Radials / Counterpoise

Every Antenna Requires A Current Return Path

Antennas are part of an RF circuit. Transmitters are the energy source. Antennas and their RF wave or image, are the load. Energy cannot be properly distributed or used without connection to and from a load - energy out and back. Kirchoff's Law rules. Radials, a form of counterpoise - as are a "ground-plane" or "the other wire" of a dipole or yagi element - provide the return current path to complete the RF circuit.

Antenna advertisements and documentation that claim no radials/counterpoise needed must either be designed with appropriate counterpoise to provide for return current (and should be able to explian/prove it), or they are lying.

Absent a designed-in counterpoise, something in your transmitter to antenna circuit WILL become the counterpoise/return path. Typically this would be your coax/feedline but it could also be your power, microphone or other cables/devices inter-connected with the transmitter. This constitutes wholly unwanted stray RF, and that is what causes interference to other electronics - TV, radio, computers, etc.

If you have stray RF, and think you are solving the problem with ferrite beads/choking, you are not. You are only limiting the choked wire/device from being the return path, shifting the return current flow to something else.

Better to understand, know or implement a known appropriate counterpoise (radial) to properly close the RF circuit.

SteppIR Article on Radials

QEX Article on Radials
Also review his paper on insulated vs bare conductors - at least the conclusion.)

LUXORION Project Coverage of Radials

Univ of Hawaii Coverage of Radials

GSGC (Antenna Tuners) Technote on Radials

RossRadio: Why Radials

Grounding versus Counterpoise

 

© 2017 de Jim Aspinwall, No1PC
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