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Dan Richardson wrote in message . ..
On 30 Sep 2003 09:11:02 -0700, (Brian) wrote: Danny, can you give us a match/swr for each band? The antenna is supposed to not need matching. Brian Brain, According to the manual the antenna uses a 50 to 800 Ohm broadband matching transformer at the feed point. Assuming then that the antenna's feed point should be near the 800-Ohm figure I ran a sweep for 3.5, 7, 10.1, 14.2 and 28.5 MHz referencing a 800-Ohm impedance to calculate the SWR. I got the following results: 3.5 1.40:1 7.0 1.88:1 10.1 1.92:1 14.2 1.96:1 21.2 2.37:1 28.5 2.41:1 Those figures appear to be in close agreement with the manufacture's claim. That said I feel that worrying about the SWR's effects on antenna operation is somewhat like worrying how well a car will run based on the amount of air pressure in the tires. 73 Danny, K6MHE Danny, thanks for running the numbers. I appreciate it. And feel free to drive your car w/o air pressure in your tires. Maybe you've got the Presedential and Armored Car series tires. Since I don't, I prefer air in my tires, and in my antennas, I prefer an SWR somewhat below my transmitter's SWR protection circuit's limit. 73, BrIan/N0IMD |
Dan Richardson wrote in message . ..
On 30 Sep 2003 09:11:02 -0700, (Brian) wrote: Danny, can you give us a match/swr for each band? The antenna is supposed to not need matching. Brian Brain, According to the manual the antenna uses a 50 to 800 Ohm broadband matching transformer at the feed point. Assuming then that the antenna's feed point should be near the 800-Ohm figure I ran a sweep for 3.5, 7, 10.1, 14.2 and 28.5 MHz referencing a 800-Ohm impedance to calculate the SWR. I got the following results: 3.5 1.40:1 7.0 1.88:1 10.1 1.92:1 14.2 1.96:1 21.2 2.37:1 28.5 2.41:1 Those figures appear to be in close agreement with the manufacture's claim. That said I feel that worrying about the SWR's effects on antenna operation is somewhat like worrying how well a car will run based on the amount of air pressure in the tires. 73 Danny, K6MHE Danny, thanks for running the numbers. I appreciate it. And feel free to drive your car w/o air pressure in your tires. Maybe you've got the Presedential and Armored Car series tires. Since I don't, I prefer air in my tires, and in my antennas, I prefer an SWR somewhat below my transmitter's SWR protection circuit's limit. 73, BrIan/N0IMD |
On 2 Oct 2003 10:24:25 -0700, (Brian) wrote:
Dan Richardson wrote in message . .. On 30 Sep 2003 09:11:02 -0700, (Brian) wrote: Danny, can you give us a match/swr for each band? The antenna is supposed to not need matching. Brian Brain, According to the manual the antenna uses a 50 to 800 Ohm broadband matching transformer at the feed point. Assuming then that the antenna's feed point should be near the 800-Ohm figure I ran a sweep for 3.5, 7, 10.1, 14.2 and 28.5 MHz referencing a 800-Ohm impedance to calculate the SWR. I got the following results: 3.5 1.40:1 7.0 1.88:1 10.1 1.92:1 14.2 1.96:1 21.2 2.37:1 28.5 2.41:1 Those figures appear to be in close agreement with the manufacture's claim. That said I feel that worrying about the SWR's effects on antenna operation is somewhat like worrying how well a car will run based on the amount of air pressure in the tires. 73 Danny, K6MHE Danny, thanks for running the numbers. I appreciate it. And feel free to drive your car w/o air pressure in your tires. Maybe you've got the Presedential and Armored Car series tires. Since I don't, I prefer air in my tires, and in my antennas, I prefer an SWR somewhat below my transmitter's SWR protection circuit's limit. 73, BrIan/N0IMD I guess I choose a poor analogy regarding SWR. On my list SWR is the least of my worries as it is one of the easiest to fix. I would be much more interested in the antenna's pattern (launching the signal in a direction and angle I wish), what amount of gain it has at that direction/angle and what efficiency it operated at. Back to the analogy of a car. I would be more interested in how the engine ran, transmission worked and so forth. A flat tire (read excessive SWR) is easy to fix but rebuilding an engine is another matter. 73 Danny |
On 2 Oct 2003 10:24:25 -0700, (Brian) wrote:
Dan Richardson wrote in message . .. On 30 Sep 2003 09:11:02 -0700, (Brian) wrote: Danny, can you give us a match/swr for each band? The antenna is supposed to not need matching. Brian Brain, According to the manual the antenna uses a 50 to 800 Ohm broadband matching transformer at the feed point. Assuming then that the antenna's feed point should be near the 800-Ohm figure I ran a sweep for 3.5, 7, 10.1, 14.2 and 28.5 MHz referencing a 800-Ohm impedance to calculate the SWR. I got the following results: 3.5 1.40:1 7.0 1.88:1 10.1 1.92:1 14.2 1.96:1 21.2 2.37:1 28.5 2.41:1 Those figures appear to be in close agreement with the manufacture's claim. That said I feel that worrying about the SWR's effects on antenna operation is somewhat like worrying how well a car will run based on the amount of air pressure in the tires. 73 Danny, K6MHE Danny, thanks for running the numbers. I appreciate it. And feel free to drive your car w/o air pressure in your tires. Maybe you've got the Presedential and Armored Car series tires. Since I don't, I prefer air in my tires, and in my antennas, I prefer an SWR somewhat below my transmitter's SWR protection circuit's limit. 73, BrIan/N0IMD I guess I choose a poor analogy regarding SWR. On my list SWR is the least of my worries as it is one of the easiest to fix. I would be much more interested in the antenna's pattern (launching the signal in a direction and angle I wish), what amount of gain it has at that direction/angle and what efficiency it operated at. Back to the analogy of a car. I would be more interested in how the engine ran, transmission worked and so forth. A flat tire (read excessive SWR) is easy to fix but rebuilding an engine is another matter. 73 Danny |
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