I have two "versions" of the ADF4351 dds. One is the AD eval board, and the other the TPI synthesizer (http://www.rf-consultant.com/calibrated-signal-generator/) at $280 that might do the job. The latter device performs well. It will be as good as the 4351, I think. It has a programmable attenuator. A good price. Requires a Healthy! USB port. Don
Magnus Danielson > You should be able to use DDS test-boards and by timing your last write, > you should be able to time the frequency jump. > > The STEL-1173 takes 6 bytes, but writing the last one latches all 6 > bytes over to a single 48 bit word. I expect that other DDSes have the > same distinct transfer-phase if you only look in the datasheet for the > details. > > Some of the modern DDSes can take 10 MHz directly and step it up > internally before hitting the DDS core, but it may be that you need to > synthesize a higher clock from the 10 MHz first. > > Cheers, > Magnus > > On 10/07/2014 07:02 PM, Jim Lux wrote: >> >> At work, I'm putting together a multichannel stepped frequency CW radar >> breadboard, and I'm looking for something to serve as a source that I >> can step quickly. >> I'm looking at stepping every millisecond or so. Right now, I use a >> Ardunino type microcontroller driving a serial DAC driving a VCO, but >> that's a bit wonky and noisy, although it's easy to get the step timing >> right on. The spectral purity is, shall we say, downright ugly. >> >> Since I'm going to be doing precision ranging with this, the spectral >> purity has to be reasonably good (not 1E-15 at 1000 seconds good, >> fortunately).. >> >> I was thinking about a PTS synthesizers (beloved of time-nuts for all >> kinds of reason), and they're nice because they are quiet, and switch >> really fast (microseconds). However, they all seem to have BCD or GPIB >> interfaces (only). Sure, I can code up something on an Arduino or other >> microcontroller to drive the BCD on the PTS, but maybe there's something >> else out there that might work as well? And is already off the shelf. >> >> >> I could hook a Prologix on the back of a PTS with GPIB, and hit it over >> the ethernet, but I'm not sure I'd be able to get the steps to occur >> when I want them (ethernet and determinism do not go well together). >> >> Maybe some DDS in a box product? That will take my nice clean 10 MHz >> reference? >> >> Ultimately, I'm looking at output frequencies in single digit GHz, but >> something that can be mixed/multiplied up will work just fine. >> >> I'm looking for something that is off the shelf-ey as much as possible. >> Using surplus gear is ok, because I really only need 3 or 4 channels and >> that might be scroungeable, but spending hours wiring up weird adapters >> or locating connectors that haven't been made since 1943 is something >> I'd like to avoid. >> >> >> _______________________________________________ >> time-nuts mailing list -- [email protected] >> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > -- "The power of accurate observation is commonly called cynicism by those who have not got it." -George Bernard Shaw Dr. Don Latham AJ7LL Six Mile Systems LLC 17850 Six Mile Road Huson, MT, 59846 mail: POBox 404 Frenchtown MT 59834-0404 VOX 406-626-4304 Skype: buffler2 www.lightningforensics.com www.sixmilesystems.com _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
