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Re: AT&T Plano, IL

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  • ozob99@yahoo.com
    ... GEP ... I had not heard of that..since Greenhill was a overseas cable terminal I guess the standard capacity was nt needed; but it seems like using a
    Message 1 of 10 , Nov 4, 2001
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      --- In coldwarcomms@y..., Mark Foster <mfoster@c...> wrote:
      > At 08:41 PM 11/4/2001 +0000, you wrote:
      > >including a rare 20 tube
      > >L3(perhaps the only one),to Norway I think;& I believe there were
      GEP
      > >antennae on the tower.
      >
      > How about a 6 tube L4 from Cheshire to Greenhill?

      I had not heard of that..since Greenhill was a overseas cable
      terminal I guess the standard capacity was'nt needed; but it seems
      like using a standard cable with only 6 tubes equipted would have
      been cheaper than making a special 6 tube cable??..or was this just 6
      tubes "hot"?
    • Mark Foster
      ... AT&T Cable map shows 6 tube cable.
      Message 2 of 10 , Nov 4, 2001
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        At 09:47 PM 11/4/2001 +0000, you wrote:
        >I had not heard of that..since Greenhill was a overseas cable
        >terminal I guess the standard capacity was'nt needed; but it seems
        >like using a standard cable with only 6 tubes equipted would have
        >been cheaper than making a special 6 tube cable??..or was this just 6
        >tubes "hot"?

        AT&T Cable map shows 6 tube cable.
      • ozob99@yahoo.com
        ... 6 ... OK, just seemed strange, I assume there must have been a reason to make a short section of 6 tube cable;perhaps to interface with that particular TAT
        Message 3 of 10 , Nov 4, 2001
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          --- In coldwarcomms@y..., Mark Foster <mfoster@c...> wrote:
          > At 09:47 PM 11/4/2001 +0000, you wrote:
          > >I had not heard of that..since Greenhill was a overseas cable
          > >terminal I guess the standard capacity was'nt needed; but it seems
          > >like using a standard cable with only 6 tubes equipted would have
          > >been cheaper than making a special 6 tube cable??..or was this just
          6
          > >tubes "hot"?
          >
          > AT&T Cable map shows 6 tube cable.

          OK, just seemed strange, I assume there must have been a reason to
          make a short section of 6 tube cable;perhaps to interface with that
          particular TAT cable.
        • ozob99@yahoo.com
          ... type. A, ... coaxial, but ... Coax-8 ... requirement. ... consisted of ... but was ... The multiplexing scheme or bandwidth was not the critical factor;
          Message 4 of 10 , Nov 4, 2001
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            --- In coldwarcomms@y..., Harold Peach <hpeach@p...> wrote:
            > As I understand it, Coax-8, Coax-12, and Coax-20 defined the cable
            type. A,
            > N, K, L3, Improved L3, L4, and L5 were multiplexing standards. The
            > multiplexing standard required a certain diameter individual
            coaxial, but
            > not a certain cable type. So, while L3 multiplexing usually used
            Coax-8
            > cable; Improved L3, Coax-12; and L4, Coax-20, this was not a
            requirement.
            > An example is how the Airmont to Mojave transcontinental route
            consisted of
            > a Coax-12 cable type that originally used Improved L3 multiplexing,
            but was
            > later upgraded to P-140 multiplexing.



            The multiplexing scheme or bandwidth was not the critical factor;
            the line bandwidth required an optimal impedence and minimal SWR for
            lowest transmission loss ;the diameter was critical for "corona", the
            arcing point of the power feed voltage,which varied on power
            loops.L1/L3 used AC voltages up to 1800; L4 used DC up to 1200-1500
            as best I remember.The original L1 tube was .270 diameter, and some
            L3 overbuilds used existing cable of this diameter instead of laying
            new L3 standard cable of .375(e.g. Richmond-Faulkner).In older Central
            Offices you may find broadband(MG/MMX) connections up to the cable
            terminal using older RG type 75 ohm coax about 3/8" diameter, as well
            as the modern "mini" coax of about 1/8" diameter used since the
            1960's.

            I recall there were a few 22 tube L4/5 cables.

            Phillips P-140 was also used on some L4 20 tube cables.





            >
            > At 04:04 PM 11/4/2001 -0500, you wrote:
            > >At 08:41 PM 11/4/2001 +0000, you wrote:
            > > >including a rare 20 tube
            > > >L3(perhaps the only one),to Norway I think;& I believe there were
            GEP
            > > >antennae on the tower.
            > >
            > >How about a 6 tube L4 from Cheshire to Greenhill?
            > >
            > >
            > >
            > >Your use of Yahoo! Groups is subject to
            http://docs.yahoo.com/info/terms/
          • ozob99@yahoo.com
            ... multiplexing, ... the ... Central ... well ... Another analogy came to mind since you mentioned some cable pair carriers;a non-loaded 19 gauge cable pair
            Message 5 of 10 , Nov 4, 2001
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              --- In coldwarcomms@y..., ozob99@y... wrote:
              > --- In coldwarcomms@y..., Harold Peach <hpeach@p...> wrote:
              > > As I understand it, Coax-8, Coax-12, and Coax-20 defined the cable
              > type. A,
              > > N, K, L3, Improved L3, L4, and L5 were multiplexing standards. The
              > > multiplexing standard required a certain diameter individual
              > coaxial, but
              > > not a certain cable type. So, while L3 multiplexing usually used
              > Coax-8
              > > cable; Improved L3, Coax-12; and L4, Coax-20, this was not a
              > requirement.
              > > An example is how the Airmont to Mojave transcontinental route
              > consisted of
              > > a Coax-12 cable type that originally used Improved L3
              multiplexing,
              > but was
              > > later upgraded to P-140 multiplexing.
              >
              >
              >
              > The multiplexing scheme or bandwidth was not the critical factor;
              > the line bandwidth required an optimal impedence and minimal SWR for
              > lowest transmission loss ;the diameter was critical for "corona",
              the
              > arcing point of the power feed voltage,which varied on power
              > loops.L1/L3 used AC voltages up to 1800; L4 used DC up to 1200-1500
              > as best I remember.The original L1 tube was .270 diameter, and some

              > L3 overbuilds used existing cable of this diameter instead of laying
              > new L3 standard cable of .375(e.g. Richmond-Faulkner).In older
              Central
              > Offices you may find broadband(MG/MMX) connections up to the cable
              > terminal using older RG type 75 ohm coax about 3/8" diameter, as
              well
              > as the modern "mini" coax of about 1/8" diameter used since the
              > 1960's.
              >

              > I recall there were a few 22 tube L4/5 cables.
              >
              > Phillips P-140 was also used on some L4 20 tube cables.



              Another analogy came to mind since you mentioned some cable pair
              carriers;a non-loaded 19 gauge cable pair served as a transmission
              medium for K,N,N2,N3,ON,Lenkurt,Collins,Lynch,et al carrier systems,
              using different bandwidths,modulation schemes,etc.The repeater spacing
              & equalization differed with each of course, but the "line" was
              campatible with all.





              >
              >
              >
              >
              >
              > >
              > > At 04:04 PM 11/4/2001 -0500, you wrote:
              > > >At 08:41 PM 11/4/2001 +0000, you wrote:
              > > > >including a rare 20 tube
              > > > >L3(perhaps the only one),to Norway I think;& I believe there
              were
              > GEP
              > > > >antennae on the tower.
              > > >
              > > >How about a 6 tube L4 from Cheshire to Greenhill?
              > > >
              > > >
              > > >
              > > >Your use of Yahoo! Groups is subject to
              > http://docs.yahoo.com/info/terms/
            • dsandow@garden.net
              ... Indeed there was a reason. TAT-5 (Greenhill RI) was built during the height of the cable vs. satellite era. Every additional overseas facility had to go
              Message 6 of 10 , Nov 5, 2001
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                >
                > OK, just seemed strange, I assume there must have been a reason to
                > make a short section of 6 tube cable;perhaps to interface with that
                > particular TAT cable.

                Indeed there was a reason.

                TAT-5 (Greenhill RI) was built during the height of the cable vs.
                satellite era. Every additional overseas facility had to go through
                a rigorous adversarial proceeding before the FCC, to "protect" Comsat.

                On one side, ATT (proven reliability of cable), the record carriers
                (data comm was not happy about the round-trip delay of satellite),
                and DoD (survivability, privacy and round-trip data).

                On the other side, Comsat (formed in 1964 to evolve the technology
                invented by ATT with Telstar in 1962), the earth station vendors
                (looking for overseas sales) and the State Department (which was
                gung-ho about the international satellite treaties with everybody,
                and did not want to see USA lose out on its satellite leadership
                because COMSAT couldn't maintain its dominance if it couldn't get USA
                traffic streams onto satellite (at the expense of cable streams)).

                So the traffic was to be split 50-50, and every Construction
                Authorization was severly restrictive about how much capacity could
                be built, equipped, and fired up (not always the same!). The
                6-tube entrance link to the cable station was "collateral damage".
                ATT was only allowed to build as much cable into the cable station as
                was needed to connect to the "authorized" underseas cable. And
                "unequipped tubes" could not possibly be allowed, since ATT might
                cheat some day and try to sneak in another underseas cable. No sir,
                don't build ANYTHING more than we give you permission to build.

                This same logic prevailed when ATT built its first fiber TAT. It was
                a 6 strand cable. 2 strands (1 T/R pair) for UK, 2 for France, 2 for
                protection switching. None for growth.

                (For historical perspective, the FCC of the late '60s early '70s had
                not shaken off the momentum from the policies created during the LBJ
                era - "Remember guys - I own a TV station - go find something else to
                regulate.")
              • ozob99@yahoo.com
                ... that ... Comsat. ... USA ... as ... to ... OK, sounds familiar;unreasonable but reasonable for politics...there was a crash program in the 1970 s to get
                Message 7 of 10 , Nov 5, 2001
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                  --- In coldwarcomms@y..., dsandow@g... wrote:
                  > >
                  > > OK, just seemed strange, I assume there must have been a reason to
                  > > make a short section of 6 tube cable;perhaps to interface with
                  that
                  > > particular TAT cable.
                  >
                  > Indeed there was a reason.
                  >
                  > TAT-5 (Greenhill RI) was built during the height of the cable vs.
                  > satellite era. Every additional overseas facility had to go through
                  > a rigorous adversarial proceeding before the FCC, to "protect"
                  Comsat.
                  >
                  > On one side, ATT (proven reliability of cable), the record carriers
                  > (data comm was not happy about the round-trip delay of satellite),
                  > and DoD (survivability, privacy and round-trip data).
                  >
                  > On the other side, Comsat (formed in 1964 to evolve the technology
                  > invented by ATT with Telstar in 1962), the earth station vendors
                  > (looking for overseas sales) and the State Department (which was
                  > gung-ho about the international satellite treaties with everybody,
                  > and did not want to see USA lose out on its satellite leadership
                  > because COMSAT couldn't maintain its dominance if it couldn't get
                  USA
                  > traffic streams onto satellite (at the expense of cable streams)).
                  >
                  > So the traffic was to be split 50-50, and every Construction
                  > Authorization was severly restrictive about how much capacity could
                  > be built, equipped, and fired up (not always the same!). The
                  > 6-tube entrance link to the cable station was "collateral damage".
                  > ATT was only allowed to build as much cable into the cable station
                  as
                  > was needed to connect to the "authorized" underseas cable. And
                  > "unequipped tubes" could not possibly be allowed, since ATT might
                  > cheat some day and try to sneak in another underseas cable. No sir,
                  > don't build ANYTHING more than we give you permission to build.
                  >
                  > This same logic prevailed when ATT built its first fiber TAT. It was
                  > a 6 strand cable. 2 strands (1 T/R pair) for UK, 2 for France, 2 for
                  > protection switching. None for growth.
                  >
                  > (For historical perspective, the FCC of the late '60s early '70s had
                  > not shaken off the momentum from the policies created during the LBJ
                  > era - "Remember guys - I own a TV station - go find something else
                  to
                  > regulate.")


                  OK, sounds familiar;unreasonable but reasonable for politics...there
                  was a crash program in the 1970's to get thousands of domestic PSN
                  circuits rerouted onto satellite just to fill it up for regulatory
                  reasons; then later they were rerouted back on L & radio...btw some
                  of these circuits were split,transmit & rec, between the bird &
                  terrestial,creating tricky echo cancelling schemes.
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