.. _sphx_glr_api_gallery_communications_decibels:

Decibels
--------

Logarithmic power ratios.


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  <div id='sg-tag-list' class='sphx-glr-tag-list'></div>


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    <div class="sphx-glr-thumbnails">

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    <div class="sphx-glr-thumbcontainer" tooltip="Early telephone engineers measured loss in &quot;miles of standard cable&quot;, a unit that depended on frequency. In 1924 the Bell System replaced it with the transmission unit, ten times the base-ten logarithm of a power ratio, and in 1929 W. H. Martin named it the decibel. Logarithms turn the products of gains and losses along a line into sums, so a long chain of amplifiers and cables can be budgeted by addition. db, dbm and their inverses convert both ways.">

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  .. image:: /api/gallery/communications/decibels/images/thumb/sphx_glr_plot_01_bell_decibel_thumb.png
    :alt:

  :doc:`/api/gallery/communications/decibels/plot_01_bell_decibel`

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      <div class="sphx-glr-thumbnail-title">The decibel: the Bell System's transmission unit</div>
    </div>


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    </div>


.. toctree::
   :hidden:

   /api/gallery/communications/decibels/plot_01_bell_decibel