[TenTec] RFI Issues

Stuart Rohre rohre at arlut.utexas.edu
Thu May 17 13:27:27 PDT 2012


Pepe,

In your case, the earth rod is serving as a safety ground, and a 
lightning return path.  Such an long run to an earth connection is not 
needed for the antennas, if balanced types, but for the electrical code 
requirements re lightning and power safety.  There are several types of 
"grounds":   Or a better term is returns.  For example, certainly the 
circuit returns on an aircraft or space craft do not return to a 
physical earth connection, yet their electronics can function in flight.

An unbalanced quarter wave vertical antenna needs an RF ground to 
complete the "image", the missing half dipole, and that is best served 
by radials or a ground screen or plane.  Most earth ("dirt") is a poor 
conductor of RF.  And its performance varies through the dry and rainy 
periods at a given location.

AC powered equipment in modern service has a safety ground requirement 
so that any metal enclosure containing AC wiring, is ultimately bonded 
to earth.

An earth ground on the beam boom and tower helps to discharge any static 
buildup of charge when thunderstorms approach.

Thus, removing a bond to earth may not show up as a difference in your 
radio reception, but the bond has another vital function to perform for 
the safety of you and your equipment.

Stuart
K5KVH


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