Thanks all. So sounds like for my app....DTMF generator, resonator ought to work just fine. Bob Axtell wrote:Ceramic resonators are my preferred design standard. They are less accurate than crystals, but they have MANY advantages: 1. Stability has improved dramatically in recent years. Sealing the resonator will solve most long-term drift effects. Ceramic resonators are affected by moisture (as are crystals, but crystals are inherently sealed well). Usually a simple semi-hard plastic coating after mounting on the PCB will prevent long-term drift. 2. Incredible ability to handle physical shock. That's why NO TV remote control uses a crystal- only ceramic resonators. 3. Easy to startup, impossible to accidentally oscillate at an overtone. Just install it and forget it. The 3-pin types contain their phase-shift caps builtin. No reason to EVER buy 2-pin unless you plan to replace a crystal. --Bob alan smith wrote: >Since I have always used crytals or oscillators, I don't know alot about the ceramic resonators. First, whats the difference between the 3 pin and 2 pin devices. Second, for a colorburst frequency are they as stable as a crystal? certainly appears cheaper. > > > > >--------------------------------- > Yahoo! FareChase - Search multiple travel sites in one click. > > -- Note: To protect our network, attachments must be sent to attach@engineer.cotse.net . 1-520-777-7606 USA/Canada http://beam.to/azengineer -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist --------------------------------- Yahoo! FareChase - Search multiple travel sites in one click. -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist