How to Convert Decimal Attenuation to DB

In the early days of the telephone, signal power loss along a cable was a significant factor in the design of communication networks. In the 19th century, the power lost in one mile of standard telephone cable was a common yardstick. Engineers introduced the decibel, or dB, as a universal measurement of attenuation, the ratio of power output to the power of the signal fed into a cable. The decibel, a logarithmic unit, was named for Alexander Graham Bell, the inventor of the telephone.

Things You'll Need

• Scientific calculator

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Instructions

Instructions

• 1

  Write down the decimal attenuation value that you want to convert to dB. Note that an attenuation value should be less than 1.

• 2

  Enter the value into the scientific calculator and calculate its logarithm to base 10. This should be a negative decimal number. For example, if the attenuation value is 0.5, then the logarithm to base 10 is 0.301. Write down your answer.

• 3

  Multiply your answer by 10. The result is the decimal attenuation value converted to dB.

• 4

  Record your result. Check that it is a negative decimal number.