Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!mailrus!ames!lll-tis!lll-winken!lll-lcc!rzh
From: rzh@lll-lcc.aRpA (Roger Hanscom)
Newsgroups: sci.electronics
Subject: Whispering Wires
Keywords: none
Message-ID: <1736@lll-lcc.aRpA>
Date: 29 Jun 88 16:26:58 GMT
Organization: Lawrence Livermore Labs, Livermore Ca
Lines: 19


>In article <3025@mit-hermes.ai.mit.edu.AI.MIT.EDU>, jpexg@mit-hermes.ai.mit.edu.AI.MIT.EDU (John Purbrick) writes:
>> I was out in the country a few days ago and passed under some high-tension
>> wires. The power lines were emitting a sort of hissing, crackling sound,
>> with no detectable 60Hz component that I could hear. What causes this effect?
>> If it makes a difference, the weather that day was very hot and fairly humid.
>
>What you heard is corona discharge. The same principle applies to 
>electrostatic discharge from any conductor. Dirt, temperature, humidity
                                                                ^^^^^^^^
>all come into play in determining how severe the problem is. It will

I work near a **VERY** large DC power supply.  The climate here is quite
dry, and the power company's overhead lines coming into it crackle and
buzz even on the hottest (and driest) of days.  But when the humidity
goes up (like one of those foggy, winter days), the thing goes wild!!
It appears that humidity causes the bulk of the phenomenon.

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