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  • Re: Edinburgh Evening News - Wednesday 14 September 1938 - POST OFFICE

    From JMB99@21:1/5 to All on Sun Nov 12 11:33:49 2023
    Sunday Mirror - Sunday 28 May 1939

    Dog Saved Two Miles of Digging
    EVERY dog has his day, but never has a dog had such a day as Rex, Home
    Office trained Labrador.
    By smelling what he thought was hundreds of cats, Rex saved the Post
    Office two miles of digging.
    The cat and dog idea was a brainwave. This is how it happened.
    Sixteen miles of underground cables are connected to the new Post Office
    " anti-sunspot" transatlantic radio-telephone receiving station being
    built at Cooling Marshes, near Rochester, Kent.
    One day it was noticed that the air in the maintain a high electrical insulation, was leaking through a number of minute punctures.
    Station Out of Action
    The leakages put the cable, and consequently the station, out of action
    and might have caused serious damage by permitting the infiltration of
    water into the cable.
    Mr. H. S. Lloyd, who trains dogs for the Home Office, was summoned.
    He brought Rex with him, and a gas that smelt strongly of " eats "—that
    is how the Post Office put it—was introduced into the air pumped into
    the cable.
    Rex was brilliant. They led him over the path of the cable. Every time
    he smelt cats he set about digging furiously. He found fourteen leaks.

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  • From Liz Tuddenham@21:1/5 to mb@nospam.net on Sun Nov 12 11:30:44 2023
    JMB99 <mb@nospam.net> wrote:

    New technique?
    [...]

    Diversity reception. A bank of identical receivers with their AGC lines linked, whichever receives the strongest carrier suppresses the others. Originally the P.O. and Bell Systems did it with relays and semi-manual control, but the linked AGC system was used throughout WWII and well
    into the 1960s.

    The receivers could be connected to aerials with wide geographical
    spacing, in which case the receivers were situated near the aerials and
    the AGC lines were linked by landline. Alternatively, the receivers
    were co-located but identical transmissions were sent simultaneously in different wavebands, so the multipath fading effects were different for
    each one.

    Double-diversity needed four receivers: two different wavelengths and
    two spaced aerials - I believe that was what the Bell/GPO system used.


    --
    ~ Liz Tuddenham ~
    (Remove the ".invalid"s and add ".co.uk" to reply)
    www.poppyrecords.co.uk

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  • From JMB99@21:1/5 to All on Sun Nov 12 11:24:36 2023
    On 12/11/2023 10:07, JMB99 wrote:
    New technique?



    Edinburgh Evening News - Wednesday 14 September 1938

    POST OFFICE ACTS SUN-SPOT THREAT TO RADIO SPECIAL STATION AND NEW TECHNIQUE



    Refers to Cooling Marshes - a friend's father worked there.

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  • From JMB99@21:1/5 to Liz Tuddenham on Sun Nov 12 12:52:16 2023
    On 12/11/2023 11:30, Liz Tuddenham wrote:
    JMB99 <mb@nospam.net> wrote:

    New technique?
    [...]

    Diversity reception. A bank of identical receivers with their AGC lines linked, whichever receives the strongest carrier suppresses the others.


    There is a HE report on it.

    Cooling Radio Station, Hoo Peninsula, Kent: An Archaeological
    Investigation of a Short-Wave Receiving Station

    Report Number:
    110/2010
    Series:
    Research Department Reports
    Pages:
    73

    It used MUSA then MEDUSA

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  • From Liz Tuddenham@21:1/5 to mb@nospam.net on Mon Nov 13 10:59:31 2023
    JMB99 <mb@nospam.net> wrote:

    On 12/11/2023 11:30, Liz Tuddenham wrote:
    JMB99 <mb@nospam.net> wrote:

    New technique?
    [...]

    Diversity reception. A bank of identical receivers with their AGC lines linked, whichever receives the strongest carrier suppresses the others.


    There is a HE report on it.

    Cooling Radio Station, Hoo Peninsula, Kent: An Archaeological
    Investigation of a Short-Wave Receiving Station

    Report Number:
    110/2010
    Series:
    Research Department Reports
    Pages:
    73

    It used MUSA then MEDUSA

    Thanks for that - so it was MUSA, not diversity..


    I seem to remember reading about the American end of that system in
    either the Bell Labs Record or the Bell System Technical Journal. There
    were some interesting comments about the differences between Bell and
    the G.P.O. in the attitudes they held towards their customers. Bell
    wanted to reduce inconvenience to callers by providing a good
    person-to-person service, even if it meant more apparatus - whereas the
    G.P.O. wanted to optimise the use of minimal appartus even if it meant inconveniencing their customers.


    --
    ~ Liz Tuddenham ~
    (Remove the ".invalid"s and add ".co.uk" to reply)
    www.poppyrecords.co.uk

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