VCH-2021 is the first successful realization of hydrogen maser with a single state selection system. It demonstrates absolutely record frequency stability for active H-masers.
Best technologies including internal stand-alone Cavity Auto Tuning system are inherited from the previous model VCH-1003M.
New option: optical output with wavelengths 1310 nm and 1550 nm.
Key Applications:
– National Time Keeping Service.
– Deep space tracking and navigation.
– VLBI systems.
– GNSS satellite monitoring.
Factory test results
Specifications
Output signals:
– sine: 5 MHz; 10 MHz, 100 MHz, 1±0.2 V RMS into 50 Ohms;
– pulse: 1 Hz, Amplitude: >2.5 V into 50 Ohms, width: (15±5) µs.
Rise time <2ns, positive polarity;
– optical: wavelengths 1310 nm and 1550 nm, modulated by 100 MHz and 1 Hz signals, respectively; power of optical radiation (0.1-1) mW.
Metrological characteristics are given in the table:
| Averaging time, τ | Frequency stability (Allan deviation) 5 MHz, 10 MHz, 100 MHz | ||
|---|---|---|---|
| Standard | Option L | ||
| 3 Hz measuring bandwidth | 0.5 Hz measuring bandwidth | 3 Hz measuring bandwidth | |
| 1 s | 1.0·10 -13 | 5.0·10 -14 | 7.0·10 -14 |
| 10 s | 1.5·10 -14 | 0.9·10 -14 | 1.0·10 -14 |
| 100 s | 3.0·10 -15 | 2.5·10 -15 | 2.5·10 -15 |
| 1000 s | 1.0·10 -15 * | ||
| 1 hour | 8.0·10 -16 * | ||
| 1 day |
1.0·10
-16
*
(typical value 8.0·10 -17 ) |
||
| * Specified only under laboratory conditions: ambient temperature in the range ±0.1 °С, changing rate <0.3 °C/hour. ADEV at 1 day is specified for measurements with removed linear frequency drift | |||
Frequency drift is no more 2.0·10
-15
per day at release and no more 3.0·10
-16
per day after 1 year of continuous operation.
Temperature sensitivity: ≤1.5·10
-15
/ °C.
Magnetic sensitivity: ≤ 5·10
-15
/Gauss.
Frequency trim range: 1·10
-10
.
Frequency setting resolution: 10
-16
.
Manual synchronization to external 1 PPS TTL signal in the range: ±15 ns.
Phase noise (SSB Phase Noise, dBc/Hz):
| Standard | Option L | |||||
| Offset from carrier | 5 MHz | 10 MHz | 100 MHz | 5 MHz | 10 MHz | 100 MHz |
| 1 Hz | ≤−118 | ≤−112 | ≤−92 | ≤−130 | ≤−121 | ≤−100 |
| 10 Hz | ≤−135 | ≤−129 | ≤−109 | ≤−148 | ≤−135 | ≤−115 |
| 100 Hz | ≤−149 | ≤−143 | ≤−122 | ≤−151 | ≤−145 | ≤−125 |
| 1 kHz | ≤−156 | ≤−149 | ≤−122 | ≤−158 | ≤−150 | ≤−130 |
| 10 kHz | ≤−158 | ≤−153 | ≤−153 | ≤−158 | ≤−153 | ≤−153 |
| 100 kHz | ≤−158 | ≤−153 | ≤−153 | ≤−158 | ≤−153 | ≤−153 |
Harmonic distortion:
≤−40 dBc (for 5 MHz output).
Non-harmonic distortion:
<−100 dBc in the range from 10 Hz to 10 kHz.
Full data monitoring and functions control. Application software running under Microsoft Windows and Linux.
Operating temperature range:
10…30 °C.
Storage temperature range:
−30…50 °C.
Power supply:
AC(85÷264)V, (49÷51)Hz; DC(24÷27)V.
Power consumption:
150 V·A (AC), 100 W (DC).
Weight:
<115 kg.
Weight in shipping container:
<200 kg.
Dimensions (W×H×D):
445×950×625mm.
Warranty:
3 years (7 years extended).
Lifetime:
15 years.
