Posted by
S55M on
Mar 30, 2005; 6:41pm
URL: http://elecraft.85.s1.nabble.com/OT-math-question-tp376370p376378.html
dBm's
Just remember this (no maths:))) :
Every 3dB increase is power multiplied by 2 times (1W to 2W is 30dBm to
33dBm)
So 1W+3dB (1x2=2) is 2W+3dB (2x2=4)4W+3dB(4x2=8)8W and so on.
Every 10dB increase is power multiplied by 10 (1W to 10W is 30dBm to 40dBm
100W to 1KW is 50 dBm to 60 dBm the easy one HI)
And dont care abt digits on calcullator (try to see 0,5dB on Your S-meter or
ask someone on the band to change the power from 100W to 50W or from 10W to
5W (3dB) You will see practically no difference.
Why dBm? Because dBm is power related to 1mW=0dBm .
S55M-Adi
----- Original Message -----
From: "W3FPR - Don Wilhelm" <
[hidden email]>
To: <
[hidden email]>; <
[hidden email]>
Sent: Wednesday, March 30, 2005 8:23 PM
Subject: RE: [Elecraft] OT: math question
> dB = 10 log (P2/P1)
> For your example of 5 watts to 100 watts, is an increase of 13.01029996
dB -
> pardon the rounding but that is all the digits my calculator shows :>).
>
> 73,
> Don W3FPR
>
> > -----Original Message-----
> >
> > How would one calculate the amplifier gain (in dB) required to go
> > from one
> > power level to another? For example from 5W to 100W.
> >
> > K3UJ
>
>
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