Pomoc - dBu, dBm, dB a zvukarina

[Pavel Troller]

Zdravim,
  proc nejuknete na Wiki ?
Cituji:
In professional audio, a popular unit is the dBu (see below for all the units). The "u" stands for "unloaded", and was probably chosen to be similar to lowercase "v", as dBv was the older name for the same thing. It was changed to avoid confusion with dBV. This unit (dBu) is an RMS measurement of voltage which uses as its reference approximately 0.775 VRMS. Chosen for historical reasons, the reference value is the voltage level which delivers 1 mW of power in a 600 ohm resistor, which used to be the standard reference impedance in telephone circuits.
  Cili je to jasne, reference je klasickych 0.775, ale meri se to bez zateze, nikoliv pri tech 600 Ohmech.

  Zdravi Pavel

> A nebudou to uV, ale to se mi zda malo ?
> Jirka
> Dne 9. 4. 2014 20:59, Petr Simek napsal(a):
>> On Wed, 9 Apr 2014, Admin HWnews wrote:
>>
>>> Propojil jsem si basovou hlavu TC electronic BH-250, ktera ma balancovany vystup:
>>> ===================================
>>> Bal. Out Max.  +2dBu
>>> Bal. Out Optimal Load Impedance  600 Ohm
>>
>> To +2dBu je vykon vuci mikrowattu ? Tedy neco jako dBm ? To by na
>> impedanci 600 Ohm davalo asi 33mV .
>>
>>> RV
>>
>> *------------------------------------------------------------------------*
>> |                          Petr Simek   APS JU                           |
>> | psimek na jcu.cz                              |
>> *------------------------------------------------------------------------*
>> _______________________________________________