Hi,
> On Fri, 23 Oct 2020 19:32:16 -0400 > Bob kb8tq <kb...@n1k.org> 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. 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 -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
