Instruction Manual

14
piece of equipment. They are for connection to a desktop ground bus system common
to all equipment, if you prefer to use such a system.
Independent ground wire connections are counterproductive. Never use RF isolators
between the amplifier and radio. Never use long independent wires to external grounds.
Never connect desk equipment to ground rods that do not bond into the mains entrance
ground rod.
Station RF Ground
Common rumor is a station equipment ground reduces RFI (radio frequency
interference), reduces lightning damage, or improves signal levels. Generally, changes
in RFI or signal quality, with the addition or removal of a station ground, indicate an
antenna or feed line installation problem. Typical problems causing desktop RF
problems include the following:
ɀ Lack of suitable baluns.
ɀ Improper feed line routing near antennas, or improperly designed antennas.
ɀ Antennas too close to the operating position.
ɀ Poor equipment cabinet design, such as non-bonded or grounded equipment
covers or panels.
ɀ Poorly designed low-level audio line shield entrances, such as shields allowed to
enter cabinets instead of grounding at the enclosure entrance.
ɀ Improper antenna feed line building entrance, lacking a properly grounded
entrance panel.
ɀ Rather than patching a system problem at the desk, it is much better to correct
the actual problem source.
Coaxial Line Isolators
The goal of every operating position is to maintain all equipment cabinets and housings
at the same RF potential. Never install coaxial line isolators between desktop radio
equipment. Isolators on or near the desk are contrary to this goal, and actually promote
or encourage RF potential differences between different desk equipment. If an RF
problem appears at the operating position, correction, repair, or replacement of
defective equipment is in order.
Proper line-isolator installation points are either just outside the operating room entrance
and/or close to the problem’s actual source. If the antenna system has excessive
common mode current on feedlines, the desktop has defective cables or connectors, or
if equipment has poor equipment cabinet design such as poor cover bonding to chassis,
locate and correct the actual problem.