I'm new to the world of oscilloscopes and electronics in general, so I'm on a real steep learning curve and probably making a very simpl mistake. Please be gentle!
I'm trying to use the spectrum analyzer to create a frequency response curve from a CD player's analogue output. I'm using a test CD to do a frequency sweep from 20Hz to 20Khz and have the analyzer set to show peak dB as the sweep passes.
However, I am not getting the results I expected.
On the scope, the input is reading from -3 to 3V instead of the expected +/-2V as per the player's spec. And on the spectrum analyzer, the readings are all at +10dB, even though the sweep is recorded at 0dB. I assuming some sort of termination problem as I'm simply connecting the player's output directly to the scope.
On a related note, I've been measuring video output from a DVD player. I am getting the correct readings from the scope (1V pp on Y output) - this time using 75ohm termination, but again, all spectrum analyzer readings are at +10dB.
Finally, using the scope's signal generator to generate a 2.5Khz square wave at 5V, ie indeed see the wave in the scope view, but again it is at 10dB in the spectrum view when I would expect the 2.5Khz peak to be 0dB?
Any insights into where I'm screwing up would be much appreciated.