sdrangel/plugins/channelrx/demodwfm
f4exb ffb6ad3009 Use double storage type for all moving average instances 2017-05-12 00:03:56 +02:00
..
CMakeLists.txt Channel plugins: Removed useless link dependency on QT OpenGL and Multimedia 2016-10-27 08:46:06 +02:00
demodwfm.pro Windows build: set SSE options for all demodulator plugins 2016-11-07 18:57:52 +01:00
readme.md WFM Demod: added documentation 2017-04-26 11:08:38 +02:00
wfmdemod.cpp Remved default constuctors in Moving average and AGC classes 2017-05-11 18:39:00 +02:00
wfmdemod.h WFM Demod: implemented the signal gauge 2017-04-26 11:09:07 +02:00
wfmdemodgui.cpp WFM Demod: implemented the signal gauge 2017-04-26 11:09:07 +02:00
wfmdemodgui.h Use double storage type for all moving average instances 2017-05-12 00:03:56 +02:00
wfmdemodgui.ui WFM demod: Set fixed geometry. Audio mute 2017-04-26 10:04:02 +02:00
wfmplugin.cpp Code warnings in Eclipse cleanup 2017-05-05 10:40:45 +02:00
wfmplugin.h Tx ph.1: plugins (2) 2016-10-13 23:42:08 +02:00

readme.md

WFM demodulator plugin

Introduction

This plugin can be used to listen to a wideband or narrowband FM modulated signal. "Wideband" means that the bandwidth can vary from 40 to 250 kHz. It can also demodulate narrowband signals with bandwidths of 25 or 12.5 kHz.

Interface

WFM Demodulator plugin GUI

1: Frequency shift from center frequency of reception direction

The "+/-" button on the left side of the dial toggles between positive and negative shift.

2: Frequency shift from center frequency of reception value

Use the wheels to adjust the frequency shift in Hz from the center frequency of reception. Left click on a digit sets the cursor position at this digit. Right click on a digit sets all digits on the right to zero. This effectively floors value at the digit position.

3: Channel power

Average total power in dB relative to a +/- 1.0 amplitude signal received in the pass band.

4: Level meter in dB

  • top bar (green): average value
  • bottom bar (blue green): instantaneous peak value
  • tip vertical bar (bright green): peak hold value

5: RF bandwidth

This is the bandwidth in kHz of the channel signal before demodulation. It can be set in steps as 12.5, 25, 40, 60, 75, 80, 100, 125, 140, 160, 180, 200, 220 and 250 kHz.

6: AF bandwidth

This is the bandwidth of the audio signal in kHz (i.e. after demodulation). It can be set in continuous kHz steps from 1 to 20 kHz.

7: Volume

This is the volume of the audio signal from 0.0 (mute) to 10.0 (maximum). It can be varied continuously in 0.1 steps using the dial button.

8: Squelch threshold

This is the squelch threshold in dB. The average total power received in the signal bandwidth before demodulation is compared to this value and the squelch input is open above this value. It can be varied continuously in 0.1 dB steps from 0.0 to -100.0 dB using the dial button.

9: Audio mute

Use this button to toggle audio mute for this channel. The button will light up in green if the squelch is open. This helps identifying which channels are active in a multi-channel configuration.