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Re: First Bell System microwave link?

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  • ozob99
    ... relative. ... multi-channel ... As ... in ... mw. ... route ... of ... I found a pic of the TRC-6: http://hereford.ampr.org/millist/pic/trc-6.jpg This site
    Message 1 of 13 , May 11, 2003
      --- In coldwarcomms@yahoogroups.com, "ozob99" <ozob99@y...> wrote:
      > --- In coldwarcomms@yahoogroups.com, "Albert LaFrance"
      > <albertjlafrance@c...> wrote:
      > > ----- Original Message -----
      > > From: "ozob99" <ozob99@y...>
      > > To: <coldwarcomms@yahoogroups.com>
      > > Sent: Wednesday, March 12, 2003 10:42 AM
      > > Subject: [coldwarcomms] Re: First Bell System microwave link?
      > >
      > > Your finding about the link's 8-channel capacity may be a very
      > important
      > > clue. Specifically, it makes me wonder if perhaps the California
      > link used
      > > the military (Signal Corps) AN/TRC-6 equipment or a close
      relative.
      > >
      > > The AN/TRC-6 was one of the first - maybe the first -
      multi-channel
      > > microwave radio systems, being deployed toward the end of WW-II.
      As
      > I
      > > recall, it carried around 8-12 voice channels on a radio channel
      in
      > the 4
      > > GHz band, using a klystron RF source with an output of about 200
      mw.
      > >
      > > Rather than the frequency-division multiplexing used in
      > high-capacity,
      > > broadband systems like TD-X (the AT&T Boston-NYC experimental
      route
      > of 1947)
      > > and TD-2, the AN/TRC-6 sampled the voice channels and
      > > time-division-multiplexed the samples into a
      > pulse-position-modulated
      > > signal. The combination of sampling - usually associated with
      > digital
      > > communications - and analog modulation is an interesting feature
      of
      > that
      > > system.
      > >
      > > Albert
      > >
      >
      >
      > Evidently this was the case, the 8 channel TRC-6 was developed by
      > AT&T; as detailed on this page:
      >
      > http://www.cae.wisc.edu/~wenyinf/misc/01132829.pdf


      I found a pic of the TRC-6:

      http://hereford.ampr.org/millist/pic/trc-6.jpg

      This site has tons of pics & specs on military comms gear.
    • ozob99
      Another article on Catalina microwave: https://news.google.com/newspapers?nid=2131&dat=19460530&id=36xkAAAAIBAJ&sjid=wYQNAAAAIBAJ&pg=2152,1092832&hl=en
      Message 2 of 13 , Feb 13, 2016
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