Article View: sci.electronics
Article #5262Re: St Elmo's Fire - 100 v/m ?
From: kenny
Date: Wed, 25 Jul 1990 19:29
Date: Wed, 25 Jul 1990 19:29
22 lines
1331 bytes
1331 bytes
...A foot from your nose, the air is at a potential of +200V. ..Just curious... ..Why can't this be measured with a DVM? .Because that 10 megohm input DVM is also a much better conductor than air. .Maybe with something like an electrometer... ?? Yup. There's an article in an old Amateur Scientist column (back in the Stong era) about this. The circuit presented is ridiculous by today's standards -- lots and lots of vacuum tubes. I bet someone could do a real nice job with an instrumentation-grade FET-input opamp. Have to be really careful about common-mode noise elimination. Also would have to bleed the charge off the antenna periodically. I may design such a beast eventually; a measure of atmospheric charge is a valuable datum for short-term weather forecasting. Kevin, KE9TV kenny@cs.uiuc.edu ke9tv@uiuc.edu
Technical Details
Message-ID:
<21000088@m.cs.uiuc.edu>Path:
arc1-ca.pugleaf.net!utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sdd.hp.com!zaphod.mps.ohio-state.edu!brutus.cs.uiuc.edu!ux1.cso.uiuc.edu!ux1.cso.uiuc.edu!m.cs.uiuc.edu!kennyReferences:
<26@<5498>Show Full Headers
Complete Article Headers
Path: arc1-ca.pugleaf.net!utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sdd.hp.com!zaphod.mps.ohio-state.edu!brutus.cs.uiuc.edu!ux1.cso.uiuc.edu!ux1.cso.uiuc.edu!m.cs.uiuc.edu!kenny From: kenny@m.cs.uiuc.edu Newsgroups: sci.electronics Subject: Re: St Elmo's Fire - 100 v/m ? Message-ID: <21000088@m.cs.uiuc.edu> Date: 25 Jul 90 19:29:00 GMT References: <26@<5498> Lines: 22 Nf-ID: #R:<5498:26:m.cs.uiuc.edu:21000088:000:829 Nf-From: m.cs.uiuc.edu!kenny Jul 25 14:29:00 1990