Here it is. Another winter project. This was e-mailed to me by a few anonymous readers. So I had to do some tracking to find the source. Credit to Andrew Sparky and WB6DHW
The UHFSDR is a Software Defined Transceiver covering the 1.75 MHz to 700 MHz frequency range. A Si570 is used for frequency control. Two LVPECL 4 GHz max.flip flops produce I and Q LO signals at 1/2 the Si570 frequency. A pair of 1-1000MHz Double Balanced Mixers are used to convert signals to and from base band.
A receiver pre-amp (2dB noise figure) and a transmit pre-amp(50mW max output) are provided as well as antennal switching plus provision for separate receive and transmit connections.
For additional information, download the Assembly Manual.
The BOM, schematic, and board layout are Here.
A HiRes(3.7MByte.) picture of the completed board is Here
Link to WD6DHW’s Website