DDS Sig gen Question

[nay27uk]

Hi all not been on for a while but have some questions regarding DDS Signal generators.

Just found this on eBay and it says it is 0-40Mhz.

Questions are

1) Can it be used to tune HF receivers
2) Can it be modulated
3) How the hell do you use it

http://www.ebay.co.uk/itm/1pce-DDS-Sign ... 53fa41fc44

[Andy]

It looks like it needs to be controlled by a serial or parallel bus from a PC. Not sure what software would be needed. Also the output will be at a fairly high level and you'll need a calibrated attenuator to get sensible results from it.

[Andy]

Repeat post again. Sorry.

[kr0ne]

You need a microcontroller, or similar, to control it.

They give a reasonably good signal, but normally require a buffer amp of some sort to be usable.

They're actually really easy to get going if you're familiar with microcontrollers. If not, take a look at the Arduino platform - it's a really easy (and quick) way to get started with microcontrollers.

http://arduino.cc/

http://www.ebay.co.uk/itm/Arduino-UNO-R ... 27d380f981

[mattltm]

Add one of these and you have a complete 0-30MHz VFO & Signal Generator, maybe!

http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... 1217439093

[nay27uk]

Cheers for the replies guys.

mattltm are you saying add that and the one I posted a link to on the baord that kr0ne posted a link to

[M0KRL]

If you need ideas of how to implement these DDS modules just search for the VK5TM website. He has sample code for a PIC chip as well as PCB layout designs. I have built one based on his designs and it works great with tuning step select from 1hz upto 1mhz, with both sine and square wave output and LCD display, as others have said, the module needs buffering for a lot of purposes, but just as a signal source upto the top of the HF bands, and usable harmonics above, you can't beat them for the price. Karl

[kr0ne]

mattltm are you saying add that and the one I posted a link to on the baord that kr0ne posted a link to

Sorry - missed this... I think the link mattltm posted is a standalone thing, so you would just add the DDS module and some other components.

There are also complete (built) units available fairly cheaply on eBay that use the same modules inside.