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Re: [coldwarcomms] Re: Off topic, but.... More waveguide

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  • David
    ... What kind of capacity are we talking about?
    Message 1 of 17 , Jul 27, 2011
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      On 7/28/11 12:34 AM, Richard Wells wrote:

      > The route was a trial route only. No WT4 ever went into service. Plans
      > were underway to engineer and install routes between major metro
      > centers. There was one such system proposed for NYC. It would
      > terminate just outside the city and use DR18 digital radio along with
      > digital coax to bring the signals into the city. Each of the latter two
      > systems were also trialed in that same time frame near NYC.
      >


      What kind of capacity are we talking about?
    • Richard Wells
      The basic building block were 276 mbs channels which matched the per pair digital coax systems that was being trialed along with the channel pair capacity of
      Message 2 of 17 , Jul 27, 2011
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        The basic building block were 276 mbs channels which matched the per pair digital coax systems that was being trialed along with the channel pair capacity of the DR18 radio.

        For information on the WT4 system visit this link:

        http://www.alcatel-lucent.com/bstj/vol56-1977/articles/bstj56-10-2147.pdf

        To: coldwarcomms@yahoogroups.com
        From: wb8foz@...
        Date: Thu, 28 Jul 2011 00:51:00 -0400
        Subject: Re: [coldwarcomms] Re: Off topic, but.... More waveguide




























        On 7/28/11 12:34 AM, Richard Wells wrote:



        > The route was a trial route only. No WT4 ever went into service. Plans

        > were underway to engineer and install routes between major metro

        > centers. There was one such system proposed for NYC. It would

        > terminate just outside the city and use DR18 digital radio along with

        > digital coax to bring the signals into the city. Each of the latter two

        > systems were also trialed in that same time frame near NYC.

        >



        What kind of capacity are we talking about?


















        [Non-text portions of this message have been removed]
      • widebandit
        WT4 used 124 digital rf channels - 62 in each direction - in the mm frequency band 40 - 110 GHz (kinda like doing SONET the hard way)... Transmission plan
        Message 3 of 17 , Jul 28, 2011
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          WT4 used 124 digital rf channels - 62 in each direction - in the mm frequency band 40 - 110 GHz (kinda like doing SONET the hard way)...

          Transmission plan called for 59 working duplex channels and 3 protection duplex channels...

          Each channel carried a single 274.176 Mb/s T-4 signal (the T4 in WT4)...

          T4 or DS-4 carried six DS-3, or 4,032 equivalent voice circuits...

          Total route capacity was therefore 4,032 x 59 = 237,888 equivalent voice circuits...

          Plans were in the works to expand WT4 PSK modulation scheme to allow two 274 MB/s rails per channel - effectively doubling capacity to 475,776 equivalent voice circuits...

          The conventional wisdom is that fiber-optic technology made WT4 obsolete, but fiber-optic was not yet viable when WT4 was developed...

          One problem was traffic engineering. It was common practice for AT&T traffic engineers to use the Erlang equations to determine long-haul trunk capacity and then add 10-15% as a 'back-pocket' reserve...

          Well, the Erlang equations were automated about the time WT4 was being developed and AT&T management found that this 'back-pocket' reserve was sufficient to cover about two-years of system growth, thereby pushing the WT4 service date back enough to allow fiber to catch up.

          The other problem was the commercial failure of Picturephone. WT4 was developed in part to provide a broadband digital medium to carry the 6.3 Mb/s DS-2 Picturephone signal. Once Picturephone went away, the need for large numbers of DS-2 channels went away...

          To quote W.D. Warters' WT4 introductory paper, submitted in April 1977: "In recent years, after several decades of consistently rapid growth and continuing need for ever-larger systems, the growth rate of the Bell System long-haul network has declined. Thus the immediate need for a system of such large capacity as WT4 has decreased and, as of this writing, the date of first commercial deploymnent of waveguide is uncertain."...

          WT4 was abandoned a little more than two-years after the field evaluation trial installation...

          - waw -
          >
          > On 7/28/11 12:34 AM, Richard Wells wrote:
          >
          > > The route was a trial route only. No WT4 ever went into service. Plans
          > > were underway to engineer and install routes between major metro
          > > centers. There was one such system proposed for NYC. It would
          > > terminate just outside the city and use DR18 digital radio along with
          > > digital coax to bring the signals into the city. Each of the latter two
          > > systems were also trialed in that same time frame near NYC.
          > >
          >
          >
          > What kind of capacity are we talking about?
          >
        • charlie Fargis
          ever read up on the labs guys who came up with their first audio amp. The line in the book read something like this, too much distortion in the speaker to
          Message 4 of 17 , Jul 28, 2011
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            ever read up on the labs guys who came up with their first audio amp.
            The line in the book read something like this, "too much distortion in the speaker to carbon microphone repeater.
            Carbon particles were too heavy. Electrons in a vacuum tube are much lighter and thus more easily controlled.
            Now thats using your noggin.

            To: coldwarcomms@yahoogroups.com
            From: mcowen@...
            Date: Wed, 27 Jul 2011 08:20:07 -0700
            Subject: Re: [coldwarcomms] Re: Off topic, but.... More waveguide




























            Quite fascinating! That was still back in the day when Bell Labs

            invested a LOT of money in pure research. Somebody had an idea, and

            they funded the research to see if it led anywhere. Why do you think

            they had so many inventions? They paid really smart people to be

            creative and play! It didn't always pan out, but when it did, it

            sure gave them a huge corporate advantage and pride. Things like the

            transistor weren't developed by people trapped in cubicles tasked to

            develop "x" and ONLY "x", like many companies do today. They

            realized the value in spinoff ideas could be cash cows, and sometimes

            even change the world as we know it. For 2 more examples, look at

            the "C" language, and UNIX. The engineering quality and flexibility

            originally designed in is phenomenal! Like anybody had any idea what

            a web server was in 1970, yet UNIX derivatives remain the preferred

            server OS online. Show me any other computing device or software

            that is still in current and widespread usage after 40+ years, yet is

            essentially unchanged at its core level since its introduction. It's

            a VERY short list.



            Somewhere I once saw a "Bell" publication with a small blurb about

            Shockley and his team developing a thing called a "transistor", and

            that it -might- be an interesting invention. I'd love to obtain a

            copy of it, if anyone knows the document I'm referring to, and where

            I can get a copy.



            Mike



            At 07:12 AM 7/27/2011, you wrote:

            >On the contrary, that is fascinating!

            >

            >Was the WT4 at Netcong in service for any period of time? Do you have any

            >technical documents about it?

            >

            >Those of you who are in microwave engineering might be able to answer this,

            >but I am blown away that someone figured out that putting a helix and teflon

            >into a waveguide made it more tolerable of bending in the te01

            >mode. My intuition would say that introducing more metal and dielectric

            >into a waveguide sensitive to even joint mismatches could only hurt the

            >situation.

            >

            >How was this likely developed back in that day? Is there quantitative ways

            >of backing into that, or was it more engineering judgement that led someone

            >to just try it? I would think to "solve" for something like that would

            >require 3D simulation ability.

            >

            >I know in our business we do alot by intuition and judgement and verify

            >safety through calculations. I always saw electrical or radio engineering

            >as being more quantitative than civil engineering, but like I said, I don't

            >know if you could come up with that helix design quantitatively at that time

            >(or today)?

            >

            >Very curious....

            >

            >On Wed, Jul 27, 2011 at 1:59 AM, widebandit <widebandit@...> wrote:

            >

            > > **

            > >

            > >

            > >

            > >

            > > --- In coldwarcomms@yahoogroups.com, "lasertower" <osr@...> wrote:

            > > >

            > > >

            > > > A search for waveguide and lightening protection came up with a few PDFs.

            > > While the Bell System might have given up on buried waveguide,

            > some one else

            > > might have capitalized on the research.

            > > >

            > > > The VLA antenna array used 40-60 Ghz buried waveguide prior to switching

            > > to fiber optic. Unique in being a multidrop waveguide.

            > > >

            > > >

            > > >

            > >

            > http://www.google.com/url?sa=t&source=web&cd=3&ved=0CCEQFjAC&url=http%3A%2F%2Fwww.aoc.nrao.edu%2F~pharden%2FPHOTOS%2FVLA_LEGACY%2Fvla.htm&rct=j&q=vla%20waveguide&ei=UtMuToWCGJCDsAKGiLlK&usg=AFQjCNGqBHLiW-y_Cr71psTJ4Y6e4qXmjQ&cad=rja

            > > >

            > > >

            > >

            > http://www.google.com/url?sa=t&source=web&cd=2&ved=0CBsQFjAB&url=http%3A%2F%2Fwww.vla.nrao.edu%2Fmemos%2Felec%2F231%2F&rct=j&q=vla%20waveguide&ei=UtMuToWCGJCDsAKGiLlK&usg=AFQjCNFuCTyGU6BSFYDOAiznIr_aFg92Eg&cad=rja

            > > >

            > > > VLAs circular waveguide was a copper wire spiraled inside a teflon

            > > insulator inside a steel jacket.

            > > >

            > >

            > > It is called Helix waveguide. Presuming transmission via low-loss TE-01

            > > mode, the copper helix backed by a teflon dielectric acts as a mode filter

            > > to suppress unwanted modes that are generated if the waveguide is not

            > > perfectly(!) straight.

            > >

            > > In VLA the delayed echoes caused by mode conversion would ruin it's

            > > capability as a large-baseline interferometer - hence the continuous run of

            > > mode suppressed helix WG.

            > >

            > > Since even slight curvature of helix WG also presents high loss to TE-01

            > > mode, it is even more important that a continuous run of helix WG be as

            > > straight as possible.

            > >

            > > Because of inevitable route curves and bends, AT&T's WT4 60mm WG system

            > > used 29-ft helix WG mode filter sections spaced at half-mile intervals

            > > (about 1% helix WG); each half-mile length of WG was called a mode filter

            > > section - mfs.

            > >

            > > WT4 WG route planning included placement of the helix WG mode filters in

            > > relatively straight portions of the run to minimize TE-01 mode loss caused

            > > by helix WG curvature, so some variation of the half-mile spacing was

            > > permissible.

            > >

            > > The intention of WT4 was to insert up to six mfs (3-miles of WG) into a

            > > pre-placed steel pipe sheath using a mechanical pusher.

            > >

            > > The only WT4 WG installation was an 8.5 mile field evaluation route of 17

            > > mfs terminating at Netcong NJ. Each mfs was pushed separately and

            > the 3-mile

            > > push capability was never demonstrated in the field.

            > >

            > > For some of you this may be too much information - for others not enough -

            > > unfortunately for those of you in the former category, I fall into the

            > > latter category, so get over it already.

            > >

            > > - waw -

            > >

            > > > Very interesting.

            > > >

            > > > Steve

            > > >

            > >

            > >

            > >

            >

            >

            >

            >--

            >Jim Browne

            >

            >

            >[Non-text portions of this message have been removed]

            >

            >

            >

            >------------------------------------

            >

            >Yahoo! Groups Links

            >

            >

            >

            ----------------------------------------------------------

            Mike Cowen Practice random acts of kindness

            and selfless acts of beauty.

            mcowen@... -Anonymous


















            [Non-text portions of this message have been removed]
          • widebandit
            But, the Audion tube as an amplifier was Lee DeForest s invention - not Bell Labs - he was kind enough to demonstrate the device to Bell Labs engineers
            Message 5 of 17 , Jul 28, 2011
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              But, the Audion tube as an amplifier was Lee DeForest's invention - not Bell Labs' - he was kind enough to demonstrate the device to Bell Labs engineers October 30 and 31 1912...

              This happened while Bell Labs engineers were still trying to get past Denver by fooling around with pair loading, mechanical (carbon) repeaters, mercury arc repeaters, and magnetic amplifiers...

              Up to this point, Bell Labs engineers knew they needed some type of "inertia-less" repeater, but had no idea as to what form such a repeater would take. Fortunately, they were able to take DeForest's device and run with it...

              AT&T's initial reaction to Bell Labs engineers was - Why didn't you guys think of this? (The audion had already been used as a telegraph detector.)...

              To quote Thomas Shaw's "The Conquest of Distance by Wire Telephony" - published in the October 1944 Bell System Technical Journal: "There was, of course, considerable chagrin that these prospects had not been recognized much earlier in the Telephone Company's research work on repeaters, but no time was wasted in attempts to develop alibis."

              <http://www.alcatel-lucent.com/bstj/>

              - waw -
              >
              > ever read up on the labs guys who came up with their first audio amp.
              > The line in the book read something like this, "too much distortion in the speaker to carbon microphone repeater.
              > Carbon particles were too heavy. Electrons in a vacuum tube are much lighter and thus more easily controlled.
              > Now thats using your noggin.
              >
              > Quite fascinating! That was still back in the day when Bell Labs
              >
              > invested a LOT of money in pure research. Somebody had an idea, and
              >
              > they funded the research to see if it led anywhere. Why do you think
              >
              > they had so many inventions? They paid really smart people to be
              >
              > creative and play! It didn't always pan out, but when it did, it
              >
              > sure gave them a huge corporate advantage and pride. Things like the
              >
              > transistor weren't developed by people trapped in cubicles tasked to
              >
              > develop "x" and ONLY "x", like many companies do today. They
              >
              > realized the value in spinoff ideas could be cash cows, and sometimes
              >
              > even change the world as we know it. For 2 more examples, look at
              >
              > the "C" language, and UNIX. The engineering quality and flexibility
              >
              > originally designed in is phenomenal! Like anybody had any idea what
              >
              > a web server was in 1970, yet UNIX derivatives remain the preferred
              >
              > server OS online. Show me any other computing device or software
              >
              > that is still in current and widespread usage after 40+ years, yet is
              >
              > essentially unchanged at its core level since its introduction. It's
              >
              > a VERY short list.
              >
              > Somewhere I once saw a "Bell" publication with a small blurb about
              >
              > Shockley and his team developing a thing called a "transistor", and
              >
              > that it -might- be an interesting invention. I'd love to obtain a
              >
              > copy of it, if anyone knows the document I'm referring to, and where
              >
              > I can get a copy.
              >
              > Mike
              >
            • charlie Fargis
              So the answer is yes. :) (A body s mass measures its inertia and also whether light or heavy) and I never said the Audion was a BTL invention. I said they
              Message 6 of 17 , Jul 29, 2011
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                So the answer is yes. :)
                (A body's mass measures its inertia and also whether light or heavy)
                and
                I never said the Audion was a BTL invention. I said they figured out how to use it and invented Negaive Feedback which stabilized amplifiers.

                To: coldwarcomms@yahoogroups.com
                From: widebandit@...
                Date: Thu, 28 Jul 2011 21:23:09 +0000
                Subject: [coldwarcomms] Lee DeForest - was - Off topic, but.... More waveguide




























                But, the Audion tube as an amplifier was Lee DeForest's invention - not Bell Labs' - he was kind enough to demonstrate the device to Bell Labs engineers October 30 and 31 1912...



                This happened while Bell Labs engineers were still trying to get past Denver by fooling around with pair loading, mechanical (carbon) repeaters, mercury arc repeaters, and magnetic amplifiers...



                Up to this point, Bell Labs engineers knew they needed some type of "inertia-less" repeater, but had no idea as to what form such a repeater would take. Fortunately, they were able to take DeForest's device and run with it...



                AT&T's initial reaction to Bell Labs engineers was - Why didn't you guys think of this? (The audion had already been used as a telegraph detector.)...



                To quote Thomas Shaw's "The Conquest of Distance by Wire Telephony" - published in the October 1944 Bell System Technical Journal: "There was, of course, considerable chagrin that these prospects had not been recognized much earlier in the Telephone Company's research work on repeaters, but no time was wasted in attempts to develop alibis."



                <http://www.alcatel-lucent.com/bstj/>



                - waw -

                >

                > ever read up on the labs guys who came up with their first audio amp.

                > The line in the book read something like this, "too much distortion in the speaker to carbon microphone repeater.

                > Carbon particles were too heavy. Electrons in a vacuum tube are much lighter and thus more easily controlled.

                > Now thats using your noggin.

                >

                > Quite fascinating! That was still back in the day when Bell Labs

                >

                > invested a LOT of money in pure research. Somebody had an idea, and

                >

                > they funded the research to see if it led anywhere. Why do you think

                >

                > they had so many inventions? They paid really smart people to be

                >

                > creative and play! It didn't always pan out, but when it did, it

                >

                > sure gave them a huge corporate advantage and pride. Things like the

                >

                > transistor weren't developed by people trapped in cubicles tasked to

                >

                > develop "x" and ONLY "x", like many companies do today. They

                >

                > realized the value in spinoff ideas could be cash cows, and sometimes

                >

                > even change the world as we know it. For 2 more examples, look at

                >

                > the "C" language, and UNIX. The engineering quality and flexibility

                >

                > originally designed in is phenomenal! Like anybody had any idea what

                >

                > a web server was in 1970, yet UNIX derivatives remain the preferred

                >

                > server OS online. Show me any other computing device or software

                >

                > that is still in current and widespread usage after 40+ years, yet is

                >

                > essentially unchanged at its core level since its introduction. It's

                >

                > a VERY short list.

                >

                > Somewhere I once saw a "Bell" publication with a small blurb about

                >

                > Shockley and his team developing a thing called a "transistor", and

                >

                > that it -might- be an interesting invention. I'd love to obtain a

                >

                > copy of it, if anyone knows the document I'm referring to, and where

                >

                > I can get a copy.

                >

                > Mike

                >


















                [Non-text portions of this message have been removed]
              • lasertower
                Are there any public details on Digital Coax ? Steve
                Message 7 of 17 , Jul 29, 2011
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                  Are there any public details on "Digital Coax"?

                  Steve
                • OZOB99
                  ... Search p140 in archives for this Phillips system. Mojave-Socorro route may have been the longest. Snippet from a mojave national preserve paper: During
                  Message 8 of 17 , Jul 30, 2011
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                    --- In coldwarcomms@yahoogroups.com, "lasertower" <osr@...> wrote:
                    >
                    >
                    >
                    > Are there any public details on "Digital Coax"?
                    >
                    > Steve


                    Search p140 in archives for this Phillips system.

                    Mojave-Socorro route may have been the longest.

                    Snippet from a mojave national preserve paper:

                    "During the 1960s the American Telephone and
                    Telegraph Corporation (AT&T) constructed an
                    underground communications cable network
                    throughout the United States. In the early 1980s
                    the system was upgraded to accommodate current
                    technological advances using Phillips technology;
                    hence, it was renamed the P140 coaxial cable
                    system. AT&T, which owns and operates
                    approximately 709 miles of the system between
                    Mojave, California, and Socorro, New Mexico, has
                    removed communications cable, marker posts,
                    manholes, and repeater stations (incompatible
                    with the company's current fiber optic network)
                    from a 220-mile right-of-way that crosses the park"

                    I'd sure there are some non-Bell technical pubs on digital coax but most hits will be home theater stuff.

                    Also see dov in this archive.
                  • arkyjoe123
                    There was an Alcatel CIT140 system installed at Ellisville on the North and South routes. One working, one standby line. I never had much to do with it, as it
                    Message 9 of 17 , Jul 30, 2011
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                      There was an Alcatel CIT140 system installed at Ellisville on the North and South routes. One working, one standby line. I never had much to do with it, as it just sit there and worked. They had quite a bit of trouble getting it turned up. Had to dig up and fix a few bad splices in the coax to meet impulse noise specs. Improperly crimped splices were OK for analog, but too noisy for the digital.

                      73, JOE W4YOI



                      --- In coldwarcomms@yahoogroups.com, "OZOB99" <ozob99@...> wrote:
                      >
                      >
                      >
                      > --- In coldwarcomms@yahoogroups.com, "lasertower" <osr@> wrote:
                      > >
                      > >
                      > >
                      > > Are there any public details on "Digital Coax"?
                      > >
                      > > Steve
                      >
                      >
                      > Search p140 in archives for this Phillips system.
                      >
                      > Mojave-Socorro route may have been the longest.
                      >
                    • widebandit
                      No problem... I just wanted to point out that BTL was on the verge of committing to either the mercury arc as a repeater amplifier, or an improved mechanical
                      Message 10 of 17 , Jul 30, 2011
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                        No problem...

                        I just wanted to point out that BTL was on the verge of committing to either the mercury arc as a repeater amplifier, or an improved mechanical repeater when DeForest walked in the door in 1912...

                        That BTL was able to turn DeForest's Audion into a viable transcontinental telephone repeater (in more than enough time for the 1915 San Francisco Panama-Pacific Expo) speaks volumes of their expertise...

                        But they had missed the potential of the Audion completely...

                        It only took fifteen years after that for H.S. Black to discover negative feedback:

                        <http://www.alcatel-lucent.com/bstj/vol13-1934/articles/bstj13-1-1.pdf>

                        And another forty-five or so to develop feed-forward, pre-distortion techniqes to the point of allowing 6,000 simultaneous transcontinental conversations on a single AR6A microwave channel:

                        <http://www.alcatel-lucent.com/bstj/vol62-1983/articles/bstj62-10-3249.pdf>

                        But - in the words of the wicked witch of the west: "These things must be handled delicately..."

                        I wonder if DeForest ever thought that maybe a 1% royalty on every tube produced might have been a better deal than selling the patent rights?...

                        - waw -

                        >
                        > So the answer is yes. :)
                        > (A body's mass measures its inertia and also whether light or heavy)
                        > and
                        > I never said the Audion was a BTL invention. I said they figured out how to use it and invented Negaive Feedback which stabilized amplifiers.
                        >
                        >
                        >
                        > But, the Audion tube as an amplifier was Lee DeForest's invention - not Bell Labs' - he was kind enough to demonstrate the device to Bell Labs engineers October 30 and 31 1912...
                        >
                        > This happened while Bell Labs engineers were still trying to get past Denver by fooling around with pair loading, mechanical (carbon) repeaters, mercury arc repeaters, and magnetic amplifiers...
                        >
                        > Up to this point, Bell Labs engineers knew they needed some type of "inertia-less" repeater, but had no idea as to what form such a repeater would take. Fortunately, they were able to take DeForest's device and run with it...
                        >
                        > AT&T's initial reaction to Bell Labs engineers was - Why didn't you guys think of this? (The audion had already been used as a telegraph detector.)...
                        >
                        > To quote Thomas Shaw's "The Conquest of Distance by Wire Telephony" - published in the October 1944 Bell System Technical Journal: "There was, of course, considerable chagrin that these prospects had not been recognized much earlier in the Telephone Company's research work on repeaters, but no time was wasted in attempts to develop alibis."
                        >
                        > <http://www.alcatel-lucent.com/bstj/>
                        >
                        > - waw -
                        >
                        > >
                        > > ever read up on the labs guys who came up with their first audio amp.
                        > >
                        > > The line in the book read something like this, "too much distortion in the speaker to carbon microphone repeater.
                        > > Carbon particles were too heavy. Electrons in a vacuum tube are much lighter and thus more easily controlled.
                        > > Now thats using your noggin.
                        > >
                        > Quite fascinating! That was still back in the day when Bell Labs invested a LOT of money in pure research. Somebody had an idea, and they funded the research to see if it led anywhere. Why do you think they had so many inventions? They paid really smart people to be creative and play! It didn't always pan out, but when it did, it sure gave them a huge corporate advantage and pride. Things like the transistor weren't developed by people trapped in cubicles tasked to develop "x" and ONLY "x", like many companies do today. They realized the value in spinoff ideas could be cash cows, and sometimes even change the world as we know it. For 2 more examples, look at the "C" language, and UNIX. The engineering quality and flexibility originally designed in is phenomenal! Like anybody had any idea what a web server was in 1970, yet UNIX derivatives remain the preferred server OS online. Show me any other computing device or software that is still in current and widespread usage after 40+ years, yet is essentially unchanged at its core level since its introduction. It's a VERY short list.
                        >
                        > Somewhere I once saw a "Bell" publication with a small blurb about Shockley and his team developing a thing called a "transistor", and that it -might- be an interesting invention. I'd love to obtain a copy of it, if anyone knows the document I'm referring to, and where I can get a copy.
                        >
                        > Mike
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