the problem with single point grounds is that they used to work
in the current hi speed hi freq environment they don't work anymore
(according to info in the SI list)
nail everything to a common multi-point single ground, understand the
implications of the return paths of the signals you are routing
use cuts rather than splits
at least that is the PC religion of the moment as I understand it
the Lomax 'virtual short' is nevertheless very cool, and works, and is
very useful for directing power flow, particularly on double sided bds
I have used it without DRC or fab problems

Dennis Saputelli

Abd ul-Rahman Lomax wrote:
> 
> Because the question frequently arises of how to connect two or more
> grounds while maintain DRC and the separation of the grounds except at a
> single point, and because the instructions as to how to do this can be
> misinterpreted, I have uploaded to the protel-user filespace a PCB file
> with two virtual short footprints in it, two grounds which are shorted by
> the footprints, and a Design Rule which allows the close proximity which is
> the key to this method. The gap is 2 microinches and the design rule allows
> 1 microinch for that footprint.
> 
> The file is in the filespace at
> 
> http://groups.yahoo.com/group/protel-users/files/
> 
> and the direct URL for file download is
> 
> http://groups.yahoo.com/group/protel-users/files/virtual_short.zip
> [EMAIL PROTECTED]
> Abdulrahman Lomax
> P.O. Box 690
> El Verano, CA 95433

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