OH2NLT Experimental Digital HF receiver

"From Antenna to Numbers"

Main objective of this project is to learn signal processing. I am a self educated DSP man, not a professional. I have made this Digital HF Receiver hardware platform to test various Digital Radio concepts. Main components are Texas Instruments AFEDRI8201 IF ADC chip and Microchip dsPIC30F6014A DSP. Test board also contains RF band pass filters for 3,5 and 7 MHz HAM band. AFEDRI8201 AUX DAC is used for audio output. User interface is built on LCD, quadrature encoder and few buttons & potentiometers. More details can be found from schematic diagrams.

AFEDRI8201 chip provides all blocks for high speed RF signal processing. From AFEDRI chip we get "low sample speed" I and Q signals for future processing. Microchip 30F6014 DSP/controller is easy environment to do this low speed processing and general system control functions.

This is exciting project !

More information will be added here while the project evolves.

Test software for the Digital RX board. This code is more collection of test and experimentation routines than fully functional receiver with fancy user interface. Anyway receiver is fully operational with this. I am pleased to hear if other experimenters are developing code for AFEDRI8201 chip. Software is compiled with Microchip C30 compiler. Limited "student version" should also work. There are no time critical things in the main code requiring compiler optimization. Time critical things (filter calculations) are coded with assembler.

Some audio samples recorded 22.09.2006 evening. Recordings are done with wide test filters loaded in the AFEDRI8201 chip. Recording location is Espoo Finland and antenna is 80m dipole low in the bushes. MP3 samples are left channel only.