Hi,
I need to generate a 125Khz sine wave for a laboraty test. I use the PXI 5441 generator to that purpose. I can generate my 125 Khz sine wave with a +-6V p-p without any problem with the fgen utilities (verified by scope good level and freq). I also wanted to verified the output power level by spectral measurement. The load impedance of my analyser is 50 ohms. The ouput impedance of the PXI5441 is 50 ohms too (75 ohms option NOT selected). So I thought I would have a +25 dBm output power (4.2Vrms in a 50 ohms load). This is not the case. At 125 Khz the measured output power is -2.44 dBm. This level is frequency dependant too. The output power level of a sine wave with a resistive load impedance should not depend of the frequency. So why I obtain these results? Where am I wrong? I use the high gain amplifier path. The flatness for this path is between -1.2 to 0.5 dB.
I use FGEN driver 2.9 and Labview 11.0.1.
I will try to install the NI FGEN 2.9.3 driver but I think it won't solve my problem. Any idea?
Thanks in advance.
Stephanie
