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K carrier info wanted

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  • long-lines@att.net
    Looking for any and all information on K carrier. A Google search reveals little. Previous postings suggest: 1) designed for 1000 mile routes, 2) 17 mile
    Message 1 of 8 , Mar 22, 2010
      Looking for any and all information on K carrier. A Google search reveals little. Previous postings suggest:

      1) designed for 1000 mile routes,
      2) 17 mile repeater spacings

      True, not true? Can any one quote references?

      Also looking for route carrying capacities. How many pairs/circuits/channels typical, minimum, maximum, for a single cable system?

      More specifically how small of a K system route would they build/has any one of heard of (there's got to have been practical cost/benefit limits)? Ditto on the large scale; how big could a single route get?

      Can one "over-build" K carrier with N carrier in some fashion (akin to J-over-C carrier:
      http://long-lines.net/tech-equip/misc/J-Carrier.html) ? Or would you have to demux the N to the VF level and feed into the K, and vice versa?

      Has anyone seen/heard of N, or other carrier cables, being buried in a K carrier ROW?

      Would one "upgrade" from K to N? Why (not)?

      (two members on this list have found N repeaters in two different locations on a route labeled on route maps as K, and N the huts found to date do *not* match the locations of the K huts shown on the maps)

      Suggested reading?
      c.


      [Non-text portions of this message have been removed]
    • s82917
      A good general reference on the development and implementation of K carrier is in A History of Engineering and Science in the Bell System - Transmission
      Message 2 of 8 , Mar 22, 2010
        A good general reference on the development and implementation of K carrier is in "A History of Engineering and Science in the Bell System - Transmission Technology". Now out of print, some larger libraries will have it, or you might find a copy at some rare book dealers. That book also has info on N carrier.

        Bell System Technical Journal and Bell Laboratories Record also had articles on K carrier.

        And, if you can find it, there was a detailed article with many good photos in a 1941 edition of Bell Telephone Magazine on the installation of the first K carrier cable through Utah and Nevada to the west coast.

        I'm sure others will post more details, but basically K carrier transmitted 12 voice circuits per wire pair, with repeaters spaced about 17 miles. One reference I saw stated that it was to provide high quality voice circuits up to 4000 miles. K carrier was applied to some existing voice band cables, and also to new cables specifically installed for that type of service.

        N carrier was intended for short haul service, typically 15 to 100 miles.

        Terry


        --- In coldwarcomms@yahoogroups.com, long-lines@... wrote:
        >
        > Looking for any and all information on K carrier. A Google search reveals little. Previous postings suggest:
        >
        > 1) designed for 1000 mile routes,
        > 2) 17 mile repeater spacings
        >
        > True, not true? Can any one quote references?
        >
        > Also looking for route carrying capacities. How many pairs/circuits/channels typical, minimum, maximum, for a single cable system?
        >
        > More specifically how small of a K system route would they build/has any one of heard of (there's got to have been practical cost/benefit limits)? Ditto on the large scale; how big could a single route get?
        >
        > Can one "over-build" K carrier with N carrier in some fashion (akin to J-over-C carrier:
        > http://long-lines.net/tech-equip/misc/J-Carrier.html) ? Or would you have to demux the N to the VF level and feed into the K, and vice versa?
        >
        > Has anyone seen/heard of N, or other carrier cables, being buried in a K carrier ROW?
        >
        > Would one "upgrade" from K to N? Why (not)?
        >
        > (two members on this list have found N repeaters in two different locations on a route labeled on route maps as K, and N the huts found to date do *not* match the locations of the K huts shown on the maps)
        >
        > Suggested reading?
        > c.
        >
        >
        > [Non-text portions of this message have been removed]
        >
      • Jake
        The A History of Engineering and Science in the Bell System books show up on eBay from time to time. My account has an alert set to email me when they show
        Message 3 of 8 , Mar 23, 2010
          The "A History of Engineering and Science in the Bell System" books show up on eBay from time to time. My account has an alert set to email me when they show up.

          With some patience and about $200, I was able to acquire the whole series over a period of a year based on the list posted here <http://groups.yahoo.com/group/coldwarcomms/message/14680> as well as both versions of Engineering and Operations in the Bell System.

          I wish they were in digital format so more people could reference them.

          -Jake

          On Mar 22, 2010, at 6:16 PM, s82917 wrote:

          > A good general reference on the development and implementation of K carrier is in "A History of Engineering and Science in the Bell System - Transmission Technology". Now out of print, some larger libraries will have it, or you might find a copy at some rare book dealers. That book also has info on N carrier.
          >
          > Bell System Technical Journal and Bell Laboratories Record also had articles on K carrier.
          >
          > And, if you can find it, there was a detailed article with many good photos in a 1941 edition of Bell Telephone Magazine on the installation of the first K carrier cable through Utah and Nevada to the west coast.
          >
          > I'm sure others will post more details, but basically K carrier transmitted 12 voice circuits per wire pair, with repeaters spaced about 17 miles. One reference I saw stated that it was to provide high quality voice circuits up to 4000 miles. K carrier was applied to some existing voice band cables, and also to new cables specifically installed for that type of service.
          >
          > N carrier was intended for short haul service, typically 15 to 100 miles.
          >
          > Terry
          >
          > --- In coldwarcomms@yahoogroups.com, long-lines@... wrote:
          > >
          > > Looking for any and all information on K carrier. A Google search reveals little. Previous postings suggest:
          > >
          > > 1) designed for 1000 mile routes,
          > > 2) 17 mile repeater spacings
          > >
          > > True, not true? Can any one quote references?
          > >
          > > Also looking for route carrying capacities. How many pairs/circuits/channels typical, minimum, maximum, for a single cable system?
          > >
          > > More specifically how small of a K system route would they build/has any one of heard of (there's got to have been practical cost/benefit limits)? Ditto on the large scale; how big could a single route get?
          > >
          > > Can one "over-build" K carrier with N carrier in some fashion (akin to J-over-C carrier:
          > > http://long-lines.net/tech-equip/misc/J-Carrier.html) ? Or would you have to demux the N to the VF level and feed into the K, and vice versa?
          > >
          > > Has anyone seen/heard of N, or other carrier cables, being buried in a K carrier ROW?
          > >
          > > Would one "upgrade" from K to N? Why (not)?
          > >
          > > (two members on this list have found N repeaters in two different locations on a route labeled on route maps as K, and N the huts found to date do *not* match the locations of the K huts shown on the maps)
          > >
          > > Suggested reading?
          > > c.
          > >
          > >
          > > [Non-text portions of this message have been removed]
          > >
          >
          >
        • charlie Fargis
          K and ON were typically Long Lines engineered and N, N2 and N3 were RBOC/Local compnay engineered. WRT Overbuild not really. But there was a rather interested
          Message 4 of 8 , Mar 23, 2010
            K and ON were typically Long Lines engineered and
            N, N2 and N3 were RBOC/Local compnay engineered.
            WRT Overbuild not really.
            But there was a rather interested conglomeration
            the N3-L connector
            L and K carrier used the same A channel bank
            In fact K carrier cable outages were restored/patched using L or R carrier
            the N3-L connector basically translated N frequencies to L frequencies
            When the N3 carrier tone got too close to the LMX 104 khz pilot frequecy
            the whole system system would go up and down and levels. The fix was a whopping big
            capacitor to stabilize the gain.

            > To: coldwarcomms@yahoogroups.com
            > From: jakematic@...
            > Date: Tue, 23 Mar 2010 08:03:22 -0400
            > Subject: Re: [coldwarcomms] Re: K carrier info wanted
            >
            > The "A History of Engineering and Science in the Bell System" books show up on eBay from time to time. My account has an alert set to email me when they show up.
            >
            > With some patience and about $200, I was able to acquire the whole series over a period of a year based on the list posted here <http://groups.yahoo.com/group/coldwarcomms/message/14680> as well as both versions of Engineering and Operations in the Bell System.
            >
            > I wish they were in digital format so more people could reference them.
            >
            > -Jake
            >
            > On Mar 22, 2010, at 6:16 PM, s82917 wrote:
            >
            > > A good general reference on the development and implementation of K carrier is in "A History of Engineering and Science in the Bell System - Transmission Technology". Now out of print, some larger libraries will have it, or you might find a copy at some rare book dealers. That book also has info on N carrier.
            > >
            > > Bell System Technical Journal and Bell Laboratories Record also had articles on K carrier.
            > >
            > > And, if you can find it, there was a detailed article with many good photos in a 1941 edition of Bell Telephone Magazine on the installation of the first K carrier cable through Utah and Nevada to the west coast.
            > >
            > > I'm sure others will post more details, but basically K carrier transmitted 12 voice circuits per wire pair, with repeaters spaced about 17 miles. One reference I saw stated that it was to provide high quality voice circuits up to 4000 miles. K carrier was applied to some existing voice band cables, and also to new cables specifically installed for that type of service.
            > >
            > > N carrier was intended for short haul service, typically 15 to 100 miles.
            > >
            > > Terry
            > >
            > > --- In coldwarcomms@yahoogroups.com, long-lines@... wrote:
            > > >
            > > > Looking for any and all information on K carrier. A Google search reveals little. Previous postings suggest:
            > > >
            > > > 1) designed for 1000 mile routes,
            > > > 2) 17 mile repeater spacings
            > > >
            > > > True, not true? Can any one quote references?
            > > >
            > > > Also looking for route carrying capacities. How many pairs/circuits/channels typical, minimum, maximum, for a single cable system?
            > > >
            > > > More specifically how small of a K system route would they build/has any one of heard of (there's got to have been practical cost/benefit limits)? Ditto on the large scale; how big could a single route get?
            > > >
            > > > Can one "over-build" K carrier with N carrier in some fashion (akin to J-over-C carrier:
            > > > http://long-lines.net/tech-equip/misc/J-Carrier.html) ? Or would you have to demux the N to the VF level and feed into the K, and vice versa?
            > > >
            > > > Has anyone seen/heard of N, or other carrier cables, being buried in a K carrier ROW?
            > > >
            > > > Would one "upgrade" from K to N? Why (not)?
            > > >
            > > > (two members on this list have found N repeaters in two different locations on a route labeled on route maps as K, and N the huts found to date do *not* match the locations of the K huts shown on the maps)
            > > >
            > > > Suggested reading?
            > > > c.
            > > >
            > > >
            > > > [Non-text portions of this message have been removed]
            > > >
            > >
            > >
            >
            >
            >
            > ------------------------------------
            >
            > Yahoo! Groups Links
            >
            >
            >


            [Non-text portions of this message have been removed]
          • OZOB99
            ... 50-250 pairs in each direction(separate cables as already mentioned), buried & aerial & combo; a few pairs for VF OW,alarm,contactors,etc. ... much larger
            Message 5 of 8 , Mar 26, 2010
              recollections on some of the unanswered questions:

              --- In coldwarcomms@yahoogroups.com, long-lines@... wrote:
              >
              > Looking for any and all information on K carrier. A Google search reveals little. Previous postings suggest:
              >
              > 1) designed for 1000 mile routes,
              > 2) 17 mile repeater spacings
              >
              > True, not true? Can any one quote references?
              >
              > Also looking for route carrying capacities. How many pairs/circuits/channels typical, minimum, maximum, for a single cable system?


              50-250 pairs in each direction(separate cables as already mentioned), buried & aerial & combo; a few pairs for VF OW,alarm,contactors,etc.


              >
              > More specifically how small of a K system route would they build/has any one of heard of (there's got to have been practical cost/benefit limits)? Ditto on the large scale; how big could a single route get?


              much larger with more cable pairs & larger repeater buildings,but coax & radio carrier nullified any need to expand from the original 1930's & 40's routes.




              Can one "over-build" K carrier with N carrier in some fashion (akin to J-over-C carrier:
              > http://long-lines.net/tech-equip/misc/J-Carrier.html) ? Or would you have to demux the N to the VF level and feed into the K, and vice versa?


              overbuild on same pairs not viable, but many routes had both K & N on pairs in same cable; and N repeaters sometimes placed in the K repeater station or a building addition to it; N repeater spacing was flexable using span pads, so you could design to use nearby K stations.The Richmond-Washington A & B cables had a number of N systems from Richmond to small towns North; & Washington the same South.


              >
              > Has anyone seen/heard of N, or other carrier cables, being buried in a K carrier ROW?

              if no spare pairs in the K cables, and a need, i'm sure there were a few cases of this.



              >
              > Would one "upgrade" from K to N? Why (not)?

              no, short haul/long haul as mentioned already; K being superior in transmission & reliability characteristics.


              >
              > (two members on this list have found N repeaters in two different locations on a route labeled on route maps as K, and N the huts found to date do *not* match the locations of the K huts shown on the maps)


              on a route with both there would be N repeaters between K repeaters.


              > Suggested reading?

              There were some combo(in tandem) K channel groups around the country; e.g JK,JKL,KR,KL systems using group connectors(pad & filters) between the line transmission technologies.
            • long-lines@att.net
              Many thanks to all that responded, sent links and files. Keep them coming! It sounds like route carrying capacities ranged from around 300 to 2600 two-way
              Message 6 of 8 , Mar 27, 2010
                Many thanks to all that responded, sent links and files. Keep them coming!

                It sounds like route carrying capacities ranged from around 300 to 2600 two-way ckts (+/-).

                It makes sense that the N.H. K hut I was in last week had six cables exiting through floor conduits (3N+3S?). These cables were 1.25+/- in diameter (next time I'm up that way I'll have to get a piece and check the pair count, but I'm guessing 1.25 inch, lead covered, 19 gauge cable can't be more than 50 pair).

                It sounds reasonable that we have found N carrier repeater huts on a documented K carrier route (N. Hampton to Pittsfield MA); which means we probably haven't found the K huts yet.


                c.

                -------------- Original message from long-lines@...: --------------

                Looking for any and all information on K carrier. A Google search reveals little. Previous postings suggest:

                1) designed for 1000 mile routes,
                2) 17 mile repeater spacings

                True, not true? Can any one quote references?

                Also looking for route carrying capacities. How many pairs/circuits/channels typical, minimum, maximum, for a single cable system?

                More specifically how small of a K system route would they build/has any one of heard of (there's got to have been practical cost/benefit limits)? Ditto on the large scale; how big could a single route get?

                Can one "over-build" K carrier with N carrier in some fashion (akin to J-over-C carrier:
                http://long-lines.net/tech-equip/misc/J-Carrier.html) ? Or would you have to demux the N to the VF level and feed into the K, and vice versa?

                Has anyone seen/heard of N, or other carrier cables, being buried in a K carrier ROW?

                Would one "upgrade" from K to N? Why (not)?

                (two members on this list have found N repeaters in two different locations on a route labeled on route maps as K, and N the huts found to date do *not* match the locations of the K huts shown on the maps)

                Suggested reading?
                c.


                [Non-text portions of this message have been removed]
              • widebandit
                Some notes on J open-wire and K cable carrier: J & K carrier developed together in 1930s. Type J - 4000-mile open wire Type K - 4000-mile 19-gauge toll cable
                Message 7 of 8 , Mar 27, 2010
                  Some notes on J open-wire and K cable carrier:

                  J & K carrier developed together in 1930s.
                  Type J - 4000-mile open wire
                  Type K - 4000-mile 19-gauge toll cable
                  Type J - 4000-mile top frequency: 140 kHz
                  Type K - 4000-mile top frequency: 60 kHz
                  Type J - repeater spacing 75-100 mi (40 poles/mi!)
                  Type K - repeater spacing 17 mi

                  Type J open-wire to be compatible with widely deployed 3-channel C-carrier – 32 kHz top frequency.
                  Type J used virtual 4-wire frequency plan with East-West channels and West-East channels on same wire pair but in different frequency bands - same as C-carrier - with an elaborate transposition plan to minimize cross-talk.
                  Type K used physical 4-wire frequency plan with east-west & west-east channels using the same line-frequency but each on a separate pair in separate cables to minimize cross-talk.

                  Carrier systems prior to J & K were stand-alone, each with a multiplex plan to meet a specific requirement. Channel spacing was around 3 kHz with no standardized carrier frequencies.

                  For J & K, Bell Labs decided to separate the multiplex from the line-interface and develop a common multiplex that would also become a building block for future wide-band technologies like coaxial cable and radio (little did they know...!).

                  Available bandwidth of about 50 kHz for cable, 100 kHz for open wire limited channel capacity to 12 x 4 kHz SSB carrier channels – 48 kHz total bandwidth.

                  Type A channel bank was developed to multiplex 12 VF telephone circuits into a 60-108 kHz group.

                  4 kHz channel spacing allowed for improved frequency range of newer telephone sets, and gave a standard multiplier for a common office carrier supply system that could provide carrier frequencies for dozens and eventually hundreds(!) of channel banks.

                  Group band of 60-108 kHz was influenced by Bell Labs decision to use crystal-lattice channel filters. Available Brazilian quartz was not a good source for larger, lower frequency crystals. Crystal mfg techniques were not yet able to produce stable higher frequency crystals.

                  J-carrier frequency assignments: 36-84 kHz; 92-140 kHz
                  K-carrier frequency assignment 12-60 kHz
                  Both modulation plans required translation of the 60-108 kHz group to the line-frequency assignment, but this was seen as a way to allow a clean separation between the multiplex and the line.

                  4000-mile system objective is a uniquely North-American concept. European carrier systems were in the 1500-kilometer range with most extending only a few hundred km.

                  ...waw...

                  > Many thanks to all that responded, sent links and files. Keep them coming!
                • OZOB99
                  more K trivia; after 50 years its comes back slowly,fragmented even. primarily for those who have nt dug into the references cited. K aux stations had a type
                  Message 8 of 8 , Mar 30, 2010
                    more "K" trivia; after 50 years its comes back slowly,fragmented even.

                    primarily for those who have'nt dug into the references cited.

                    K aux stations had a type A alarm system to one of the adjacent terminals using DC signals on cable pairs; any of 10 alarm conditions signals the terminal office with an audible alarm & lighting 1 or more of 10 lamps in a jackfield. Typical alarms assigned to lamp numbers were: 152V power plant high-low voltage, AC PWR fail,rectifier fail,open door, high-low building temp,blown fuse,low back-up grid battery(dry cell).The only "command" that could be sent to the station was a rescan; which was often done during maintenance activities and always after a tech finished the repairs and closed the door.

                    The station batteries were only good for about 5-8 hours, and a sustained(15-30 min) AC power failure mandated a trailer mounted 10KW alternator sent out to power the station.

                    K carrier required emergency grid batteries(C) in case of power failures.This was supplied by a string of 1.5V "Blue Bell" dry cells(remember Fahnestock clips?);by the 1970's, probably one of the last telephone applications of this battery(from 1916).

                    Some stations included reversable type 12 VF program amps(repeaters)
                    carrying 5/8KH network radio service; and as mentioned, "N"/"ON" carrier repeaters and/or terminals.

                    The original K routes(K1) used a pilot wire in the cable to sense resistance changes due to temperature variations and adjust flat gain via a "pilot wire regulator", a precision galvanometer device(made by Leeds & Northrup) controlling autosyn(aka selsyn,synchro)motor gain controls in line amps. Later K2 was implemented using 12,28,56 & 60KH line pilots to adjust flat,bulge & slope equaization via thermisters in feedback loops.

                    K carrier testsets were WeCo 17B oscillator,31B TMS(selective voltmeter), 30A thermo-couple power meter; jack field was 135 ohm double plug for shielded patch cords.

                    Previous posts have mentioned Naval Radio Station NSS(Annapolis)VLF signals audible in some K systems along the mid east coast; this was apparently due to longitudinal unbalances,high resistance leaks,non-linearities, etc in the stations or cable(especially aerial). Anyone know if this occured in New England near NAA Cutler? or in the NorthWest near NLK Jim Creek?
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