USE GPSDO 10 MHz to make super accurate DDS siggen?

[cdev]

The HackRF one seems to implement something like this internally with its DDS clock generation. This seems like one of the most useful things that can be done with a GPSDO.

Has anybody implemented this and if so, how was it done. How did you control it?

[Rerouter]

Find a DDS with a frequency in, hook it up to a GPSDO 10Mhz output, and away you go, be aware that because of the constant tuning of the oscillator there can be some jitter introduced, vs a rubidium Oscialltor, where its stable, but not garenteed to be exactly 10Mhz

[cdev]

Which DDS would you recommend?

[DaJMasta]

If you're looking to make your own, there's a number of standards from Analog Devices and a few projects on the forum that have used them.  In a commercial function gen, you'd have the 10MHz input be a reference for the internal oscillator PLL, but if you selected the frequency right, you could always just clock the DDS chip directly from the oscillator input.

A basic DDS generator is not going to be too hard to build up (and you can get some cheap on ebay as single boards with a screen), but as the speed increases you run into more and more issues with layout and parasitics.  Selecting the right output amp is also very important if you want more than a basic TTL range or similar, since typically function generators that can be hooked up to various things need a decent amount of drive current available.

[DimitriP]

W3PM  GPS referenced DDS VFO

http://www.knology.net/~gmarcus/VFO/GPS_Sig_Gen_v1_1.pdf

http://www.knology.net/~gmarcus/VFO/

Enjoy!

[bingo600]

W3PM  GPS referenced DDS VFO

http://www.knology.net/~gmarcus/VFO/GPS_Sig_Gen_v1_1.pdf

http://www.knology.net/~gmarcus/VFO/

Enjoy!

I'd get a AD9851 Module instead , has an internal 6x clock multiplier.
Making it usefull to 60MHz w. 10MHz in.

/Bingo