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.
Specifications
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) | 1 s | ≤3.0·10 −13 |
|---|---|---|
| 10 s | ≤3.0·10 −14 | |
| 100 s | ≤7.0·10 −15 | |
| 1000 s | ≤3.0·10 −15 | |
| 1 hour | ≤2.0·10 −15 | |
| 1 day | ≤5.0·10 −15 |
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.
