Hi John, Andy Talbot G4JNT developed the a Jupiter based GPSDO for just this purpose, several are used by hill-toppers in the UK. http://www.scrbg.org/g4jnt/freqlock.htm The idea was that it would settle and be accurate in the time it took to seet up the microwave part of the station.
I hope that helps/ Alan G3NYK ----- Original Message ----- From: "John Ackermann N8UR" <[EMAIL PROTECTED]> To: "Discussion of precise time and frequency measurement" <[email protected]> Sent: Tuesday, December 11, 2007 8:56 PM Subject: Re: [time-nuts] need recomendation for a portable 10mhz reference oscilator > Hal Murray wrote: > > I'm picturing an open hill top at night with clear skies so there would be > > lots of radiation cooling. Of course, with an open hill top, GPS recption > > would be easy. > > As great as GPSDO are, the problem with using them in a portable > environment is the time it takes to do a survey and then get to final > lock; mountain-toppers may not be in one place long enough. > > One thought I've had is to use a cheap Rubidium for long term stability, > and phase lock a good OCXO to it for short term stability and phase > noise (ie, use a loop time constant of perhaps 100 seconds). That would > make a portable package that would meet both the short and long term > stability requirements. > > John > > _______________________________________________ > 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.
