Herbert P. Stratemeyer – A Pioneer in Quartz and Atomic Frequency Standards 1931-2001
The frequency control community lost one of its pioneers in the field of quartz oscillators and rubidium atomic clocks when Herbert P. Stratemeyer died on November 20, 2001. Herb was born in 1931 in Mainz, Germany. Although too young to have participated actively in World War II, he nevertheless suffered along with the rest of the civilian population in its later days and aftermath. He received a Diplom Physik degree from the University of Mainz in 1954. During that time, he participated in early single sideband amateur radio experiments with Art Collins and others.
Herb began his career in frequency control in the quartz crystal industry in England. In 1954 he immigrated to the United States to accept a position as a Development Engineer at the General Radio Company in Cambridge Massachusetts. At that time, General Radio was the leading manufacturer of electronic instruments. He worked on quartz frequency standards and quartz crystals for filter applications. His first solid-state oscillator, the Model 1115, set new performance standards for low phase noise. Herb Stratemeyer became a U.S. citizen in 1962.
In the early 1960’s, Herb’s work turned to atomic clocks, specifically rubidium atomic frequency standards that were just becoming commercially available. Much basic investigation was necessary to develop these devices into practical products, and to devise the processes necessary for manufacturing their lamps and cells. His other contributions included work on frequency synthesizers and quartz crystal measuring systems.
The emphasis on rubidium frequency standards at General Radio soon shifted to military and space units. One such device was the NASA Spacecraft Atomic Timing System (SATS), which was the first rubidium clock developed and qualified for space. Another was the physics package for the Collins AFS-81 ruggedized rubidium frequency standard (RFS) used for many years by the U.S. Navy in the Verdin VLF communications system. Other projects included RFS designs for missile and tactical aircraft applications. Preliminary work was also done on rubidium clocks for the GPS program. Many of those units had performance equal to or better than most such devices today (although they were much larger and more expensive). In particular, the work at General Radio led to the eventual development of the ultra-stable rubidium clocks used in the Block IIR and IIF GPS satellites. Herb retired from General Radio (then GenRad) in 1975, but continued to consult in the field of atomic clocks at EG&G in the early 1980’s. During his retirement, he became a computer “guru” in the 1980’s and 1990’s. His other interests included gunsmithing, hunting and photography.
Herb was an active participant in the frequency control community, regularly attending the Frequency Control Symposium during the Atlantic City era, and contributing to the watershed 1964 IEEE-NASA Symposium on Short-Term Frequency Stability. He was also a loyal IRE/IEEE member.
Throughout his career, Herb was a mentor to the next generation of “clock engineers”, sharing both his knowledge and work ethic. Herb was an “engineer’s engineer”, displaying exceptional technical judgment and keen insight directed toward making things work. He was a man of great intellect with many talents who excelled in whatever he did. He was also a man of great professional and personal integrity who had a positive influence on all the people and programs he worked with. Those of us whose lives he touched will miss him greatly.