NBFM Transmit
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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
- [1]
- Block definition
- [2]