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"Steve Lizard" wrote: I don't know Bruce, but I guess the average power of this is something just less than 5 KW on long range and the distance between the radiator and helmsman is around 10 ft and when rotating at 24 rpm the helmsman is in the zone 14% of the time, so the average power exposure is still 700 watts at the Slot Line and 300 Watts at 10 ft. Still, that can't be healthy over time. Perhaps I did not do the math correctly, but that's what I came up with. Steve Yep, you got that right Steve, You don't "Know"...... The Average Power is not the Peak Pulse Power, but it IS, your Peak Pulse Power. * the Pulse Length, * the Pulse Repetition Rate. Typically in a Marine Xband 10Kw Radar the Maximum Average Power is about 20 Watts, now if your 4 Foot slot-Line antenna has a Horizontal 3 db Beam-width of say 3°, then divide that into 360°, and you are being sweeped less than 1% of the time, so figure, now it is 2 Watts Average Power. Now figure that Power is at the Magnetron and not the Antenna Face, so you lose, oh say 1.5 db in the Waveguide, Rotary Joint, etc, so now your down to say 1.5 Watts, spread over the Face Antenna, which is 4Ft X 4" or 192 Sq Inches, and 1.5 Watts spread over 192 Sq Inches, would be in the neighborhood of 8 Milliwatts per Square Inch, as the Output Power Density for the Typical 10Kw Marine Xband Radar, at the Antenna Face. Now if one figures the Inverse Square Law into Distance from the Antenna Face, the Power Density is even LESS significant..... Like I said do the MATH, and it becomes a Non-Issue.... You get more Non-Ionizing radiation from the Sun, on a Cloudless day, by FAR...... -- Bruce in alaska add path after fast to reply |
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