![elektor sdr elektor sdr](https://www.saintummers.at/repair/images/sdr/elektor-uno.jpg)
spectrum display AGC to allow display of very small signals automatic codec gain adjustment depending on the sample input level wideband FM demodulation with deemphasis EEPROM save & load of important settings kind of menu system now working with many variables that can be set by the encoders dynamic frequency indicator figures and graticules on spectrum display x-axis automatic IQ amplitude and phase imbalance correction plays MP3 and M4A (iTunes files) from SD card with the awesome lib by Frank Bösing (his old MP3 lib, not the new one) Automatic gain control (high end algorithm by Warren Pratt, wdsp) sample rate from 48k to 234k and decimation-by-8 for efficient realtime calculations real SAM - synchronous AM demodulation with phase determination by atan2f implemented from the wdsp lib implemented nine different AM demodulation algorithms for comparison (only two could stand the test and one algorithm was finally left in the implementation)
![elektor sdr elektor sdr](https://www.elektor.de/media/catalog/product/cache/0f46a8209da9de2ac0689ee3586e8a8f/e/l/elektor-sdr-praxis-bundle_ferrit.jpg)
efficient DC elimination after AM demodulation efficient AM demodulation with ARM functions efficient spectrum display using a 256 point FFT on the first 256 samples of every 4096 sample-cycle efficient frequency translation without multiplication
ELEKTOR SDR SOFTWARE
I & Q - correction in software (manual correction or automatic correction)
ELEKTOR SDR PLUS
12kHz to 30MHz Receive PLUS 76 - 108MHz: undersampling-by-3 with slightly reduced sensitivity (-9dB) Part of the evolution of this project has been documented here:
ELEKTOR SDR CODE
the T4 versions of the code also work with toolchain ARM ver. tested with Arduino 1.8.12 & Teensyduino 1.52 with Teensy 4.1: tested in combination with SGTL5000 on D07JBH PCB board with ugly style adaptor board with Teensy 4.0: compile with "Optimize: Faster", never use "Optimize: smallest code", the latter will not work! Maybe with the newest fix in Teensyduino, higher speeds could work, but this is untested with Teensy 3.6: compile with 180MHz F_CPU, other speeds not supported. spectral NR uses FFT-iFFT overlap-add with 50% overlap with overlap - save = overlap-discard complex bandpass main filtering FFT Fast Convolution = Digital Convolutionbuffer_spec_FFT digital step attenuator: PE4306 used in my setup Preselection: switchable RF lowpass or bandpass filter has also been successfully used with Msi001 tuner chip (Esteban Bonito & tisho), but not yet incorporated in this sketch Teensy 3.6 or Teensy 4.0 or Teensy 4.1 (Teensy 3.1/3.2/3.5 not supported) Teensy audio board or ADC PCM1808 and DAC PCM5102a
![elektor sdr elektor sdr](https://s3.manualzz.com/store/data/029211567_1-5bd48bd5f9799bf0f6c754841f943bc5.png)
(IQ boards with up to 256kHz bandwidth supported -> which basically means nearly 100% of the existing boards on the market) simple quadrature sampling detector board producing baseband IQ signals (Softrock, Elektor SDR etc.) SOFTWARE FOR A FAST CONVOLUTION-BASED RADIO