Constant Source const_source_x from gnuradio import gr gr.sig_source_$(type.fcn)(0, gr.GR_CONST_WAVE, 0, 0, $const) set_offset($const) Output Type type enum Complex complex fcn:c const_type:complex Float float fcn:f const_type:real Int int fcn:i const_type:int Short short fcn:s const_type:int Constant const 0 $type.const_type out $type