Power gain G is defined as the ratio of output
power to input power:
G = Pout/Pin
Bel power gain G' is defined as the common logarithm
(log to the base 10) of power gain:
G' = log G
If a circuit has a power gain of 100, it's bel power
gain is G' = log 100 = 2
The prefix used in common practice is deci (one tenth,
or 10 E-1) We abbreviate decibel as dB.
****
For instance, if the input power to an rf amplifier is
1/2 (.5) W and the output power is 15 W.
G = 15/.5 = 30 the power output is 30 times greater
than the input power.
Bel power gain G' ("G prime") is the common log (use
your calculator) logarithm of power gain.
G' = log 30 = 1.477 (Bel)
multiply by 10 for decibel power gain:
1.477 * 10 = 14.77 dB gain.
The mentioned 15 watt output (for .5 watt input) amp
has 14.77 dB power gain.
You're not getting old if you still asking
questions.
cheers,
skipp
www.radiowrench.com/sonic
> "Brent" <[EMAIL PROTECTED]> wrote:
> well for some reason i just can not think of this.
> or im getting to old
> ,,hehe
>
> what is the formula for DB ( power )?
>
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