RE: RF Ground Connections - Wire Type

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Mccauley, Daniel H by way of Terry Fritz <twftesla-at-qwest-dot-net>" <daniel.h.mccauley-at-lmco-dot-com>


	I'm going to have to disagree with your assessment.  For high
voltage transients, stranded or braided wire outperforms solid wire in all
instances.  This is the primary reason you use braided wire for lightning
protection in house security systems etc...  Another example is the use of
stranded wire vs. solid in audio applications.  

	Dan




> My recent measurements of conductor AC resistance confirm that stranded
> wire is a POOR choice.  While one should strive for a high surface area,
> this only applies to solid conductors.  RF currents want to travel only on
> the outermost surface - they will not travel on strands inside the bundle.
> When a strand goes from the surface of the bundle to inside the bundle,
> the
> current will try to hop to an outer strand, through whatever surface
> oxides
> might be in its path.  I did not compare finely stranded conductors with
> coarsely stranded conductors, but I would speculate that a coarsely
> stranded conductor might have a lower AC resistance, as it's a closer
> approximation to a solid conductor.
> 
> Steel cable, solid or otherwise, would be a very poor conductor due to the
> inherently higher resistance of steel compared to copper.
> 
> Since heavy gauge solid wire is inflexible and not practical for a cable,
> I
> would recommend a copper ribbon for the best possible conductor.  Home
> Depot sells copper roof flashing by the foot, you would have to cut it
> into
> strips and solder them together.
> 
> Now to the practical aspects.  An RF ground, good or bad, will have
> virtually no effect on the coil's performance.  Several list members have
> accidentally forgotten to connect their secondary base to a ground of any
> sort, and there was NO impact on performance!  The real reason for using a
> ground has more to do with preventing RF interference and HV RF nasties
> from entering your house wiring.
> 
> Gary Lau
> MA, USA
> .  
> 
>  -----Original Message-----
> From: 	Tesla list [mailto:tesla-at-pupman-dot-com] 
> Sent:	Tuesday, July 16, 2002 10:09 AM
> To:	tesla-at-pupman-dot-com
> Subject:	RF Ground Connections - Wire Type
> 
> Original poster: "Mccauley, Daniel H by way of Terry Fritz
> <twftesla-at-qwest-dot-net>" <daniel.h.mccauley-at-lmco-dot-com>
> 
> 
> 
> 	Do you think steel braided cable (kind used in ground discharge
> sticks, winches, etc...) would be a good connection.  Theres a lot of
> surface area there, its cheap, but not sure on the material.
> 
> 	Thanks
> 	Dan
> 
> 
> 
> 
> 
> > Use a proper copper ground rod available at almost any electric supply
> > shop
> > or hardware store.
> > 
> > Do not use a galvanized pipe.  Use copper.  You want the best possible
> > ground you can get.  Also for lead wire use 2 to 4 gauge fine stranded
> > welding cable.
> > 
> > Dr. Resonance
> > 
> > 
> > 
> > 
> > ----- Original Message -----
> > From: "Tesla list" <tesla-at-pupman-dot-com>
> > To: <tesla-at-pupman-dot-com>
> > Sent: Sunday, July 14, 2002 8:06 PM
> > Subject: Simple RF Ground
> > 
> > 
> > > Original poster: "Daniel McCauley by way of Terry Fritz
> > <twftesla-at-qwest-dot-net>" <dhmccauley-at-spacecatlighting-dot-com>
> > >
> > > I currently live in a townhouse so I don't have a large (well actually
> i
> > > don't have any except for a small patio area with a small garden).
> > >
> > > What is the simplest type of RF ground construction i can live with my
> > coil
> > > (15kv, 60mA)
> > >
> > > Can i get away with just a pipe hammered into the soil and then
> running
> > the
> > > RF ground cable to my living room where i'll have a chicken wire
> carpet
> > > under my coil???
> > >
> > > Thanks
> > >
> > > Dan
> > >
> > >
> > >
> > >
> > >
> > >
> > 
> > 
> > 
> 
> 
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