How safe is radar ?

Discussion in 'Powerboats' started by parkland, Oct 30, 2012.

  1. parkland
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    parkland Senior Member

    I see that radar units are rated in kW of power.

    This is a surprise to me, I had no idea they were so powerful.

    Is it even safe to stand around them, or should they be up high on a mast?
     
  2. michael pierzga
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    michael pierzga Senior Member

    Don't stand in the CONE of the radar broadcast or your....err emmm...pants may catch fire.

    Yes... a poorly situated radar is bad for your health.

    I dont know the impact of the new broadband radars. Whether they come with health and safety warnings.
     
  3. parkland
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    parkland Senior Member

    Wow you learn something new every day.

    I would never have guessed in a million years that they used that much juice.

    Is that actual radio power output, or is it an EIRP rating? (Like including the antenna gain??)
     
  4. michael pierzga
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    michael pierzga Senior Member

  5. DCockey
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    DCockey Senior Member

    The power rating is the peak power of the transmitted pulses. The duration of the transmitted pulses of conventional radar is extremely short so the average power transmitted is only a very small fraction of the peak power and will be fraction of the input power4 to the radar unit.

    Broadband radar works on a different principal with a much lower peak power, longer length (continous) pulse which changes frequency. Again the average transmitted power will be a fraction of the input power. I've seen claims that its transmitted power (presumably average) is a small fraction of the transmitted power of a cell phone.
     
  6. parkland
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    parkland Senior Member

    OK so then those ratings are calculated using antenna gain also then.

    Same thing with wireless wifi long range radios i'm used to.
     
  7. PAR
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    PAR Yacht Designer/Builder

    The microwave oven is a direct descendant of a ham sandwich (or candy bar, depending on which story you want to believe), left in or near the cone of a WW II radar set. A light went off in the operators head and the first microwaves offered to the public where called a "radarange".
     
  8. parkland
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    parkland Senior Member

    I thought it was a candy bar in a guys pocket... :D
     
  9. PAR
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    PAR Yacht Designer/Builder

    I saw an interview with the two guys working the new high power radar setup, several years ago, as part of a documentary. This is where I got the ham sandwich, which was apparently provided by one of the local house wives, helping out at the station in England. The candy bar/sandwich debate has raged for decades.
     
  10. hoytedow
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    hoytedow Wood Butcher

    Highway patrol officers here in The States had testicular cancer allegedly due to the habit of resting radar guns on their laps between scanning cars for speed violations.

    http://www.osha.gov/SLTC/radiofrequencyradiation/fnradpub.html
     
  11. troy2000
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    troy2000 Senior Member

    I owned one of those original Amana Radaranges. I bought it second-hand for $400.00, and my girlfriend at the time was the envy of the neighborhood.... one of our friends wouldn't drink coffee heated in it. She said, "you guys go right ahead and die of radiation poisoning if you want to."
     
  12. tom28571
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    tom28571 Senior Member

    RADAR waves travel at the speed of light or about 328 yards per micro second. That means that, in order to get a readable return pulse at close range, the transmitted pulse must be of extremely short duration. RADAR on small boats will have a pulse width of a small fraction of a microsecond or nanoseconds so, averaged over time, the power is very small. Large, long range search RADAR's have wide and powerful transmitted pulses and can be dangerous to life near the antenna and in the beam.
     
  13. michael pierzga
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    michael pierzga Senior Member

    I think its still wise to stay out of the radar beam.

    Remember how they told you that mobile phones are safe ?

    Hah !!!!! just look at people like yacht brokers who talk all day on mobiles.. After a few years they start mumbling , talking trash and herky jerking like a deranged man. Its the mobile phone radiation that did it.
     
  14. Submarine Tom

    Submarine Tom Previous Member

    Parkland,

    It's as safe as the person using it.

    Right Hoyt?
     
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  15. hoytedow
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    hoytedow Wood Butcher

    Yep; Just like guns and gasoline.
     
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