MHM 2010
The world’s most widely installed active hydrogen maser for applications that require extreme frequency stability, low phase noise and long service life.
The Symmetricom® MHM 2010™ is the world’s most widely installed active hydrogen maser for applications that require extreme frequency stability, low phase noise and long service life. It is the only commercially available active hydrogen maser with stand-alone cavity switching auto tuning manufactured in the USA. This technique enables the MHM 2010 to deliver long-term stability normally only attributed to the most stable of cesium atomic standards.
Hydrogen masers operate on the principal that when hydrogen atoms are provided the proper environment, they emit radiation of a precise frequency (1420 MHz) and spectral line width (21 cm). Phase locking this extremely small power, high purity signal to a very high performance quartz oscillator, provides the user with incredible long-term stability, as well as excellent phase noise.
Active masers are typically 4 times more stable than passive hydrogen masers and 100 times more stable than high performance cesium. Active maser advantages in metrology include superior noise (eliminating the necessity for reference clock noise corrections) and 10,000 times shorter interval to reach a specified frequency stability compared to high performance cesium.
Each MHM 2010 is manufactured to exacting quality standards and carefully checked at each stage to insure a top quality product. Once built, the units are subjected to extensive performance testing, verifying all aspects of operation. All maser product design, manufacturing and testing are conducted at a Symmetricom facility dedicated to these operations.
Auto-Tuning
The MHM 2010 incorporates an automatic frequency control system to maintain the cavity at a constant frequency relative to the hydrogen emission line. This technique enables the MHM 2010 to deliver long-term stability normally only attributed to the most stable of cesium atomic standards.
Environmental Sensitivity
The MHM 2010 is designed to for low sensitivity to temperature, magnetic field and power supply changes.
Outputs
The MHM 2010 provides multiple 5, 10, and 100 MHz outputs and 1PPS. Multiple configurations can be ordered to optimize for varied applications.
Low Phase Noise Output Option
The MHM 2010 can be factory configured with low phase noise outputs that enable higher resolution measurements in VLBI applications.
Low lifetime cost of ownership, maintenance free operation
Lifetime cost of ownership for active masers is a critical consideration. The MHM 2010 is designed for long life and low maintenance. The hydrogen supply is adequate for over 20 years of operation. An efficient hydrogen state selector minimizes the load on ion pumps (< 0.01 mole per year), and the pumps themselves are designed for greater than 20 year life at nominal hydrogen flux. The Teflon bulb coating virtually eliminates any recoating requirement and has a demonstrated life of over 20 years. Should it be required, the MHM 2010 is designed for on-site module replacement.
