U.S. Patents Awarded to Inventors in Michigan (Sept. 1)
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For more information on targeted products and services news service, please contact: Myron Struck, Managing Editor, News Service Targeted LLC, Springfield, Va., 703/304-1897, editor @ targetednews. com; http://targetednews.com.The Ground Loop « Engineering Radio
Audio Engineers will know this subject well. Grounding has many purposes, including electrical safety, lightning protection, RF shielding and audio noise mitigation. Although all types of grounds are related in that they are designed to conduct stray electrons to a safe place to be dissipated, the designs of each type are somewhat different. What might be an excellent audio ground may not be the best lightning ground and vice versa. Sometimes good audio grounds can lead to stray RF pickup.
The basic ground loop looks something like this:
) to be induced on another part of the circuit. In cabling applications, this will result in a loud, usually 60 cycle hum impressed on the audio or video being transmitted through the cable.The resistance can come from something as mundane as the length of the conductor going to ground. This can often happen when using shielded audio wire in installations when the connected equipment is already grounded through the electrical plug.
There are two proven methods for eliminating ground loops, both of which are best implemented in the design phase of construction (aren’t most things).
The first is a single ground point topology, also known as a common point or star grounding system. A common ground system consists of one grounding point or buss bonded together so that it has the same potential. All grounded equipment is then connected to that point creating a single path to ground. All modern electrical equipment has a path to ground via the third prong of its electrical cord. Problems can or will occur when audio equipment is plugged into separate AC circuits, grounded via the electrical plug and then tied together via an audio ground. The longer the separate grounding paths, the more severe 60 cycle (or some harmonic thereof) hum can result.
To eliminate this problem, the shields should be broken at one end of the audio cable. Never cut the third prong off of an electric cord, which can create another problem called electrocution. Given the choice between a ground loop and electrocution, I’d stay away from electrocution, mine or somebody else’s.
Eliminate Stray Rf - Bookshelf
Stray
After narrowly escaping an attack by a Stray, Faythe, a shape-shifting young werecat and rebellious member of a Pride, discovers that two of her fellow female ...Stray
Practical RF system design
Combining theoretical results and models with examples, he challenges readers to address such practical issues as: * How standing wave ratio affects system gain ...Practical RF Circuit Design for Modern Wireless Systems: Passive circuits and systems
This is a tested and insightful book that contains answers to most of the questions practical engineers are asking.RF system design of transceivers for wireless communications
Overall, this reference and text covers a wide range of topics from general principles of communication theory, as it applies to digital radio designs, to ...Everyday Walkthroughs Directory
RF Interference
The stray ground path is on the shield alone, an unbalanced current, ... The line isolator in particular should eliminate the stray RF at the source and would be ...
MFJ915
MFJ-915 will reduce or eliminate stray RF often found on coax. ... Stray RF also results in a loss of radiated power from the antenna, which will lead to a great reduction in ...
MFJ-915 RF ISOLATOR
The RF Isolator can reduce or eliminate stray RF often found on coax. ... Stray RF. can result in a loss of radiated power from the antenna, which will lead to a ...
MFJ Enterprises Inc.
MFJ-915 will reduce or eliminate stray RF often found on coax. ... Stray RF also results in a loss of radiated power from the antenna, which will lead to a great reduction in ...
BALUN UNUN
This transformer acts as a RF isolator reduce or eliminate stray RF often found on coax. Power is radiated by the antenna not the feedline. ...