Passive Hydrogen Maser VCH-1008

The VCH-1008 Passive Hydrogen Maser is a compact hydrogen maser with excellent frequency stability and utilises state-of-the-art technology. Full digital processing of the modulation and servo loop signals makes it ideal for high accuracy applications. An internal GPS/GLONASS option is available and provides automatic output signal frequency calibration.

Key applications:
- National Time Keeping Service
- Space tracking and navigation
- Verification of frequency signals
- Scientific research

Output signals:
Sine: 5 MHz; 10 MHz; 100 MHz, (10.2) V RMS into 50 Ω load.
Pulse: 2,048 MHz (square pulse), 1,5÷2,8 V (pp) into 75 Ω (ITU-T G.703 part15).
1Hz; 1/60 Hz, positive polarity pulse, width 100.1 μs, TTL level at 50 Ω, rise time: <10 ns.

Metrological characteristics are given in the table:
Relative frequency accuracy 3×10−13
(factory calibration)
(in option with GPS calibrator)
Output signals frequency corrector resolution
retuning range
Frequency stability
(Allan deviation at 251C, environmental
effects are excluded)
1 s ≤5.0×10−13
10 s ≤2.0×10−13
100 s ≤5.0×10−14
1 hour ≤9.0×10−15
1 day ≤4.0×10−15
Phase noise spectral density (dBc/Hz)
(5 MHz output)
Frequency offset Spectral density (dBc/Hz)
1 Hz ≤−105
10 Hz ≤−130
100 Hz ≤−145
1000 Hz ≤−155
Manual synchronization to external 1 pps
TTL signal accuracy
≤25 ns
Time synchronization to UTC using GPS ≤50 ns (using optional GPS calibrator)
Temperature sensitivity in temperature operating range
(10−35 C)
≤1×10−14 1/C
Magnetic sensitivity ≤2×10−14 1/Oersted

Digital control and monitoring: all operating parameters on local LCD display, or also available remotely.
Interface: RS-232C; USB; LAN.
Power supply: 100240 V AC, 5060 Hz, or 2230 VDC.
Power consumption: 120 VA AC, 100 W DC.
Options: 1. DC power supply 38.457.6 V (two inputs); 2. Built-in battery to prevent temporary power failure; 3. Internal GPS calibrator for automatic calibration.
Dimensions (W×H×D): 470 mm×200 mm×530 mm.
Weight: 33 kg.
Warranty: 3 years.
Life time: 15 years.

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