Yaesu FT-450 Operation Manual

Also see for FT-450: Brochure & specs Reference Manual User manual Technical supplement

Page 12 FT-450 OPERATION MANUALINSTALLATIONGROUNDINGThe FT-450 transceiver, like any other HF communications apparatus, requires an effective ground system formaximum electrical safety and best communications effectiveness. A good ground system can contribute tostation efficiency in a number of ways: It can minimize the possibility of electrical shock to the operator. It can minimize RF currents flowing on the shield of the coaxial cable and the chassis of the transceiver.Such currents may lead to radiation, which can cause interference to home entertainment devices orlaboratory test equipment. It can minimize the possibility of erratic transceiver/accessory operation caused by RF feedback and/orimproper current flow through logic devices.An effective earth ground system may take several forms. For a more complete discussion, see an appropriateRF engineering text. The information below is intended only as a guideline.Typically, the ground connection consists of one or more copper-clad steel rods, driven into the ground. Ifmultiple ground rods are used, they should be positioned in a “V” configuration, and bonded together at the apexof the “V” which is nearest the station location. Use a heavy, braided cable (such as the discarded shield fromtype RG-213 coaxial cable) and strong cable clamps to secure the braided cable(s) to the ground rods. Be sureto weatherproof the connections to ensure many years of reliable service. Use the same type of heavy, braidedcable for the connections to the station ground bus (described below).Inside of the station, a common ground bus consisting of a copper pipe of at least 25 mm (1”) diameter shouldbe used. An alternative station ground bus may consist of a wide copper plate (single-sided circuit board materialis ideal) secured to the bottom of the operating desk. Grounding connections from individual devices such astransceivers, power supplies, and data communications devices (TNCs, etc.) should be made directly to theground bus using a heavy, braided cable.Do not make ground connections from one electrical device to another, and thence to the ground bus. This so-called “Daisy-Chain” grounding technique may nullify any attempt at effective radio frequency grounding. Seethe drawing below for examples of proper grounding techniques.Inspect the ground system - inside the station as well as outside - on a regular basis so as to ensure maximumperformance and safety.Besides following the above guidelines carefully, note that household or industrial gas lines must never be usedin an attempt to establish an electrical ground. Cold water pipes may, in some instances, help in the groundingeffort, but gas lines represent a significant explosion hazard, and must never be used.LinearAmplifier TNCTransceiverLinearAmplifier TNCTransceiver"Daisy Chain"PROPER GROUND CONNECTIONIMPROPER GROUND CONNECTION