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#11
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On Thu, 20 Jan 2005 21:22:22 GMT, Bruce in Alaska
wrote: The only reason one would need to worry about Safety, would be if the consumer or commercial Radar Antenna, had an exposed rotating antenna, and it could hit someone in the head, while operating. All the notions about RF Exposure in S and Xband for Marine Radars is nothing but Oldwives Tales, and outdated equipment, concerns. ========================================= I hope you're right Bruce because my old boat had a 4kw scanner right in front of the flybridge. Raytheon recommends at least 2 meters separation and that one was right on the cusp. I never operated it unless necessary. The jury is still out on the RF exposure medical studies, and each new one frequently conflicts with the old depending on who sponsored the research. Meanwhile I'll still try to stay out of the beam of anything as much as possible. |
#12
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I gotta go with Wayne on this one. I did a great study on mircrowave
exposure effects...mainly because of a microwave site near neighborhoods. Depending on what country you choose, the allowable exposure is variable. No two people will agree on the effects. The problem is in trying to prove a negative. Me? I stay as far away from RF as possible....particullarly ionizing radiation. Eyeballs are really sensitive to RF. Norm B On Thu, 20 Jan 2005 20:56:52 -0500, Wayne.B wrote: On Thu, 20 Jan 2005 21:22:22 GMT, Bruce in Alaska wrote: The only reason one would need to worry about Safety, would be if the consumer or commercial Radar Antenna, had an exposed rotating antenna, and it could hit someone in the head, while operating. All the notions about RF Exposure in S and Xband for Marine Radars is nothing but Oldwives Tales, and outdated equipment, concerns. ========================================= I hope you're right Bruce because my old boat had a 4kw scanner right in front of the flybridge. Raytheon recommends at least 2 meters separation and that one was right on the cusp. I never operated it unless necessary. The jury is still out on the RF exposure medical studies, and each new one frequently conflicts with the old depending on who sponsored the research. Meanwhile I'll still try to stay out of the beam of anything as much as possible. |
#13
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On Thu, 20 Jan 2005 19:30:06 -0800, engsol
wrote: Me? I stay as far away from RF as possible....particullarly ionizing radiation. ================================ RF and ionizing radiation are two entirely different animals. RF is electromagnetic, ionizing is from sub-atomic particles, at least in my laymans view of the universe... |
#14
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On Thu, 20 Jan 2005 23:05:25 -0500, Wayne.B wrote:
On Thu, 20 Jan 2005 19:30:06 -0800, engsol wrote: Me? I stay as far away from RF as possible....particullarly ionizing radiation. ================================ RF and ionizing radiation are two entirely different animals. RF is electromagnetic, ionizing is from sub-atomic particles, at least in my laymans view of the universe... There is a frequency above which RF becomes ionizing. To be honest the work I did in that area was so long ago I just don't remember the numbers. |
#15
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In article ,
engsol wrote: .mainly because of a microwave site near neighborhoods. Here again if you do the math, and figure the antenna bandwidths, and RF Paths to and from the site, you will know that there is insignificant exposer to RF from a microwave communications site, anywhere on the ground, or in the nearfield of the antennas. Bruce in alaska -- add a 2 before @ |
#16
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engsol wrote:
On Thu, 20 Jan 2005 23:05:25 -0500, Wayne.B wrote: On Thu, 20 Jan 2005 19:30:06 -0800, engsol wrote: Me? I stay as far away from RF as possible....particullarly ionizing radiation. ================================ RF and ionizing radiation are two entirely different animals. RF is electromagnetic, ionizing is from sub-atomic particles, at least in my laymans view of the universe... There is a frequency above which RF becomes ionizing. To be honest the work I did in that area was so long ago I just don't remember the numbers. I think EM radiation has to be up the the X Ray part of the spectrum to be ionizing. |
#17
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On Fri, 21 Jan 2005 10:07:17 -0800, engsol wrote: On Thu, 20 Jan 2005 23:05:25 -0500, Wayne.B wrote: On Thu, 20 Jan 2005 19:30:06 -0800, engsol wrote: Me? I stay as far away from RF as possible....particullarly ionizing radiation. ================================ RF and ionizing radiation are two entirely different animals. RF is electromagnetic, ionizing is from sub-atomic particles, at least in my laymans view of the universe... There is a frequency above which RF becomes ionizing. To be honest the work I did in that area was so long ago I just don't remember the numbers. No common radar band is ionizing. They can be hazardous if they are powerful enough to cook you, like a microwave oven. Rodney Myrvaagnes NYC J36 Gjo/a "Be careful. The toe you stepped on yesterday may be connected to the ass you have to kiss today." --Former mayor Ciancia |
#18
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On Fri, 21 Jan 2005 19:37:00 GMT, Bruce in Alaska wrote:
In article , engsol wrote: .mainly because of a microwave site near neighborhoods. Here again if you do the math, and figure the antenna bandwidths, and RF Paths to and from the site, you will know that there is insignificant exposer to RF from a microwave communications site, anywhere on the ground, or in the nearfield of the antennas. Bruce in alaska Bruce, you're right as rain. Even considering the near field nulls and nodes the radiation reaching the ground (at any given range) from a dish on a tower is less than the radiation from the sun at that frequency. The reason I brought up the neighborhood microwave site is because I had to appear before the Portland City Council to defend our (my company's) desire to establish one. I was the Project Manager for the MW network, and had to "prove" there was no hazard. Actually it was a bad post on my part, as .I didn't explain my position very well. Norm B |
#19
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In article ,
engsol wrote: On Fri, 21 Jan 2005 19:37:00 GMT, Bruce in Alaska wrote: In article , engsol wrote: .mainly because of a microwave site near neighborhoods. Here again if you do the math, and figure the antenna bandwidths, and RF Paths to and from the site, you will know that there is insignificant exposer to RF from a microwave communications site, anywhere on the ground, or in the nearfield of the antennas. Bruce in alaska Bruce, you're right as rain. Even considering the near field nulls and nodes the radiation reaching the ground (at any given range) from a dish on a tower is less than the radiation from the sun at that frequency. The reason I brought up the neighborhood microwave site is because I had to appear before the Portland City Council to defend our (my company's) desire to establish one. I was the Project Manager for the MW network, and had to "prove" there was no hazard. Actually it was a bad post on my part, as .I didn't explain my position very well. Norm B Yep, reminds me of when RCA Americom wanted to build an EarthStation for the Aurora 1 Comms Sat on Vashon Island, Washington, so they could bring the Alaska Longlines Traffic into the ESS4 Switch in Seattle. The neighbors went TOTALLY nuts and delayed the project for a couple of years in the KIng County Planning Commission. Some fool got this group together and strung it out forever. RCA even went so far as getting Dr. Renolds from the UW Applied Physics Lab to testify on their behalf, and that didn't satisfy them. Total foolishness, to the extreme. They finally built the EarthStation, but had to paint the 10Meter Dish Brown/Green so it would "Blend into the neighborhood", and that was the only consession that they were granted in the end. Bruce in alaska who knows the foolishness of the uneducated...... -- add a 2 before @ |
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