Re: How to change Vrms to dBm?

From: Robert Baer <robertbaer@xxxxxxxxxxxx>
Date: Tue, 18 Mar 2008 19:36:36 -0800

ElectricQuadrupole@xxxxxxxxx wrote:

Hello,

I have a power spectra in dB relative to 1Vrms / sqrt(Hz) and I want
to change units to dBm (dB power relative to 1mW). Signal was measured
at 1 kOhm load. How to change this units?

E.C.

Depends on the impedance and standard.
In audio there two standards: Western Electric which i think was 500 ohms, and modern audio which i think is 600 ohms; if i am wrong,then switch the numbers.
In RF, there are nominally two standards: 50 ohms and 75 ohms.
If you did your work at a different impedance level (say 93 or 110 ohms) then use that.
.

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References:
- How to change Vrms to dBm?
  - From: ElectricQuadrupole

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