[Amps] RF exposure limits in reality

[W8AV at aol.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