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Static Crashes, August 9th Fact-of-the-Day

A previously-syndicated Fact-of-the-Day

It is well known that lighting causes static crashes, but it isn't so well known that the annoying crashes have two causes and one can be minimized. Lightning pulses have fast rise and fall times that fill the radio spectrum with noise. Noise components within a receiver passband are received along with desired signals. However, there is a second way noise is received. All practical receivers exhibit cross-modulation due to nonlinearity. Cross modulation causes high amplitude noise from frequencies outside the passband to modulate desired signals. There is significantly less interference from lightning using a receiver that has excellent linearity over a wide amplitude range than using a typical receiver. ©2004 Martek International All rights reserved.


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