1.Rick Campbell, KK7B, "High-Performance, Single-Signal Direct Conversion Receivers", QST January 1993.
2. Johan Forrer, "Using the Motorola DSP56002EVM for Amateur Radio DSP Projects," QEX, August 1995.
3 . The R2 circuit board is available from Kanga for $20. A complete kit including parts to populate the R2 board is about $92.
4 . Leon W. Couch II, Digital and Analog Communication Systems, 4th Ed., Macmillan Publishing Company, 1993. A bandpass signal is one whose spectra is concentrated about a carrier frequency.
5 .KANGA US, Bill Kelsey, 3521 Spring Lake Drive, Findlay, Ohio 45840 Phone: 419-423-4604 e-mail: kanga@bright.net and the world wide web: http://qrp.cc.nd.edu/kanga/
6. This software is called flashboot.asm, by Helmut Strickner, and is available on the TAPR site at ftp://ftp.tapr.org/tapr/SIG/hfsig/upload/flshboot.zip.
7. Crystal Semiconductor Data Sheet for the CS4215 16-Bit Multimedia Audio Codec. Crystal Semiconductor Corporation, 1993.
8. The codec uses a digital filter in it's sigma delta A/D converter that has a pipeline of 16 data points, so we must wait until those have passed before we check for the overload condition.
9. John Wiseman, "A Complete DSP Design Example Using FIR Filters", QEX, July 1996.
10. MATLAB, The MathWorks Inc., 1995.
11 . G. Breed, " A New Breed of Receiver," QST, January 1988.
12. Right here! http://www.wwc.edu/~frohro/R2-DSP.html
13. Rick Campbell, "High-Performance Single-Signal Direct-Conversion Receivers," QST , January 1993, Figure 6a. G. Breed, " A New Breed of Receiver," QST, January 1988.