Schematics for Experiments in DDS

This page contains the schematics for basically 2 types of Direct Digital Synthesis (DDS) variable frequency oscillators (VFOs):  a relatively basic, but wideband DDS, AD9850, and a much more versatile and even wider-band, AD9854.  The AD9854 can produce 2 quadrature outputs which is useful or driving phased direct-conversion receivers.

Both of these "oscillators" are controlled by a PIC Microcontroller, 18F2520.  They use an rotary encoder for variability, and LCD for frequency and other display.