[SI-LIST] Re: AC Coupled Signals
- From: "Jeon, Tae-Kwang" <Tae-Kwang.Jeon@xxxxxxx>
- To: <signalintegrity@xxxxxxxxxxx>, <Istvan.Novak@xxxxxxx>, <jeff.loyer@xxxxxxxxx>
- Date: Wed, 3 Oct 2007 12:03:21 -0600
Hi All,
So, for those of you who don't get the voltage transfer function yet,
here it is.
Vo/Vs=3DS21*(1+GL)*(1-GL)/(1-S11*GS-S22*GL-S21*S12*GL*GS+S11*S22*GL*GS)
Where, GS=3D(Zs-Zo)/(Zs+Zo) and GS=3D(ZL-Zo)/(ZL+Zo)
I have also noticed that it can be obtained from ABCD matrix too since
the coefficient A is equal to Vs/Vo. So, 1/A is the voltage transfer
function.
Regards,
TK
-----Original Message-----
From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx]
On Behalf Of Stephen Zinck
Sent: Tuesday, October 02, 2007 11:52 AM
To: Istvan.Novak@xxxxxxx; jeff.loyer@xxxxxxxxx
Cc: si-list@xxxxxxxxxxxxx
Subject: [SI-LIST] Re: AC Coupled Signals
Thank you for your insight Istvan and Jeff, and to all who contributed
to=20
this thread...
Best regards,
Steve
Stephen P. Zinck
Interconnect Engineering Inc.
P.O. Box 577
South Berwick, ME 03908
Phone - (207) 384-8280
Email - szinck@xxxxxxxxxxxxxxxxxxxxxxxxxxx
Web - www.interconnectengineering.com
----- Original Message -----=20
From: "Istvan Novak - Board Design Technology" <Istvan.Novak@xxxxxxx>
To: <jeff.loyer@xxxxxxxxx>
Cc: <si-list@xxxxxxxxxxxxx>
Sent: Tuesday, October 02, 2007 1:38 PM
Subject: [SI-LIST] Re: AC Coupled Signals
> Jeff,
> Yes, the results might be surprising at first. And as noted earlier,
> you dont need to assume different source and load impedances
> to get difference voltage transfer ratios: if the S22 and S11 values
> differ or change, it will also result in a change. So going back to
> the starting scenario: when you move around an AC-coupling
> capacitor, there will be minimal or no change if the capacitor is
> 'transparent' and more change when it is not.
>
> Regards,
> istvan
>
>
>
>
> Loyer, Jeff wrote On 10/02/07 12:14,:
>
>>A late-night epiphany has finally clued me in to reconciling the
>>physics.
>>
>>I was doing my pulse response simulation with the source and load
>>impedances equal. When I changed my source impedance to 8 ohms
>>(typical, but arbitrary) and left my load impedance at 50 ohms, the
>>pulse responses were dramatically different, depending on which side I
>>excited the system from. I believe this is what you were alluding to,
>>though I didn't comprehend it as such.
>>
>>This makes sense, and demonstrates how 2 systems can have IDENTICAL
>>insertion loss and yet have dramatically different pulse response/eye
>>diagrams. Very interesting...
>>
>>Thanks for sharing your insights.
>>
>>Jeff Loyer
>>
>>
>>-----Original Message-----
>>From: Istvan.Novak@xxxxxxx [mailto:Istvan.Novak@xxxxxxx]=3D20
>>Sent: Monday, October 01, 2007 4:15 PM
>>To: Loyer, Jeff
>>Cc: si-list@xxxxxxxxxxxxx
>>Subject: Re: [SI-LIST] Re: AC Coupled Signals
>>
>>Jeff,
>>
>>My talented friend, Gustavo Blando, with whom we analyzed this
situation
>>a few years back, reminded me that the voltage-transfer function
>>formulas can be found for instance in "MicroWave Transistor
Amplifiers",
>>Guillermo Gonzales, Page 185.
>>You can also look at L. S. Dutta, T. Hillmann-Ruge, "Application of
Ring
>>Oscillators to Characterise Transmission Lines in VLSI Circuits," IEEE
>>Transactions on Components, Packaging, and Manufacturing Technology -
>>Part B., Vol. 18, No. 4, November 1995, pp. 651-657. Note that you
will
>>find various expressions; you may want to pick the Vout/Vsource
>>formulas, as opposed to Vout/Vin. You will see that the voltage
transfer
>>ratio is, in general, different from S21.
>>
>>Regards,
>>Istvan Novak
>>SUN Microsystems
>>
>>
>>Loyer, Jeff wrote:
>>
>>
>>
>>>Hello Istvan,
>>>You're keying in to what was surprising to me. For the =
asymmetric=3D20
>>>lossy network I simulated, I noted that the pulse response
remained=3D20
>>>constant, regardless of direction of simulation. Of course, S11
and=3D20
>>>S22 changed dramatically.
>>>
>>>The pulse response was not a derivation of the s-params; it was
merely=3D20
>>>Vout (the circuit driven with an arbitrarily chosen 2V source) of
a=3D20
>>>simulation of the actual network (3 lossy lines).
>>>
>>>So, it appears that the pulse response and insertion loss =
remained=3D20
>>>constant, even though the return loss varied dramatically. I
wasn't=3D20
>>>surprised to have the insertion loss stay constant, but couldn't
have=3D20
>>>predicted whether the pulse reponse would also remain constant,
though=3D20
>>>I suspected it would. This implies the eye diagram would also be
the=3D20
>>>same, regardless of direction of excitation.
>>>
>>>Having the pulse response remain constant appears contrary to =
your=3D20
>>>experience. Any explanation?
>>>
>>>Thanks for your thoughts,
>>>Jeff Loyer
>>>
>>>
>>>-----Original Message-----
>>>From: Istvan.Novak@xxxxxxx [mailto:Istvan.Novak@xxxxxxx]=3D3D20
>>>Sent: Monday, October 01, 2007 4:46 AM
>>>To: Loyer, Jeff
>>>Cc: istvan.novak@xxxxxxxxxxx; si-list@xxxxxxxxxxxxx
>>>Subject: Re: [SI-LIST] Re: AC Coupled Signals
>>>
>>>Hi Jeff,
>>>
>>>Let me see if I can summarize this in simple physical terms. The=3D20
>>>scattering matrix deals with power values. In a reciprocal
network,=3D20
>>>the 'through' power is the same regardless of the direction we go.
The
>>>
>>>
>>
>>
>>
>>>node voltages, on the other hand, depend on the local impedance
levels,
>>>
>>>
>>
>>
>>
>>>which are related to S11, S22 and source and load reflection=3D20
>>>coefficients.=3D3D20
>>>
>>>So probably a more generalized condition is that we can shuffle
around=3D20
>>>reciprocal building blocks inside a cascaded network, and the
resulting
>>>
>>>
>>
>>
>>
>>>eye diagram will stay the same as long as we do not change S11 and
S22.
>>>
>>>Going back to your simulations: if you calculate the pulse response
of=3D20
>>>your example circuits strictly from S21 of the network, I agree,
it=3D20
>>>will not change, since S21 will not change as you move the
reciprocal=3D20
>>>building blocks around.=3D3D20 Your eye diagram, however, should be =
=3D
>>>
>>>
>>usually
>>
>>
>>
>>>calculated as Vout/Vsource (and for sake of simplicity, we =
usually=3D20
>>>assume linear driver and receiver impedances, where their
linearity=3D20
>>>does not change this argument). This voltage transfer ratio can =
be=3D20
>>>analytically calculated if you wish, from the S-parameter flow graph.
=3D20
>>>The resulting formula is symmetrical in S12 and S21, but
asymmetrical=3D20
>>>in S11, S22 as well as source and load reflection =
coefficients.=3D3D20
If =3D
>>>
>>>
>>
>>
>>
>>>you simulate the transfer response or the pulse response of=3D20
>>>Vout/Vsource in HSPICE, you should see the change as soon as the=3D20
>>>electrical symmetry is changed.
>>>
>>>Regards,
>>>
>>>Istvan Novak
>>>SUN Microsystems
>>>
>>>
>>>
>>>
>>>
>>>
>>>Loyer, Jeff wrote:
>>>
>>>=3D20
>>>
>>>
>>>
>>>>Hi Istvan,
>>>>Could you point me towards more information on the "voltage=3D20
>>>>transfer=3D3D20 ratio", and the difference between it and s21/s12?
When =3D
>>>>
>>>>
>>I
>>
>>
>>
>>>>did the=3D3D20 pulse response of a system where S21 =3D3D3D3D S12
(though =3D
>>>>
>>>>
>>S11=3D20
>>
>>
>>>>and S22 were =3D3D
>>>> =3D20
>>>>
>>>>
>>>>
>>>=3D20
>>>
>>>
>>>
>>>>very different, and the reflections were significant), it came =3D
>>>>
>>>>
>>out=3D3D20=3D20
>>
>>
>>>>equal (p21 =3D3D3D3D p12, see my posting of 9/15). Thus, I think
the=3D20
>>>>eye=3D3D20 diagram will =3D3D3D come out equal if S21 =3D3D3D3D S12. =
=3D
>>>>
>>>>
>>=3D3D3D20
>>
>>
>>>>Thanks,
>>>>Jeff Loyer
>>>>
>>>>
>>>>-----Original Message-----
>>>>From: si-list-bounce@xxxxxxxxxxxxx=3D3D20
>>>>[mailto:si-list-bounce@xxxxxxxxxxxxx]
>>>>On Behalf Of Istvan Novak
>>>>Sent: Saturday, September 29, 2007 12:38 AM
>>>>To: Chris.Cheng@xxxxxxxx
>>>>Cc: lifeatthesharpend; signalintegrity@xxxxxxxxxxx;=3D20
>>>>ron@xxxxxxxxxxx;=3D3D20 si-list@xxxxxxxxxxxxx
>>>>Subject: [SI-LIST] Re: AC Coupled Signals
>>>>
>>>>Chris and All,
>>>>
>>>>I think the source of misunderstandigs might stem from the fact
that=3D20
>>>>in
>>>> =3D20
>>>>
>>>>
>>>>
>>>=3D20
>>>
>>>
>>>
>>>>linear, time-invariant, reciprocal networks S21=3D3D3D3DS12 =
regardless
=3D
>>>>
>>>>
>>of=3D20
>>
>>
>>>>=3D3D
>>>> =3D20
>>>>
>>>>
>>>>
>>>the
>>>
>>>=3D20
>>>
>>>
>>>
>>>>sequence of the smaller building blocks within the network, =
BUT,=3D20
>>>>the=3D3D20 eye diagram shows us voltage transfer ratio between =
source
=3D
>>>>
>>>>
>>and=3D20
>>
>>
>>>>load,=3D3D20 and it is NOT S21; the voltage transfer ratio DOES =
depend
=3D
>>>>
>>>>
>>on=3D20
>>
>>
>>>>the=3D3D20 sequence of contributing blocks. This happens also with =
=3D
>>>>
>>>>
>>linear
>>
>>
>>
>>>>source=3D3D20 and load and even if the source and load are
perfectly=3D20
>>>>matched.=3D3D3D20
>>>>
>>>>The only case when the voltage transfer ratio remains the same =
in=3D20
>>>>spite
>>>> =3D20
>>>>
>>>>
>>>>
>>>=3D20
>>>
>>>
>>>
>>>>of moving building blocks around, if/when reflections at the=3D20
>>>>boundaries
>>>> =3D20
>>>>
>>>>
>>>>
>>>=3D20
>>>
>>>
>>>
>>>>of the particular building block are negligible.
>>>>
>>>>Thanks
>>>>
>>>>Istvan Novak
>>>>SUN Microsystems
>>>>
>>>>
>>>>
>>>>Chris Cheng wrote:
>>>>=3D3D20
>>>>
>>>> =3D20
>>>>
>>>>
>>>>
>>>>>I think the point is tuning S22 for the non-ideal load. S12 or S21
=3D
>>>>>
>>>>>
>>=3D3D
>>
>>
>>>>> =3D20
>>>>>
>>>>>
>>>>>
>>>=3D3D3D3D
>>>
>>>=3D20
>>>
>>>
>>>
>>>>>=3D3D3D
>>>>> =3D3D20
>>>>>
>>>>> =3D20
>>>>>
>>>>>
>>>>>
>>>>=3D3D20
>>>>
>>>> =3D20
>>>>
>>>>
>>>>
>>>>>remains being equal (symmetric).
>>>>>
>>>>>-----Original Message-----
>>>>>From: lifeatthesharpend [mailto:lifeatthesharpend@xxxxxxxxx]
>>>>>Sent: Friday, September 28, 2007 2:44 PM
>>>>>To: signalintegrity@xxxxxxxxxxx; ron@xxxxxxxxxxx; Chris Cheng
>>>>>Cc: si-list@xxxxxxxxxxxxx
>>>>>Subject: Re: [SI-LIST] Re: AC Coupled Signals
>>>>>
>>>>>
>>>>>What is the total loss at each point? (reciever, driver side of
cap,=3D20
>>>>>=3D3D
>>>>> =3D20
>>>>>
>>>>>
>>>>>
>>>=3D3D3D
>>>=3D20
>>>
>>>
>>>
>>>>> =3D3D20
>>>>>
>>>>> =3D20
>>>>>
>>>>>
>>>>>
>>>>=3D3D3D3D
>>>>
>>>>=3D3D20
>>>>
>>>> =3D20
>>>>
>>>>
>>>>
>>>>>receiver side of cap) in dB=3D3D3D3D20
>>>>>
>>>>>It seems to stand to reason that if you lose xxx mV when the
signal=3D20
>>>>>is
>>>>> =3D3D20
>>>>>
>>>>> =3D20
>>>>>
>>>>>
>>>>>
>>>>=3D3D20
>>>>
>>>> =3D20
>>>>
>>>>
>>>>
>>>>>=3D3D3D3D stronger at the driver and some smaller portion of that =
=3D
>>>>>
>>>>>
>>when=3D3D20
>>
>>
>>
>>>>>the=3D3D3D20 caps =3D3D3D3D are placed closer to the recever is =
normal
=3D
>>>>>
>>>>>
>>since=3D20
>>
>>
>>>>>=3D3D
>>>>> =3D20
>>>>>
>>>>>
>>>>>
>>>loss=3D3D20
>>>=3D20
>>>
>>>
>>>
>>>>>has=3D3D3D20 ocurred in the =3D3D3D3D media. The total signal loss =
of
the =3D
>>>>>
>>>>>
>>=3D3D
>>
>>
>>>>> =3D20
>>>>>
>>>>>
>>>>>
>>>system=3D3D20
>>>=3D20
>>>
>>>
>>>
>>>>>could=3D3D3D20 still be the same.=3D3D3D3D20
>>>>>
>>>>>Leonard.=3D3D3D3D20
>>>>>
>>>>>
>>>>>
>>>>>----- Original Message ----=3D3D3D3D20
>>>>>From: Stephen Zinck <signalintegrity@xxxxxxxxxxx>=3D3D3D3D20
>>>>>To: ron@xxxxxxxxxxx; Chris.Cheng@xxxxxxxx=3D3D3D3D20
>>>>>Cc: si-list@xxxxxxxxxxxxx=3D3D3D3D20
>>>>>Sent: Friday, September 28, 2007 12:19:22 PM=3D3D3D3D20
>>>>>Subject: [SI-LIST] Re: AC Coupled Signals=3D3D3D3D20
>>>>>
>>>>>
>>>>>Hello SI-LISTers,=3D3D3D3D20
>>>>>
>>>>>I thought for my part in this discussion, I should do some=3D20
>>>>>due=3D3D3D20=3D3D20 diligence =3D3D3D3D on=3D3D3D3D20 this AC =
coupling =3D
>>>>>
>>>>>
>>capacitor=3D20
>>
>>
>>>>>placement =3D3D
>>>>> =3D20
>>>>>
>>>>>
>>>>>
>>>location=3D3D3D20
>>>
>>>=3D20
>>>
>>>
>>>
>>>>>question.=3D3D3D3D20
>>>>>
>>>>>Scott McMorrow, Steve Weir and I had some off-line discussions that
=3D
>>>>>
>>>>>
>>=3D3D
>>
>>
>>>>> =3D20
>>>>>
>>>>>
>>>>>
>>>=3D3D3D
>>>=3D20
>>>
>>>
>>>
>>>>> =3D3D20
>>>>>
>>>>> =3D20
>>>>>
>>>>>
>>>>>
>>>>=3D3D3D3D=3D3D3D20
>>>>=3D3D20
>>>>
>>>> =3D20
>>>>
>>>>
>>>>
>>>>>tended=3D3D3D3D20 to suggest my position dependency results may =
have
=3D
>>>>>
>>>>>
>>=3D3D
>>
>>
>>>>> =3D20
>>>>>
>>>>>
>>>>>
>>>been=3D3D3D20
>>>
>>>=3D20
>>>
>>>
>>>
>>>>>caused by local=3D3D3D3D20 resonances from other impedance=3D20
>>>>>discontinuities =3D3D
>>>>> =3D20
>>>>>
>>>>>
>>>>>
>>>=3D3D3D
>>>=3D20
>>>
>>>
>>>
>>>>> =3D3D20
>>>>>
>>>>> =3D20
>>>>>
>>>>>
>>>>>
>>>>in=3D3D3D20
>>>>=3D3D20
>>>>
>>>> =3D20
>>>>
>>>>
>>>>
>>>>>the system I was=3D3D3D3D20 simulating. Based on this, I set out to
=3D3D
>>>>> =3D20
>>>>>
>>>>>
>>>>>
>>>develop=3D3D20
>>>=3D20
>>>
>>>
>>>
>>>>>=3D3D3D
>>>>> =3D3D20
>>>>>
>>>>> =3D20
>>>>>
>>>>>
>>>>>
>>>>a=3D3D3D20
>>>>=3D3D20
>>>>
>>>> =3D20
>>>>
>>>>
>>>>
>>>>>simulation model that =3D3D3D3D had=3D3D3D3D20 a minimum of =3D
>>>>>
>>>>>
>>discontinuities =3D3D
>>
>>
>>>>> =3D20
>>>>>
>>>>>
>>>>>
>>>(no=3D3D3D20
>>>
>>>=3D20
>>>
>>>
>>>
>>>>>backplane vias/connectors/trace, etc.). =3D3D3D3D
>>>>>
>>>>>
>>>>>I used:=3D3D3D3D20
>>>>>
>>>>>- Spice models of non-linear 3.125Gbit/s silicon (driver =3D
>>>>>
>>>>>
>>and=3D3D3D20=3D3D20=3D20
>>
>>
>>>>>receiver)=3D3D3D3D20
>>>>>- S-parameter based package models for both driver and =3D3D
>>>>> =3D20
>>>>>
>>>>>
>>>>>
>>>receiver.=3D3D3D3D20
>>>=3D20
>>>
>>>
>>>
>>>>>- A 0.01uF capacitor and its associated parasitics (via, trace,
pad,=3D20
>>>>>=3D3D
>>>>> =3D20
>>>>>
>>>>>
>>>>>
>>>=3D3D3D
>>>=3D20
>>>
>>>
>>>
>>>>> =3D3D20
>>>>>
>>>>> =3D20
>>>>>
>>>>>
>>>>>
>>>>=3D3D3D3D
>>>>
>>>>=3D3D20
>>>>
>>>> =3D20
>>>>
>>>>
>>>>
>>>>>mount,=3D3D3D3D20 component).=3D3D3D3D20
>>>>>- 2D lossy W-Element transmission line (with di-electric and=3D20
>>>>>skin=3D3D3D20 =3D3D
>>>>> =3D20
>>>>>
>>>>>
>>>>>
>>>=3D20
>>>
>>>
>>>
>>>>>effect =3D3D3D3D
>>>>>
>>>>>losses included).=3D3D3D3D20
>>>>>
>>>>>I made the capacitor model such that I could "slide" it up and=3D20
>>>>>down=3D3D20 a=3D3D3D20
>>>>>15 =3D3D3D3D
>>>>>
>>>>>inch trace between the driver and receiver. I iteratively =3D3D
>>>>> =3D20
>>>>>
>>>>>
>>>>>
>>>simulated=3D3D3D20
>>>
>>>=3D20
>>>
>>>
>>>
>>>>>for =3D3D3D3D the=3D3D3D3D20 following length =
combinations:=3D3D3D3D20
>>>>>
>>>>>- 500 mil trace from driver to AC coupling capacitor with 14500 mil
=3D
>>>>>
>>>>>
>>=3D3D
>>
>>
>>>>> =3D20
>>>>>
>>>>>
>>>>>
>>>=3D3D3D
>>>=3D20
>>>
>>>
>>>
>>>>> =3D3D20
>>>>>
>>>>> =3D20
>>>>>
>>>>>
>>>>>
>>>>=3D3D3D3D=3D3D3D20
>>>>=3D3D20
>>>>
>>>> =3D20
>>>>
>>>>
>>>>
>>>>>trace to=3D3D3D3D20 receiver.=3D3D3D3D20
>>>>>- 5000 mil trace from driver to AC coupling capacitor with 10000
mil=3D20
>>>>>=3D3D
>>>>> =3D20
>>>>>
>>>>>
>>>>>
>>>=3D3D3D
>>>=3D20
>>>
>>>
>>>
>>>>> =3D3D20
>>>>>
>>>>> =3D20
>>>>>
>>>>>
>>>>>
>>>>=3D3D3D3D
>>>>
>>>>=3D3D20
>>>>
>>>> =3D20
>>>>
>>>>
>>>>
>>>>>trace=3D3D3D3D20 to receiver.=3D3D3D3D20
>>>>>- 10000 mil trace from driver to AC coupling capacitor with 5000
mil=3D20
>>>>>=3D3D
>>>>> =3D20
>>>>>
>>>>>
>>>>>
>>>=3D3D3D
>>>=3D20
>>>
>>>
>>>
>>>>> =3D3D20
>>>>>
>>>>> =3D20
>>>>>
>>>>>
>>>>>
>>>>=3D3D3D3D
>>>>
>>>>=3D3D20
>>>>
>>>> =3D20
>>>>
>>>>
>>>>
>>>>>trace=3D3D3D3D20 to receiver.=3D3D3D3D20
>>>>>- 14500 mil trace from driver to AC coupling capacitor with 500 mil
=3D
>>>>>
>>>>>
>>=3D3D
>>
>>
>>>>> =3D20
>>>>>
>>>>>
>>>>>
>>>=3D3D3D
>>>=3D20
>>>
>>>
>>>
>>>>> =3D3D20
>>>>>
>>>>> =3D20
>>>>>
>>>>>
>>>>>
>>>>=3D3D3D3D=3D3D3D20
>>>>=3D3D20
>>>>
>>>> =3D20
>>>>
>>>>
>>>>
>>>>>trace to=3D3D3D3D20 receiver.=3D3D3D3D20
>>>>>
>>>>>The results show around 125 mV (differential) difference=3D20
>>>>>between=3D3D3D20=3D3D20 the=3D3D3D3D20 capacitor at the source =
versus
the=3D20
>>>>>capacitor at the=3D3D3D20=3D3D20 destination, with =3D3D3D3D =
the=3D3D3D3D20
=3D
>>>>>
>>>>>
>>benefit=3D20
>>
>>
>>>>>going to the capacitor=3D3D20 placed=3D3D3D20 closest to the =
receiver.
=3D
>>>>>
>>>>>
>>125 mV
>>
>>
>>
>>>>>is =3D3D3D3D a=3D3D3D3D20 lot to =3D3D
>>>>> =3D20
>>>>>
>>>>>
>>>>>
>>>give=3D3D20
>>>=3D20
>>>
>>>
>>>
>>>>>away...=3D3D3D3D20
>>>>>
>>>>>I am not going to pretend to understand the physics behind=3D20
>>>>>these=3D3D3D20=3D3D20 results =3D3D3D3D but=3D3D3D3D20 I thought it =
worth =3D
>>>>>
>>>>>
>>while to at
>>
>>
>>
>>>>>least show the =3D3D
>>>>> =3D20
>>>>>
>>>>>
>>>>>
>>>=3D3D3D
>>>=3D20
>>>
>>>
>>>
>>>>> =3D3D20
>>>>>
>>>>> =3D20
>>>>>
>>>>>
>>>>>
>>>>basis=3D3D3D20
>>>>=3D3D20
>>>>
>>>> =3D20
>>>>
>>>>
>>>>
>>>>>for my statements.=3D3D3D3D20
>>>>>
>>>>>I would be happy to evolve the simulation environment if
someone=3D3D20 =3D
>>>>>
>>>>>
>>
>>
>>
>>>>>has=3D3D3D20 a=3D3D3D3D20 suggestion...=3D3D3D3D20
>>>>>
>>>>>I have put together a document that I can post to an ftp site =
or=3D20
>>>>>email
>>>>> =3D3D20
>>>>>
>>>>> =3D20
>>>>>
>>>>>
>>>>>
>>>>=3D3D20
>>>>
>>>> =3D20
>>>>
>>>>
>>>>
>>>>>=3D3D3D3D if=3D3D3D3D20 anyone would like a copy...=3D3D3D3D20
>>>>>
>>>>>Kind regards,=3D3D3D3D20
>>>>>Steve=3D3D3D3D20
>>>>>
>>>>>Stephen P. Zinck=3D3D3D3D20
>>>>>Interconnect Engineering Inc.=3D3D3D3D20
>>>>>P.O. Box 577=3D3D3D3D20
>>>>>South Berwick, ME 03908=3D3D3D3D20
>>>>>Phone - (207) 384-8280=3D3D3D3D20
>>>>>Email - szinck@xxxxxxxxxxxxxxxxxxxxxxxxxxx=3D3D3D3D20
>>>>>Web - www.interconnectengineering.com=3D3D3D3D20
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> =3D3D20
>>>>>
>>>>> =3D20
>>>>>
>>>>>
>>>>>
>>>>=3D3D20
>>>>
>>>> =3D20
>>>>
>>>>
>>>>
>>>------------------------------------------------------------------
>>>To unsubscribe from si-list:
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>>>
>>>or to administer your membership from a web page, go to:
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>>>=3D20
>>>
>>>=3D20
>>>
>>>
>>>
>>------------------------------------------------------------------
>>To unsubscribe from si-list:
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>>
>>or to administer your membership from a web page, go to:
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>>
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>>Old (prior to June 6, 2001) list archives are viewable at:
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>>
>>
>>
>>
>
>
>
> ------------------------------------------------------------------
> To unsubscribe from si-list:
> si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field
>
> or to administer your membership from a web page, go to:
> //www.freelists.org/webpage/si-list
>
> For help:
> si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field
>
>
> List technical documents are available at:
> http://www.si-list.net
>
> List archives are viewable at:
> //www.freelists.org/archives/si-list
> or at our remote archives:
> http://groups.yahoo.com/group/si-list/messages
> Old (prior to June 6, 2001) list archives are viewable at:
> http://www.qsl.net/wb6tpu
>
>
>=20
------------------------------------------------------------------
To unsubscribe from si-list:
si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field
or to administer your membership from a web page, go to:
//www.freelists.org/webpage/si-list
For help:
si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field
List technical documents are available at:
http://www.si-list.net
List archives are viewable at: =20
//www.freelists.org/archives/si-list
or at our remote archives:
http://groups.yahoo.com/group/si-list/messages
Old (prior to June 6, 2001) list archives are viewable at:
http://www.qsl.net/wb6tpu
=20
------------------------------------------------------------------
To unsubscribe from si-list:
si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field
or to administer your membership from a web page, go to:
//www.freelists.org/webpage/si-list
For help:
si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field
List technical documents are available at:
http://www.si-list.net
List archives are viewable at:
//www.freelists.org/archives/si-list
or at our remote archives:
http://groups.yahoo.com/group/si-list/messages
Old (prior to June 6, 2001) list archives are viewable at:
http://www.qsl.net/wb6tpu
Other related posts:
