I’m using GNU Radio v 3.7.11 on Windows 10, 1903 with Intel i5-3550 CPU and on Linux Ubuntu 18.04, with i7-3720 CPU. Both have 16GB mem.
Further, I have connected a HackRF One with firmware 2017.02.1. To the HackRF One I have connected a Siglent SDG1025 Waveform generator, with external GPS disciplined oscillator. I used a DC blocker and 30 db attenuation
between de generator and the HackRF One.
The waveform generator generates a sinewave of 9.76 MHz, I have setup GNU Radio with a osmocom Source with 2M sps and Frequency of 10.3 MHz.
To the osmocom Source I have connected first a QT GUI Frequency Sink.
To my surprise I see an AM modulated signal of around 70 kHz on the 9.76 Mhz carrier. I have tried many things, removed the external oscillator and used the internal one, tried a different waveform generator (HP33120A),
but same result, on both machines.
Today by coincidence I found that there is NO AM modulated signal when using WX GUI and the WX GUI FFT Sink.
Anyone any thoughts on this? Qt will prevail over Wx in the future, but for me this is unexpected behavior and I would like to stick to Wx.
