On the Rockmite yahoo group today, Chuck Carpenter, W5USJ posted a very nice explanation of series vs. paralel resonant crystals along with a link to a FAQ on crystal oscillator design at: http://www.foxonline.com/techfaqs_cry.htm#a4 Chuck' post follows: RMers, Here's some info sent to me by Rich at ESS. Chuck, The group that requested 7114 requested it in Series Resonant crystal. Most of the other crystals that I sell are Parallel Resonant. I have included an explanation from Fox Crystal Co. web site. They are not my supplier but the information applies to all crystals and their manufacturers. This should get you where you want to be. The information that everyone needs to know is #6. 4 and 5 will help people make a circuit oscillate where they want it. This is from: http://www.foxonline.com/techfaqs_cry.htm#a4 More information can be found at: http://www.oscilent.com/spec_pages/PNDescrpt/Load_Cap.htm 4. The load capacitance (CL) of my parallel resonant crystal is rated at 20...