Quartzlock E10-GPS Instruction Manual

Model E10-GPS Operation Manual
E10-GPS Manual A5 4 December 2013
Page 1
E10-
GPS Disciplined
Rubidium Frequency Reference
USER’S HANDBOOK
Quartzlock UK Ltd
Gothic, Plymouth Road, Totnes, Devon TQ9 5LH, England.
Tel: [phone] Fax: [phone]
Web: www.quartzlock.com E-mail: [e-mail]

Model E10-GPS Operation Manual
E10-GPS Manual A5 4 December 2013
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Revision
Date
Description
By
1
1st Nov 2013
Initial Release
N. Law

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Contents
1Safety Considerations .............................................................. 4
1.1 General............................................................................ 4
1.1.1 Before Applying Power............................................4
1.1.2 Before Cleaning.......................................................4
1.2 Voltage, Frequency and Power Characteristics............... 4
1.2.1 Universal Full Range AC Input Power Adaptor .......4
1.2.2 Unit Power Requirements........................................5
1.3 Environmental Conditions................................................5
1.3.1 Temperature............................................................5
1.3.2 Magnetic Field......................................................... 5
1.4 Cleaning Instructions ....................................................... 5
2Rubidium Frequency Reference...............................................6
2.1 Rubidium Frequency Reference ......................................6
3Operating Procedure ................................................................8
3.1 Introduction......................................................................8
3.2 Getting Started.................................................................8
4Specification............................................................................. 9
5Unit Outline.............................................................................12
6Accessories ............................................................................12
6.1 Plug Top Supply.............................................................12
7Appendix –Connector, Jumper and Link References ............13

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1 Safety Considerations
1.1 General
This product and related documentation must be reviewed for familiarisation
before operation. If the equipment is used in a manner not specified by the
manufacturer, the protection provided by the instrument may be impaired.
1.1.1 Before Applying Power
Verify that the product is set to match the available charger and the correct
fuse is installed.
1.1.2 Before Cleaning
Disconnect the product from operating power before cleaning.
WARNING
Bodily injury or death may result from failure to heed a
warning. Do not proceed beyond a warning until the
indicated conditions are fully understood and met.
CAUTION
Damage to equipment, or incorrect measurement data,
may result from failure to heed a caution. Do not proceed
beyond a caution until the indicated conditions are fully
understood and met.
1.2 Voltage, Frequency and Power Characteristics
1.2.1 Universal Full Range AC Input Power Adaptor
Class II power (no earth)
Overvoltage, short circuit & over temperature protection
GS, UL/cUL & CE approval
Voltage 100 - 240V AC

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Frequency 50 - 60Hz
Power characteristics 600mA Max
Output Voltage 15V DC 1.2A
1.2.2 Unit Power Requirements
Input Voltage 12Vdc –18Vdc
Input Current 1.7A max
1.3 Environmental Conditions
1.3.1 Temperature
Operating (ambient)
-20oC to +50oC
Charging
0oC to +45oC
Storage
-20oC to +40oC
1.3.2 Magnetic Field
Sensitivity
≤2x10-11/ Gauss
Atmospheric Pressure
-60m to 4000m
<1x10-13/ mbar
1.4 Cleaning Instructions
To ensure long and trouble free operation, keep the unit free from dust and
use care with liquids around the unit.
Be careful not to spill liquids onto the unit. If the unit does get wet, turn the
power off immediately and let the unit dry completely before turning it on
again.
Never spray cleaner directly onto the unit or let liquid run into any part of it.
Never use harsh or caustic products to clean the unit.

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2 Rubidium Frequency Reference
2.1 Rubidium Frequency Reference
A Rubidium frequency reference owes its outstanding accuracy and superb
stability to a unique frequency control mechanism. The resonant transition
frequency of the Rb 87 atom (6,834,682,614 Hz) is used as a reference
against which an OCXO output is compared. The OCXO output is
multiplied to the resonance frequency and is used to drive the microwave
cavity where the atomic transition is detected by Electro-optical means. The
detector is used to lock the OCXO output ensuring its medium and long-
term stability.
The first realised Rubidium frequency reference arose out of the work of
Carpenter (Carpenter et al 1960) and Arditi (Arditi 1960). It was a few years
until the first commercial devices came onto the market and this was
primarily due to the work of Packard and Schwartz who had been strongly
influenced by the work of Arditi a few years before on Alkali atoms (of
which Rb 87 is one). Unlike much of the research done into frequency
references at that time, practical realization of a Rubidium maser was high on
the researchers’ agenda. This was mainly due to an understanding that such a
device would have extremely good short-term stability relative to size and
price. In 1964, Davidovits brought such research to fruition, with the first
operational Rubidium frequency reference.
The Rubidium frequency reference, like its more expensive cousin, the
Hydrogen maser, may be operated either as a passive or as an active device.
The passive Rubidium frequency standard has proved the most useful, as it
may be reduced to the smallest size whilst retaining excellent frequency
stability. The applications for such a device abound in the communication,
space and navigation fields.
The Rubidium frequency reference may be thought of as consisting of a cell
containing the Rubidium in its vapour state, placed into a microwave cavity
resonant at the hyperfine frequency of the ground state. Optical pumping
ensures state selection. The cell contains a buffer gas primarily to inhibit wall
relaxation and Doppler broadening. The Rubidium frequency reference
essentially consists of a voltage controlled crystal oscillator, which is locked
to a highly stable atomic transition in the ground state of the Rb 87 atom.
There are several reasons why Rubidium has an important role to play as a
frequency reference. Perhaps more important is its accuracy and stability.

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Accuracy is comparable with that of the standard Caesium with an operating
life approximately 5 times that of Caesium. Moreover the stability of a
Rubidium frequency reference over short time-scales -100s of seconds-
betters that of Caesium (Caesium is more stable over longer time periods, in
the regions of hours to years).
There are, however, a few drawbacks to the use of Rubidium as a frequency
reference. In the past, these included the limited life of the Rubidium lamp
(since improved to >10 years), The Caesium is affected to a greater degree
than this, whilst the Hydrogen Maser operates differently and is not affected.
The thermal stability of Rubidium is inferior to that of Caesium or Hydrogen
Masers, and the Rubidium previously required frequency access to a primary
reference signal or synchronization source to maintain long-term Caesium
level accuracy.
The cost of a Rubidium frequency reference is significantly cheaper than a
Caesium, with a much reduced size and weight. Due to its small size, low
weight and environmental tolerance the Rubidium frequency reference is
ideal for mobile applications. Indeed, Rubidium atomic clocks are beginning
to be implemented into the new generation of GPS satellites. This is in part
due to the extended life of the Rubidium physics package compared to that
of Caesium. The Rubidium is also extremely quick to reach operational
performance, within 10 minutes reaching 5 parts in 10-11.

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3 Operating Procedure
3.1 Introduction
The basic E10-GPS unit contains three principal internal units:
1) The Rubidium Atomic Frequency Standard.
2) The Internal GPS Chipset.
3) The Associated External Power Supply.
3.2 Getting Started
Check that the appropriate supply voltage is being used. Connect the
external supply to the unit (at the rear) and switch on.
Switch on the unit via the front panel switch, the ‘ON’ indicator LED will
come on and it will remain on.
The 10 MHz output is available from the SMA socket on the unit.
The units’ warm time is approximately 7 minutes. Frequency stabilization
time is up to 15 minutes depending on the detailed specification of the
particular Rubidium fitted.

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4 Specification
1. Accuracy
Disciplined to GPS or to EXT. 1PPS
a. Frequency ≤1E-12 (after disciplined for one day,
24 hours average, 25℃)
b. Time ±100ns (relative to GPS or Ext. input,
25℃)
2. Holdover
a. (no GPS) Frequency ≤5E-12/day
b. Time ≤1μs/24 hours
3. Short Term Stability
a. ≤3E-11@1s
b. ≤1E-11@10s
c. ≤3E-12@100s
4. Phase Noise
a. ＜-100dBc@10Hz
b. ＜-130dBc@100Hz
c. ＜-140dBc@1kHz
5. Harmonics
a. ＜-40dBc
6. Spurious
a. ＜-80dBc
7. Temperature Coefficient
a. ±3E-10 over -20℃～+50℃
8. Time to Lock (@25℃)
a. ＜7 min
9. Earth Magnetic Field Sensitivity
a. ≤2E-11
10. Retrace
a. ≤2E-11
11. Output & Input

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a. Output 1×10MHz Sine wave (7～13)dBm/50Ω SMA
b. 1×1PPS TTL/50Ω SMA
c. PC channel (RS232) for Time & Locality & Other Data
and Frequency Control
d. Input GPS Antenna/50Ω SMA
e. Ext. 1PPS/50Ω BNC
f. Mode of operations
a. Disciplined to GPS
b. Disciplined to external 1PPS
c. Auto Select: first priority to
external 1PPS and second to
internal GPS receiver.
12. Remote Setting
a. Via Serial Port Software for PC Export UTC time.
b. Export the location of the local place, including longitude,
latitude and length.
c. Export the model of the Atomic Oscillator.
d. Export the version number of the software.
e. Adjust the accuracy of 10MHz.
13. Power Supply
a. Input Voltage 12VDC
b. Power Dissipation 22W@ Warm-up, 9W@ Steady
(25℃)
14. Dimensions & weight
a. Dimensions ≤127±0.5×94±0.5×38±0.5
b. Weight <0.6kg
15. Environment
a. Operating Temperature -40℃～+60℃
b. Storage Temperature -40℃～+70℃
c. Humidity ≤90%
16. MTBF
≥100000h
17. Universal Power Adaptor
a. Class II power (no earth)
b. Protection Over voltage, short circuit & over
temperature

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c. Approvals GS, UL/cUL & CE
d. Voltage 100 to 240V AC
e. Frequency 50 to 60Hz
f. Power characteristics 600mA Max
g. Output Voltage 15V DC 1.7A
18. Warm Time
@ 25oC 5 Minutes to lock
19. Retrace
≤2x10-11
20. Magnetic Field Sensitivity
<2x10-11
21. Mechanical
a. Size 103 x 55 x 122 mm
b. Weight 500g
22. Warranty
24 months
23. Temperature
a. Operating -20oC to +50oC
b. Storage -20oC to +40oC
24. Temperature Coefficient
a. Ambient 2x10-10
25. MTBF
100,000 hours
26. Environmental
RoHS
27. EMI
a. Compliant to FCC Part 15 Class B

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5 Unit Outline
6 Accessories
6.1 Plug Top Supply

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7 Appendix –Connector, Jumper and Link
References
J1 (SMA) 10MHz Output
J2 (SMA) 1PPS Output
J3 Pin 1 –+12Vdc
Pin 2 –Ground
Pin 3 –Lock Signal
Pin 4 –1PPS External Input
Pin 5 –Ground
Pin 6 –RS232 TX
Pin 7 –Lock Tag
Pin 8 –1PPS Out GPS
Pin 9 –RS232 RX
J4 (SMA) GPS Antenna