Re: [Discuss-gnuradio] NCO and VCO frequencies

[Jason Abele]

> Objective : we need to make this desired frequency only dependant on the NCO
> frequency and independant on the the VCO frequency, so first we should know
> how gnuradio control these two values so that we could develop a method to
> make it only dependant on NCO frequency.

take a look at uhd::tune_request_t and uhd::tune_result_t

http://www.ettus.com/uhd_docs/doxygen/html/structuhd_1_1tune__result__t.html
http://www.ettus.com/uhd_docs/doxygen/html/structuhd_1_1tune__request__t.html

You can use the policy_t, inter_freq (VCO) and dsp_freq (NCO) to
control the tuning.

Also, tune_request's can be passed into calls to set_center_freq() on
gr-uhd sink and source block and get a tune_result back:

http://www.ettus.com/uhd_docs/doxygen/html/classuhd_1_1usrp_1_1multi__usrp.html#a9b61448f392466e20572fdcb042e8ec6

Jason