Topics: H-maser, Active Hydrogen Maser, Passive Hydrogen Maser, Allan Deviation, Frequency Stability, 3-Cornered Hat

Three masers

Here's the first results of comparisons among three masers.

Stability out to 10,000 seconds - active to passive

Comparator: TSC 5110A S/N 036 upper lab
(ch A) ST = Sigma Tau Active Hydrogen Maser MHM-2010 S/N 208
(ch B) PHM = KVARZ CH1-76 Passive Hydrogen Maser

TSC5110A plot: ST to PHM after 60k seconds (17 hours)

Stability out to 10,000 seconds - active to active

Comparator: TSC 5110A S/N 006 lower lab
(ch A) AHM = KVARZ CH1-75 Active Hydrogen Maser
(ch B) ST = Sigma Tau Active Hydrogen Maser MHM-2010 S/N 208

TSC5110A plot: AHM to ST after 60k seconds (17 hours)

Short-term noise

At the same scale (5E-13/div) note AHM short-term noise is a fraction of PHM:

Comparison with other frequency standards