NBFM Transmit: Difference between revisions

From GNU Radio
Jump to navigation Jump to search
No edit summary
(add example flowgraph)
 
Line 18: Line 18:
== Example Flowgraph ==
== Example Flowgraph ==


Insert description of flowgraph here, then show a screenshot of the flowgraph and the output if there is an interesting GUI. Currently we have no standard method of uploading the actual flowgraph to the wiki or git repo, unfortunately.  The plan is to have an example flowgraph showing how the block might be used, for every block, and the flowgraphs will live in the git repo.
This flowgraph shows a signal source feeding a Narrow Band FM modulator driving a PlutoSDR Sink block.
 
[[File:Pluto_NFM_xmt_fg.png|800px]]


== Source Files ==
== Source Files ==

Latest revision as of 02:09, 25 May 2020

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.

Pluto NFM xmt fg.png

Source Files

Python files
[1]
Block definition
[2]