I am trying to remove a few spurs that show up in the GPS L1 frequency band (see the attached figure) with center frequency of 1575.42 MHz.
The TwinRX/X310 is operated inside a shielded space and the spurs are coming within the receiver itself.
Whether I use the tune_request (shown below) to invoke the Integer_N PLL or not, the results seem to be the same, i.e., spurs show up.
Can anyone review the code below and tell me what I am doing wrong and how to remove spurs in TwinRX?
Thank you.
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A portion of python code (generated from gnuRadio and modified)
### Sampling rate: 50 MHz
center_freq=1575.42e6
req = uhd.tune_request(center_freq)
req.args = uhd.device_addr(','.join(["mode_n=integer","int_n_step=1e4"]))
self.uhd_usrp_source_0_0_0.set_subdev_spec("A:0 A:1 B:0 B:1", 0)
self.uhd_usrp_source_0_0_0.set_samp_rate(samp_rate)
self.uhd_usrp_source_0_0_0.set_time_unknown_pps(uhd.time_spec(0))
self.uhd_usrp_source_0_0_0.set_center_freq(req, 0)
self.uhd_usrp_source_0_0_0.set_antenna("RX1", 0)
self.uhd_usrp_source_0_0_0.set_gain(88, 0)
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