Active On-Board Hydrogen Maser for Radioastron Space Mission VCH-1010
VCH-1010 is an on-board hydrogen frequency standard designed to provide a highly stable reference signal for the space telescope of the Space–Ground Radio Interferometer during radio astronomy research.
The device generates a stable 1 pulse per second (1 PPS) signal throughout the "RadioAstron" mission.
The output of the device is also used for the excitation of a carrier frequency of 15 GHz for high informational radio channel (VIRK) transmitter, which is also a phase-stable channel for measuring parameters of the On-Board Hydrogen Maser.
Output signals nominal values: 1 Hz, 5 MHz, 15 MHz
Relative frequency accuracy ±3×10−13 (with periodic adjustments by Astro Space Center of PN Lebedev Physics Institute)
|Frequency stability 5 MHz (Allan deviation for
5 MHz signal)
at ±1 °C ambient temperature change in operating temperature range and temperature change rate of no more than 0,3° C/hour
Long term frequency stability <±2,0·10–14/day
Temperature sensitivity(ambient temperature changes within ± 1°C) <±5,0·10–15
Power supply sensitivity (changes within ±1 V) <±2,0·10–14
Magnetic field sensitivity(changes within ±1 Gs) <±2,0·10–14
Harmonic distortion in 5 MHz and 15 MHz output signals, less than - 30 dB
Non-Harmonic distortion in 5 MHz and 15 MHz output signals, less than −100 dB for <100kHz carrier offset
SSB phase noise spectral density, no more than
| (10±3) Hz || −120 dB/Hz |
| 100 Hz±10 % || −140 dB/Hz |
| 1 kHz±10 % || −145 dB/Hz |
| 10 kHz±10 % || −150 dB/Hz |
In terms of resistance special factors the Hydrogen Maser meets the requirements of section 3.3 of the general technical requirements to scientific equipment of the spacecraft "Spektr-R".
Dimensions: ∅460×729 mm.
Weight: 60 kg.