[BC] Part 15 radio station

[Richard Fry]

>The NRC specifies that ALL antennas mounted outside be properly 
>grounded...  Thus, the NEC would clearly overrule the FCC part 15 rules 
>with regards to a SAFETY ground. The RF ground-now that is quite another 
>matter!
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A wire from a Part 15 AM tx chassis to a buried ground rod/conductor may be 
considered by the user to be a NEC-required safety ground for the 3-meter 
antenna, but in reality the antenna is not directly connected to that 
conductor.  Instead, such a "safety ground" becomes one arm of an 
off-center-fed dipole, whose lower tip is connected to r-f ground.

An expanded-band Part 15 AM system mounted 20 feet above the earth and 
using a 20-foot ground conductor produces about 5 times the groundwave 
field intensity for the same applied power as when it is mounted with its 
base at earth level, with essentially no ground conductor length.  This 
gain is equivalent to using about 25 times the power with the system 
mounted at earth level.

RF