Home |
Search |
Today's Posts |
|
#1
|
|||
|
|||
Yagi efficiency
On 24 Sep 2006 11:29:08 -0700, "
wrote: As my girlfriend likes to say "WORDS MEAN THINGS!" Having a weird definition of efficiency doesn't help anyone out. Needing an antenna with super-high-gain at one particular elevation and azimuth angle is a weird, but... sort of valid question... but has nothing to do with the efficiency of said antenna. Dan Hi Dan, From discussions of years past with the chipster, his novel k2 fractal flyer antenna (heavily constrained with unique parameters) offered the "best" gain at 10 degrees that couldn't be bettered by anyone. He took umbrage when this claim was examined in the modeler ("you can't make a copy of that antenna! I own the rights!"): http://www.qsl.net/kb7qhc/antenna/fr...r/k2/index.htm It turned out that the word "Best" meant -4.63 dBi - which I promptly bettered by more than half a dB (in an unpublished design I call the Foolish fractal Flyer). The chipster also made efficiency claims similar to Art's (that is, using the same corruption of language). It didn't take long to flush that efficiency with the same merits. The moral of inventing meanings for words is that those meanings have a short shelf life. This kind of thing doesn't even last out a week in the white house press room. 73's Richard Clark, KB7QHC |
#2
|
|||
|
|||
Yagi efficiency
The moral of inventing meanings for words is that those meanings have
a short shelf life. This kind of thing doesn't even last out a week in the white house press room. True, true. If only all this word-twisting energy could be harnessed as valid antenna design... the chipster seems to have relegated himself these days to fairly innocuous posts elsewhere regarding staying on the good side of your neighbors' graces by putting up visually low profile antennas... Certainly a change from the f-word antenna wars of old. I was a regular reader of r.r.a.a. in those days... not much of a poster back then, though. I wonder if a thousand-mile long, five mile high stack of rhombics might meet Art's requirements... of course, at that point you could just run open wire line to any distant receiver. That would be quite efficient, from Art's standpoint. 73, Dan |
#3
|
|||
|
|||
Yagi efficiency
Dan,
you know quite well what the post that started this thread asked for. I only added the TOA comments to fill in some body where I was coming from not for advice on what antenna to build. People are quibling over the word "efficiency" which I find rather wierd especially since I am supposed to be in the company of fellow engineers. The subject was antenna radiation patterns and ascertaining the relative volume of the main lobe which is the reason for an antenna and comparing it to the total volume of the array which one accepts to obtain the desirable primary lobe. Oh yes, when we talk of efficiency one must multiply the ratio by 100 Some may have forgotten that! Obviously this group comprises of a swarm of tadpoles with a few little goldfish in a small pond none of which are qualified to be termed faculty. Now you have something to get your teeth into since you deign to respond to the initial post This term "I don't understand" is usually used by student who enter class after late night partying and it didn't work then either. A dull brain is a dull brain unless one activates it. Carry on with a thread of your own choice and quibble amongst yourselves about what "is" is really meant by use of the word "is" For what was a very short question this thread has gone amok and is way to long Art wrote: The moral of inventing meanings for words is that those meanings have a short shelf life. This kind of thing doesn't even last out a week in the white house press room. True, true. If only all this word-twisting energy could be harnessed as valid antenna design... the chipster seems to have relegated himself these days to fairly innocuous posts elsewhere regarding staying on the good side of your neighbors' graces by putting up visually low profile antennas... Certainly a change from the f-word antenna wars of old. I was a regular reader of r.r.a.a. in those days... not much of a poster back then, though. I wonder if a thousand-mile long, five mile high stack of rhombics might meet Art's requirements... of course, at that point you could just run open wire line to any distant receiver. That would be quite efficient, from Art's standpoint. 73, Dan |
#4
|
|||
|
|||
Yagi efficiency
On 24 Sep 2006 13:41:43 -0700, "art" wrote:
you know quite well what the post that started this thread asked for. Yes, it is quite clearly offered in the Subject line, isn't it? People are quibling over the word "efficiency" which I find rather wierd And that is the second word of only two words in the Subject line, isn't it? when we talk of efficiency one must multiply the ratio by 100 Are we to expect 96 more duplications of your post? 73's Richard Clark, KB7QHC |
#5
|
|||
|
|||
Yagi efficiency
Dan wrote:
"---of course at that point you could just run open wire line to any distant receiver." Yes, if it isn`t too distant. If the 1000-mile open wire line lost 0.1 dB per 100 feet, loss would be 52.8 dB per mile or about 53 thousand db in its entire length, hardly a useable transmission line. On the other hand, suppose the wavelength were 160 meters. In the first wavelength of a radio signal radiated in free space, you would lose 22 dB. In the second, you would lose an additional 6 dB. Doubling the distance again to a total of 7 wavelengths, or 1120 meters, total space loss would be 34 dB. At a distance of 2240 meters from the transmitter, the loss is 40 dB which is less that our open wire line would lose in its 1st mile, a shorter distance. Every mile of wire line extracts the same loss. Very long wire lines become useless without repeaters to boost signal above the noise level. Doubling line-of-sight radio path distance only increases path loss 6dB, no matter how long the path is. As for efficiency, J.D. Kraus says: "The efficiency of an antenna is defined as the ratio between the power radiated by it and the power delivered into the antenna." (page 866 of 3rd ed. of "Antennas". Best regards, Richard Harrison, KB5WZI |
#6
|
|||
|
|||
Yagi efficiency
Dan,
you know quite well what the post that started this thread asked for. I only added the TOA comments to fill in some body where I was coming from not for advice on what antenna to build. People are quibling over the word "efficiency" which I find rather wierd especially since I am supposed to be in the company of fellow engineers. The subject was antenna radiation patterns and ascertaining the relative volume of the main lobe which is the reason for an antenna and comparing it to the total volume of the array which one accepts to obtain the desirable primary lobe. Oh yes, when we talk of efficiency one must multiply the ratio by 100 Some may have forgotten that! Obviously this group comprises of a swarm of tadpoles with a few little goldfish in a small pond none of which are qualified to be termed faculty. Now you have something to get your teeth into since you deign to respond to the initial post This term "I don't understand" is usually used by student who enter class after late night partying and it didn't work then either. A dull brain is a dull brain unless one activates it. Carry on with a thread of your own choice and quibble amongst yourselves about what "is" is really meant by use of the word "is" For what was a very short question this thread has gone amok and is way to long Art wrote: The moral of inventing meanings for words is that those meanings have a short shelf life. This kind of thing doesn't even last out a week in the white house press room. True, true. If only all this word-twisting energy could be harnessed as valid antenna design... the chipster seems to have relegated himself these days to fairly innocuous posts elsewhere regarding staying on the good side of your neighbors' graces by putting up visually low profile antennas... Certainly a change from the f-word antenna wars of old. I was a regular reader of r.r.a.a. in those days... not much of a poster back then, though. I wonder if a thousand-mile long, five mile high stack of rhombics might meet Art's requirements... of course, at that point you could just run open wire line to any distant receiver. That would be quite efficient, from Art's standpoint. 73, Dan |
#7
|
|||
|
|||
Yagi efficiency
art wrote:
The subject was antenna radiation patterns and ascertaining the relative volume of the main lobe which is the reason for an antenna and comparing it to the total volume of the array which one accepts to obtain the desirable primary lobe. Take the integral of the gain of the antenna over the angles in azimuth and elevation that you consider to define the boundaries of the main lobe and divide that by the integral of the gain of the antenna over all angles . You'll need your gain as a function of the angles. That's the number you're looking for, I suppose. I guess it's a decent measure of sidelobe suppression... but so is the ratio of the gain of the main lobe to the gain of the biggest sidelobe. 73, Dan |
#8
|
|||
|
|||
Yagi efficiency
art wrote:
Dan, you know quite well what the post that started this thread asked for. I only added the TOA comments to fill in some body where I was coming from not for advice on what antenna to build. People are quibling over the word "efficiency" which I find rather wierd especially since I am supposed to be in the company of fellow engineers. Interesting Art, you find that weird, and I find it as an explanation! 8^) - 73 de Mike KB3EIA - |
#9
|
|||
|
|||
Yagi efficiency
Dan,
you know quite well what the post that started this thread asked for. I only added the TOA comments to fill in some body where I was coming from not for advice on what antenna to build. People are quibling over the word "efficiency" which I find rather wierd especially since I am supposed to be in the company of fellow engineers. The subject was antenna radiation patterns and ascertaining the relative volume of the main lobe which is the reason for an antenna and comparing it to the total volume of the array which one accepts to obtain the desirable primary lobe. Oh yes, when we talk of efficiency one must multiply the ratio by 100 Some may have forgotten that! Obviously this group comprises of a swarm of tadpoles with a few little goldfish in a small pond none of which are qualified to be termed faculty. Now you have something to get your teeth into since you deign to respond to the initial post This term "I don't understand" is usually used by student who enter class after late night partying and it didn't work then either. A dull brain is a dull brain unless one activates it. Carry on with a thread of your own choice and quibble amongst yourselves about what "is" is really meant by use of the word "is" For what was a very short question this thread has gone amok and is way to long Art wrote: The moral of inventing meanings for words is that those meanings have a short shelf life. This kind of thing doesn't even last out a week in the white house press room. True, true. If only all this word-twisting energy could be harnessed as valid antenna design... the chipster seems to have relegated himself these days to fairly innocuous posts elsewhere regarding staying on the good side of your neighbors' graces by putting up visually low profile antennas... Certainly a change from the f-word antenna wars of old. I was a regular reader of r.r.a.a. in those days... not much of a poster back then, though. I wonder if a thousand-mile long, five mile high stack of rhombics might meet Art's requirements... of course, at that point you could just run open wire line to any distant receiver. That would be quite efficient, from Art's standpoint. 73, Dan |
#10
|
|||
|
|||
Yagi efficiency
Dan,
you know quite well what the post that started this thread asked for. I only added the TOA comments to fill in some body where I was coming from not for advice on what antenna to build. People are quibling over the word "efficiency" which I find rather wierd especially since I am supposed to be in the company of fellow engineers. The subject was antenna radiation patterns and ascertaining the relative volume of the main lobe which is the reason for an antenna and comparing it to the total volume of the array which one accepts to obtain the desirable primary lobe. Oh yes, when we talk of efficiency one must multiply the ratio by 100 Some may have forgotten that! Obviously this group comprises of a swarm of tadpoles with a few little goldfish in a small pond none of which are qualified to be termed faculty. Now you have something to get your teeth into since you deign to respond to the initial post This term "I don't understand" is usually used by student who enter class after late night partying and it didn't work then either. A dull brain is a dull brain unless one activates it. Carry on with a thread of your own choice and quibble amongst yourselves about what "is" is really meant by use of the word "is" For what was a very short question this thread has gone amok and is way to long Art wrote: The moral of inventing meanings for words is that those meanings have a short shelf life. This kind of thing doesn't even last out a week in the white house press room. True, true. If only all this word-twisting energy could be harnessed as valid antenna design... the chipster seems to have relegated himself these days to fairly innocuous posts elsewhere regarding staying on the good side of your neighbors' graces by putting up visually low profile antennas... Certainly a change from the f-word antenna wars of old. I was a regular reader of r.r.a.a. in those days... not much of a poster back then, though. I wonder if a thousand-mile long, five mile high stack of rhombics might meet Art's requirements... of course, at that point you could just run open wire line to any distant receiver. That would be quite efficient, from Art's standpoint. 73, Dan |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
Tape Measure Yagi Antenna Questions | Antenna | |||
SUPER J-POLE BEATS YAGI BY 1 dB | Antenna | |||
GP -> yagi driven element? | Antenna | |||
Yagi, OWA and Wideband Yagi etc etc | Antenna | |||
Quad vs Yagi (or log) | Antenna |