Spectrum when using center frequencies under 1MHz

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kkao
Posts: 6
Joined: Wed Jun 25, 2014 11:42 pm

Spectrum when using center frequencies under 1MHz

Post by kkao » Wed May 10, 2017 11:01 pm

Hello,
I'm trying to receive signals with XB-200 using​ a​ ​center frequency under 1MHz.
There seems to be some peaks like spurious components in a spectrum, even though any transmitter isn't connected.

The spectrum shows positive and negative peaks at the same frequency as a center frequency when the Nyquist frequency is higher than the center frequency. (freq700kHz_sampling2MHz.PNG)
freq700kHz_sampling2MHz.PNG
freq700kHz_sampling2MHz.PNG
When the Nyquist frequency is lower, returning components appear. (freq700kHz_sampling1MHz.PNG)
freq700kHz_sampling1MHz.PNG
freq700kHz_sampling1MHz.PNG

Is a similar spectrum seen in your environment when using​ a​ ​center frequency under 1MHz?
If that happens, could you suggest the reason, and some workaround to eliminate these peaks?

I attached a diagram of a simple model I confirmed.
Attachments
SimulinkModel-xb200_test.JPG
SimulinkModel-xb200_test.JPG

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