Thread: Test Equipment
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chung
 
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Default Test Equipment

Michael wrote:
Chung wrote:

Michael wrote:

Can someone recommend a satisfactory test unit to measure 'peak'
frequency coming from an amplifier.

Thanks



What exactly do you mean by "peak" frequency?

An amplifier typically reproduces the input signal, with a little bit
of distortion and noise added. Are you talking about the frequency
response of the amplifier, or are you looking for oscillations? For
the former, a scope and a function generator works fine. For the
latter, you need a good scope or a spectrum analyzer. In both cases,
you need to have a load that resembles speakers used (assuming you are
testing power amps).



I am testing for ultrasonic frequencies (greater than 100khz) coming
from SACD's through my amplifier. I want to know what the highest
frequency that is reproduced.


In that case you are looking at the frequency response of the amplifier.
The "highest frequency that is produced" is not a good measure since
your amplifier has a smooth roll-off. It can probably reproduce a 100KHz
input, but the gain at that frequency will be lower than that at 1 KHz
for instance. A common spec is the -3dB bandwidth of the amplifier.

You need a function generator that goes up to the highest frequency you
want to test for, and you need a scope to measure the level of that
amplified signal. And you need a load for the amplifier.