Using External Reference Oscillator
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incaseywood
- Posts: 2
- Joined: Mon Jul 15, 2013 3:32 pm
- Location: Utah, USA
Using External Reference Oscillator
I am having trouble using an external reference oscillator for the clock input. The FFT's that I have been able to get using GNU Radio Companion have been appeared pretty noisy and my best assumption is that it is due to the internal clock of the bladeRF. After finally finding an SMA to SMB adapter, I finally tried to connect my oscillator, but the results were pretty similar to those taken without an external clock. Other SDR's like the Ettus USRP's have an option within the GRC block to use external reference, but the blade does not and I have not yet been able to find a way to tell it to use the external clock. Has anyone else faced similar problems?
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bpadalino
- Posts: 303
- Joined: Mon Mar 04, 2013 4:53 pm
Re: Using External Reference Oscillator
We haven't implemented the external reference option in the CLI yet, though we have tested it using test programs by setting the Si5338 to use the SMB as the clock input.
Just curious, why do you believe it is the oscillator? There was an issue where the LMS polarity coming out of reset does not match what the FPGA code was expecting. Essentially this will cause I_n to be paired up with Q_n+1 causing a massive phase imbalance to occur and really just issues all around. To fix this, setting the polarity register 0x5a and set it to 0xa0
Can you describe what you mean as a pretty noisy FFT?
Just curious, why do you believe it is the oscillator? There was an issue where the LMS polarity coming out of reset does not match what the FPGA code was expecting. Essentially this will cause I_n to be paired up with Q_n+1 causing a massive phase imbalance to occur and really just issues all around. To fix this, setting the polarity register 0x5a and set it to 0xa0
Can you describe what you mean as a pretty noisy FFT?