Don't underestimate the importance of a good ground system!

# Ground Characteristics, Lightning Protection Grounds, Radio Frequency Grounds, and Practical Grounding Systems

Earth characteristics, grounding material characteristics, benefits and practical issues related to grounding systems- Buried Radial
**Characteristics of a Buried Radial Wire from DC up to Radio Frequencies**The earth electrode system of a radio transmitter using a vertical mast as the radiator consists of a number of buried wires radiating from a common connecting point directly under the antenna. For high efficiency power radiation the effective series resistance looking into the earthing system must be as low as possible. This program models a single isolated radial from DC up to 30 MHz ... - Counterpoise
**Behaviour of Coil-Loaded Antenna Counterpoise, or Artificial Ground**The primary purpose of this program is to calculate the number of turns on a loading coil of given length and diameter needed to resonate a wire to 1/4-wavelength. The wire length must therefore be less than 1/4-wavelength ... - Resistance
**Measurement of Soil Resistivity & Calculation of Earth Electrode Resistance**

- Simple Methods of Measuring Resistance Between Electrodes Stray soil currents flowing in the vicinity and electro-chemical potentials on electrodes, make soil resistance measurements impossible using the ohms range of a multirange meter. Much larger test currents must be used. Errors due to electrodes becoming polarised by DC test currents can be reduced by rapidly reversing a DC supply or by using 50 Hz AC power via an isolating transformer ...
- Typical Soil Characteristics of Various Terrains An ohm-metre is the resistance between opposite faces of a 1-metre cube of the material. The above values are averages taken over large distances ...
- Resistivities of Various Materials Resistivities in ohm-metres at 20 C ...
- Calculate Soil Resistivity When Resistance of One Rod is Known To obtain a measurement representative of the soil in the vicinity of the rod and down to a useful depth, the rod should be driven to a depth of at least 0.5 metres, preferably 1 metre. It should be spaced away from any other buried conductors by at least five times its own depth in the soil ...
- The 4-Rod (Wenner) Method of Measuring Soil Resistivity The four rods need not be of same diameter but should all be forced into the soil to approximately the same depth and tamped in at the soil surface ...
- The 3-Rod Method of Measuring Soil Resistivity All three rods are at the same depth and have the same diameter ...
- Resistance of Buried Plates and Surface Mats Run this program ...
- Resistance of 1 Rod, and Arrays of 2, 3, 4 Rods in Parallel Run this program ...
- Resistance of a System of Shallow-Buried Radial Wires Run this program ...
- Notes on Behaviour of Earth Electrodes at Radio Frequencies Basic soil characteristics, Resistivity Rp and Permittivity K, change very little versus frequency. But as frequency increases the magnitude of the soil impedance Z decreases due to the shunt capacitance. The capacitance in shunt with Rp is K times 8.85 picofarads and therefore Z has a negative angle ...

- Shallow-Buried 2
**Choosing Length & Number of Shallow-Buried Radials Version 2**A buried radial is a lossy single-wire transmission line. It has four primary parameters, R,L,C & G. It has secondary parameters: Alpha the attenuation constant and Beta the phase constant closely related to the velocity factor. The characteristic impedance is complex with components Ro and Xo. All these parameters can be estimated from line dimensions of length, wire diameter and burial depth in conjunction with soil resistivity and permittivity ... (*See Version 3 below*) - Shallow-Buried 3
**Choosing Length & Number of Shallow-Buried Radials Version 3**This is Version 3 of the information and computer program above. - Soil Skin
**Skin Depth in the Ground vs. Frequency for Given Soil Characteristics**Alternating currents in the ground are attenuated exponentially as depth increases, like Exp(-A*Depth). Where A is an attenuation factor depending on soil resistivity R, permittivity K, and on frequency ...

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