[BC] Part 15, er ... parts

[Richard Fry]

Barry Mishkind:
>Along with that is a question related to radiation: If the entity
>owns the property, is the max radiation measured at the property
>line, or still at the antenna?
_____________

The Part 15 FM field strength limit is defined as 250 uV/m in any direction 
3 meters away from the radiator.  FM tx power is not defined by Part 15. 
But the most popular eqpt configuration for many "Part 15" FM users is a tx 
rated for 25 mW or more output power applied to an antenna with a peak gain 
about the same as a 1/2-wave dipole.  That combination produces a field 
strength WA-AY above the FCC's peak value defined for Part 15 FM.

Part 15 AM is defined (most generously) by a 100 mW limit on the tx input 
power, used with an antenna no longer than 3 meters including the feedline 
and ground lead.  There is a lot of creative and unscientific definition 
among Part 15 AM users about what constitutes the ground lead.  Often the 
end result is an antenna system radiation efficiency and field strengths 
far higher than the FCC definition could generate.

Property lines don't apply, except in the case of AM "campus radio," and in 
most cases that limit is much more restrictive beyond the campus borders 
than the 100 mW tx and antenna with a radiating length of 3 meters can 
produce.

RF