By chance I found the answer to my problem: the "Sound" app has a tab "Applications". While REW sends a waveform to the output, then in this tab "ALSA plug-in [java]: ...%" is displayed. When I discovered this, the gain was set to 39% instead of 100%.
I still do not know where this particular...
Get the highest screen resolution you can afford. REW smallest window size is 1024x720. A higher screen resolution allows for seeing something else at the same time, for example for notes or folder contents. Otherwise you need to switch forth and back.
I had used REW for several months on my desktop computer with Linux Mint 20 without problems, until a few days ago the output signal has always been 30dB smaller than the level set in the generator or measurement setup. My voltmeter shows the much smaller signal, and REW displays the...
I guess that the output impedance of the UMC 202HD is in the kiloOhm range (I could not find the value in the manual), thus the driving current for your DUT is too small. The signal across the DUT gets too small at higher frequencies, therefore you getting close to the noise floor. A back of the...