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Tilted radiator
A sloper antenna when resonant produces more gain
than a vertical dipole resonant at the same frequency. True or false? prove it |
Tilted radiator
"Art Unwin" wrote in message ... A sloper antenna when resonant produces more gain than a vertical dipole resonant at the same frequency. True or false? prove it run it through your neutrino based weak force enabled optimizer program and see what you get! |
Tilted radiator
On Sep 12, 7:12*pm, "Dave" wrote:
"Art Unwin" wrote in message ... A sloper antenna when resonant produces more gain than a vertical dipole resonant at the same frequency. True or false? prove it run it through your neutrino based weak force enabled optimizer program and see what you get! a tilted radiator |
Tilted radiator
"Art Unwin" wrote in message ... A sloper antenna when resonant produces more gain than a vertical dipole resonant at the same frequency. True or false? prove it Model parameters for sloping dipole: 60 ft at one end 13.3 ft at the other (45 deg slope). Horizontal dipole at 60 ft. Length of both antennas 66 ft. Sloping dipole resonant at 7.225 MHz, same length horizontal 7.3 MHz. Average ground parameters: conductivity 5 mS/m, and relative permittivity 13. Horizontal dipole maximum gain off the sides (As expected). Sloping antenna double lobed pattern with maximum gain at 80 degrees either side of lowest end. Softwa Nittany's GNEC. Simulation results: EL. angle Sloping dipole Horizontal dipole (deg.) Gain (dbi) Gain (dbi) 10 -1.5 +1.2 20 +1.4 +6 30 +2.4 +7 40 +2.7 +6.4 50 +2.7 +4.7 70 +2 -0.6 90 +1.5 -3.5 73, Frank |
Tilted radiator
Simulation results:
EL. angle Sloping dipole Horizontal dipole (deg.) Gain (dbi) Gain (dbi) 10 -1.5 +1.2 20 +1.4 +6 30 +2.4 +7 40 +2.7 +6.4 50 +2.7 +4.7 70 +2 -0.6 90 +1.5 -3.5 73, Frank PS. Finite ground (Sommerfeld/Norton method). |
Tilted radiator
On Sep 12, 7:55*pm, "Frank" wrote:
Simulation results: EL. angle * *Sloping dipole *Horizontal dipole (deg.) * * * * * *Gain (dbi) * *Gain (dbi) 10 * * * * * * * * *-1.5 * * * * * * +1.2 20 * * * * * * * * *+1.4 * * * * * * +6 30 * * * * * * * * *+2.4 * * * * * * +7 40 * * * * * * * * *+2.7 * * * * * * +6.4 50 * * * * * * * * *+2.7 * * * * * * +4.7 70 * * * * * * * * *+2 * * * * * * * *-0.6 90 * * * * * * * * *+1.5 * * * * * * -3.5 73, *Frank PS. *Finite ground (Sommerfeld/Norton method). FINE FRANK DAVE WILL SUPPLY THE ARRANGEMENT THAT GIVES MAXIMUM GAIN as well as being resonant. Yours are not resonant as I assume you would have supplied the info The navy would not change to a antenna that was not resonant. Art |
Tilted radiator
FINE FRANK DAVE WILL SUPPLY THE ARRANGEMENT THAT GIVES MAXIMUM GAIN
as well as being resonant. Yours are not resonant as I assume you would have supplied the info The navy would not change to a antenna that was not resonant. Art The antenna is resonant. Input impedance: 84.8 + j 1.3 at 7.25 MHz. Not that I regard resonance as having any significance other than the input impedance is resistive. Frank |
Tilted radiator
On Sep 12, 8:41*pm, "Frank" wrote:
FINE FRANK DAVE WILL SUPPLY THE ARRANGEMENT THAT GIVES MAXIMUM GAIN as well as being resonant. Yours are not resonant as I assume you would have supplied the info The navy would not change to a antenna that was not resonant. Art The antenna is resonant. Input impedance: 84.8 + j 1.3 *at 7.25 MHz. Not that I regard resonance as having any significance other than the input impedance is resistive. Frank Correct, as long as it is resistive. So what angle did the Navy tip their antennas to achieve maximum gain? They were not satisfied with the vertical antennas performance and wanted something better. So the question is what needs to be done to provide better performance ie gain? Yup they experimented in each and every way and fell upon.....what? Even tho they cannot explain it. David can tell you in less than 5 minuits which is the time the program requires to provide the answer. Art Unwin KB9MZ......xg |
Tilted radiator
"Art Unwin" wrote in message ... On Sep 12, 7:55 pm, "Frank" wrote: The navy would not change to a antenna that was not resonant. sure they would, there is no reason to have a resonant antenna... a non-resonant one radiates just fine when you have the power to get the current into it. its all in the driving and matching networks. |
Tilted radiator
On Sep 12, 7:47*pm, "Frank" wrote:
"Art Unwin" wrote in message ... A sloper antenna when resonant produces more gain than a vertical dipole resonant at the same frequency. True or false? prove it Model parameters for sloping dipole: 60 ft at one end 13.3 ft at the other (45 deg slope). *Horizontal dipole at 60 ft. *Length of both antennas 66 ft. *Sloping dipole resonant at 7.225 MHz, same length horizontal 7.3 MHz. Average ground parameters: conductivity 5 mS/m, and relative permittivity 13. *Horizontal dipole maximum gain off the sides (As expected). *Sloping antenna double lobed pattern with maximum gain at 80 degrees either side of lowest end. *Softwa Nittany's GNEC. Simulation results: ..... snip .... The original question said VERTICAL dipole , but you modeled a HORIZONTAL dipole? Or was one of these just a typo? FWIW, I modeled your horizontal dipole in EZNEC and came up with slightly DIFFERENT results: Resonant frequency about 7.335 Mhz Resistance about 81 ohms Max gain about 6.54 dBi at 30 degrees I am INexperienced in using EZNEC and wonder if I'm doing something wrong? --Myron, W0PBV. |
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