- DBrn
The symbol dBrn or dB(rn) is an abbreviation for
decibels abovereference noise .Weighted
noise power in dB is referred to 1.0picowatt . Thus, 0 dBrn = -90dBm . Use of 144 line, 144-receiver, orC-message weighting , orflat weighting , can be indicated in parentheses.With C-message weighting, a one-
milliwatt , 1000 Hz tone will read +90 dBrn, but the same power aswhite noise , randomly distributed over a 3 kHz band will read approximately +88.5 dBrn, because of thefrequency weighting.With 144 weightings, a one milliwatt, 1000 Hz white noise tone will also read +90 dBrn, but the same 3 kHz power will only read +82 dBrn, because of the different
frequency weighting .References
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