

| Subject: | Re: Grounds (was Quality Inverters) NVC |
| From: | Jack |
| Date: | Wed, 20 Jun 2007 11:07:01 -0700 |
Well, when you're speaking of RF antennas, then the "ground" should really be known as the "counterpois" whether it's the actual earth, as with a long-wire antenna, or as the Vanagon's body or as the radials common to VHF vertical antennas. This isn't to say that a transmitter or all the station electronics shouldn't be grounded when you have that option - I've used a copper-steel rod driven into the earth outside the window for that purpose regardless of what antenna or transmission line is in use. But this is getting into a technical field too far removed from Vanagons. Not to mention that my RF background is gradually slipping away from disuse. //Jack W6SGA Date sent: Tue, 19 Jun 2007 23:31:57 -0700 From: David Kao <dtkao0205@YAHOO.COM> Subject: Re: Grounds (was Quality Inverters) To: vanagon@GERRY.VANAGON.COM Send reply to: David Kao <dtkao0205@YAHOO.COM> > To me ground means ground (the earth). When I hang a long wire (antenna) for > my HF transceiver the ground has to be physically connected to ground. If > not > I won't receive signal from far away or my signal won't reach too far. But > you sure can fake it. For example when I set up a CB antenna on my westy The > Westy chassis is no problem as a good ground for the antenna. > > Maybe this is just a different ground that has nothing to do with the ground > you guys are talking about. Never mind. I don't want to steal the thread. > > David > > > --- Jack <john.cook58@VERIZON.NET> wrote: > > > Not directly related to inverters but perhaps of some interest. > > > > A pet peeve of mine regards the word, "Ground". As used in electricity > and > > electronics, the word is an unfortunate historical artifact which, in my > humble > > opinion, should be removed from use, since it's too often misunderstood. > It > > implies some magic iso-potential conductor connected to earth which rarely > > exists outside of a text book. Given common conditions such as high fault > > currents, fast rise/fall surges (e.g., sparks), that "ground" is anything > but > > iso-potential. This misunderstanding can lead to serious problems, even > from > > designers who should know better. (This isn't even beginning to deal with > high > > speed digital circuitry, analog instrumentation, A/D, D/A and RF systems.) > > > > Much better to use the words, frame, shell, chassis, shield, common, 3rd > wire, > > green wire, etc. Those more descriptive terms provide better understandings > of > > what the conductor is and (sometimes) what its purpose is. In large > system > > schematics, we might see the identifiers, frame-1, frame-2, frame-3, > shield-1, > > etc., even though the connections may be tied together somewhere. > > > > Sorry to rant. And sorry if the above makes little sense to you. You have > to > > have been there. > > > > //Jack > > > > > > > ______________________________________________________________________________ > ______ > Got a little couch potato? > Check out fun summer activities for kids. > http://search.yahoo.com/search?fr=oni_on_mail&p=summer+activities+for+kids&cs= > bz > > > -- > No virus found in this incoming message. > Checked by AVG Free Edition. > Version: 7.5.472 / Virus Database: 269.9.1/857 - Release Date: 6/20/2007 2:18 > PM >
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