AD9951 DDS & DDS-4 digital VFO

The Direct Digital Synthesis (DDS) Unit described in this document is based on the Analog Devices AD9951/54 family chips.
Featuring advanced technology, high speed 14 bit Digital to Analog Converter, capable of generating a frequency-agile analog
output sinusoidal waveform at up to 200 MHz with a fine tuning resolution of 32 bits.



DDS assembled inside metal box (90 x 35 mm)



The Unit consists of a 2-layer pcb providing maximum flexibility in a minimum size, it includes room and facilities for:

The Unit can be interfaced to a micro based controller trough a suitable 6 pin connector.

      This Project has been developed thank to the strictly collaborated work of i0CG, Giuliano and i0GLU, Giancarlo.



AD9951 spectrogram with 50 MHz Spam F. out = 42.8 MHz


AD9951 spectrogram with 50 MHz Spam F. out = 15 MHz (only armonics are visible)


The  spectrogram for the OLD AD9851 DDS with F.= 42.8 MHz


ED2 Prototype


I0CG DDS controller ED3 based to PIC182620

New DDS VFO for vintage radio (Drake & Collins)in the new case now available (March 2011)

DDS_4 is vailable nearly no soldering KIT (the electronics board are assembled and tested)

New Features of V 3.3:

Optical encoder for tuning,

opto-coupled USB interface,

CAT control via Ham Radio Deluxe,

Reference oscillator software set-up,

RF output level programmable from +7 dBM to -60 dBm, one dB step

IF frequency is programmable to adiust any RX or homebrew RX/trx

Download: DDS-4 manual for use with Vintage radio (Collins, Drake....)

Download: DDS-4 Manuale Versione in Italiano V3.3 del Marzo 2011

Youtube demo

For any information's ask to