--- In [email protected], "Adnan Yusuf" <[EMAIL PROTECTED]> wrote: > > I am planning to build the SDR for the masses. I am sure all of you > must have heard of it. ... I have studied the function and working > of the Tayloe Detector but I am clueless about where to get one > from. ... > > Yours truly, > Adnan Yusuf >
Before you get started, you might want to look at what others are doing. I have 4 examples below. Dan Tayloe has created a kit from his idea, called the firefly. see: http://groups.yahoo.com/group/FireFly-SDR-transceiver/ In the files section you can find a schematic which includes his detector. His kits start at $65 (when I bought one last summer). The receiver is an SDR style, while the 2 watt transmitter is a variable crystal oscillator type (non-SDR style, called a VXO). Tony Parks has both a receiver (about $12) and and a 1 watt transmit/ receive kit (about $32) both of which use the Tayloe style detector (but not the johnson divide by 4 counter). The transmitter also uses an I & Q phasing type transmitter, and uses a sound card to both generate and receive the base band I and Q signals. Please see: http://groups.yahoo.com/group/softrock40/ Tony also has schematics for his older and current generation boards. A lot of people use the free rocky software, see: http://www.dxatlas.com/rocky to operate these radios. Please see the ARRL site: www.arrl.org/tis/info/pdf/030304qex020.pdf for an artical by Gerald Youngblood that soon became the SDR-1000 radio, and includes schematics on the Tayloe detector. He calls it the QSD, since versions of it existed before Tayloe made it popular (I consider it half of a switch capacitor audio filter, where instead of re-sampling the capacitor voltages back up to the center frequency, you use them direcly, when you impliment the four capacitor version of a switched capacitor filter - you can do a goole search to see what I mean). Dave Brainer has combined a Tayloe detector with a AD9951 DDS chip controlled by a PIC processor with USB control from a host PC. see: http://groups.yahoo.com/group/dds_controller/ for more info. He also has schematics on his website http://WB6DHW.com and has bare boards for $8 there. His sensitivity compares well with a commerial receiver up to 50 Mhz by his account. I hope that helps. Enjoy the ride. - Gary Greene (W2ZV)
