Oven-controlled crystal oscillators (OCXOs) developed by NEL Frequency Controls deliver ultra-low phase noise in a dual-frequency reference model (DFRM). The O-CDFXYZXX-X-X-10MHz/100MHz DRFM consists of a 10- and a 100-MHz OCXO, both of which are packaged in hermetically sealed metal cans. The 100-MHz unit is phase/frequency-locked to the 10-MHz OCXO. The 10-MHz unit offers strong frequency stability over temperature (from 2 ppb peak to peak), time (aging from 0.25/ppb per day), supply, and load variations. The 100-MHz OCXO provides ultra-low phase noise on the noise floor, along with high output power. Phase noise equivalents include: 115 dBc/Hz at 1-Hz offset; 145 dBc/Hz at 10-Hz offset for 10 MHz; 125 dBc/Hz at 10-Hz offset; and 180 dBc/Hz at 100 kHz for 100 MHz. Applications include instrumentation, high-performance synthesizers, radar, and telecom equipment.