed a single element into two closely coupled elements and where one is short and one is long relative to a driven element I wonder who was the first to assign these terms Or was it a poor translation from Japanese ( Uda and Yagi) ? Regards Art Cecil Moore" wrote in message ... John Smith wrote: Well, everything stated may be true... but I have never seen a beam where you would confuse the reflectors from the directors by physical size... if in doubt and you wish to confirm this--just look up! Warmest regards, John Given a beam with two identical driven elements, which is the reflector and which is the director? :-) -- 73, Cecil http://www.qsl.net/w5dxp ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
"John Smith" bravely wrote to "All" (11 May 05 09:21:00)
--- on the heady topic of " Reflector Vs Director" It's all about the frequency, physical length, and spacing... JS Reply-To: "John Smith" JS Xref: aeinews rec.radio.amateur.antenna:30111 JS Well, everything stated may be true... but I have never seen a beam JS where you would confuse the reflectors from the directors by physical JS size... if in doubt and you wish to confirm this--just look up! JS Warmest regards, JS John JS -- JS Sit down the six-pack!!! STEP AWAY!!! ...and go do something... JS " wrote in JS message news:u85ge.72716$c24.9252@attbi_s72... JS | When modelling close spaced element antenma JS | assemblies it is possible that some elements are JS | physically longer than the "driven" element. JS | Is the length of a element sufficient enough to JS | declare that element a " reflector" or are there JS | other caveates involved.( i.e. phase) JS | As background to this question I would point JS | out that that it is possible to have two closed JS | spaced (positioned) elements one of which is JS | shorter and one of which is longer than JS | the "driven " element, this combination being JS | placed either forward or to the rear of the JS | "driven " element. JS | Regards JS | Art .... There's always free cheese in a mousetrap. |
Art,
Think again about what you wrote. "I have oft times changed a single element into two closely coupled elements and where one is short and one is long relative to a driven element." Why would you mis-attribute your application of standard terminology to a new experimental situation as a "poor translation"? The appropriate terminology for the various elements is generally pretty clear from the physical design and performance of a Yagi antenna. When your experiments go beyond the original design you are on your own. 73, Gene W4SZ wrote: Seems to me Cecil that the terms "Reflector" and "Director" are very poor words to describe antenna elements for an HF array . I have oft times changed a single element into two closely coupled elements and where one is short and one is long relative to a driven element I wonder who was the first to assign these terms Or was it a poor translation from Japanese ( Uda and Yagi) ? Regards Art |
Exactly Gene.
This is why the thread asked for a "definition" first for director and reflector. As you are probably aware a yagi reflector does not reflect anything. Some would say that a dish "reflects but not a element. I am still a bit gun shy after the last episode where TOA was not defined in the IEEE dictionary thus many feined knowledge on the subject. I suspect tho that the nomenclature started with the Yagi and then spread to other array design descriptions. If however a Yagi reflector does actually "reflect" then your scolding is correctly directed at me.Perhaps we should first look in a dictionary for the word "reflector" Regards Art "Gene Fuller" wrote in message ... Art, Think again about what you wrote. "I have oft times changed a single element into two closely coupled elements and where one is short and one is long relative to a driven element." Why would you mis-attribute your application of standard terminology to a new experimental situation as a "poor translation"? The appropriate terminology for the various elements is generally pretty clear from the physical design and performance of a Yagi antenna. When your experiments go beyond the original design you are on your own. 73, Gene W4SZ wrote: Seems to me Cecil that the terms "Reflector" and "Director" are very poor words to describe antenna elements for an HF array . I have oft times changed a single element into two closely coupled elements and where one is short and one is long relative to a driven element I wonder who was the first to assign these terms Or was it a poor translation from Japanese ( Uda and Yagi) ? Regards Art |
If a yagi reflector, reflects nothing, what would account for the forward
gain of only a driven element and a "non-reflector?" I am not asking to be a smartass, but looking for some evidence of the ethers properties... (some might say I am looking for aliens? grin) Warmest regards, John -- Sit down the six-pack!!! STEP AWAY!!! ...and go do something... " wrote in message news:tEvge.74692$c24.13529@attbi_s72... | Exactly Gene. | This is why the thread asked for a "definition" first for director and | reflector. | As you are probably aware a yagi reflector does not reflect anything. | Some would say that a dish "reflects but not a element. | I am still a bit gun shy after the last episode where TOA was not | defined in the IEEE dictionary thus many feined knowledge on the subject. | I suspect tho that the nomenclature started with the Yagi and then | spread to other array design descriptions. | If however a Yagi reflector does actually "reflect" then your scolding | is correctly directed at me.Perhaps we should first look in a dictionary | for the word "reflector" | Regards | Art | | "Gene Fuller" wrote in message | ... | Art, | | Think again about what you wrote. | | "I have oft times changed a single element into two closely coupled | elements and where one is short and one is long relative to a driven | element." | | Why would you mis-attribute your application of standard terminology to a | new experimental situation as a "poor translation"? | | The appropriate terminology for the various elements is generally pretty | clear from the physical design and performance of a Yagi antenna. When | your experiments go beyond the original design you are on your own. | | 73, | Gene | W4SZ | | | wrote: | Seems to me Cecil that the terms "Reflector" and | "Director" are very poor words to describe antenna | elements for an HF array . | I have oft times changed a single element into two | closely coupled elements and where one is short | and one is long relative to a driven element | I wonder who was the first to assign these terms | Or was it a poor translation from Japanese ( Uda and Yagi) ? | Regards | Art | | |
Gene Fuller wrote: Art, Think again about what you wrote. "I have oft times changed a single element into two closely coupled elements and where one is short and one is long relative to a driven element." Why would you mis-attribute your application of standard terminology to a new experimental situation as a "poor translation"? The appropriate terminology for the various elements is generally pretty clear from the physical design and performance of a Yagi antenna. When your experiments go beyond the original design you are on your own. 73, Gene W4SZ wrote: Seems to me Cecil that the terms "Reflector" and "Director" are very poor words to describe antenna elements for an HF array . I have oft times changed a single element into two closely coupled elements and where one is short and one is long relative to a driven element I wonder who was the first to assign these terms Or was it a poor translation from Japanese ( Uda and Yagi) ? Regards Art |
wrote:
I wonder who was the first to assign these terms Or was it a poor translation from Japanese ( Uda and Yagi) ? Please note that John didn't mention Yagi's. He only mentioned "beams". :-) -- 73, Cecil http://www.qsl.net/w5dxp ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
wrote:
If however a Yagi reflector does actually "reflect" then your scolding is correctly directed at me.Perhaps we should first look in a dictionary for the word "reflector" From the IEEE Dictionary: "reflector element - A parasitic element located in a direction other than forward of the driven element of an antenna intended to increase the directivity of the antenna in the forward direction." "director element - A parasitic element located forward of the driven element of an antenna, intended to increase the directivity of the antenna in the forward direction." By this definition, a log-periodic has no reflectors and no directors. -- 73, Cecil http://www.qsl.net/w5dxp ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
Yes, I see that Cecil, but I suspect he is not a ham
and thus would not know the difference between different arrays. But if he is really looking for "Aliens" he may well be looking in the right direction but his LED's have a skewed correct "reflector". With respect to your two element example you stated that they were both driven. When coupled correctly it is only necessary to feed one element in an array and allow the coupled element to be of similar phase and if possible of a higher current flow to give you that 3 db additive advantage . Plus single digit elevation angle for max gain even tho the array is fed at 1 WL height.( 20 metres) I could send you actual model details if it is of interest. Or a photo if that interests you more. Regards Art "Cecil Moore" wrote in message ... wrote: I wonder who was the first to assign these terms Or was it a poor translation from Japanese ( Uda and Yagi) ? Please note that John didn't mention Yagi's. He only mentioned "beams". :-) -- 73, Cecil http://www.qsl.net/w5dxp ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
Interesting Cecil. Not only does it rely only on position versus
the driven element but they use the term reflector in the same breath as a parasitic device! Presumably length is not a factor. Mirror, Mirror on the wall now we will call you a parasite depending who is looking at you Just don't paint your antenna and use plenty of LED's so that the shiny surfaces will reflect. I give up, there are to many conflicting definitions. In my case it would appear that I have one driver, six reflectors and one parasitic driver, that should be explicit enough. Thanks everybody for your help Art "Cecil Moore" wrote in message ... wrote: If however a Yagi reflector does actually "reflect" then your scolding is correctly directed at me.Perhaps we should first look in a dictionary for the word "reflector" From the IEEE Dictionary: "reflector element - A parasitic element located in a direction other than forward of the driven element of an antenna intended to increase the directivity of the antenna in the forward direction." "director element - A parasitic element located forward of the driven element of an antenna, intended to increase the directivity of the antenna in the forward direction." By this definition, a log-periodic has no reflectors and no directors. -- 73, Cecil http://www.qsl.net/w5dxp ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
Well, I am not as bad as those guy with their "photon projecting
antennas"--my antennas propagate a wave though a medium--for want of a better word--I use ether to describe that medium... but, if anyone knows a better name--I am open... grin Warmest regards, John -- Sit down the six-pack!!! STEP AWAY!!! ...and go do something... " wrote in message news:KSwge.72444$NU4.47928@attbi_s22... | Yes, I see that Cecil, but I suspect he is not a ham | and thus would not know the difference between | different arrays. But if he is really looking for "Aliens" | he may well be looking in the right direction but his LED's | have a skewed correct "reflector". | With respect to your two element example you stated that | they were both driven. When coupled correctly it is only | necessary to feed one element in an array and allow the | coupled element to be of similar phase and if possible | of a higher current flow to give you that 3 db additive | advantage . Plus single digit elevation angle for max gain | even tho the array is fed at 1 WL height.( 20 metres) | I could send you actual model details if it is of interest. | Or a photo if that interests you more. | Regards | | Art | | | | | "Cecil Moore" wrote in message | ... | wrote: | I wonder who was the first to assign these terms | Or was it a poor translation from Japanese ( Uda and Yagi) ? | | Please note that John didn't mention Yagi's. He only | mentioned "beams". :-) | -- | 73, Cecil http://www.qsl.net/w5dxp | | ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet | News==---- | http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ | Newsgroups | ----= East and West-Coast Server Farms - Total Privacy via Encryption | =---- | | |
On Wed, 11 May 2005 19:09:12 -0700, "John Smith"
wrote: Well, I am not as bad as those guy with their "photon projecting antennas" Makes it infinitely easier to reckon which is the director or the reflector - just look. If you see yourself holding the flashlight, you are the director looking at the reflector. Now for the real challenge: What would you see if you looked into a conjugate mirror? Hint(s): it won't matter much if you are holding a flashlight OR a searchlight. No matter of semantics will change the perception either. Nothing to close couple (you are close enough already). No issue of size (as long as you can see the mirror frame - but having said that, this will then turn the answer on the shape of the frame I suppose). No impact will be discovered if there's another mirror behind it. No one needs to worry about translation problems from japanese. You won't find the answer in Kraus (or the IEEE dictionary I suspect). Computation of gain comes with the answer (and in all likelihood so will considerable error). 73's Richard Clark, KB7QHC |
"John Smith" wrote in message ... Well, I am not as bad as those guy with their "photon projecting antennas"--my antennas propagate a wave though a medium- Very good, An antena array is a collection of antennas all of which transmit interferring waves that are both additive and interfering negatives in the far field In other words just a collection of dipole radiators. which is then termed as an "array" which may or may not qualify as a "beam". For a Yagi style antenna position is all important which is not necessarily true for all antenna arrays, especially those of non liear form. .. In fact Uda and another guy wrote up the original design and Yagi stepped in later to provide a translation into English . For me I cannot see a relationship between positions of radiators other than with the Yagi and where the terms used suffered in the translation yet still gave a a mental picture that loosely matched a mirror or a reflector as an explanation. of how gain can occur. It would appear from the answers received that a true definition has not yet been agreed upon that is all encompassing in true electrical terms. Cheers and beers Art better word--I use ether to describe that medium... but, if anyone knows a better name--I am open... grin Warmest regards, John -- Sit down the six-pack!!! STEP AWAY!!! ...and go do something... " wrote in message news:KSwge.72444$NU4.47928@attbi_s22... | Yes, I see that Cecil, but I suspect he is not a ham | and thus would not know the difference between | different arrays. But if he is really looking for "Aliens" | he may well be looking in the right direction but his LED's | have a skewed correct "reflector". | With respect to your two element example you stated that | they were both driven. When coupled correctly it is only | necessary to feed one element in an array and allow the | coupled element to be of similar phase and if possible | of a higher current flow to give you that 3 db additive | advantage . Plus single digit elevation angle for max gain | even tho the array is fed at 1 WL height.( 20 metres) | I could send you actual model details if it is of interest. | Or a photo if that interests you more. | Regards | | Art | | | | | "Cecil Moore" wrote in message | ... | wrote: | I wonder who was the first to assign these terms | Or was it a poor translation from Japanese ( Uda and Yagi) ? | | Please note that John didn't mention Yagi's. He only | mentioned "beams". :-) | -- | 73, Cecil http://www.qsl.net/w5dxp | | ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet | News==---- | http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ | Newsgroups | ----= East and West-Coast Server Farms - Total Privacy via Encryption | =---- | | |
Oh yes, the important spacing--we agree on that alright (the rest too--I see
that physical/electrical length as important to--but "electrical length" and "magnetic field shape" are related on an almost linear scale), but what is "in" that "spacing"--now there is the nut of this... that "magnetic field" is not a "proton projection" and my antenna does not "glow"--and that "space" ain't no wire--or is it? Warmest regards, John -- Sit down the six-pack!!! STEP AWAY!!! ...and go do something... "Asimov" wrote in message ... | "John Smith" bravely wrote to "All" (11 May 05 09:21:00) | --- on the heady topic of " Reflector Vs Director" | | | It's all about the frequency, physical length, and spacing... | | | JS Reply-To: "John Smith" | JS Xref: aeinews rec.radio.amateur.antenna:30111 | | JS Well, everything stated may be true... but I have never seen a beam | JS where you would confuse the reflectors from the directors by physical | JS size... if in doubt and you wish to confirm this--just look up! | | JS Warmest regards, | JS John | JS -- | JS Sit down the six-pack!!! STEP AWAY!!! ...and go do something... | JS " wrote in | JS message news:u85ge.72716$c24.9252@attbi_s72... | JS | When modelling close spaced element antenma | JS | assemblies it is possible that some elements are | JS | physically longer than the "driven" element. | JS | Is the length of a element sufficient enough to | JS | declare that element a " reflector" or are there | JS | other caveates involved.( i.e. phase) | JS | As background to this question I would point | JS | out that that it is possible to have two closed | JS | spaced (positioned) elements one of which is | JS | shorter and one of which is longer than | JS | the "driven " element, this combination being | JS | placed either forward or to the rear of the | JS | "driven " element. | JS | Regards | JS | Art | | ... There's always free cheese in a mousetrap. | |
John Smith wrote:
"Oh yes, the important spacing--" Proximity determines induction in a parasiteic element. Far from an energy source, the parasite captures little energy and re-radiates little. The mutual impedance between elements is small when spacing is large. A parasite must be nearly resonant to become excited. Behavior is similar to a reed in a resonant-reed frequency indicator. The resonant reed is strongly excited. Other reeds are little excited at the wrong frequency. An out of tune antenna element has its current impeded by reactance. A resonant element has no reactance. Detuning a parasitic element is slight if excitation is to be maintained, but it is enough to make the element reflect or direct as desired. Magnetic fields are naturally produced around current-carrying conductors and around displacement currents too. Electric and magnetic force lines are mutually perpendicular. In space, the plane containing crossed electric and magnetic lines is called the wave front. Travel direction of the front is perpendicular to the crossed electric and magnetic lines. Wave theory accurately predicted radio behavior before anyone thought of acceleration causing photon emissions. Best regards, Richard Harrison, KB5WZI |
"John Smith" bravely wrote to "All" (11 May 05 22:25:13)
--- on the heady topic of " Reflector Vs Director" The only thing I know is that an antenna is a tricky compromise between a myriad of physical constants that make it up. Simply changing the dimensions of an element will affect the optimum spacing for maximum gain. But then so too having maximum gain as a goal will often reduce bandwidth. So some compromise to gain/bandwidth must be made to have a real antenna at the end of the process. Many such mutually defeating compromises must be juggled with to achieve this. Then, as if this wasn't enough, one must add the interaction with the environment, thinks like weather, proximity to objects, noise, etc. A*s*i*m*o*v JS Reply-To: "John Smith" JS Xref: aeinews rec.radio.amateur.antenna:30174 JS Oh yes, the important spacing--we agree on that alright (the rest JS too--I see that physical/electrical length as important to--but JS "electrical length" and "magnetic field shape" are related on an JS almost linear scale), but what is "in" that "spacing"--now there is JS the nut of this... that "magnetic field" is not a "proton projection" JS and my antenna does not "glow"--and that "space" ain't no wire--or is JS it? .... Children come from God. He can't stand the noise either. |
If I lay two marbles on a flat sheet on a bed, and their spacing is close--I
take my finger and push one marble down into the material of the bed--so as it deforms or "warps" the shape of the bedding, the other marble is "pulled" towards it--if the two marbles are far apart--the second is unaffected... If ether has a property similar to that bed, I can warp that ether and cause objects to be affected--in relationship to their proximity to the "warp" I am causing... If I place a piece of paper over a magnet--gently sprinkle iron powder over the paper--I see lines--claimed to be a "magnetic field".... .... do you think these "lines" are photons (waves?)shooting from one end of the magnet to the other (of course they would actually be lying outside the metal of the magnet in a "static" state).... or is this iron powder a "warping" of the ether I am looking at? Warmest regards, John -- Sit down the six-pack!!! STEP AWAY!!! ...and go do something... "Richard Harrison" wrote in message ... | John Smith wrote: | "Oh yes, the important spacing--" | | Proximity determines induction in a parasiteic element. Far from an | energy source, the parasite captures little energy and re-radiates | little. The mutual impedance between elements is small when spacing is | large. | | A parasite must be nearly resonant to become excited. Behavior is | similar to a reed in a resonant-reed frequency indicator. The resonant | reed is strongly excited. Other reeds are little excited at the wrong | frequency. An out of tune antenna element has its current impeded by | reactance. A resonant element has no reactance. | | Detuning a parasitic element is slight if excitation is to be | maintained, but it is enough to make the element reflect or direct as | desired. | | Magnetic fields are naturally produced around current-carrying | conductors and around displacement currents too. Electric and magnetic | force lines are mutually perpendicular. In space, the plane containing | crossed electric and magnetic lines is called the wave front. Travel | direction of the front is perpendicular to the crossed electric and | magnetic lines. | | Wave theory accurately predicted radio behavior before anyone thought of | acceleration causing photon emissions. | | Best regards, Richard Harrison, KB5WZI | |
Richard Clark wrote: What would you see if you looked into a conjugate mirror? You need to define the particular aspect being conjugated. For example, the person I see in the mirror appears to be right handed. In another sense the object in the mirror moves synchronously with me as if it were coupled to me. Any mirror exhibits conjugate behavior in some sense. Perhaps you're alluding to phase conjugation - an interesting effect. Hint(s): it won't matter much if you are holding a flashlight OR a searchlight. No matter of semantics will change the perception either. Nothing to close couple (you are close enough already). No issue of size (as long as you can see the mirror frame - but having said that, this will then turn the answer on the shape of the frame I suppose). No impact will be discovered if there's another mirror behind it. No one needs to worry about translation problems from japanese. You won't find the answer in Kraus (or the IEEE dictionary I suspect). Computation of gain comes with the answer (and in all likelihood so will considerable error). Effluvium for the sake of effluence, and vice versa. ac6xg |
Jim Kelley wrote:
the person I see in the mirror appears to be right handed. Hey Jim, if a mirror reverses left and right, why doesn't it also reverse up and down? :-) -- 73, Cecil, http://www.qsl.net/w5dxp ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 100,000 Newsgroups ---= East/West-Coast Server Farms - Total Privacy via Encryption =--- |
Cecil:
That is easy, our eyes actually see an image which IS upside down... the brain reverses this for us... when we look in the mirror--it stops the reversal!!! Tricky dern thing!!! grin Warmest regards, John -- Sit down the six-pack!!! STEP AWAY!!! ...and go do something... "Cecil Moore" wrote in message ... | Jim Kelley wrote: | the person I see in the mirror appears to be right handed. | | Hey Jim, if a mirror reverses left and right, | why doesn't it also reverse up and down? :-) | -- | 73, Cecil, http://www.qsl.net/w5dxp | | | ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- | http://www.newsfeeds.com The #1 Newsgroup Service in the World! 100,000 Newsgroups | ---= East/West-Coast Server Farms - Total Privacy via Encryption =--- |
Cecil Moore wrote: Jim Kelley wrote: the person I see in the mirror appears to be right handed. Hey Jim, if a mirror reverses left and right, why doesn't it also reverse up and down? :-) :-) Excellent. ac6xg |
"John Smith" bravely wrote to "All" (12 May 05 08:02:11)
--- on the heady topic of " Reflector Vs Director" JS Reply-To: "John Smith" JS Xref: aeinews rec.radio.amateur.antenna:30186 JS If I place a piece of paper over a magnet--gently sprinkle iron powder JS over the paper--I see lines--claimed to be a "magnetic field".... JS ... do you think these "lines" are photons (waves?)shooting from one JS end of the magnet to the other (of course they would actually be lying JS outside the metal of the magnet in a "static" state).... or is this JS iron powder a "warping" of the ether I am looking at? The lines are the after-effects of placing the iron powder in the path of "virtual" photons. These are photons that exist too briefly to be detected. Spacetime is not an empty vacuum but is a frothing of energy and virtual particles of all kinds. The virtual photons responsible for the observed permanent magnet's field travel only a small fraction of a wavelength but their wavelength is almost infinite. (i.e. c/F=3dinfinite, when F=3dzero). A*s*i*m*o*v .... "If you try to fail, and succeed, which have you done?" -George Carlin |
Cecil:
It that mirror or yours working correctly? Did you try hanging it upside down? You don't live below the equator do you? Cause, yanno, water spins one way going down a drain in the northern, opposite in the southern--somethin' 'bout gravity--or the warping of the ether... grin Warmest regards, John -- Sit down the six-pack!!! STEP AWAY!!! ...and go do something... "Cecil Moore" wrote in message ... | Jim Kelley wrote: | the person I see in the mirror appears to be right handed. | | Hey Jim, if a mirror reverses left and right, | why doesn't it also reverse up and down? :-) | -- | 73, Cecil, http://www.qsl.net/w5dxp | | | ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- | http://www.newsfeeds.com The #1 Newsgroup Service in the World! 100,000 Newsgroups | ---= East/West-Coast Server Farms - Total Privacy via Encryption =--- |
On Thu, 12 May 2005 10:04:12 -0700, Jim Kelley
wrote: You need to define the particular aspect being conjugated. For example, Hi Jim, In fact I don't (which is the whole point of ANY characteristic being conjugated) because it doesn't matter. There is no aspect (of what you observe) that is without its conjugate being mirrored. However, your presumption: the person I see in the mirror appears to be right handed. already disqualifies your answer. The "effluvium" as you described it, was literally true, and necessary. Being ignored, it has precipitated my projected expectation: ... Computation of gain comes with the answer (and in all likelihood so will considerable error). The "effluvium" as you described it, was literally true as the discussion (also anticipated) has been reduced to the frame of the mirror (as so commonly happens in these threads) while abandoning the substance of the conjugate mirror. This, of course, compounds the observation above about the rapid descent into errant discussion. Anyway, the original challenge: What would you see if you looked into a conjugate mirror? is meaningful within the context of the Subject line, but perhaps is a bit too abstract (after all, it does require a knowledge of sight and conjugation, not a simple coupling of experience). For those who fear Shakespeare, there is only one three syllable word. Someone may yet stumble on the answer. ;-) 73's Richard Clark, KB7QHC |
"John Smith wonders if Richard is really Shakespeare reincarnated--and, was
Shakespeare a Hindu, like Cecil?" Warmest regards, John -- Sit down the six-pack!!! STEP AWAY!!! ...and go do something... "Richard Clark" wrote in message ... | On Thu, 12 May 2005 10:04:12 -0700, Jim Kelley | wrote: | | You need to define the particular aspect being conjugated. For example, | | Hi Jim, | | In fact I don't (which is the whole point of ANY characteristic being | conjugated) because it doesn't matter. There is no aspect (of what | you observe) that is without its conjugate being mirrored. However, | your presumption: | the person I see in the mirror appears to be right handed. | already disqualifies your answer. | | The "effluvium" as you described it, was literally true, and | necessary. Being ignored, it has precipitated my projected | expectation: | ... Computation of gain comes with the answer (and in all | likelihood so will considerable error). | | The "effluvium" as you described it, was literally true as the | discussion (also anticipated) has been reduced to the frame of the | mirror (as so commonly happens in these threads) while abandoning the | substance of the conjugate mirror. This, of course, compounds the | observation above about the rapid descent into errant discussion. | | Anyway, the original challenge: | What would you see if you looked into a conjugate mirror? | is meaningful within the context of the Subject line, but perhaps is a | bit too abstract (after all, it does require a knowledge of sight and | conjugation, not a simple coupling of experience). For those who | fear Shakespeare, there is only one three syllable word. | | Someone may yet stumble on the answer. ;-) | | 73's | Richard Clark, KB7QHC |
Richard Clark wrote:
What would you see if you looked into a conjugate mirror? Please specify the system. -- 73, Cecil http://www.qsl.net/w5dxp ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
Richard:
I am confused... is "conjugate mirror" used in regards or "isogamic copulation" or "orgasmic copulation"--and does this involve mirrors on the ceiling? If so, a younger guy(s) and/or gal(s) may be needed here... grin And, really, I wondering if a definition can be given in mixed company!!!! Warmest regards, John -- Sit down the six-pack!!! STEP AWAY!!! ...and go do something... "Richard Clark" wrote in message ... | On Thu, 12 May 2005 10:04:12 -0700, Jim Kelley | wrote: | | You need to define the particular aspect being conjugated. For example, | | Hi Jim, | | In fact I don't (which is the whole point of ANY characteristic being | conjugated) because it doesn't matter. There is no aspect (of what | you observe) that is without its conjugate being mirrored. However, | your presumption: | the person I see in the mirror appears to be right handed. | already disqualifies your answer. | | The "effluvium" as you described it, was literally true, and | necessary. Being ignored, it has precipitated my projected | expectation: | ... Computation of gain comes with the answer (and in all | likelihood so will considerable error). | | The "effluvium" as you described it, was literally true as the | discussion (also anticipated) has been reduced to the frame of the | mirror (as so commonly happens in these threads) while abandoning the | substance of the conjugate mirror. This, of course, compounds the | observation above about the rapid descent into errant discussion. | | Anyway, the original challenge: | What would you see if you looked into a conjugate mirror? | is meaningful within the context of the Subject line, but perhaps is a | bit too abstract (after all, it does require a knowledge of sight and | conjugation, not a simple coupling of experience). For those who | fear Shakespeare, there is only one three syllable word. | | Someone may yet stumble on the answer. ;-) | | 73's | Richard Clark, KB7QHC |
Asimov:
Then: If I were shrunk to the size were an atom is the size of an orange and, I am holding it in my hand--and I look over at the next closest atom, in the block of lead I am standing in, and it appears to be about a football field length away... and if we agree on the preceeding... I have a LOT of this "free energy" and "virtual photons" in my body--correct? Indeed, my antenna has a LOT of it, in its' metal, does it not? And, it is swimming in it, is it not? And, if so, kinda strange no formula takes that into account, right? Warmest regards, John -- Sit down the six-pack!!! STEP AWAY!!! ...and go do something... "Asimov" wrote in message ... "John Smith" bravely wrote to "All" (12 May 05 08:02:11) --- on the heady topic of " Reflector Vs Director" JS Reply-To: "John Smith" JS Xref: aeinews rec.radio.amateur.antenna:30186 JS If I place a piece of paper over a magnet--gently sprinkle iron powder JS over the paper--I see lines--claimed to be a "magnetic field".... JS ... do you think these "lines" are photons (waves?)shooting from one JS end of the magnet to the other (of course they would actually be lying JS outside the metal of the magnet in a "static" state).... or is this JS iron powder a "warping" of the ether I am looking at? The lines are the after-effects of placing the iron powder in the path of "virtual" photons. These are photons that exist too briefly to be detected. Spacetime is not an empty vacuum but is a frothing of energy and virtual particles of all kinds. The virtual photons responsible for the observed permanent magnet's field travel only a small fraction of a wavelength but their wavelength is almost infinite. (i.e. c/F=infinite, when F=zero). A*s*i*m*o*v .... "If you try to fail, and succeed, which have you done?" -George Carlin |
On Thu, 12 May 2005 17:46:17 -0700, "John Smith"
wrote: I am confused This was not unexpected. |
On Thu, 12 May 2005 19:23:55 -0500, Cecil Moore
wrote: Please specify the system. Further elaboration is unnecessary. |
Richard Clark wrote:
Cecil Moore wrote: Please specify the system. Further elaboration is unnecessary. OK, the answer is that if the conjugate mirror involves RF waves, as it does in "Reflections", you would see nothing. -- 73, Cecil http://www.qsl.net/w5dxp ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
"John Smith" bravely wrote to "All" (12 May 05 18:16:40)
--- on the heady topic of " Reflector Vs Director" JS Reply-To: "John Smith" JS Xref: aeinews rec.radio.amateur.antenna:30219 JS Asimov: JS Then: JS If I were shrunk to the size were an atom is the size of an orange JS and, I am holding it in my hand--and I look over at the next closest JS atom, in the block of lead I am standing in, and it appears to be JS about a football field length away... and if we agree on the JS preceeding... I have a LOT of this "free energy" and "virtual photons" JS in my body--correct? JS Indeed, my antenna has a LOT of it, in its' metal, does it not? And, JS it is swimming in it, is it not? And, if so, kinda strange no formula JS takes that into account, right? Yes there is but the average net result of this energy is always zero. However, it can be detected as the Casimir Effect, Lamb Shift, and Van de Waals Forces which arise from the random motions of electrons. Some people have even described this effect as responsible for Dark Energy or Zero Point Energy, Fermi Sea, Quantum Ocean, or whatever descriptive term you like best. Some have speculated it is also responsible for the observed accelerating expansion of the universe. Some explanations-- Lamb Shift: " The effect of virtual particles can be measured, and in fact won a nobel prize for the physicist who did. the lamb shift is the shift in the spectrum of an electron around a nucleus caused by virtual particles swarming around it. " Casimir Effect: " The following comes from the Usenet Physics FAQ (http://math.ucr.edu/home/baez/physics/faq.html) and includes some references: Original by Philip Gibbs 24-January-1997 What is the Casimir Effect? The Casimir effect is a small attractive force which acts between two close parallel uncharged conducting plates. It is due to quantum vacuum fluctuations of the electromagnetic field. The effect was predicted by the Dutch physicist Hendrick Casimir in 1948. According to the quantum theory, the vacuum contains virtual particles which are in a continuous state of fluctuation (see physics FAQ article on virtual particles). Casimir realized that between two plates, only those virtual photons whose wavelengths fit a whole number of times into the gap should be counted when calculating the vacuum energy. The energy density decreases as the plates are moved closer which implies there is a small force drawing them together. The attractive Casimir force between two plates of area A separated by a distance a can be calculated to be, pi2 h-bar c F = ----------- A 240 a4 where h-bar is Planck's constant over two pi and c is the speed of light. The tiny force was measured in 1996 by Steven Lamoreaux. His results were in agreement with the theory to within the experimental uncertainty of 5%. Particles other than the photon also contribute a small effect but only the photon force is measurable. All Bosons such as photons produce an attractive Casimir force while Fermions make a repulsive contribution. If electromagnetism was supersymmetric there would be fermionic photinos whose contribution would exactly cancel that of the photons and there would be no Casimir effect. The fact that the Casimir effect exists shows that if supersymmetry exists in nature it must be a broken symmetry. According to the theory the total zero point energy in the vacuum is infinite when summed over all the possible photon modes. The Casimir effect comes from a difference of energies in which the infinities cancel. The energy of the vacuum is a puzzle in theories of quantum gravity since it should act gravitationally and produce a large cosmological constant which would cause space-time to curl up. The solution to the inconsistency is expected to be found in a theory of quantum gravity. References H.B.G. Casimir, Proc. Kon. Ned. Akad. Wetensch. B51, 793 (1948) S. Lamoreaux, Phys Rev Lett, 78, p5 (1996) " A*s*i*m*o*v .... Be nice to your kids. They'll choose your nursing home. |
| All times are GMT +1. The time now is 12:21 PM. |
|
Powered by vBulletin® Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
RadioBanter.com