As promised. I've just tested a handful of 20MHz ceramic resonators with builtin caps. The board I tested it on has two pics, one is connected to the resonator, the other is a slave via a 100 ohm resistor from master's OSCOUT to slave OSCIN. So it's tougher than your usual single PIC setup. The good news is, all the resonators I tested worked, although I would not use some of them as you will see. In case you don't know, these are all overtone resonators. The fundamental (6.666 MHz) is mechanically suppressed so no tank is required. All these resonators are surface mount. Unfortunately there is very little standarization in packaging. Master PIC is a 16F876A set to HS mode. Slave is a 16F877A set to HS mode. Scope probe is a Tektronix 6109B 100MHz x10 of unknown capacitance, probably somewhere around 11 pF. All the resonators are available at Digikey, since they are fast and I have an account there :) Enjoy the results! -Bob Panasonic EFJ-C2005E5B (digikey PA200CCT-ND) 1.0 mm pitch, marked with weird squiggly code $0.41 in 100s Starts and runs If started with scope probe attached runs at fundamental Feedback amplitude lower than output ECS ECS-HFR-20.00-B-TR (digikey XC1094CT-ND) 1.0 mm pitch, easy to read 20.00 $0.42 in 100s Starts and runs If started with scope probe attached runs at fundamental Feedback amplitude lower than output ECS ECS-CR2-20.00-B-TR (digikey XC1109CT-ND) 1.5 mm pitch, marked 20.0M $0.42 in 100s Starts and runs even with scope attached to either lead High and balanced amplitude Panasonic EFO-BM2005E5 (digikey PX200BCT-ND) 1.35 mm pitch, easy to read 20.0 $0.48 in 100s Starts and runs even with scope attached to either lead Very high and balanced amplitude TDK CCR20.0MXC7T (digikey 445-1649-1-ND) 1.0 mm pitch, 20 marked by laser hard to see $0.42 in 100s Starts and runs even with scope attached to either lead High amplitude, higher on feedback Murata CSTCE20M0V53-R0 (digikey 490-1199-1-ND) 1.2 mm pitch, tiny metal package, marked in code E.e. $0.53 in 100s Starts and runs even with scope attached to either lead Very high and balanced amplitude AVX PBRC-20.00HR (digikey 478-2114-1-ND) 2.5 mm pitch, marked 20.00Z $0.62 in 100s Starts and runs even with scope attached to either lead Very high amplitude, higher on feedback -- -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist