>      All the theoretical reason for doing or not doing are fine and dandy,
>      and I respect Mr. Einarson very much, but the proof is in the pudding.
>      If people are tieing visa directly to the plance and have not had
>      problems, and indeed have increased the performance of their design,
>      then we MUST take another look at why we do things. I believe that
>      many of the things we do, and many of the rules of thumb we follow are
>      legacy items - there may have been a good reason at one time, but
>      technology has made the "reason" obsolete. This does not mean that I
>      do or do not advocate this particular item (I have asked the editors
>      of PC Fabrication and Circuits Assembly to comment on this via issue),
>      but that if there is something that seems to work, we should look at
>      it and ask questions.
>      I will be glad to put this particular issue on the schedule for one of
>      PCD's projects in early '97, ie. have several shops build a board with
>      via tied straignt to the gnd or pwr plane, run it over a wave etc. and
>      see what happens. As Lee Ritchey says "don't believe it just because
>      someone says so, ask for physicl proof.)
> 
>      Pete Waddell
           *

DITTO! Very well put Pete. I can't encourage everyone enough, if you want the
latest scoop on high-speed design related issues, please attend a Lee Richey or
James Blankenhorn (SMT Plus) course. There should be one coming up at the PCB
Design Conference, East Coast. Old design practices are out-dated when it comes
to high-speed design (>100Mhz).

Sincerely,
Mitch Morey
Sr. PCB Designer
TRW, Inc.
Redondo Beach, CA 90278
Phone: (310)814-5765
Fax:   (310)812-4949
EMAIL: [log in to unmask]

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     PCB layout is like fine art. You have to DIE to be famous!
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