Hi John, thanks, I am more interested in the inner workings of the 10 MHz oscillators, and why they are about 10 db shy in phase noise. And yes I have build 100 MHz oscillators with -145 . Thanks , Ulrich In a message dated 12/2/2014 6:29:10 P.M. Eastern Standard Time, john@miles.io writes: NEL has great OCXOs. Also worth checking out Wenzel (they own Croven Crystals and will sell them separately), Rakon, and Vectron. I haven't seen any 100 MHz OCXOs rated for -145 at 100 Hz, but -135 can be had. -- john, KE5FX Miles Design LLC > -----Original Message----- > From: time-nuts [mailto:time-nuts-bounces@febo.com] On Behalf Of Ulrich > Rhode via time-nuts > Sent: Tuesday, December 02, 2014 10:27 AM > To: time-nuts@febo.com > Subject: Re: [time-nuts] 10 MHz oscillators vs 100 MHZ > > Hi from NJ, > > I am more involved in 100 Mhz to 128 MHz crystal oscillators and their > measurements, 10 MHz design is new for me. > > I have analyzed and measured the famous HP 10 MHz SC based oscillator, > disassembled it, admired and measured the crystal. Does anyone still makes > such > a large and good device. Congratulations to the "inventor" of this > oscillator !! > > Looking at 100 MHz oscillators, they have 18 to 20 dBm output and are > advertised at -145 dBc/Hz at 100 Hz offset and - 187 dBc/Hz at 1 MHz, the 10 > MHz > oscillator just gets -165 dBc/Hz far off with NEL looking as the best. > > Who can get me up to speed ? > > Thanks, Ulrich , N1UL