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Re: [Amps] RF exposure limits in reality

To: amps@contesting.com
Subject: Re: [Amps] RF exposure limits in reality
From: W8AV@aol.com
Date: Wed, 18 Aug 2004 15:25:59 -0400
List-post: <mailto:amps@contesting.com>
>The thing i'm confused about is the difference, and I mean the REAL
>difference, between controlled and uncontrolled environments. ?My dipoles
>are at around 35 to 38 feet off the ground and the shack is about 10 feet
>above the ground (split level house). ?So i'm roughly 25 feet away from
>the center of the dipole - unsure if a 1KW CW signal qualifies as
>controlled or uncontrolled operation.


The difference between controlled and uncontrolled exposure is not the mode per 
se.

Uncontrolled exposure is exposure of members of the general public to levels of 
nonionizing radiation that are in excess of the permitted level set forth by 
the FCC.  Members of the general public are those who are unaware of their 
exposure such as someone that wanders near an AM broadcast tower who has no 
knowledge that the tower is being used as an antenna.

Controlled exposure is exposure by individuals who are aware of the POSSIBLE 
effects of nonionizing radiation on human tissue.  These are persons who can 
take the necessary precautions to avoid exposure, such as the chief engineer of 
the above theoretical AM broadcast station.  By living on private property, you 
can prevent uncontrolled exposure since you can take steps to prevent 
tresspassing by the general public.

The way I read the rules concerning amateur radio, so long as your antennas are 
situated on your property and the property boundary is sufficiently removed 
from the antenna radiation center to meet the guidelines outlined Part 97 of 
the FCC Rules and/or Supplement B to FCC OET Bulletin No. 65 (this is what the 
part 97 distances and the N5XU calculations are based on) you will comply with 
uncontrolled exposure guidelines since you can prevent tresspassing on your 
property.  You and your family fall under the controlled guidelines since you 
are knowledeable (or are supposed to be as a condition of the grant of your 
license) on what steps to take to prevent excessive exposure.

In the ham bands the uncontrolled exposure limits are 5 times tighter than the 
controlled exposure limits and the whole body average exposure times are 20% of 
the controlled exposure times.  I agree with Vic that the rules are a bit 
overly restrictive, but them's the rules.

Hope that this helps you understand the difference between the two.  Look at it 
this way, if you comply with the uncontrolled limits, you will more than comply 
with the controlled limits.

73..........de Goose, W8AV
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