User contributions for Jesternofool

30 March 2025

• 01:3301:33, 30 March 2025 diff hist −84‎ SuggestedReading ‎ Provided link to Gary Schafer's update frequency demodulator page (just one page now, not spread amongst three) current

23 March 2025

• 02:5102:51, 23 March 2025 diff hist +934‎ UChar To Float ‎ Added a second example - the raw output values of a RTL-SDR (collected using the "rtl_sdr" command) current
• 02:4902:49, 23 March 2025 diff hist 0‎ File:Uchar-to-Float-time-sink-from-RTLSDR-file.png ‎ Jesternofool uploaded a new version of File:Uchar-to-Float-time-sink-from-RTLSDR-file.png current
• 02:4202:42, 23 March 2025 diff hist +125‎ N File:Uchar-to-Float-time-sink-from-RTLSDR-file.png ‎ Time sink showing the raw output values from a RTL-SDR. The samples were collected using the "rtl_sdr" command.
• 02:3502:35, 23 March 2025 diff hist +221‎ N File:Uchar-to-Float-block-usage-with-RTLSDR-flowgraph.png ‎ Flowgraph showing the usage of the 'UChar to Float' block to read the values of a file collected from a RTL-SDR using the "rtl_sdr" command in a terminal. The values so collected are unsigned 8-bit integers. current
• 02:1202:12, 23 March 2025 diff hist +109‎ m Float To Char ‎ Clarified the role of the 'Scale' value in the block. current
• 02:1002:10, 23 March 2025 diff hist +1,765‎ Float To Char ‎ Added more detailed description plus an example flowgraph.
• 01:5701:57, 23 March 2025 diff hist +174‎ N File:Float-to-Char-scale-150-1.png ‎ Sinusoid with an amplitude of 1 after passing through a 'Float to Char' block with a 'Scale' value of 150. The top and bottom has been clipped to +127 and -128. current
• 01:5201:52, 23 March 2025 diff hist +216‎ N File:Float-to-Char-scale-127-1-zoomed.png ‎ Zoomed-in view of sinusoid with an amplitude of 1 after being passed through the 'Float to Char' block with a 'Scale' value of 127. Note that all of the amplitudes have been quantized to integer values. current
• 01:4701:47, 23 March 2025 diff hist +114‎ N File:Float-to-Char-scale-127.png ‎ A sinusoid with an amplitude of 1 after going through the Float to Char with a 'Scale' value of 127. current
• 01:3401:34, 23 March 2025 diff hist +270‎ N File:Float-to-Char-scale-1.png ‎ Time sink showing a sinusoid created with a 32-bit floating point number (blue) and after going through a "Float to Char" block with a scale of 1 (red). The signal after going through the "Float to Char" has been quantized to integer values of -1, 0 and 1. current
• 01:3001:30, 23 March 2025 diff hist +75‎ N File:Float-to-Char-flowgraph.png ‎ Flowgraph showing an example using the "Float to Char" block. current

6 January 2025

• 03:5903:59, 6 January 2025 diff hist +211‎ Talk:Tutorials ‎ →‎Tutorials should have a section on "Signal Basics": new section current

31 December 2024

• 16:2716:27, 31 December 2024 diff hist +4‎ m Quadrature Demod ‎ Corrected some links current
• 03:3303:33, 31 December 2024 diff hist +3,521‎ Quadrature Demod ‎ Revised to add more conceptual understanding to go with the math. Added several diagrams for a polar discriminator, along with a link to the James Shima paper on the polar discriminator.
• 03:2903:29, 31 December 2024 diff hist 0‎ File:Polar-discriminator-output-time-domain.png ‎ Jesternofool uploaded a new version of File:Polar-discriminator-output-time-domain.png current
• 03:1803:18, 31 December 2024 diff hist +378‎ N File:Polar-discriminator-output-time-domain.png ‎ The output of the polar discriminator is the frequency deviation of the input FM signal. FM broadcast stations in the US use deviation values between 75 kHz (the typical value) up to ~82 kHz (in some instances). By setting the "Gain" value in the Quadrature Demod block to samp_rate/(2*pi), the output will have amplitude values of the deviation of the FM carrier.
• 03:1203:12, 31 December 2024 diff hist +130‎ N File:FM-demod-with-quad-demod-block.png ‎ Gnu Radio flowgraph showing FM demodulation of a FM broadcast station (USA) using the Quadrature Demodulation block. current
• 02:0302:03, 31 December 2024 diff hist +612‎ N File:Polar-discriminator-GRC-block-diagram.png ‎ Gnu Radio Companion equivalent flowgraph of the "Quadrature Demod" block. This is a polar discriminator circuit. The input complex samples are split. One sample is sent to a Multiply block, while the second set are delayed and conjugated before being fed into the Multiply block. The output of the Multiply block will also be complex samples, except they are now the phase difference between consecutive samples. The Complex to Arg block calculates the actual phase, in radians, for each of these... current
• 01:3801:38, 31 December 2024 diff hist +252‎ N File:Polar-Discriminator-Delay-Conjugate-Method.jpg ‎ Block diagram of polar discriminator. The input complex samples are split. One sample goes straight to a multiplier. The second sample is delayed and conjugated (the imaginary component has its sign flipped), then input to the multiplier. current
• 01:2901:29, 31 December 2024 diff hist +161‎ N File:Phase-change-constellation-diagram.jpg ‎ Constellation diagram showing how frequency modulation will cause consecutive samples to change phase, as frequency is a change of phase over time. current

14 July 2024

• 13:4113:41, 14 July 2024 diff hist +321‎ Frequency Shifting ‎ Added scenarios where frequency shifting is useful, and some minor grammatical changes current
• 01:2501:25, 14 July 2024 diff hist +2,043‎ Low Pass Filter Example ‎ Added section on viewing the full impulse response. current
• 01:1201:12, 14 July 2024 diff hist +81‎ N File:Frequency-sink-properties-annotated.png ‎ Properties of frequency sink utilized in impulse response flowgraph current
• 01:1001:10, 14 July 2024 diff hist +71‎ N File:LPF-properties-annotated.png ‎ Low pass filter properties for impulse response flowgraph current
• 00:4600:46, 14 July 2024 diff hist +102‎ N File:LPF-filter-with-vector-source-flowgraph.png ‎ Flowgraph of lowpass filter showing how to display the spectrum of its impulse response. current
• 00:2500:25, 14 July 2024 diff hist +80‎ N File:Filter-impulse-response-spectrum.png ‎ This is the spectrum of the impulse response of a low pass filter. current

6 July 2024

• 22:3622:36, 6 July 2024 diff hist +33‎ m Correlate Access Code - Tag ‎ Made link to "Correlate Access Code" more user-readable.
• 22:3322:33, 6 July 2024 diff hist +108‎ Correlate Access Code ‎ Added link to "Correlate Access Code - Tag" block, as that was the replacement for this block. current

23 May 2024

• 22:1522:15, 23 May 2024 diff hist +6‎ USRP Sink ‎ Cleaned up some grammar
• 17:3117:31, 23 May 2024 diff hist +32‎ Complex to Mag ‎ Added diagram showing magnitude calculation from IQ sample values. current
• 17:2717:27, 23 May 2024 diff hist +82‎ N File:Complex-mag.jpg ‎ Diagram showing how the magnitude of a complex sample is calculated. current

11 May 2024

• 12:5212:52, 11 May 2024 diff hist +587‎ ATSC ‎ Added update covering ATSC 3.0 vs ATSC 1.0
• 12:5012:50, 11 May 2024 diff hist +116‎ N File:ATSC04-Ch38.jpg ‎ ATSC 1.0 spectrum and spectrogram. The spectral line on the left edge of the signal is the pilot tone. current
• 12:3112:31, 11 May 2024 diff hist +220‎ N File:ATSC-Ver3-Ch25-02.png ‎ Spectrum and spectrogram of ATSC 3.0 signal. The portion of the signal seen to the right of the 3.0 signal is a ATSC 1.0 transmission. The pilot tone for that transmission is the spectral line on the right. current

3 May 2024

• 01:2401:24, 3 May 2024 diff hist +19‎ File Sink ‎ Corrected format for integer. It IS two's complement.

30 April 2024

• 22:0322:03, 30 April 2024 diff hist −6‎ File Sink ‎ Corrected format (binary, not two's complement) for integer types.
• 00:2200:22, 30 April 2024 diff hist +1,189‎ File Sink ‎ Expanded upon number type for storage.

20 April 2024

• 17:5517:55, 20 April 2024 diff hist +124‎ Reading Binary Files ‎ Added math formatting to exponentials

13 April 2024

• 19:5919:59, 13 April 2024 diff hist −2‎ m FFT Low Pass Filter ‎ Corrected link syntax. current
• 19:5519:55, 13 April 2024 diff hist +1,644‎ N FFT Low Pass Filter ‎ Created page, added description, parameters, example, and source files.
• 19:3219:32, 13 April 2024 diff hist +159‎ N File:NwrReceiver.jpg ‎ NOAA Weather Radio (NWR) receiver, to include both frequency and time domain displays. This flowgraph demonstrates the FFT Low Pass Filter block. current
• 18:5618:56, 13 April 2024 diff hist +924‎ Complex to Arg ‎ Added a mathematical description section, an example flowgraph, and the source files. current
• 18:4018:40, 13 April 2024 diff hist +255‎ N File:Complex2ArgDemo.jpg ‎ This flowgraph demodulates a FM broadcast station. It demonstrates using the "Complex to Arg" block. The blocks from the output of the lowpass filter to the output of the "Multiply Const" block are equivalent to the "Quadrature Demod" block. current
• 17:3117:31, 13 April 2024 diff hist +3,419‎ Complex to Mag Squared ‎ Expanded description and added two examples using the Complex to Mag^2 block. current
• 17:2217:22, 13 April 2024 diff hist +163‎ N File:MeasureFmSignalPower.grc ‎ Flowgraph used to measure the signal-to-noise ratio (SNR) of a FM broadcast station. This flowgraph demonstrates a use of the Complex to Mag^2 block. current
• 17:2017:20, 13 April 2024 diff hist +169‎ N File:ComplexMagSquaredSpectrum.grc ‎ Flowgraph used to create a basic spectral display. This is used to demonstrate how a spectral display is created using the FFT and Complex to Mag^2 blocks. current
• 17:1317:13, 13 April 2024 diff hist +151‎ N File:ComplexMagSquaredSpectrum.jpg ‎ Flowgraph used to create a basic spectral display. This demonstrates several blocks, including the FFT and Complex to Mag Squared blocks. current
• 17:0317:03, 13 April 2024 diff hist +67‎ N File:Complex-to-Mag2-block-properties.png ‎ Property window for the Complex to Mag Squared block. current
• 17:0017:00, 13 April 2024 diff hist +72‎ N File:Complex-to-Mag2-block.png ‎ This is the GRC display of a Complex to Mag Squared block. current