Tiny DDS Card for SDR

from JA7TDO

A circuit and printed circuit board

AD9833 can generate the waveform to 12.5MHz, when a 25MHz standard oscillator is used. The signal generated in AD9833 is increased 4 times by ICS512 of IC for multiplier. In SDR which used the Johnson counter, since it devide to one fourth by 74AC74, it is possible to receive all the frequency ranges of AD9833 as a result.

You can use DDS-33 with Soft66DB.

Printed circuit board (figure seen from the solder side)


DDS-33 front and back

Pin header is already soldered now.

connection method

Need 25 pin D-sub connector with a personal computer, and four pin connectors. A printer cable is connected to the printer port of a personal computer. It usually passes along a power supply, The pin of the pin header which connection of a pin has in the No. 1 pin side of 74HCT244 is a ground. Please prepare power supply 5V independently.

Pin layout for PC and +5V.

Please download control software from the homepage of Analogdevices.Install after thawing the downloaded file. After connecting the power supply of Soft66DB, launch the installed control software and SDR software(Rocky).

The target frequency is put in from the screen of control software. A master clock is O.K. in default 25MHz. Please check Square by Output Option. If the target frequency is set up and a return is pushed, a setup of a DDS card will be performed.

From control software, two frequency, FREQ0 and FREQ1, can be set. If it is a 48kHz sound card, and two main frequency is set, is placed and it changes by Select FREQ Req, the whole band can be covered in general at 40m band.

You can buy DDS-33 via PAYPAL. MY PayPal e-mail address is

DDS-33 Price is only $30USD include shipping fee. All components are soldered without header pin.

Please click this buttom,you can order.If you want get Soft66DB ,please mail me feel free.

MY Address
Kazunori Miura
ZIP-CODE 998-0054

GAS is related project.


最終更新日: 06.10.7