"xpyttl" writes:

A lot of the modern signal generator projects are based on the Analog
Devices AD9850. Analog Devices actually encourages hams to use their sample
service, so the part itself is no problem. It is relatively simple to
program, so you may choose the microcontroller of your choice, although most
of the projects out there seem to lean toward the PIC.

The challenge could well be the circuit board. The 9850 is only available
in TSSOP so you need a good quality circuit board to attach it to. If your
PCB skills are good this won't be a problem. But if not, you might need to
hunat around for a protoboard or something of that ilk that you can get in
your location. Unfortunately, these tend to be kind of pricey.


Back in 1996, one of Novatech's early products was a small DDS board based
upon the AD9850. It was later upgraded to the AD9851 to allow higher
output frequency. We no longer build this item, but I looked in the back
stock area and found that there were hundreds of blank boards left. You
can see the schematic at: http://www.novatech-instr.com/Fun/dds6m_sch.pdf
and a photo at: http://novatech-instr.com/images/dds6mf.jpg

If you want one of these blank boards FREE, send a self-address, stamped
($0.60) envelope to:

Novatech Instruments, Inc.
attn: DDS6m board
P.O. Box 55997
Seattle, WA 98155-0997

and I'll get one out to you. The price is right and might get you
over the soldering hump. The discrete parts are 1206, 0805 and 3216.
We have a bunch of the key parts (micros, AD9851BRS, etc), but we'd
have to come up with a price for that.

Steve.

--
Steven D. Swift, , http://www.novatech-instr.com
NOVATECH INSTRUMENTS, INC. P.O. Box 55997
206.301.8986, fax 206.363.4367 Seattle, Washington 98155 USA