-------- In message <5e3f68620fdb8f2e5d62e9907a44c6eb.squir...@email.powweb.com>, "Chris Caudle" writes: >On Wed, November 29, 2017 3:51 pm, Poul-Henning Kamp wrote: >> While it is tempting and probably easiest to use a DDS style >> generator, I recommend a synthesized one instead, to avoid >> trouble with numeric spurs. > >Can you describe the distinction you are making between a synthesized >generator, and a direct-digital synthesized generator? I do not >understand what would be meant by a synthesizer which is not DDS.
What used to be called a "Synthesized Signal Generator" was a almost or even entirely analog beast, which means almost all distortion is harmonic (2f, 3f, 4f, ...) This is a good place to start, in particular the App-note at the bottom: http://hpmemoryproject.org/news/5100/hp5100_page_00.htm DDS is "Direct Digital Synthesis" where you basically generate the desired signal with a computer and D/A converter. Because this discrete rather than continuous in time, there are all sorts of "weird" distortion products, and aliasing artifacts. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.