CH1-76 PASSIVE HYDROGEN MASER

The CH1-76 Passive Hydrogen MASER is a frequency standard of a passive type. As in an active MASER the CH1-76 comprises a beam source, a sorting magnet and a storage quartz bulb situated in a cavity and coated with fluoroplastic. The Passive MASER differs from the Active MASER in that an atom medium in a bulb is not self-excited and provides an atom emission
caused by an external signal the frequency of which is nearly equal to the hydrogen atoms emission frequency. Thanks to this the requirements to a cavity quality (Q) are reduced.

APPLICATIONS
• National Timekeeping
• National Frequency Standards
• VLBI
• Navigation
• Telecommunications
• GPS Satellite Monitoring
• Astro Laser Range Finding
• Laboratory Standard
• Astronomy
• Baseline Definition
• Calibration
• Calibration of Caesium or Rubidium and Quartz
• Climatology
• Defense
• Determination or Earth Rotation
• Earthquake Research
• Fast Missile Tracking
• Geodesy
• Geodynamics
• Glacial Movement
• Gravity Prospecting
• Intelligence
• Plate Tectonics
• Position fixing
• Secure Communications
• Space Navigation
• Support of Radar
• Heat Transport

Frequency Outputs  
(2) 5MHz, sine 50Ω, 1±0.2 Vrms
(2) 1Hz pulse (1 pps) 50Ω, >2.5V peak
Pulse Width 10 to 20 μs
Rise Time <30 ns
Jitter <0.1 ns

Clock Synchronization  
Automatic within 200 ns of reference pulse  
Amplitude 2.5 to 5V

Stability (5MHz Outputs)
Avg Time τ(s) Allan Variance σy(2,τ)
1s ≤1.5E-12
10s ≤ 5E-13
100s ≤1.5E-13
1000s ≤ 5E-14
1 hour ≤ 3E-14
1 day ≤ 1E-14

Temp/Freq Coefficient ≤2E-14
Drift ≤1.E-15/day
Accuracy ±1.5E-12/years
Frequency Trim Range 1E-10
Setting Resolution 1E-14
Retrace ≤3E-14 after 24 hrs of op.

Phase Noise (dBc)  
Hz from carrier 5MHz outputs
1 -100
10 -120
100 -140
1000 -150
10000 -150
Spurs  
Harmonics <30 dBc
Non-Harmonics <100 dBc

Power Input - AC 220 Vac, ±10%, 100,120 V±10%,
  240 V+5-10%; 45-65Hz

Power Input - DC (automatic battery back-up)
As an alternative to AC, the CH176 can be powered by
an external 22-30 VDC supply.

Power Consumption (AC) <140 VA
  (DC) <90 watts
Warm-up Time ≤10 hours to lock (typically 6 hrs)
Operating Temp +5 to +35°C
Storage Temp -50°C to +50°C
Magnetic Sensitivity ±2E-14/Gauss
Pressure 630 to 795 mm Hg (84 - 106 kPA)
Humidity Up to 80% at 25°C
Size (HxWxD) 11” x 19” x 22” (28x48x56 cm)
Weight 120 lbs (55kg)
Warranty 1 year (2 - 5 year options)
Service Life 15 years

CH1-76 Passive Hydrogen PDF DOCUMENT