Introduction:

     In view of acquiring safety within operations of all kinds of devices and for its better maintenance, the only gateway is measures taken to consolidate the time tested mandatory Rescue operation. Designed Rescue operation depends  primarily on dependency of Operational system (OS) on Inputs and sensitivity  of OS to identify and fix issues, through safety automation system.

HAM system has unique safety measures and these are termed as Grounding & Earthing. As HAM devices are primarily involved in sending signals through WAN Radio frequencies, its devices are prone to environmental disturbances which may carry influx due to atmospheric disturbances or incompatible job load. Grounding and Earthling insures the functionality of each device enforced, gets optimum inputs and current to function as well as they are protected from unwanted environmental disturbances such as storm, thunders and side effects of natural catastrophes.

Grounding/Earthing:

Now, considering the purely electrical point of view, earthing can be said as a type of grounding. Grounding is referred as the common return path of two or more devices, not necessarily connected to the earth. This will restrict the leakage current flow through devices. In case devices to be grounded are far enough from each other and not able to get connected to obtain a common ground then both grounds can be connected to earth considering the whole earth as a uniform equipotential electrode is called an Earthing.

Methods:

Let’s see the Topic from the aspects of Ham Radio Technology. For Ham Stations, there are mainly 3 types of Grounding. First is Electrical Safety Grounding, second is RF (Radio Frequency) Signal Grounding and the third is Lightning Surge Grounding.

Wind flowing across the station antenna can create an electric charge, the wind takes away some of the charges and as a result, the wire becomes positively charged. To complete the circuit, charges need a path that must be a ground path. So in ham stations, grounds with necessary safety resistance are provided.

If proper grounding is not provided to the system, then operator ham may get undesired and problematic functioning and results. Station microphone and metallic parts may give RF shock, distortion and noise in the audio signal communication may appear, high harmonics in the transmission line may get produced and by its production it may affect the Power Supply and so on the system, these also may lead to unwanted switching and misbehaviour in computer screens and many other problems may occur. If at the station, there is a possibility of surge attack and proper surge absorbing and grounding devices are not provided, then it may damage the radio’s front terminal. So it is very important to provide grounding to any ham station for protection and effective functioning of the devices.

Electrical Safety Grounding defends you from an electrical shock hazard if one of the mains or high voltage power supply line touches the chassis due to some kind of fault. The requirement for this grounding is spelled out in National Electrical Code (NEC). Most of the world standards associations have adopted the National Electrical Code for electrical installation and its practicing including India’s Indian Standards (IS). The safety ground conductor in plug sockets should be connected to the ground according to these laws, and also radio chassis should be connected to the safety ground.

RF Grounding is required only for certain types of antennas, ones which require current flow to ground to complete the antenna circuit. An example is a quarter-wave vertical. One wire of the feedline connects to the antenna base, and the other connects to ground. The connection to ground should have a low RF resistance otherwise power to be grounded will face the heating loss. If the length of an antenna is lesser than one-fourth of the fundamental wavelength, then for greater efficiency number of radial wires will be required. Basically, a relation between antenna length and efficiency is in the inverse proportion. A half wavelength base-fed vertical needs only a very modest ground (i.e. ground rod). The requirements for various other end-fed antennas depend on their length. In the case of antennae like a dipole or a ground plane, RF Grounding is not required.

Whereas Lightning Surge Grounding is very much more important than other two because the surge attack is capable of giving very hazardous results. This grounding is very much essential in areas located at the higher heights from the sea level where there is a huge possibility of a lightning strike. But it is not that much essential in areas where the possibility of surge attack is negligible. Surge attack can easily burn out and damage the equipment of the ham station. So to overcome the problem, surge absorbers or lightning arrestors are to be employed to save the station antenna and the station itself.

Hence, in Ham Station Grounding all three types has its own importance and necessity accordingly they are implemented for the system’s and ham shack operator’s safety.