HI We’re not building a synthesizer here. We are putting together a simple piece of test gear. The purpose of the test gear is to measure phase noise down into the -170 dbc / Hz range …..
Bob > On Jul 12, 2022, at 4:05 PM, Mike Monett via time-nuts > <time-nuts@lists.febo.com> wrote: > > To Bob kb8tq: > > Unfortunately, most of your post made very little sense. D-flops are noisy, > and the higher you go in frequency, the noisier they are. This is clear > from the schematic. Here is the schematic for a MC1670 D-flop: MC1670SC.PDF. > > Most of the noise is generated in the input SR latch. When the clock signal > arrives, the input latch state is transferred to the output SR latch. > Obviously, the sheer number of transistors involved is going to generate > noise. > > Unfortunately, the D-flop is needed in every known synthesizer. Keeping > this noise out of the signal is the goal of every designer. Stanford > Research Systems is one company that has mastered the art. See > > https://www.thinksrs.com/products/siggen.html > > But you need to know how much noise is involved. That is where my new > method can help. I am busy collecting parts - the HMC984LP4E's will arrive > tomorrow, and I am looking for a pair of low noise VCXO's. > > I will have to regenerate test equipment that I haven't used in 5 decades > to measure deadband, loop bandwidth, damping, crosstalk, jitter response, > etc. I will also get a DBM to compare the results. > > I will also need ripple filters for the electronics. I have described this > before in 2N3906G.PNG > > All this will take time - maybe months. But I have intended on making my > own phase noise analyzer for a long time, and this will be an excellent way > to get started. > > Along the way, there are plenty of other projects to attend to: a 4GHz to > 8GHz low noise signal generator using YIG oscillators, a GPSDO to supply an > accurate 10MHz reference, a new method of eliminating the sampling jitter > in the 1PPS signal from the GPDSO, a low noise VCXO to supply a 10MHz > reference from the 1PPS signal, an ultra stable signal generator to allow > sampling of signals up to 150GHz, and so on. > > As there is little else to talk about, I will go silent while I am working > on these projects. > > Bye > > Mike > <MC1670SC.PDF><2N3906G.PNG>_______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe send an email to time-nuts-le...@lists.febo.com _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe send an email to time-nuts-le...@lists.febo.com