I built a double balanced tayloe. A friend and I made pc boards so the module
would plug into my Racal RA6830.
Softrock is a lot quicker and cheaper. frank
garys_dad <[EMAIL PROTECTED]> wrote:
--- 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)
