Try the automata website:
http://www.automata.com/capblity/spectech/z0/z0.htm

This page describes each type of construction and there
is also a modeling package that allows you to input data
and get impedance values.

good luck,



At 10:58 AM 5/13/98 -0400, you wrote:
>Try Polar Instruments.
>
>----------
>> From: [log in to unmask]
>> To: [log in to unmask]
>> Subject: [TN] dual stropline
>> Date: Wednesday, May 13, 1998 10:20 AM
>>
>>      I am looking to see if anyone has the calculations for " Dual
>>      Stripline " controlled impedance in a spreadsheet type of formula. I
>>      have all the others, but this particular type has just reared it's
>>      ugly head, and we haven't done this board type before. I am just
>>      trying to make sure that my calculations, and lay-ups are accurate.
>>      Keep in mind I'm not a Math Wizard, hence the need for the
>spreadsheet
>>      type of format. Any help will be deeply appreciated. If what you
>have
>>      is not proprietary e-mail to [log in to unmask] with any help or
>>      files. Again, thanks in advance.
>>
>>
>>                              Ernie Smith
>>
>>                              Electropac Co. Inc.
>>
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Josh Moody
Materials Quality Engineer
Hewlett-Packard - Richardson (HPSD)
ph# (972) 497-4617
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