DESCRIPTION

The CH1-76A Passive Hydrogen Maser is designed to operate as a high-stability frequency source with precise, spectrally pure 5 MHz output.

The CH1-76A is the first in the world Time and Frequency Hydrogen Maser of a passive type. Its principle of operation is based on hydrogen atom emission, but hydrogen atoms emit only by the action of an external signal from a crystal oscillator. The quantum device is used as a frequency discriminator in an automatic frequency tuning system of a crystal oscillator.

APPLICATIONS

National time and frequency services, ground control and surveillance points of satellite radionavigation systems, transportable clocks, a reference standard for verification of other standards and oscillators and for scientific research.

SPECIFICATIONS

Frequency Outputs: 5 MHz (sine), 1±0.2 V rms into 50 OhmTiming Output: 1 Hz (pulse)

Amplitude: ³2.5 V into 50 Ohm

Width: 10–20 ms

Rise time: <30 ns

Jitter: <0.1 ns

Frequency stability (Allan Deviation):

Averaging time	σ(τ)
	Specifications	Typical Values
1 s	≤1.5´10–12	≤4.8´10-13
10 s	≤5´10–13	≤1.5´10–13
102 s	≤2´10–13	≤4.5´10–14
103 s	≤5´10–14	≤1.5´10–14
1 h	≤3 ´10–14	≤8.5 ´10–15
1 day	≤1´10–14	≤4´10–15

Drift (Aging): <3´10–15/day

Accuracy: ±1.2´10–12/year

Temperature sensitivity: ≤2 ´10–14/ °C

Magnetic field sensitivity: ±2.10–14/Gauss

Frequency trim range: 1´10–10

Setting resolution: 1´10–14 Steps

Phase noise:

Offset from carrier	SSB phase noise, dBc/Hz
10 Hz	–110
100 Hz	–125
1 kHz	–150
10 kHz	–150

Harmonic distortion: < 30 dB

Non-harmonic distortion: < 100 dB

GENERAL

Power: 220±22 V, 50±1 Hz, 220±11 V, 115±6 V, 400 Hz

At power line failure the Instrument automatically switches to an external 22–30 V DC Power Supply

Power consumption: 140 VA, 90 W

Operating temperature range: 5–40 °C

Storage temperature range: –50–+50 °C

Humidity: up to 80 % at 25 °C

Size: (H ´W ´D) 28.0 ´48.0 x 55.5 cm

Weight: 51 kg

Service Life: 12 years