[SI-LIST] Re: TDR Analysis Equipment..Tektronix vs. Agilent?

Dima is out of the office, so I guess I have inherited his thread...

The content of the white paper Mike referenced is generally correct
qualitatively, but I should point out that its measurements were taken
using a prior generation of Tektronix TDR and sampling technology.  As
Dima pointed out, TDR Bandwidth and SNR have posted major gains beyond
where they were when the white paper was published!

  -- Steve

------------------------------------------------------------------------
-
Steven D. Corey, Ph.D.
Principal Engineer
Tektronix - Enabling Innovation
=20
http://www.tdasystems.com
http://www.tektronix.com
=20
email: steven.corey@xxxxxxxxxxxxx
phone: (503) 627-6816
fax:   (503) 627-2260
------------------------------------------------------------------------
-
=20

>-----Original Message-----
>From: si-list-bounce@xxxxxxxxxxxxx=20
>[mailto:si-list-bounce@xxxxxxxxxxxxx] On Behalf Of=20
>mike_resso@xxxxxxxxxxx
>Sent: Thursday, April 26, 2007 10:06 AM
>To: si-list@xxxxxxxxxxxxx
>Subject: [SI-LIST] Re: TDR Analysis Equipment..Tektronix vs. Agilent?
>
>
>
>
>It's not Agilent's style to be biased toward either TDR or VNA=20
>(remember =3D
>we sell both). However, this is simply question of accuracy.=20
>TDRs are a =3D
>great tool to start troubleshooting and design because of the simple =
=3D
>calibration and the intuitive nature of impedance profile. =20
>However, the =3D
>dynamic range limitation of the TDR degrades the accuracy of=20
>measuring =3D
>low level signal (IE crosstalk). This is especially true when=20
>you have =3D
>backplane channels over 40". This lossy transmission line will=20
>attenuate =3D
>the crosstalk amplitude tremendously. Since this question comes up so =
=3D
>often, we published a good application note entitled,=20
>"Limitations and =3D
>Accuracies of Time and Frequency Domain Analysis of Physical Layer =3D
>Devices." This app note includes data taken over a period of=20
>18 months =3D
>on various platforms. To download this app note, go here:
>http://www.home.agilent.com/agilent/redirector.jspx?action=3D3Dre
>f&cname=3D3D=3D
>AGILENT_EDITORIAL&ckey=3D3D720377&lc=3D3Deng&cc=3D3DUS
>
>
>
>
>
>-----Original Message-----
>From: si-list-bounce@xxxxxxxxxxxxx=20
>[mailto:si-list-bounce@xxxxxxxxxxxxx] =3D
>On Behalf Of dmitry.a.smolyansky@xxxxxxxxxxxxxx
>Sent: Wednesday, April 25, 2007 12:20 PM
>To: vicente.cavanna@xxxxxx; tom@xxxxxxxxxxxxx; =3D
>homer.si.mpson66@xxxxxxxxx; si-list@xxxxxxxxxxxxx
>Subject: [SI-LIST] Re: TDR Analsis Equipment..Tektronix vs Agilent?
>
>VNA energy is not uniform either. It is being "uniformized" using =3D
>calibration. The same applies for TDR. And while the TDR-based =3D
>S-parameter dynamic range is lower than that of a VNA, it is=20
>more than =3D
>adequate for serial data applications. You get about -70 dB of=20
>dynamic =3D
>range at DC and -40 dB at 50 GHz on Tektronix equipment. I would not =
=3D
>recommend this for microwave filter design, but for serial data it is =
=3D
>perfect. As a side bonus, you get true differential -=20
>individual source =3D
>per each channel, avoiding any switching errors and ensuring accurate =
=3D
>non-linear and active device characterization.
>
>Thanks,
>=3D3D20
>Dima Smolyansky
>Tektronix, Inc.
>P.O. Box 500, MS 39-111
>Beaverton, OR 97077-0001
>503-627-7180
>503-627-2260 (fax)
>
>
>-----Original Message-----
>From: si-list-bounce@xxxxxxxxxxxxx=20
>[mailto:si-list-bounce@xxxxxxxxxxxxx]
>On Behalf Of Cavanna, Vicente Vaca (Sr. ; ProCurve ASICs)
>Sent: Wednesday, April 25, 2007 9:38 AM
>To: tom@xxxxxxxxxxxxx; homer.si.mpson66@xxxxxxxxx;=20
>si-list@xxxxxxxxxxxxx
>Subject: [SI-LIST] Re: TDR Analsis Equipment..Tektronix vs Agilent?
>
> Hi Tom,
>But it is not too important to get the same energy over the=20
>measurement =3D
>frequency range (after all, the energy in the TDR stimulus is hardly =
=3D
>uniform over frequency). What is of primary importance is to have
>*sufficient* energy at the detector to overcome the noise (i.e.
>sufficient signal to noise ratio) at all frequencies of=20
>interest. I do =3D
>agree of course that the DUT plays a huge  part in how much energy =3D
>reaches the detector.
>Vicente
>
>> -----Original Message-----
>> From: si-list-bounce@xxxxxxxxxxxxx=3D3D3D20 =3D20
>>[mailto:si-list-bounce@xxxxxxxxxxxxx] On Behalf Of Tom Dagostino
>> Sent: Tuesday, April 24, 2007 6:32 PM
>> To: Cavanna, Vicente Vaca (Sr. ; ProCurve ASICs);=3D3D3D20 =3D20
>>homer.si.mpson66@xxxxxxxxx; si-list@xxxxxxxxxxxxx
>> Subject: [SI-LIST] Re: TDR Analsis Equipment..Tektronix vs Agilent?
>>=3D3D3D20
>> Vicente
>>=3D3D3D20
>> It is not a problem getting a large amount of energy to the=3D3D3D20  =
=3D
>DUT,=3D20
>>it is a problem of getting the same energy over the=3D3D3D20 =20
>measurement =3D
>
>>frequency range. =3D3D3D3D  If there is an inductive=3D3D3D20  launch =
it =3D
>will=3D20
>>act as a low pass filter.  Thus the energy=3D3D3D20  will be=20
>different at =3D
>
>>different frequencies.
>>=3D3D3D20
>> Tom Dagostino
>> Teraspeed(R) Labs
>> 13610 SW Harness Lane
>> Beaverton, OR 97008
>> 503-430-1065
>> tom@xxxxxxxxxxxxx=3D3D3D3D20
>> www.teraspeed.com=3D3D3D3D20
>>=3D3D3D20
>> Teraspeed Consulting Group LLC
>> 121 North River Drive
>> Narragansett, RI 02882
>> 401-284-1827
>>=3D3D3D20
>> -----Original Message-----
>> From: si-list-bounce@xxxxxxxxxxxxx=3D3D3D20 =3D20
>>[mailto:si-list-bounce@xxxxxxxxxxxxx] =3D3D3D3D On Behalf Of =3D
>Cavanna,=3D3D3D20 =3D20
>>Vicente Vaca (Sr. ; ProCurve ASICs)
>> Sent: Tuesday, April 24, 2007 5:20 PM
>> To: homer.si.mpson66@xxxxxxxxx; si-list@xxxxxxxxxxxxx
>> Subject: [SI-LIST] Re: TDR Analsis Equipment..Tektronix vs Agilent?
>>=3D3D3D20
>>=3D3D3D20
>>  With a VNA one can increase the power level of the=20
>stimulus=3D3D3D20  =3D
>and=3D20
>>get =3D3D3D3D more energy into and through the DUT even when=20
>the=3D3D3D20  =3D
>DUT=3D20
>>is lossy and/or =3D3D3D3D extremely reflective. With a TDR=20
>this=3D3D3D20  =3D
>is=3D20
>>not as easy to do; in fact the TDRs I =3D3D3D3D have used do=20
>not=3D3D3D20 =3D20
>>permit such control. Vicente =3D3D3D20
>> > -----Original Message-----
>> > From: si-list-bounce@xxxxxxxxxxxxx=3D3D3D3D3D20 =
=3D3D3D3D20=3D3D3D20=3D20
>> >[mailto:si-list-bounce@xxxxxxxxxxxxx] On Behalf Of Peter J
>> > Sent: Tuesday, April 24, 2007 9:36 AM
>> > To: si-list@xxxxxxxxxxxxx
>> > Subject: [SI-LIST] Re: TDR Analsis Equipment..Tektronix vs=3D3D3D20
>> Agilent?=3D3D3D3D20=3D3D3D20
>> >=3D3D3D3D3D20  Hi,  The biggest problem in using a TDR or VNA =3D
>for=3D3D3D20
>> that matter=3D3D3D20
>> >is=3D3D3D3D3D20  to get enough energy into the DUT since even a =3D
>very=3D3D3D20
>> small=3D3D3D3D3D20 =3D3D3D20
>> >inductance at the connection point from the TDR to the=3D3D3D20
>> DUT=3D3D3D3D3D20  will=3D3D3D20
>> >give an insertion loss. It's possible to get a return=3D3D3D3D3D20  =
=3D
>loss=3D20
>> >=3D3D
>of
>=3D3D3D
>
>> >-20dB at 5GHz if you work hard. At 50 GHz it's hard=3D3D3D3D3D20  =
=3D
>to=3D3D3D20
>> get -3 dB=3D3D3D20
>> >RL which means that half of the power will enter=3D3D3D3D3D20  =3D
>the=3D3D3D20
>> DUT and the=3D3D3D20
>> >rest is wasted. By using a VNA it is possible=3D3D3D3D3D20  to make =
a
>TRL=3D3D3D20
>> >calibration kit and remove the effect of the=3D3D3D3D3D20 =3D3D3D20
>> testsystem and only=3D3D3D20
>> >get the DUT characteristics.
>> > I use a short pigtail with a thin semirigid coax instead of =3D3D
>a=3D3D3D3D3D20
>=3D3D3D
>=3D3D3D20
>> >probe when I do measurements with the TDR(tektronix).=20
>It=3D3D3D3D3D20 =3D
>=3D3D
>=3D3D3D20
>> >increases the accuracy a great deal.
>> >=3D3D3D3D3D20
>> > BR
>> > Peter
>> >=3D3D3D3D3D20
>> > -----Original Message-----
>> >=3D3D3D3D3D20
>> > From: si-list-bounce@xxxxxxxxxxxxx
>> >=3D3D3D20
>> [*mailto:si-list-bounce@xxxxxxxxxxxxx*<si-list-bounce@xxxxxxxxxxxxx>]
>> > On Behalf Of ext Asbenson, Lyndell L =3D3D3D3D3D20
>> > Sent: 24. april 2007 02:27
>> >=3D3D3D3D3D20
>> > To: heidi.barnes@xxxxxxxxxx; si-list@xxxxxxxxxxxxx =3D3D3D3D3D20
>> > Cc: timothy.j.nash@xxxxxxxx; tom_cip_11551@xxxxxxxxx =3D3D3D3D3D20
>> > Subject: [SI-LIST] Re: TDR Analsis Equipment..Tektronix vs Agilent?
>> >=3D3D3D3D3D20
>> > Dedicated TDR is much easer to setup then going the VNA=3D3D3D20
>> route -Lyndell=3D3D3D20
>> >=3D3D3D3D3D20  -----Original Message----- =3D3D3D3D3D20
>> > From: si-list-bounce@xxxxxxxxxxxxx
>> >=20
>[*mailto:si-list-bounce@xxxxxxxxxxxxx*<si-list-bounce@xxxxxxxxxxxxx>
>> > ]
>> >=3D3D3D3D3D20
>> > On Behalf Of Barnes, Heidi
>> >=3D3D3D3D3D20
>> > Sent: Monday, April 23, 2007 12:17 PM =3D3D3D3D3D20
>> > To: si-list@xxxxxxxxxxxxx
>> >=3D3D3D3D3D20
>> > Cc: timothy.j.nash@xxxxxxxx; tom_cip_11551@xxxxxxxxx =3D3D3D3D3D20
>> > Subject: [SI-LIST] Re: TDR Analsis Equipment..Tektronix vs Agilent?
>> >=3D3D3D3D3D20
>> > Hi Tom,
>> >=3D3D3D3D3D20
>> > Tim is correct in that probing is not a simple task. If=3D3D3D20
>> you=3D3D3D3D3D20  have=3D3D3D20
>> >the time and patience, a Vector Network Analyzer=20
>with=3D3D3D3D3D20  =3D3D
>PCB=3D3D3D20
>> >Thru-Reflect-Line Calibration standards can provide a=3D3D3D3D3D20 =
=3D
>=3D3D3D20
>> method for=3D3D3D20
>> >getting measured electrical data for a PCB=3D3D3D3D3D20 =20
>structure that =3D
>=3D3D
>=3D3D3D
>does=3D3D3D20
>> >not include the probes or connectorized=3D3D3D3D3D20 =20
>transitions on to =3D
>=3D3D
>the
>=3D3D3D
>
>> >printed circuit board. The S-Parameter=3D3D3D3D3D20  data can =3D
>then=3D3D3D20
>> be converted=3D3D3D20
>> >to time domain for TDR analysis of=3D3D3D3D3D20  the discontinuities =
=3D
>and
>a=3D3D3D20
>> >40GHz box will give you around an=3D3D3D3D3D20  18pS rise time =3D
>pulse=3D3D3D20
>> (an edge=3D3D3D20
>> >that is ~100mils long for a PCB=3D3D3D3D3D20  dielectric constant =
=3D
>of=3D3D3D20
>> ~4) which=3D3D3D20
>> >gives a significant amount=3D3D3D3D3D20  of detail (50mils is =3D
>rather=3D3D3D20
>> ambitious=3D3D3D20
>> >unless you have money=3D3D3D3D3D20  for the top end 110GHz=20
>VNA's or 8pS =3D
>=3D3D
>=3D3D3D
>rise=3D3D3D20
>> >time TDR scopes).=3D3D3D3D3D20  The other thing to think=20
>about is that =3D
>=3D3D
>most
>=3D3D3D
>
>> >applications=3D3D3D3D3D20  running about 3Gbps are differential =3D
>so=3D3D3D20
>> it is also=3D3D3D20
>> >nice to=3D3D3D3D3D20  have a 4-Port system for measurements.
>> >=3D3D3D3D3D20
>> > Regards,
>> >=3D3D3D3D3D20
>> > Heidi
>> >=3D3D3D3D3D20
>> > -----Original Message-----
>> >=3D3D3D3D3D20
>> > From: si-list-bounce@xxxxxxxxxxxxx
>> >=20
>[*mailto:si-list-bounce@xxxxxxxxxxxxx*<si-list-bounce@xxxxxxxxxxxxx>
>> > ]
>> >=3D3D3D3D3D20
>> > On Behalf Of Nash, Timothy J
>> >=3D3D3D3D3D20
>> > Sent: Monday, April 23, 2007 11:33 AM =3D3D3D3D3D20
>> > To: tom_cip_11551@xxxxxxxxx; si-list@xxxxxxxxxxxxx =3D3D3D3D3D20
>> > Subject: [SI-LIST] Re: TDR Analsis Equipment..Tektronix vs Agilent?
>> >=3D3D3D3D3D20
>> > Hi, Tom.
>> >=3D3D3D3D3D20
>> > I have tried using a Tektronix TDR (I'm not sure of =
the=3D3D3D3D3D20
>> > model) to probe PCBs before, and found that what probe=3D3D3D20
>> you=3D3D3D3D3D20  were=3D3D3D20
>> >using, and WHAT you were probing, can make or break=20
>your=3D3D3D3D3D20 =3D
>=3D3D
>=3D3D3D20
>> >measurement. We were using a hand-held pressure-actuated =3D3D
>type=3D3D3D3D3D20
>=3D3D3D
>
>> >probe and simply bending your wrist a little would change =3D3D
>the=3D3D3D3D3D20
>=3D3D3D
>
>> >response. We had a tough time even discerning between=20
>two=3D3D3D3D3D20  =3D
>=3D3D
>=3D3D3D
>vias=3D3D3D20
>> >spaced an inch apart from each other. I believe the=3D3D3D3D3D20 =3D
>=3D3D3D20
>> probes used=3D3D3D20
>> >by most PCB manufacturers are on a robotic arm=3D3D3D3D3D20  and =
they
>are=3D3D3D20
>> >probing PCB coupons that have pre-defined TDR=3D3D3D3D3D20 =3D3D3D20
>> features. I found=3D3D3D20
>> >it very difficult to glean much useful info=3D3D3D3D3D20  from =3D
>real=3D3D3D20
>> PCB traces=3D3D3D20
>> >when the discontinuities were as close=3D3D3D3D3D20  together=20
>as=3D3D3D20
>> what you are=3D3D3D20
>> >describing. I don't believe this was=3D3D3D3D3D20  a fault of =3D
>the=3D3D3D20
>> scope - just=3D3D3D20
>> >a function of the probing method=3D3D3D3D3D20  and the =
feature=3D3D3D20
>> constraints of=3D3D3D20
>> >the PCB.
>> >=3D3D3D3D3D20
>> > Tim
>> >=3D3D3D3D3D20
>> >=3D3D3D3D3D20
>> >=3D3D3D3D3D20
>> >=3D3D3D3D3D20
>> >=3D3D3D3D3D20
>> > -----Original Message-----
>> >=3D3D3D3D3D20
>> > From: si-list-bounce@xxxxxxxxxxxxx
>> >=20
>[*mailto:si-list-bounce@xxxxxxxxxxxxx*<si-list-bounce@xxxxxxxxxxxxx>
>> > ]
>> >=3D3D3D3D3D20
>> > On Behalf Of tom_cip_11551
>> >=3D3D3D3D3D20
>> > Sent: Monday, April 23, 2007 10:47 AM =3D3D3D3D3D20
>> > To: si-list@xxxxxxxxxxxxx
>> >=3D3D3D3D3D20
>> > Subject: [SI-LIST] TDR Analsis Equipment..Tektronix vs Agilent?
>> >=3D3D3D3D3D20
>> > Hi to the Signal Integrity community.
>> >=3D3D3D3D3D20
>> > I am looking for a set of equipment with wich to do=3D3D3D20
>> TDR=3D3D3D3D3D20  analysis=3D3D3D20
>> >on=3D3D3D3D3D3D3D20 high speed PCB structures. We are =
now=3D3D3D3D3D20 =3D
>=3D3D3D20
>> building boards=3D3D3D20
>> >to run at=3D3D3D3D3D3D3D20 speeds of 3 Gb/s or faster=20
>and=3D3D3D3D3D20  =3D
>=3D3D
>I=3D3D3D20
>> would like to=3D3D3D20
>> >resolve=3D3D3D3D3D3D3D20 discontinuites within, say,=20
>50=3D3D3D3D3D20  =3D3D
>mils=3D3D3D20
>> to 80 mils=3D3D3D20
>> >of each other.
>> >=3D3D3D3D3D20
>> > I have gotten quotes from Tektronix and Agilent for=20
>TDR=3D3D3D3D3D20 =3D
>=3D3D
>=3D3D3D20
>> >equipment. =3D3D3D3D3D3D3D20 =3D3D3D3D3D20  The Tektronix=20
>system consists =3D
>of
>the=3D3D3D20
>> >DSA8200 digital sampling=3D3D3D3D3D20  =3D3D3D3D3D3D =3D
>scope,=3D3D3D3D3D3D3D20 the=3D20
>> >=3D3D
>80E04
>=3D3D3D
>TDR=3D3D3D20
>> >sampling module and the =3D3D3D3D
>> 80SICON=3D3D3D3D3D20
>> > signal integrity and=3D3D3D3D3D3D3D20 failure analysis software =3D
>(a=3D3D3D20
>> $20K=3D3D3D3D3D20 =3D3D3D20
>> >item by itself).
>> >=3D3D3D3D3D20
>> > The Agilent system consists of the 86100C scope, the =3D
>54754A=3D3D3D3D3D20
>=3D3D3D20
>> >TDR=3D3D3D3D3D3D3D20 module and various other software programs for =
=3D
>=3D3D3D
>S=3D3D3D3D3D20 =3D3D3D20
>> >parameters, Jitter=3D3D3D3D3D3D3D20 analysis, etc.
>> >=3D3D3D3D3D20
>> > I am wondering what the Signal Integrity community at =3D
>large=3D3D3D3D3D20
>=3D3D3D20
>> >is=3D3D3D3D3D3D3D20 using.
>> > Which system is more popular and, most important, =3D
>cost=3D3D3D3D3D3D3D20=3D20
>> >=3D3D
>=3D3D3D
>=3D3D3D3D3D
>> effective?
>> >=3D3D3D3D3D20
>> > What are some of the advantages and drawbacks of each?
>> >=3D3D3D3D3D20
>> > Are there other solutions on the market that are more=20
>cost=3D3D3D20=3D20
>> >effective?=3D3D3D3D20 =3D3D3D3D3D20  Thank You =3D3D3D3D3D20  Tom =
=3D
>=3D3D3D3D3D20 =3D3D
>=3D3D3D3D3D20 =3D3D3D
>=3D3D3D3D3D20
>> > ------------------------------------------------------------------
>> >=3D3D3D3D3D20
>> > To unsubscribe from si-list:
>> >=3D3D3D3D3D20
>> > si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the=3D3D3D20
>> Subject field=3D3D3D20
>> >=3D3D3D3D3D20  or to administer your membership from a web=20
>page, go to:
>> >=3D3D3D3D3D20
>> > *http://www.freelists.org/webpage/si-list*<http://www.freelist
>> s.org/webpage/si-list>
>> >=3D3D3D3D3D20
>> > For help:
>> >=3D3D3D3D3D20
>> > si-list-request@xxxxxxxxxxxxx with 'help' in the Subject=3D3D3D20
>> field =3D3D3D3D3D20=3D3D3D20
>> >=3D3D3D3D3D20 =3D3D3D3D3D20  List technical documents are available =
at:
>> >=3D3D3D3D3D20
>> > *http://www.si-list.net* <http://www.si-list.net/> =3D3D3D3D3D20  =
=3D3D
>List=3D3D3D20
>> >archives are viewable at: =3D3D3D3D3D3D3D20 =3D3D3D3D3D20 =
=3D3D3D20=3D20
>> >*http://www.freelists.org/archives/si-list*<http://www.freelis
>> ts.org/archives/si-list>
>> >=3D3D3D3D3D20
>> > or at our remote archives:
>> >=3D3D3D3D3D20  =3D3D3D
>*http://groups.yahoo.com/group/si-list/messages*<http://groups
>> .yahoo.com/group/si-list/messages>
>> >=3D3D3D3D3D20
>> > Old (prior to June 6, 2001) list archives are viewable at: =3D
>=3D3D3D3D3D20
>> > *http://www.qsl.net/wb6tpu* <http://www.qsl.net/wb6tpu>=20
>=3D3D3D3D3D20 =3D
>=3D3D
>=3D3D3D20
>> >=3D3D3D3D3D3D3D20 =3D3D3D3D3D20
>> > ------------------------------------------------------------------
>> >=3D3D3D3D3D20
>> > To unsubscribe from si-list:
>> >=3D3D3D3D3D20
>> > si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the=3D3D3D20
>> Subject field=3D3D3D20
>> >=3D3D3D3D3D20  or to administer your membership from a web=20
>page, go to:
>> >=3D3D3D3D3D20
>> > *http://www.freelists.org/webpage/si-list*<http://www.freelist
>> s.org/webpage/si-list>
>> >=3D3D3D3D3D20
>> > For help:
>> >=3D3D3D3D3D20
>> > si-list-request@xxxxxxxxxxxxx with 'help' in the Subject=3D3D3D20
>> field =3D3D3D3D3D20=3D3D3D20
>> >=3D3D3D3D3D20 =3D3D3D3D3D20  List technical documents are available =
at:
>> >=3D3D3D3D3D20
>> > *http://www.si-list.net* <http://www.si-list.net/> =3D3D3D3D3D20  =
=3D3D
>List=3D3D3D20
>> >archives are viewable at: =3D3D3D3D3D3D3D20 =3D3D3D3D3D20 =
=3D3D3D20=3D20
>> >*http://www.freelists.org/archives/si-list*<http://www.freelis
>> ts.org/archives/si-list>
>> >=3D3D3D3D3D20
>> > or at our remote archives:
>> >=3D3D3D3D3D20  =3D3D3D
>*http://groups.yahoo.com/group/si-list/messages*<http://groups
>> .yahoo.com/group/si-list/messages>
>> >=3D3D3D3D3D20
>> > Old (prior to June 6, 2001) list archives are viewable at: =3D
>=3D3D3D3D3D20
>> > *http://www.qsl.net/wb6tpu* <http://www.qsl.net/wb6tpu>=20
>=3D3D3D3D3D20 =3D
>=3D3D
>=3D3D3D20
>> >=3D3D3D3D3D3D3D20 =3D3D3D3D3D20
>> > ------------------------------------------------------------------
>> >=3D3D3D3D3D20
>> > To unsubscribe from si-list:
>> >=3D3D3D3D3D20
>> > si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the=3D3D3D20
>> Subject field=3D3D3D20
>> >=3D3D3D3D3D20  or to administer your membership from a web=20
>page, go to:
>> >=3D3D3D3D3D20
>> > *http://www.freelists.org/webpage/si-list*<http://www.freelist
>> s.org/webpage/si-list>
>> >=3D3D3D3D3D20
>> > For help:
>> >=3D3D3D3D3D20
>> > si-list-request@xxxxxxxxxxxxx with 'help' in the Subject=3D3D3D20
>> field =3D3D3D3D3D20=3D3D3D20
>> >=3D3D3D3D3D20 =3D3D3D3D3D20  List technical documents are available =
at:
>> >=3D3D3D3D3D20
>> > *http://www.si-list.net* <http://www.si-list.net/> =3D3D3D3D3D20  =
=3D3D
>List=3D3D3D20
>> >archives are viewable at: =3D3D3D3D3D3D20 =3D3D3D3D3D20 =
=3D3D3D20=3D20
>> >*http://www.freelists.org/archives/si-list*<http://www.freelis
>> ts.org/archives/si-list>
>> >=3D3D3D3D3D20
>> > or at our remote archives:
>> >=3D3D3D3D3D20  =3D3D3D
>*http://groups.yahoo.com/group/si-list/messages*<http://groups
>> .yahoo.com/group/si-list/messages>
>> >=3D3D3D3D3D20
>> > Old (prior to June 6, 2001) list archives are viewable at: =3D
>=3D3D3D3D3D20
>> > *http://www.qsl.net/wb6tpu* <http://www.qsl.net/wb6tpu>=3D3D3D20
>> =3D3D3D3D3D20  =3D3D3D3D3D3D20=3D3D3D20
>> >=3D3D3D3D3D20
>> > ------------------------------------------------------------------
>> >=3D3D3D3D3D20
>> > To unsubscribe from si-list:
>> >=3D3D3D3D3D20
>> > si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the=3D3D3D20
>> Subject field=3D3D3D20
>> >=3D3D3D3D3D20  or to administer your membership from a web=20
>page, go to:
>> >=3D3D3D3D3D20
>> > *http://www.freelists.org/webpage/si-list*<http://www.freelist
>> s.org/webpage/si-list>
>> >=3D3D3D3D3D20
>> > For help:
>> >=3D3D3D3D3D20
>> > si-list-request@xxxxxxxxxxxxx with 'help' in the Subject=3D3D3D20
>> field =3D3D3D3D3D20=3D3D3D20
>> >=3D3D3D3D3D20 =3D3D3D3D3D20  List technical documents are available =
at:
>> >=3D3D3D3D3D20
>> > *http://www.si-list.net* <http://www.si-list.net/> =3D3D3D3D3D20  =
=3D3D
>List=3D3D3D20
>> >archives are viewable at:
>> >=3D3D3D3D3D20
>> > *http://www.freelists.org/archives/si-list*<http://www.freelis
>> ts.org/archives/si-list>
>> >=3D3D3D3D3D20
>> > or at our remote archives:
>> >=3D3D3D3D3D20  =3D3D3D
>*http://groups.yahoo.com/group/si-list/messages*<http://groups
>> .yahoo.com/group/si-list/messages>
>> >=3D3D3D3D3D20
>> > Old (prior to June 6, 2001) list archives are viewable at: =3D
>=3D3D3D3D3D20
>> > *http://www.qsl.net/wb6tpu* <http://www.qsl.net/wb6tpu>=20
>=3D3D3D3D3D20 =3D
>=3D3D
>=3D3D3D
>=3D3D3D3D3D20
>> > ------------------------------------------------------------------
>> > To unsubscribe from si-list:
>> > si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the=3D3D3D20
>> Subject field=3D3D3D20
>> >=3D3D3D3D3D20  or to administer your membership from a web=20
>page, go to:
>> > http://www.freelists.org/webpage/si-list
>> >=3D3D3D3D3D20
>> > For help:
>> > si-list-request@xxxxxxxxxxxxx with 'help' in the Subject=3D3D3D20
>> field =3D3D3D3D3D20=3D3D3D20
>> >=3D3D3D3D3D20  List technical documents are available at:
>> >                 http://www.si-list.net =3D3D3D3D3D20
>> > List archives are viewable at:    =3D3D3D3D3D20
>> >            http://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
>> >  =3D3D3D3D3D20
>> >=3D3D3D3D3D20
>> >=3D3D3D3D3D20
>> ------------------------------------------------------------------
>> To unsubscribe from si-list:
>> si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the=20
>Subject field=3D20
>>=3D3D3D20  or to administer your membership from a web page, go to:
>> http://www.freelists.org/webpage/si-list
>>=3D3D3D20
>> For help:
>> si-list-request@xxxxxxxxxxxxx with 'help' in the Subject=20
>field =3D3D3D20 =3D
>
>>=3D3D3D20  List technical documents are available at:
>>                 http://www.si-list.net =3D3D3D20
>> List archives are viewable at:    =3D3D3D3D20
>>              http://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
>>  =3D3D3D3D20
>>=3D3D3D20
>>=3D3D3D20
>> ------------------------------------------------------------------
>> To unsubscribe from si-list:
>> si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the=20
>Subject field=3D20
>>=3D3D3D20  or to administer your membership from a web page, go to:
>> http://www.freelists.org/webpage/si-list
>>=3D3D3D20
>> For help:
>> si-list-request@xxxxxxxxxxxxx with 'help' in the Subject=20
>field =3D3D3D20 =3D
>
>>=3D3D3D20  List technical documents are available at:
>>                 http://www.si-list.net =3D3D3D20
>> List archives are viewable at:    =3D3D3D20
>>              http://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
>>  =3D3D3D20
>>=3D3D3D20
>>=3D3D3D20
>------------------------------------------------------------------
>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:
>http://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:    =3D3D20
>               http://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
> =3D3D20
>
>------------------------------------------------------------------
>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:
>http://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:    =3D20
>               http://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
> =3D20
>
>------------------------------------------------------------------
>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:
>http://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
>               http://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:
http://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:     
                http://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: