2009/1/9 Bruce Griffiths <[email protected]>: > A crystal filter may not be a good choice for phase stability unless an > oven is used. > Some of the older frequency standards used crystal filters within an > oven to cleanup the output signal.
There is the other issue of xtal jumps occuring randomly (?) which could cause rapid phase changes. 73, Steve > The limited crystal dissipation as may raise the phase noise floor of a > low noise OCXO significantly. > The implementation shown in AN9815 is particularly poor in this respect. > > A low Q resonant LC filter using low tempco components will have greater > phase stability. > Whilst obtaining capacitors with relatively low tempcos is relatively > easy, the tempco of most off the shelf inductors is usually unspecified. > > The significance of the increased phase instability and /or raised phase > noise floor depends on the application. > If one is multiplying the output to 10GHz then even minor temperature > fluctuations will be a concern. > > Bruce > > Darrell Robinson wrote: >> If you're simply looking for purity of signal maybe a crystal filter. >> >> Intersil application note AN9815 is interesting. >> >> Darrell >> >> >> ----- Original Message ----- >> From: "Richard W. Solomon" <[email protected]> >> To: <[email protected]> >> Sent: Thursday, January 08, 2009 10:11 AM >> Subject: [time-nuts] 10 MHz Band-Pass Filter Needed >> >> >> >>> The GPSDO I want to use has an output rich in harmonics. In some >>> cases that is good, but Murphy rules and in the application I have >>> today, it is not good. >>> >>> I need a 10 MHz Band-Pass Filter, Bandwidth is not critical, something >>> small with SMA connectors would be ideal, but I can live with BNC. >>> >>> Anyone have such a beast or know where I can get one ? I checked >>> >> Mini-Circuits >> >>> and choked on the price !! >>> >>> Thanks, Dick, W1KSZ >>> >>> _______________________________________________ >>> time-nuts mailing list -- [email protected] >>> To unsubscribe, go to >>> >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> >>> and follow the instructions there. >>> >> >> >> _______________________________________________ >> time-nuts mailing list -- [email protected] >> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. >> >> > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > -- Steve Rooke - ZL3TUV & G8KVD & JAKDTTNW Omnium finis imminet _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
