The VCH-1025 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/BEIDOU 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.
Specifications
Output signals
Sine: 5 MHz; 10 MHz; 100 MHz, (1±0.2) V RMS into 50 Ω load.
Pulse: 2,048 MHz (square pulse), 1,5÷2,8 V (amp) into 75 Ω (ITU-T G.703 part15);
1Hz (1pps out); positive polarity pulse, width 100±0.01; 10±0.01; 1±0.01; 0.1±0.01 μs, TTL level at 50 Ω, rise time: <10 ns, jitter ≤1ns rms.
Input signals
1 Hz (synch in), pulse width 100 ns min to 100 μs max, rise time ≤ 50 ns.
Metrological characteristics are given in the table:
|
Frequency stability (Allan deviation)
5 MHz, 10 MHz, 100 MHz |
Averaging time, τ | 0.5 Hz measuring bandwidth |
|---|---|---|
| 1 s | ≤2.0·10 −13 | |
| 10 s | ≤7.0·10 −14 | |
| 100 s | ≤2.5·10 −14 | |
| 1000 s | ≤7.0·10 −15 | |
| 1 hour | ≤4.0·10 −15 | |
| 1 day | ≤8.0·10 −16 * | |
| The stated frequency stability values are guaranteed only when the ambient temperature changes within ±0.1 °C, in the operating temperature range, with a temperature change rate of no more than 0.3 °C/hour, no earlier than 30 days after switching on the device. *The value of frequency stability over the averaging time interval of 1 day is given taking into account the exclusion of linear frequency drift. | ||
| Relative frequency accuracy | ±2·10 –13 (factory calibration) | ±1·10 –13 (in option with GPS calibrator) |
| Output signals frequency corrector |
resolution
tuning range |
1·10
−15
1·10 −10 |
| 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 | |
| 10000 Hz | ≤−155 | |
| Frequency drift | ≤2.0·10 -15 (per day at release) | ≤1.0·10 -15 (per day after 1 year of continuous operation) |
| Time synchronization to UTC using GPS/GLONASS/BEIDOU | ≤50 ns (in GPS/GLONASS/BEIDOU option) | |
| Temperature sensitivity in temperature operating range (5−40 C°) | ≤5·10 −15 1/C° | |
Digital control and monitoring:
all operating parameters available remotely (Windows/Linux).
Interface:
RS-232C; USB; LAN.
Power supply:
AC(100÷240)V, (50÷60)Hz; DC(22÷30)V.
Power consumption:
100 V·A (AC), 100 W (DC).
Options:
Internal GPS/GLONASS/BEIDOU calibrator for automatic calibration.
Dimensions (W×H×D):
483 mm×200 mm×550 mm.
Weight:
33 kg.
Warranty:
3 years (10 years extended).
Life time:
15 years.
