NBFM Transmit

Narrow Band FM Transmitter.

Takes a single float input stream of audio samples in the range [-1,+1] and produces a single FM modulated complex baseband output.

The only difference with WBFM Transmit is the size of the internal low pass filter for interpolation. Here it has a cutoff frequency of 4.5kHz with 2.5KHz of transition width.

Parameters
(R): Run-time adjustable


 * Audio rate: Sample rate of audio stream, >= 16k (integer)
 * Quadrature rate: Sample rate of output stream (integer). Must be an integer multiple of Audio rate.
 * Tau: Preemphasis time constant (float)
 * Max deviation (R): Maximum deviation in Hz (float)
 * Preemphasis High Corner Freq: High frequency at which to flatten preemphasis; < 0 means default of 0.925*Quadrature rate/2.0 (float)

Example Flowgraph
This flowgraph shows a signal source feeding a Narrow Band FM modulator driving a PlutoSDR Sink block.



Source Files

 * Python files
 * 


 * Block definition
 *