Hi > On Oct 25, 2020, at 3:43 AM, Bernd Neubig <[email protected]> wrote: > > > > Hi, > >> On Fri, 23 Oct 2020 19:32:16 -0400 >> Bob kb8tq <[email protected]> wrote: >> Those authors pretty much only focus on *oscillator* design. ( = >> electronics). >> Bottom is a “crystal guy”. He focuses pretty much only on how to chop up a >> chunk of quartz to get this or that result ( = frequency, temp coef, size, Q >> ). >> Very different areas of interest and not a lot of “crossing over” between >> them. >> So no, it you are looking to come up with an addition to your oscillator >> design library, go looking for a copy of one of Dr Rhode’s books rather than >> one by Bottom. > > Virgil E. Bottom's book "Introduction to Quartz Crystal Unit Design" does > contain more than this. It includes a bunch of information about often > unknown characteristics of quartz crystals, which are not covered by "pure" > oscillator designers, who often look only on the main resonance mode > parameters in their design, which they consider as ideal. Maybe also the > (other) overtones and the unwanted B-mode for SC-cut crystals are considered. > Beyond that Bottom is covering such things like an-harmonic spurious modes, > coupled modes and activity dips,. These "unwanted" characteristics come into > play in practice as surprising and unexplained failures in the field. > In the numerous failure analyses I have done, activity dips and drive level > dependence are the most frequent causes of field failure. And I regularly > have to teach the customers what this is. > His 1982 book also covers SC-cut crystals with their main characteristics. > > I agree that Bottom is primarily a "crystal guy". But it is very advantageous > for oscillator designers to know more about crystal than just the > four-element BVD equivalent electrical schematic. > And to learn that its behavior is more complex than these four idealized > linear parameters can show.
Which is why Motorola decided all us “oscillator guys” needed to go to the course …. Bob > > This is the lesson I want to teach as a physicist AND electronics engineer > after 44 years in the crystal & oscillator business. > > Regards > Bernd > > > > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
