Pendulum GPS-12, GPS-12R, GPS-12RG, GPS-12R/HS User Manual

GPS-12, GPS-12R, GPS-12R/HS &
GPS-12RG

GPS & GLONASS / GPS
Frequency Standard

s

User’s Manual

II

4031

600 12001

Rev. 05 May 2017

© 2017 Pendulum Instruments / Altaria Services

.

Table of Contents

GENERAL INFORMATION ..........IV

1 Preface

Introduction .................1-2

2 Preparation for Use

Safety Instructions ............2-2

Introduction ......................2-2

Safety Precautions ................2-2

Unpacking ...................2-3

Unpacking Instructions .............2-3

Installation ..................2-4

Supply Voltage ...................2-4

Power Switch ....................2-4

Orientation and Cooling ............2-5

Fold-down Support ................2-5

Rackmount Adapter ...............2-5

Antenna Installation ...............2-7

Connecting to a PC ................2-7

Disposal of Hazardous Material . 2-8

3 Using the Controls

Front Panel ......................3-2

Rear Panel ......................3-3

Functional Description .............3-4

User Interface ....................3-4

4 GPS-12 Monitor

What is GPS-12 Monitor? ...........4-2

Requirements ....................4-2

Versions ........................4-2

Installation ......................4-2

Main Features ....................4-2

5 Performance Check

General Information ...............5-2

Preparations .....................5-2

Front Panel Controls ...............5-3

Front Panel Outputs ...............5-3

Rear Panel I/O ...................5-3

6 Preventive Maintenance

Calibration .......................6-2

Fan Replacement .................6-3

Battery Replacement ..............6-3

7 Specifications

Stability .........................7-2

Options .........................7-4

Ordering Information ...............7-8

8 Appendix

Antenna Installation ...............8-2

9 Index

10 Service

Sales and Service Offices .........10-II

III

GENERAL INFORMATION

Warranty

The Warranty Statement is part of the folder Important Information that is included with the

shipment.

Declaration of Conformity

The complete text with formal statements concerning product identification, manufacturer and
standards used for type testing is available on request.

Convention of Notation

Mostinformationinthismanualiscommontoallmodels. When the type number is used as a refer

­ence to any of them, the designation GPS-12X has been chosen for the sake of simplicity. Otherwise
the device is referred to with its proper type number, e.g. GPS-12 or GPS-12RG. Sometimes two
type numbers are combined, e.g. GPS-12(R) means GPS-12 and GPS-12R.

Figures illustrating the menu screens are generic. Where necessary, clarifying remarks or additional
figures have been included.

GNSS stands for Global Navigational Satellite System and is an acronym that refers to all satel­lite-based navigational systems. In this manual it means either GPS or GLONASS and is, for exam­ple, used in the graphical user interface whenever reference to a particular system is not necessary.

Front Panel Design

The picture illustrating the front panel in Chapter 3 shows the GPS-12, which is the latest addition
to this product family, now consisting of three models. During a transition period the other models
will be delivered with their present front panels. The two different designs are shown below for in

­formative reasons.

IV

ENTER

!

!

2.048MHz OUT
±1.2VIN 75W

1PPS OUTPUT

TTL

GPS-12 RUBIDIUM FREQUENCY STANDARDR

GPS-12R & GPS-12RG.

GPS-12

Chapter 1

Preface

Introduction

Cesium-controlled
Frequency via Satellites

The GPS-controlled frequency standards
GPS-12(R) and the GLONASS/GPS-c on

­trolled frequency standard GPS-12RG deliver a
precision frequency and time reference every

­where in the world. They gain their long-term
frequency stability from Cesium standards in
the navigation satellite systems GPS and
GLONASS. They are also designed to provide
very high short-term stability and are cost-effi

­cient and extremely accurate frequency
standards.

These reference sources are very suitable as fre­quency standards in the telecommunication and
electronics industry. They fit both as stationary
frequency references - for instance in test sys­tems and as local references in the design depart­ment - and as portable, highly accurate reference
sources for field use.

These instruments are off-air frequency stan

­dards with an internal architecture according to
Figure 1-1. They have one antenna input and a
number of optional frequency outputs.

There is also an option for disciplining with an
external 1 pps source, e.g. an in-house cesium
standard.

Optional I/O Boards

The GPS-12X comes as standard with two

2.048/1.544 MHz square wave outputs and one
1 pps pulse output with approx. 10 µs duration.
TheGPS-12RGhasalso3x10MHzand
1x5MHzoutputs.SeeOption70Bbelow.
There are six options to choose from, options
70B, 71B, 72B, 73B, 74B and 79/01. All but the
79/01 allow for four extra frequency outputs to
be mounted. Any combination of none, one or
two of these units is possible. Only one
79/01can be mounted.

Option70Bgives3x10MHzand1x5MHz
sine wave outputs, 1 V

RMS

in 50 W.The
GPS-12RG is as standard equipped with one
such option.

Option 71B gives four sine wave outputs,
1V

RMS

in 50 W, of resp. 10 MHz, 5 MHz, 1

MHz and 0.1 MHz.

Option 72B gives 2 x 2.048 MHz clock outputs,
±1.2 V square wave in 75 W,plus
2 x 2.048 Mbps data outputs (G.703:10), for
telecommunication testing and clock synchro

-

nization.

Option 73B gives 4 x 13 MHz square wave out

-

puts with TTL levels in 50 W.

Option 74B gives 2 x 1.544 MHz plus
2 x 1.544 Mbps outputs for SONET
applications.

Option 79/01 gives 2 x 10 MHz sine
wave outputs, 1 V

RMS

in 50 W,plus
1 x 1 pps output, TTL levels in 50 W,
plus 1 x 1 pps disciplining input, TTL
levels.

1-2

Preface

Satellite

Receiver

Refererence Ou

t

Phase

Comparator

Local

Oscillator

(VCO)

Figure 1-1 Simplified block diagram of the GPS-12X.

Reference Oscillators

The GPS-12 is equipped with an oven-con

­trolled crystal oscillator (OCXO), the GPS-12R
has a standard rubidium oscillator, and the
GPS-12R/HS has a high-stability, low phase
noise rubidium oscillator. The GPS-12RG is
also equipped with the latter oscillator.

Two Operating Modes

The disciplined mode is the default mode. It
eliminates long-term frequency drift, also
called aging. As long as there is a valid satellite
signal, the local rubidium oscillator is continu

­ously adjusted to minimize the deviation from
the satellite-derived reference signal.

The hold-over mode is entered either automati­cally, if the satellite contact is lost, or manually.
The automatic adjustment is replaced by the
normal aging characteristics of the rubidium
oscillator.

The manual hold-over mode is mainly intended
for the hopefully rare occasions when the satel­lite contact is sporadic, causing unacceptable
mode switching interference.

Portability

BymeansofOption78orOption78/HS,anin

­ternal rechargeable battery unit, it is possible to
maintain stability during transportation, as the
internal reference oscillator is continuously
powered.

Field use without access to AC line power is
also practicable.

Option 78/HS has the additional feature of ac

­ceptinganexternal12V

DC

supply. Thus it is
possible to realize a true uninterruptible power
supply (UPS), as the DC source and the AC
source can be applied simultaneously. The AC
source takes precedence, as long as it is present,
and so does the external DC supply over the in

-

ternal battery, which is kept charged by one of
the external sources.

In case of a power line failure you will benefit
from double security, if you utilize an external
DC source in addition to the AC supply.

Stationary Use

Option 77 makes it possible to apply -48 V

DC

as an alternative to the standard AC line volt

-

age, thus allowing permanent use as local fre

-

quency standard in telephone exchange sta

-

tions. AC line voltage and -48 V

DC

can be ap

­plied at the same time in order to realize a true
uninterruptible power supply (UPS).

Overall Accuracy

The cesium standards of the satellites are con­trolled by primary frequency standards like the
US Naval Observatory, and ultimately to all na­tional standards (e.g. NIST, NPL, PTB, SP
etc.).

1-3

Preface

This page is intentionally left blank.

1-4

Preface

Chapter 2

Preparation for Use

Safety Instructions

Introduction

Read this chapter carefully before you install
and use the instrument.

This instrument has been designed and tested
for Measurement Category I, Pollution Degree
2, in accordance with EN/IEC 61010-1:2001
and CAN/CSA-C22.2 No. 61010-1-04 (includ

­ing approval). It has been supplied in a safe
condition. The user of this instrument must
have sufficient knowledge of it. This knowl

­edge can be gained by thoroughly studying this

manual, especially the sections on Safety Pre-

cautions and Installation in this chapter.

This instrument is designed to be used by
trained personnel only. Removal of the cover
forrepairorrack-mountingoftheinstrument
must be done by qualified personnel who are
aware of the hazards involved. There are no
user-serviceable parts inside the instrument.

Safety Precautions

All equipment that can be connected to line
power is a potential danger to life. Handling re

­strictions imposed on such equipment should

be observed.

To ensure the correct and safe operation of this
instrument, it is essential that you follow gener

­ally accepted safety procedures in addition to
the safety precautions specified in this manual.

The warranty c ommitme nts are rendered
void if unauthorized access to the interior of
the instrument has taken place during the

given warranty period.

Caution and Warning
Statements

CAUTION: Shows where incorrect

procedures can cause damage to,
or destruction of equipment or
other property.

WARNING: Shows a potential danger

that requires correct procedures or
practices to prevent personal in

-

jury.

Symbols

Shows where the protective ground
terminal is connected inside the instru­ment. Never remove or loosen this

screw .

This symbol is used for identifying the
functional ground of an I/O signal. It is
always connected to the instrument

chassis.

Indicates that the operator should con

-

sult the manual.

If in Doubt about Safety

Whenever you suspect that it is unsafe to use
the instrument, you must make it inoperative by
doing as follows:

–

Disconnect the line cord.

–

Clearly mark the instrument to prevent its
further operation.

–

Inform your local Pendulum Service Center.

For example, the instrument is likely to be un

-

safe if it is visibly damaged.

2-2 Introduction

Preparation for Use

Unpacking

Unpacking
Instructions

Check that the shipment is complete and that no
damage has occurred during transportation. If
the contents are incomplete or damaged, file a
claim with the carrier immediately. Also notify
your local Pendulum sales or service office in
case repair or replacement may be required.

Check List

The shipment should contain the following:

–

The frequency standard.

–

A line cord.

– A CD with PDF manuals for Pendulum

products, e.g. this manual.

–

If you ordered one or two of the output
options (70B, 71B, 72B, 73B, 74B), or the
disciplining option (79/01), or one of the
DC supply options (77, 78, 78/HS), they
should already be installed. See “Identifi

-

cation” below.

Note 1: The GPS-12R/HS and the

GPS-12RG are as standard
equipped with one Option 70B.

–

If you ordered one of the DC supply op

­tions (77, 78/HS), a three-pole power
D-sub socket connector is included that
mates with the corresponding rear panel
pin connector. It is intended for making a
wire harness suitable for linking the instru

-

ment to an external DC power source.

–

Other options you ordered, e.g. antenna
(option 01), antenna cable (option 02),
rack mount kit (option 22) or carrying

case (option 27/27H) are shipped in sepa

-

rate boxes.

–

Certificate of Calibration.

Identification

Options installed inside the cover are identified
on the rear panel according to the list below. Up
to two output boards in any combination can be
fitted at the same time. The combined I/O board
Option 79/01 is an exception. Only one such
board can be fitted. However, it can be com

-

bined with any other output board.

Option 70B: 4 BNC-connectors mounted in the
area designated.

Option 71B: 4 BNC-connectors mounted in the
area designated.

Option 72B: 4 BNC-connectors mounted in the
area designated.

Option 73B: 4 BNC-connectors mounted in the
area designated.

Option 74B: 4 BNC-connectors mounted in the
area designated.

Option 77: -48 V

DC

power supply & rear panel

power D-sub connector.

Option 78: Internal 16 V

DC

rechargeable bat

-

tery for GPS-12(R)

Option 78/HS: Internal 16 V

DC

rechargeable
battery & rear panel power D-sub connector for
ext. 12 V

DC

source. Intended for GPS-12R/HS

and GPS-12RG.

Option 79/01: 4 BNC-connectors mounted in
the area designated.

2-3 Unpacking Instructions

Preparation for Use

Installation

Supply Voltage

Setting

The GPS-12X frequency standard can be con

­nected to any AC supply with a voltage rating
of 90 to 265 V

rms

, 45 to 440 Hz. The frequency

standard automatically adjusts itself to the in

­put line voltage.

Depending on option chosen, the unit can also
be supplied by external DC sources, -48 V or
+12 V.

Fuse

The secondary supply voltages are electroni­cally protected against overload or short cir­cuit. The primary line voltage side is protected
by a fuse located on the power supply unit. The
fuse rating covers the full voltage range. Con­sequently there is no need for the user to re­place the fuse under any operating conditions,

nor is it accessible from the outside.

CAUTION: If this fuse is blown, it is

likely that the power supply is
badly damaged. do not

replace the
fuse. Send the frequency standard
to the local Pendulum Service Cen

-

ter.

Grounding

Grounding faults in the line voltage
supply will make any instrument con

-

nected to it dangerous. Before con

­necting any unit to the power line, you must
make sure that the protective ground functions

correctly. Only then can a unit be connected to
the power line and only by using a three-wire
line cord. No other method of grounding is per

­mitted. Extension cords must always have a
protective ground conductor.

WARNING: If a unit is moved from a

cold to a warm environment, con

­densation may cause a shock
hazard. Ensure, therefore, that the
grounding requirements are strictly
met.

WARNING: Never interrupt the

grounding cord. Any interruption
of the protective ground connec­tion inside or outside the
instrument or disconnection of the
protective ground terminal is likely
to make the instrument dangerous.

Power Switch

This instrument is equipped with a secondary
power switch. It disconnects the main
power-consuming circuits on the secondary
side of the power supply but leaves the rubid

­ium oscillator active in order to retain its
long-term characteristics. Line voltage is al

­ways present on the primary side.

WARNING: Always consider the in

­strument active as soon as it is
connected to the primary AC
power source with a power cord.

2-4 Supply Voltage

Preparation for Use

Orientation and
Cooling

The frequency standard can be operated in any
position desired. Make sure the air flow
through the ventilation slots are not obstructed.
Leave 50 mm (2 in) of space around the
instrument.

CAUTION: Never cover the ventila

­tion slots at the right or left side. If
the slots are covered, the fre

-

quency standard will overheat.

Fan Control

The speed-controlled fan is used for adjusting
the temperature inside the frequency standard
to compensate for variations in ambient tem­perature.

Fold-down Support

For bench-top use, a fold-down support is
available for use underneath the frequency
standard. This support can also be used as a
handle to carry the instrument.

Rackmount
Adapter

If you have ordered a 19 inch rack mount kit for
your instrument, it has to be assembled after de

­livery of the instrument. The rack mount kit
consists of the following:

2 brackets, (short, left; long, right)
4screws,M5x8
4screws,M6x8

WARNING: When you remove the

cover you will expose live parts
and accessible terminals which
can cause death.

2-5 Orientation and Cooling

Preparation for Use

Figure 2-1 Air flow through the GPS-12X.

Figure 2-2 Fold-down support for comfort

-

able bench-top use.

Figure 2-3 Dimensions for rackmounting

hardware.

WARNING: Capacitors inside the in

­strument can hold their charge
even if the instrument has been
separated from all voltage sources.

Assembling the Rackmount
Kit

–

Make sure the power cord is disconnected
from the instrument.

–

Turn the instrument upside down.
See Figure 2-4.

–

Undo the two screws (A) and remove
them from the cover.

–

Remove the rear feet by undoing the two
screws (B).

–

Remove the four decorative plugs (C) that
cover the screw holes on the right and left
side of the front panel.

–

Grip the front panel and gently push at the
rear.

–

Pull the instrument out of the cover.

–

Remove the four feet from the cover.

Use a screwdriver as shown in the following il

­lustration or a pair of pliers to remove the
springs holding each foot, then push out the
feet.

–

Push the instrument back into the cover.
See Figure 2-4.

–

Mount the two rear feet with the screws
(B) to the rear panel.

–

Put the two screws (A) back.

–

Fasten the brackets at the left and right
side with the screws included as illustrated
in Figure 2-6.

–

Fasten the instrument in the rack via
screws in the four rack-mounting holes

The long bracket has an opening so that cables
for Input A, B, and C can be routed inside the
rack.

n

Reversing the Rackmount Kit

The instrument may also be mounted to the
right in the rack. To do so, swap the position of
the two brackets.

2-6 Rackmount Adapter

Preparation for Use

Figure 2-4 Remove the screws and push

the frequency standard out of
the cover.

Figure 2-5 Removing the feet from the

cover.

Figure 2-6 Fitting the rackmount brackets

on the counter.

Antenna
Installation

The antenna (option 01), is intended for out

­door mounting on a wall or preferably on a
roof. The more free sky that is visible from the
antenna’s position, the better the satellite con

­tact. There is an antenna mounting kit (Option
01/50) available for this purpose.

The antenna cable is a 20 m (Option 02) or
50 m (Option 02/50), or 130 m (Option 02/130)
high quality RG213 cable that connects at one
end to the antenna and at the other end to the
rear panel of the frequency standard. For instal

­lation details and instructions on connecting
other antennas/cables than those supplied by
Pendulum, please consult the Appendix in this
manual.

ConnectingtoaPC

A PC can be connected to the USB port at the
rear of the instrument for firmware download
or communication with the optional SW pack

­age GPS-12 Monitor. A suitable cable should
have one USB-A connector (for the PC) and
one USB-B connector -for the GPS-12X.

The procedure is described in the service man

­ual, as only trained personnel should do FW up

­grades. Erroneous handling of the instrument
before and during the download may damage
the memory contents and prohibit the comple

­tion of the loading process.

2-7 Antenna Installation

Preparation for Use

Disposal of Hazardous Material

The basic instrument and all optional units ex

-

cept Option 78 and Option 78/HS have no bat

­teries or other parts containing hazardous
amounts of substances that require special at

­tention or handling instructions.

Option 78 and Option 78/HS contain a re

­chargeable NiMH battery pack that serves the
purpose of providing uninterruptible power to
the instrument. As all batteries, it has a finite
lifetime. Although NiMH-based cells are by far
less detrimental to the environment than their
NiCd-based predecessors, we strongly recom­mend to dispose of them by controlled recy­cling.

CAUTION: Make sure the battery

pack is recycled according to local
regulations.

2-8 Connecting to a PC

Preparation for Use

Chapter 3

Using the Controls

Front Panel

3-2 Front Panel

LCD display with backlight forming the
User Interface (UI) together with the
CURSOR and ENTER keys to the right.

The default messages inform the user about
Control Mode (Disciplined or Hold-over),
Satellite Status, Alarm, Power Source, User
Options and Time/Position.

POWER ON / STANDBY

key. A secondary power
switch that ligths up the red
LED above the key in standby
mode.

The CURSOR keys (with arrow symbols)
are used for moving the cursor, marked by
text inversion, around the menus on the
display. By pressing the ENTER key you
either confirm a choice or enter a submenu.
Back one step by pressing the LEFT AR

-

ROW key.

BNC Reference Output Connectors
2 x 2.048 MHz* + 1 x 1 pps / 10 MHz** or
2x1.544MHz*+1x1pps/10MHz**

* The choice is made in the User Options
submenu.

** Only newer HW versions have the
10 MHz alternative. The choice is made in
the User Options submenu.

Optional outputs can be found on the rear
panel.

Rear Panel

3-3 Rear Panel

Using the Controls

! !

! ! !

!

!

!

!

2.048 MHz OUT

2.048 MHz OUT

2.048 MHz OUT

2.048 MHz OUT

2.048 Mbps OUT

2.048 Mbps OUT

2.048 Mbps OUT

2.048 Mbps OUT

-48VDC

GPS ANTENNA IN

:

USB

;

191125

ALARM

GND

+12VDC

Antenna cable input
(N-contact)

Power input
90-265 V,
45-440 Hz

USB port for firm­ware download
from PC

Optional Outputs

Option 70B: sine wave
3x10MHz+1x5MHz

Option 71B: sine wave
1x10MHz+1x5MHz+1x1MHz+
1x0.1MHz

Option 72B: square wave
2 x 2.048 MHz +2 x 2.048 Mbps

Option 73B: square wave 4 x 13 MHz

Option 74B: square wave
2 x 1.544 MHz + 2 x 1.544 Mbps

Option 79/01: 1 x 1 pps disciplining input
+ 1 x 1 pps output + 2 x 10 MHz
low-noise outputs

Two relay-con­trolled alarm
loops, one for
urgent and one
for non-urgent
situations.

See page 3-6
for pin config

-

uration.

Optional
external DC
power inputs

Fan with automatic
speed control

Functional
Description

The GPS-12X series of frequency standards is
continuously disciplined by control signals
from satellites belonging to the GPS
[GPS-12(R)] or the GLONASS/GPS
[GPS-12RG] navigation satellite systems. The
signals have very low long-term uncertainty
(5*10

-13

per 24h), and are traceable to different
national standards for time and frequency at,
for instance, the National Institute of Standards
and Technology (NIST) via the US Naval Of

­fice (USNO). The GPS-12X contains a satellite
receiver module, generating a stable 1 pps sig

­nal, plus a local voltage-controlled rubidium or
crystal oscillator (OCXO) and a high resolution
measurement kernel that is continuously
phase-comparing the received satellite signal
and the local oscillator. This means that the lo­cal oscillator is continuously monitored and ad­justed.

The GPS-12X can operate in two different
modes. Either the local oscillator is free-run­ning with a frequency offset that increases with
time, due to aging, or the results of the phase
comparisons are used for adjusting the local os

-

cillator, thereby compensating for aging. These
two modes are called:

–

Hold-over mode (free-running local oscil

-

lator)

–

Disciplined mode (monitored and adjusted
local oscillators)

Disciplined mode is the default mode.
Hold-over mode is automatically entered when
the disciplining fails for some reason (e.g. loss
of satellite contact). Hold-over mode can also
be forced via the User Interface (UI). When the
satellite contact is lost, the GPS-12X can not be
continuously controlled (intercompared with
the satellite reference clocks in real time) and
reverts temporarily to hold-over mode specifi

-

cations.

User Interface

General Principles

The UI is straightforward. All interaction be­tween operator and instrument takes place by
navigating a cursor (marked by text inversion)
on the LCD through a set of text-based menus.
The navigating tools are just four arrow keys,

UP ( p ), DOWN ( q ), LEFT ( t ),
RIGHT ( u ), and one ENTER key. The differ

-

ent menus are described in the fol

-

lowing paragraphs.

Default Menu

This is the menu entered at start-up
and shows the current instrument sta

­tus. Here RB-osc is selected, and to
the right you can find one of the fol

­lowing short informative texts:

•

Warming up

•

Unlocked

•

Hold-over

3-4 Functional Description

Using the Controls

Satellite

Receiver

2.048 MHz Output

s

To PC (USB)

PLL-Controlled

Frequency Reference Oscillator

(Rubidium or OCXO)

1 PPS

1 PPS Output

Output Opt.

Other Frequencies

Output Opt.

User Interface (UI)

(Front Panel Keyboard & Display)

Microprocessor

&

Memory

I/O Option

1 PPS Input

1 PPS Output

10 MHz Output

Figure 3-1. The internal high-stability oscillator of the

GPS-12X is continuously compared with
and controlled by the satellite receiver.

•

Manual Hold-over

•

Disciplined by GNSS

•

Disciplined by Ext. Ref.

*

The normal end message after the transitory
start-up phase, which usually lasts less than 20
minutes, is Disciplined by GNSS.Thenweas

-

sume that the antenna installation has been per

-

formed according to given instructions. If Op

-

tion 79/01 is installed, and the instrument is dis

­ciplined by an external 1 pps reference source,
then the message is Disciplined by Ext. Ref.

Oscillator Menu

By pressing u you will enter the Osc submenu,
indicated by the corresponding label at the top
left corner:

n

Mode

Here you can change the operational mode of
the oscillator. If you want to return to the de

­fault menu, press t. By pressing ENTER or u
you will be able to select the mode. Use p or
q, and confirm your choice by returning to the
previous screen. Press t.

n

1 pps Offset (GPS12R/HS &

GPS-12RG

Here you can set the time offset of the 1 pps
output signal that is available on the front
panel. The range is ±999 ns.

GNSS Menu

Moving the cursor to GNSS in the default menu
will bring you to the GNSS submenu after
pressing ENTER or u.

Here you can see your current position and how
many satellites that you are locked to. You can
also adjust the antenna delay. The GPS-12RG
has three operational modes. See the screen be­low that appears when you enter the Mode
menu. Select the mode that gives the best per­formance at your location.

If you want to see a list of all locked satellites
and their status you should move the cursor to
Locked to andthenpressENTER or u.The
menu below will be activated.

n

Antenna Delay (not GPS-12RG)

In order to compensate for the signal delay in

-

troduced by the antenna and its connecting ca

-

ble, the 1 pps reference signal from the GPS re

-

3-5 User Interface

Using the Controls

*

Available only if Option 79/01 is installed.

ceiver can be shifted in time from this menu. If
you don’t know the exact delay, assume an
approximate value of 5 ns/m as a rule of thumb.

Alarm Menu

In this menu y ou can watch and manage the
alarm log. You can also set up the alarm behav

-

ior.

Scroll through the log entries by selecting Log.
Then press ENTER or u.

If you press ENTER or u once more, you are
given the opportunity to erase the log entries.

In the alarm Setup menu you can choose among
a number of alarm sources and decide their
alarm level, i.e. urgent, non-urgent,orno
alarm.

n

Alarm Outputs

Two relay-controlled alarm loops, one for ur

­gent and one for non-urgent situations, are
available via a D-sub connector on the rear
panel. The normally closed (NC) contacts will
open when the respective alarm criteria are
met. Figure 3-2 shows the pin configuration.

Power Source Menu

In this menu you can see what power options
are installed and the current status of those op­tions.

Note: When the unit is about to enter

Standby mode, and the battery op

­tion is installed, the screen below will
appear.

Only one of the alternative DC power supply
units, Option 77, Option 78 or Option 78/HS,
can be installed. All of them can serve as UPS
devices, i.e. you can have external (Option 77)
or internal (Option 78 and Option 78/HS) bat

-

tery backup for the AC supply. Option 77 and

3-6 User Interface

Using the Controls

ALARM LEVEL CIRCUIT (NC)

URGENT Pins 8-9

NON-URGENT Pins 1-6

Figure 3-2 Alarm connector pin

configuration.

Option 78/HS allow external DC voltage feed
instead of the standard AC line power feed.

User Options

From this submenu you can configure miscella

­neous settings and obtain important data on the
instrument and its options.

Note: The sign q at the bottom left corner

indicates that additional information
can be displayed by scrolling.

n

Language

The instrument UI is prepared for different lan­guage modules that can be downloaded over
the USB port. The standard module comprises
the following languages:

•

English

•

German (Deutsch)

•

French (Français)

•

Spanish (Español)

•

Turkish (Türkçe)

•

Russian (CJFF846)

There is also a module available containing
Chinese and Japanese. English can always be
chosen, irrespective of the active language
module.

n

Display Contrast

The adjustment range is 0-100 %. The optimum
value depends on the angle of view from which
the display is observed.

n

Time Format

The following formats are currently available:

•

YYYY-MM-DD

•

YYYY/MM/DD

•

YY-MM-DD

•

YY/MM/DD

•

DD-MM-YYYY

•

DD/MM/YYYY

•

DD-MM-YY

•

DD/MM/YY

•

MM/DD/YYYY

n

Time Zone

Here you can enter the local time zone to adjust
the clock display. The increment is 0.5 h.

n

Front Panel Outputs

Switch between 2.048 MHz and 1.544 MHz.

n

About

Information about the instrument, e.g. installed
options and firmware version.

3-7 User Interface

Using the Controls

This page is intentionally left blank.

3-8 User Interface

Using the Controls

Chapter 4

GPS-12 Monitor

What is GPS-12
Monitor?

GPS-12 Monitor is an optional software pack

-

age allowing full remote control and monitor

­ing of the instrument from a PC over the
USB-B connector on the rear panel.

Requirements

Hardware

CPU 1 GHz, RAM 256 MB, HD free space
10 MB if Microsoft.NET Framework installed,
else 500 MB, USB interface V 1.0 or later, ca

­ble with USB-A connector at one end and
USB-B connector at the other.

Software

Operating system: Win 2K, XP, Vista, Win7; 32
or 64 bit.

Libraries: Microsoft.NET Framework V 2.0 or
later.

Versions

Emulator

By downloading the unregistered version from
our website www.pendulum-instruments.com
you can get acquainted with the basic features
of the instrument without having the actual
hardware.

The emulator mode offers the operator the op

­portunity to choose among a number of differ

­ent setups. The monitor screen mirrors the real
front panel, so you can operate the virtual in

­strument with the PC mouse just about the same
way as you press the key s on the real instru

­ment.

User

If you want to be able to control the GPS-12X
remotely, you have to buy a license key t hat
opens up all the features of the monitor pro

­gram. You don’t have to download and install
another version of the software. See License
Registration below.

Installation

Open the downloaded installation file and fol

­low the on-screen instructions given by the in

­stallation wizard.

n

Prerequisites

The installer checks the PC for the operating
system and the service packs necessary to in­stall the application. It also looks for other nec­essary programs and verifies your user rights.
Any shortcomings are reported. Make sure
your PC meets the requirements under Software
above before starting the installer.

n

License Registration

GPS-12 Monitor is a proprietary application
program, so in order to use all features it must
be registered by means of a license key entered
under the Help menu. After entering a correct
license key, the program will be restarted auto

­matically in order to recognize and apply the
changes.

Main Features

•

Collecting and presenting device
data.

•

Setting up device parameters.

•

Taking snapshots of the device
screen.

•

Uploading firmware and language
packs.

4-2 What is GPS-12 Monitor?

GPS-12 Monitor

•

Checking for updates.

Collecting and Presenting
Device Data

n

User Mode

GPS-12 Monitor collects and displays data
from the GPS-12X. Normally the libraries in

­cluded in the operating system are enough to
run the application. Several instruments can be
connected simultaneously for easy selection,
but only one at a time can be operated from the
application. Switching between local mode and
remote mode is done by toggling the green
power key on the monitor screen. Remote
mode is indicated by an inverted R at the top
right corner of the display.

n

Emulator Mode

This mode, selected under Tools,ismainlyin-
tended for demonstration purposes, as no hard­ware of any kind is necessary. It allows evalua­tion of different options, for instance, and is in­dicated by an inverted E at the top left corner of
the display. Use the form under Tools ®Emula

­tor ® Options for selection of options.

Setting Up Device
Parameters

Properties and parameters that can be adjusted
are grouped in a number of forms named after
the headings on the display, e.g. Alarm options.
Mark the different properties and make the nec

­essary changes. Confirm the complete form by
pressing OK or discard all changes by pressing
Cancel.

Some forms, e.g. GPS / GNSS options, require
that you press the Edit button on the toolbar to
enter Edit mode.PressEdit again to return and
OK to confirm the new values.

Taking Snapshots of the
Device Screen

If you are in local mode and want to save the
current screen contents as a bitmap picture file,
then you can start GPS-12 Monitor and go to
Tools ® Snapshot to catch the moment. Select
a suitable file format and save the file.

Uploading Firmware and
Language Packs

The firmware is the main program of the instru

­ment, and the language packs are resource files
containing strings for menus and values in a
number of languages. These files are resident in
a Flash EPROM and can be updated when
newer versions are available. Go to Tools
®Loader. Find the new downloaded hex files
and upload them one at a time by pressing
Open. Follow the instructions on the screen.

Note 1: During uploading you must not

switch off the instrument or close the
application, until the loader reports
that it is ready.

Note 2: If running on battery, make sure it is

fully loaded before starting the
uploading.

Checking for Updates

GPS-12 Monitor is designed to check for newer
application software automatically at intervals
decided by the user. Go toTools ® Options
®Updates to set a value between 1 and 30
days. You can also check for updates manually
whenever you want by going to Help ® Check
for updates.

4-3 Main Features

GPS-12 Monitor

This page is intentionally left blank.

4-4 Main Features

GPS-12 Monitor

Chapter 5

P erf ormance Check

General
Information

WARNING: Before turning on the in

­strument, ensure that it has been
installed in accordance with the In

­stallation Instructions outlined in
Chapter 1 of the User’s Manual.

This performance procedure is intended for in

-

coming inspection to determine the acceptabil

-

ity of newly purchased instruments, or when

-

ever a quick test is convenient.

Note: The procedure does not check every

facet of the instrument. It is con

­cerned primarily with those parts of
the instrument which are essential for
determining the function of the instru­ment.

Note: This GNSS-controlled Frequency

Reference does not need to be sent
away for frequency calibration. The
instrument is continuously monitored
and adjusted by means of the GNSS
signal, as long as there is sufficient
satellite contact, and the active oper­ating mode is not

Hold-over.

It is not necessary to remove the instrument
cover to perform this procedure.

Recommended Test
Equipment

–

DSO with 50 W input

–

Pendulum CNT-90 timer/counter

–

A calibrated 1, 5 or 10 MHz reference
source with at least rubidium characteris

-

tics.

The GPS-controlled Pendulum GPS-89 or
Fluke 910R is a suitable choice, as it can
also be used for the calibration procedure
described in Chapter 5, Preventive Mainte

-

nance.

Preparations

Connect the antenna, including cable, to the an

-

tenna input (rear). Make sure the antenna posi

-

tion is satisfactory .

Power-On Test

Connect the AC power cord to the instrument
and the line power outlet. The instrument shall
automatically enter Operating mode, indicated
by the following characteristics:

•

The display backlight shall be lit.

•

The default screen shall be visible.

«

Note the message Warming Up
on the first line.

•

The Standby LED shall not be lit.

•

The fan shall start.

Wait until the instrument shows the messages

Disciplined by GNSS and Locked to X satel­lites, where X>2. It will normally take less than

20 minutes.

Press the Power/Standby key to see if the in­strument enters Standby mode, indicated by the
following characteristics:

•

The red Standby LED shall be lit.

•

The display shall go out.

•

The fan shall stop.

•

The rubidium oscillator is still pow

-

ered.

The state of the rubidium oscillator can not be
observed directly, but when you power up the
instrument again to proceed with the perfor

-

mance check, you can see from the accompany

­ing display message that the Wa rmi n g U p phase
is very short. Consequently the startup process
will be accelerated accordingly.

Power up your instrument at least 30 minutes
before continuing. This will allow the instru

­ment to reach normal operating temperature

5-2 General Information

Performance Check

andgointoDisciplined by GNSS mode with ad

-

equate margins.

Front Panel
Controls

Keyboard Test

1

Make sure the default menu is visible. See
page 3-4. Check that the cursor (marked by
text inversion) can be moved upwards and
downwards with the UP/DOWN arrows,
and that you can enter submenus with the
RIGHT ARROW key and return from the

submenu with the LEFT ARROW key.

2

Select Osc and press ENTER twice. Make
sure you see the screen below:

3

Return to the default menu by pressing the
LEFT ARROW key twice.

Front Panel
Outputs

Connect the reference frequency source to the
EXT REF input on the rear panel of the CNT-90
counter and recall the default settings.

2.048 / 1.544 MHz

Select 2.048 MHz via User Options and follow
the test directions below. Then select

1.544 MHz and repeat the test:

–

Connect a DSO with 75 W inputs to both
the 2.048 / 1.544 MHz outputs, one at a
time.

–

Verify that the signal is a square wave,
and that the low level is -1.2 V ± 10 %
and the high level +1.2 V ± 10 %.

–

Connect the counter and verify that the
frequency is:

2.048 / 1.544 MHz ± 0.002 Hz.

1pps/10MHz

The default value is 1 pps but can be changed to
10 MHz under the menu User Options on the
start screen. See note.

n

1pps

Connect a DSO with 50 W inputs to the output.
Verify that the signal is a rectangular pulse train
with a pulse width of approx. 10, 100 or 133 µs,
depending on the oscillator option,and that the
low level is <0.9V and the high level >1.8V.
Connect the counter and verify that the fre­quency is 1Hz ± 1 µHz.

n

10 MHz

Use the same test setup as above. Select
10 MHz under User Options. The pulse width
should now be approx. 50 ns and the frequency
10 MHz ± 0.01 Hz.

Note: Only newer HW versions have the

10 MHz alternative.

Rear Panel I/O

Option 70B

(3 x 10 MHz & 1 x 5 MHz)

Connect a DSO with 50 W inputs to all BNC
connectors, one at a time. Verify that the four
output signals are sinusoidal and that the volt

­age is at least 1 Vrms. Connect the counter and
verify that the frequency is 10 MHz ± 0.01 Hz
resp. 5 MHz ± 0.005 Hz.

5-3 Front Panel Controls

Performance Check

Option 71B

(0.1 & 1 & 5 & 10 MHz)

Connect a DSO with 50 W inputs to all BNC
connectors, one at a time. Verify that the four
output signals are sinusoidal and that the volt

­age is at least 1Vrms. Connect the counter and
verify that the frequency is 10 MHz ± 0.01 Hz,
5 MHz ± 0.005 Hz, 1 MHz ± 0.001 Hz and 0.1
MHz ± 0.0001 Hz respectively.

Option 72B

(2 x 2.048 MHz & 2 x 2.048 Mbps)

Connect a DSO with 75 W inputs to all BNC
connectors, one at a time. Verify that the output
signal is a rectangular pulse train with an ampli

­tude of ±1.2 V ± 0.12V. Connect the counter
and verify that the frequency at the two clock
outputs is 2.048 MHz ± 0.002 Hz. The ampli­tude at the two data outputs can be checked in
the same way. For a quick check of the validity
of the encoded HDB-3 data, do like this:

–

Connect the data outputs, one at a time, to
Input A on the counter and measure ac­cording to the procedure below.

–

Recall the default settings and make these
alterations in the INPUT A menu:

–

DC coupling

–

50 W input impedance

–

Trig 75 %

–

Select MEAS FUNC ®Period ®

Single ® A

–

Select STATistics.

The result should be the clock period time mul

­tiplied by four, i.e. 4 x 488 = 1952 ± 2 ns
Standard Deviation s <1ns

Option 73B

(4 x 13 MHz)

Connect a DSO with 50 W inputs to all BNC
connectors, one at a time. Verify that the signal
is a square wave, and that the low level is
<0.9 V and the high level >1.8 V. Connect the
counter and verify that the frequency is
13 MHz ± 0.013 Hz.

Option 74B

(2 x 1.544 MHz & 2 x 1.544 Mbps)

Connect a DSO with 75 W inputs to all BNC
connectors, one at a time. Verify that the output
signal is a rectangular pulse train with an ampli

­tude of ±1.2 V ± 0.12V. Connect the counter
and verify that the frequency at the two clock
outputs is 1.544 MHz ± 0.0015 Hz. The ampli­tude at the two data outputs can be checked in
the same way. For a quick check of the validity
of the encoded HDB-3 data, do like this:

–

Connect the data outputs, one at a time, to
Input A on the counter and measure ac­cording to the procedure below.

–

Recall the default settings and make these
alterations in the INPUT A menu:

–

DC coupling

–

50 W input impedance

–

Trig 75 %

–

Select MEAS FUNC ®Period ®

Single ® A

–

Select STATistics.

The result should be the clock period time mul

­tiplied by four, i.e. 4 x 648 = 2592 ± 2 ns
Standard Deviation s <1ns

Option 77

(-48 VDCfrom ext. source)

–

Disconnect the line power cord.

5-4 Rear Panel I/O

Performance Check

–

Connect 48 VDCto the power D-sub con

­nector with the plus pole to the ground pin
and the minus pole to the pin marked

-48VDC. Use the mating D-sub socket
connector that is included with the
instrument.

–

Check that the instrument behaves in the
same way as when it is connected to line
power only.

–

Reconnect the line power cord, and dis

-

connect the 48 V source temporarily.

–

Check that the instrument behaves nor

-

mally.

–

Reconnect the 48 V source while the in

-

strument is still operating off line power.

–

Check that the instrument behaves nor

-

mally.

–

Disconnect the line power cord and check
that the instrument continues to work
without interruption (UPS function).

Option 78 & Option 78/HS

(Int. battery backup & ext. 12 VDC)

–

Connect the instrument to line power and
press the Power/Standby button to enter
Standby mode. The red LED above the
button shall light up.

–

Let the internal battery charge for 3 hours.
Then it will reach about 80 % of its capac

-

ity.

Note: It will take another 21 hours for the

battery to reach full capacity if it was
completely discharged from the be

-

ginning.

–

Disconnect the power cord and switch on
the instrument.

–

Check that the instrument behaves nor

-

mally and is operative for about 90 min

-

utes.

n

Option 78/HS only

–

Connect 12 VDCto the power D-sub con

­nector with the minus pole to the ground
pin and the plus pole to the pin marked
+12VDC. Use the mating D-sub socket
connector that is included with the instru

­ment.

–

Check that the instrument behaves in the
same way as when it is connected to line
power only.

–

Let the internal battery charge for about
half an hour.

–

Disconnect the 12 V source.

–

Check that the instrument continues to
work without interruption (UPS function).

n

Both Options

–

Reconnect the line power cord.

–

Check that the instrument behaves nor­mally.

–

Let the internal battery charge for about
half an hour.

–

Disconnect the line power cord and check
that the instrument continues to work
without interruption (UPS function).

Option 79/01

(1 x 1 pps in & 1 x 1 pps out &
2 x 10 MHz out)

n

1ppsIn

–

Disconnect the GPS antenna.

–

Connect a stable 1 pps TTL source to the
1 pps input on the option board.

–

Select External 1 pps from the Osc
submenu on the front panel.

–

Return to the main menu.

5-5 Rear Panel I/O

Performance Check

–

Wait until the instrument shows the
message Disciplined by 1 pps. It will nor

-

mally take less than 20 minutes.

n

1 pps Out

The 1 pps output can be tested in the same way
as the 1 pps front panel output. See above.

n

10 MHz Out

The two 10 MHz outputs can be tested in the
same way as Option 71B. See above.

Alarm Output

–

Make sure the instrument is in Standby
Mode.

–

Measure the resistance between pin 8 and
pin 9 on the D-SUB alarm connector.
Expected result: open circuit (near infin­ity)

–

Measure the resistance between pin 1 and
pin 6 on the D-SUB alarm connector.
Expected result: open circuit (near infin­ity)

–

Switch on the instrument.

–

Measure the resistance between pin 8 and
pin 9 on the D-SUB alarm connector.
Expected result: closed circuit (near zero)

–

Measure the resistance between pin 1 and
pin 6 on the D-SUB alarm connector.
Expected result: closed circuit (near zero)

5-6 Rear Panel I/O

Performance Check

Chapter 6

Preventive

Maintenance

Calibration

Calibration and adjustment in the traditional
sense are not necessary as long as the instru

­ment is operating in disciplined mode. Then the
internal rubidium timebase is continuously
monitored and forced to follow the cesium
clocks of the navigational satellites. These
clocks are traceable to, for instance, NIST and
USNO. Thus the normal aging characteristics
of the internal timebase will be concealed.

However, if the device is operating in hold-over
mode for long periods, the aging characteristics
are no longer concealed. Then you may need to
reset the timebase from time to time by letting
the device operate in disciplined mode for at
least 48 hours. See also next paragraph.

n

Calibration Intervals

Normally it is quite adequate to check the fre­quency deviation between one of the reference
outputs and a corresponding, independent, ce­sium-controlled reference source once a year,
using the procedure described below. Shorter
intervals may be necessary if the main operat­ing mode is hold-over, and the allowed devia-
tion is less than the specified annual aging. See
the timebase specifications to collect the data
for these calculations.

n

Equipment

–

The DUT (Device Under Test).

–

Timer/Counter Pendulum CNT-90.

–

A GPS-controlled reference frequency
source capable of generating both 2.048
MHz and alternatively 1, 5 or 10 MHz at
an amplitude between 0.1 and 5 V

rms

in

50 W. It should also have a traceable cali

­bration history. The Pendulum GPS-89
with Option 72 is apt to the task.

–

BNC cables of suitable lenghts.

Note: There are several ways to perform

this checkup, depending on available
equipment. The setup and procedure
described in the next paragraphs are
based on the list above.

n

Setup

–

Connect the reference source (1, 5 or
10 MHz) to the EXT REF input on the
counter.

–

Connect one of the 2.048 MHz outputs on
the front panel of the DUT to Input A on
the counter.

–

Connect the 2.048 MHz reference source
to Input B on the counter.

–

Find a good antenna position, and connect
the antenna to the DUT. Power up the
DUT and the reference source at least 24
hours before starting the verification pro­cedure. Make sure the GPS contact is es­tablished and the system is working within
15 minutes after the DUT was switched
on.

–

Power up the timer/counter at least one
hour before starting the verification proce­dure.

n

Procedure

Note: Each key depression is not described

here. See the Operators Manual for
the timer/counter if you need more
information.

–

Recall the default settings of the counter.

–

Set the trigger level to Man 0.0 V on both
Input A and Input B.

–

Set the measuring time to 10 s.

–

Check that the frequency is 2.048 MHz ±

0.01 Hz.

–

Change measurement function to Time In

-

terval A to B.

6-2 Calibration

Preventive Maintenance

–

Set Number of Samples to 2, Pacing Time
to 100 s and Pacing to ON in the SET

-

TINGS menu.

–

Select STAT (statistics) and HOLD.

–

Press RESTART.

–

Wait for the measurement to finish after
100 s (marked by HOLD appearing at
the upper right corner of the display).
Check that Max and Min are both posi

­tive. Otherwise press RESTART again to
repeat the measurement.

–

Note the P-P value that equals the abso

­lute difference between the maximum and
the minimum time interval error value
(D

TIE

), and calculate the equivalent rela

­tive frequency deviation
Df=D

TIE

/ 100.

Acceptance criterion

Df calculated according to the expression above
should be less than2x10

-12

.

–

Change the DUT mode to Manual
Hold-over.

–

Press RESTART and note the intermediate
result for sample #1, i.e. before the mea­surement ends after 100 s.

–

Wait 24 h.

–

Press RESTART and note the intermediate
result for sample #1, i.e. before the mea

-

surement ends after 100 s.

–

Calculate the absolute difference between
the two results (D

TIE

).

–

Calculate Df=D

TIE

/ 86400.

Acceptance criterion

Df calculated according to the expression above
should be less than5x10

-12

.

Fan Replacement

If your frequency reference is operating
24h/day, you need to replace the fan every 5
years to maintain high reliability. For part-time
applications and low ambient temperatures, an
extended service interval is acceptable.

Fan replacement requires no special tools
(screwdrivers only). The part number of the re

-

placement fan is 4031 105 02850.

Battery
Replacement

There are no batteries in the basic instrument.

Option 78 and Option 78/HS have a NiMH bat­tery pack that is specially adapted to its pur­pose. It must not be replaced by anything else
but the original part, the order number of which
is 4031 100 67190.

Replacement is recommended when the battery
operating time falls short of one hour, provided
the battery pack has been charged in standby
mode for at least 24 hours.

Dispose of the old battery pack according to lo

-

cal recycling regulations. See also page 2-8.

6-3 Fan Replacement

Preventive Maintenance

This page is intentionally left blank.

6-4 Battery Replacement

Preventive Maintenance

Chapter 7

Specifica tions

Stability

0.1, 1,5&10MHzOutputs

n

Locked to GNSS

7-2 Stability

Specifications

Allan dev. @ 20-26 °C

1

OCXO Standard Rb HS Rb

2

(t = 24 h) <5×10

-12

<2×10

-12

<1×10

-12

(t = 100 s) <2×10

-11

<5×10

-12

<3×10

-12

(t=10 s) <2×10

-11

<1×10

-11

<1×10

-11

(t=1 s) <2×10

-11

<2×10

-11

<2×10

-11

Phase noise dBc/Hz

(offset) 1 Hz <-90 <-75 <-85

10 Hz <-120 <-95 <-125

100 Hz <-130 <-125 <-135

1 kHz <-140 <-140 <-145

10 kHz <-140 <-140 <-145

100 kHz <-140 <-140 <-145

Warm-uptolock(@+25°C) N.A. 8min 11min

Warm-up (@ +25 °C) 15 min to 5×10

-8

12minto5×10

-10

13minto1×10

-9

n

Hold-Over

1 pps Output

Note 1: Allan deviation data given for both

GNSS mode and hold-over mode ap

-

plies after ³72 h of continuous opera

-

tion.

Note 2: The GPS-12R/HS also includes the

low noise output Option 70B in order
to make its extraordinary characteris

-

tics available to the user.

Note 3: Long-term frequency stability data

given for hold-over mode applies af

­ter a 30-day settling period, during
which the oscillator has been operat

-

ing continuously.

Note 4: After ³72 h of continuous operation.

Note 5: Locked to GNSS.

Note 6: Position Hold.

7-3 Stability

Specifications

OCXO Standard Rb HS Rb

2

Aging/month

3

<1.5×10

-9

<5×10

-11

<5×10

-11

Aging/year

3

<1×10

-8

<2×10

-10

<5×10

-10

Temp. (0 °C... +50 °C) <2×10

-9

<2×10

-10

<1×10

-10

Allan dev. @ 20-26 °C

1

(t = 100 s) <2×10

-11

<5×10

-12

<3×10

-12

(t=10 s) <2×10

-11

<1×10

-11

<1×10

-11

(t=1 s) <2×10

-11

<2×10

-11

<2×10

-11

OCXO Standard Rb HS Rb

2

Jitter4rel. to UTC5or GPS

6

<1 ns rms <1 ns rms <1 ns rms

Accuracy

4

vs. UTC

5

±120 ns ±120 ns -5 to +45 ns

Hold-over drift per 24 h
(within ±2 °C)

<20µs <1µs <1µs

Standard Reference Outputs

Connector
type:
Frequency #1:

Output level:

Freq. stability:
Jitter:

Frequency #2:

Output level:

Pulse width:

Freq. stability:

3 x BNC on the front panel
2x2.048MHzalt.
2x1.544MHz
(user selectable)
Square wave ±1.2 V ± 10 %
in 75 W (G.703:10)
See Note 1 on page 7-7
See table on p. 7-3
1 x 1 pps / 10 Mpps
(user selectable)
Appr. 0 V … 5 V unloaded
Appr. 0 V … 2.0 V in 50 W
Appr. 10 µs
(1 pps & GPS-12R/HS or
GPS-12RG)
Appr. 133 µs
(1 pps & GPS-12R)
Appr. 100 µs
(1 pps & GPS-12)
Appr. 50 ns (10 Mpps)
See Note 1 on page 7-7

Alarm Outputs

Connector
type:

Signal coding:

Max. switching
voltage:
Max. switching
current:

9-p male D-Sub, 1 loop for
urgent alarm, 1 loop for
non-urgent alarm
relay open ® alarm mode
relay closed ® normal mode

60 V

DC

200 mA

Options

Option 70B Outputs*

Connector
type:
Frequencies:
Output level:
Freq. stability:

BNC
3x10MHz+1x5MHz
Sine wave >1 V

RMS

in 50 W

See Note 1 on page 7-7

Option 71B Outputs

Connector
type:
Frequencies:
Output level:
Freq. stability:

BNC
10, 5, 1 and 0.1 MHz
Sine wave >1 V

RMS

in 50 W

See Note 1 on page 7-7

*Note: The GPS-12R/HS and the

GPS-12RG are as standard
equipped with one Option 70B.

Option 72B Outputs

Connector
type:
Frequencies:

2.048 MHz
Output level:

Freq. stability:
Jitter:

2.048 Mbps:

BNC
2x2.048MHz+
2 x 2.048 Mbps

Square wave ±1.2 V ± 10 %
in 75 W (G.703:10)
See Note 1 on page 7-7
<0.01 UI
(G.703)

7-4 Options

Specifications

Option 73B Outputs

(not GPS-12RG)

Connector
type:
Frequencies:
Output level:

Freq. stability:
Jitter:

BNC
4x13MHz
Square wave TTL in 50 W
(See also Note 2 on
page 7-7)
See Note 1 on page 7-7
<0.01 UI

Option 74B Outputs

Connector
type:
Frequencies:

1.544 MHz
Output level:

Freq. stability:
Jitter:

1.544 Mbps:

BNC
2x1.544MHz+
2 x 1.544 Mbps

Square wave ±1.2 V ± 10%
in 75W (G.703:10)
See Note 1 on page 7-7
<0.01 UI
(G.703)

Option 77

n

External DC Supply (-48 VDC)

Connector
type:
Voltage:

3-pin power D-sub

-48 V

DC

±10%

Option 78 & Option 78/HS

n

Internal Backup Battery

Battery type:
Operation time:

Standby time:
Lo bat alarm:
Charging time:
External DC
Supply:*

Connector
type:

NiMH, 16.8 V, 2.3 Ah
(Bat. loaded to 100 %)
>2 h

1

or >3 h

2

>2.5 h3or >5 h

4

When 5-10 min left
3hto80%ofcapacity

11.3-18V/5-2.1A
Inlet protected against
overvoltage and wrong po

-

larity

3-pin power D-sub

Notes: 1

2
3

4

Opt. 78/HS:

Opt. 78:
Opt. 78:
Opt. 78/HS:

Opt. 78:
Opt. 78:

GPS-12R/HS &
GPS-12RG
GPS-12R
GPS-12
GPS-12R/HS &
GPS-12RG
GPS-12R
GPS-12

Power Source Priority

1. AC line voltage supply

2. *External DC supply

3. Internal battery

*Option 78/HS only: An external 12 V

DC

source can charge the internal battery as well as
power the instrument in normal mode. The bat

­tery is also being charged when the instrument
is connected to AC line power.

This means that you can get double UPS
backup security in case of AC power break

­down, provided an external DC source is also
connected.

7-5 Options

Specifications

Option 79/01

n

Reference Outputs &
Disciplining Input

Connector
type:
Outputs:
Input:
10 MHz
output level:
1 pps
output level:

1 pps
input level:

Freq. stability:

BNC
2x10MHz+1x1pps
1 pps for ext. disciplining

Sine wave >1 V

RMS

in 50 W

Square wave TTL in 50 W
(See also Note 2 on page 7-7)

Square wave TTL
LO lvl £0.8 V, HI lvl ³2.0 V
Impedance approx. 1 kW
See Note 1 on page 7-7

Controls

User Interface:

Power:

LCD supported by 4 cursor
keys and 1 ENTER key
Secondary STBY key

LED Indicator

Standby
Mode:

Power ON
Mode:

Red LED above the key is
ON

Red LED above the key is
OFF

GNSS Receiver

Trimble
IRZ

Resolution-T [GPS-12(R)]
MNP-M3 [GPS-12RG]

Antenna
connector:
Power out:

Channels

Trimble:
IRZ:

Carrier, code:

Type N, f emale
+5 V, 0.1 A on center
conductor for feeding
active antenna and line
amplifiers

12, parallel tracking
16, parallel tracking
L1, C/A

Antenna (Option 01/00)

Type:
Operating tem

­perature:
Height:
Weight:
Gain:
Connector:

active GPS only, L1 band

-40°Cto+70°C
81 mm (3.2”)
230g(8oz.)
>30 dB
TNC

Antenna (Option 01/90)

Type:

Operating tem

­perature:
Dimensions:
Gain:
Connector:

active, combined
GLONASS/GPS L1 band

-40°Cto+85°C
100x45mm
>30 dB
TNC

Antenna Cable (Option 02)

Type:
Length:
Connectors:
Attenuation:

Cable delay:

RG213
20 m, 50 m & 130 m
type N and TNC (male)
approx.

0.4 dB/m @ 1.6 GHz
approx. 5.05 ns/m

7-6 Options

Specifications

PC Connection

Interface:
Connector:
Purpose:

USB 1.1
USB, type B, female
FW loading & remote moni

­toring and control.
See Option 29/12 (GPS-12
Monitor) and Chapter 4.

Fan

Internal with temperature-controlled speed.

Display

Monochrome LCD with backlight. Resolution
320x97pixels.

Notes

1. See frequency stability specs for the
relevant oscillator type and operating
mode (GNSS-locked or hold-over).

2. Approximately 0-5Vinto an open
output,0-2Vinto a 50 W load.

Environmental Data

Temperature:

Humidity:

Altitude:

Vibration:

Shock:

Safety:

EMI:

0°C...+50°C (operating)

-40°C...+70°C (storage)
95% RH, 0°C..+30°C
(operating & storage)
<4600 m (operating)
<12000 m (storage)
3G @ 55 Hz per
MIL-T-28800D, Class 3,
Style D
Half-sine 40G per
MIL-T-28800D, Class 3,
Style D. Bench handling.
Compliant with CE:
EN 61010-1 2:nd edition,
Cat II, Pollution degree 2
Compliant with CE:
EN61326-1 (1997), A1
(1998), A2 (2001), A3
(2003); EN55022B;
EN50082-2

Dimensions and Weight

WxHxD:
Weight:

210 x 108 x 395 mm
Net 3.1 kg (6.6 lbs), ship

­ping 4.1 kg (8.8 lbs)
(excl. batteries)

Power Consumption

Line voltage:
Line frequency:
Power

GPS-12:

GPS-12R(G):

90...264 V

45...440 Hz

<40 W at warm-up
<30 W cont. operation
<60 W at warm-up
<35 W cont. operation

7-7 Options

Specifications

Ordering
Information

GPS-12:

GPS-12R:

GPS-12R/HS:

GPS-12RG:

2 x 2.048 / 1.544 MHz +
1 x 1 pps / 10 MHz std. outp.
OCXO frequency reference
Receiver for GPS

2 x 2.048 / 1.544 MHz +
1 x 1 pps / 10 MHz std. outp.
Std Rb frequency reference
Receiver for GPS

2 x 2.048 / 1.544 MHz +
1 x 1 pps / 10 MHz std. outp.
+3x10MHz+1x5MHz
rear panel std. outputs
HS Rb frequency reference
Receiver for GPS

2 x 2.048 / 1.544 MHz +
1 x 1 pps / 10 MHz std. outp.
+3x10MHz+1x5MHz
rear panel std. outputs
HS Rb frequency reference
Receiv.for GLONASS/GPS

Opt. 70B:

1

Opt. 71B:
Opt. 72B:

Opt. 73B:

2

Opt 74B:

Opt 77:
Opt 78:

3

Opt 78/HS:

4

Opt 79/01:

3x10MHz+1x5MHz
outputs

0.1 + 1 + 5 + 10 MHz outp.
2x2.048MHz+
2 x 2.048 Mbps outputs
4 x 13 MHz outputs
2x1.544MHz+
2 x 1.544 Mbps outputs

-48 V external DC supply
Internal battery backup
Internal battery backup w. ex

-

ternal DC connector for charg

­ing and continuous operation
1 x 1 pps disciplining input +
1 x 1 pps output + 2 x 10 MHz
outputs

Notes: 1

2
3
4

Standard in the GPS-12R/HS
and the GPS-12RG
Not GPS-12RG
GPS-12(R)
GPS-12R/HS & GPS-12RG

None of the options above is retrofittable,
which means that they must be ordered for fac­tory installation together with the basic unit.

Up to two of the options designated 7XB can be
fitted at the same time in any combination, e.g.
2 x Option 70B or Option 71B + Option 74B.

Note: Only one Option 79/01 can be fitted.

If Option 79/01 is ordered, only one
additional 7XB option can be or

-

dered.

Included Accessories

Users Manual in PDF on CD
Calibration certificate
18 months warranty

7-8 Ordering Information

Specifications

Options

Optional Accessories

Option 22/90:
Option 27:
Option 27H:

Option 29/12:

Option 01/00:
Option 01/90:
Option 01/50:
Option 02:
Option 02/50:
Option 02/130:
Option 90/10:

Option 90/00:

Option 95/03:
Option 95/05:
Option OM-12:

19” rack mount kit
Soft carrying case
Heavy duty hard transport
case
GPS-12 Monitor, Control &
Monitoring SW
GPS only antenna
GLONASS/GPS antenna
Antenna mounting kit
Antenna cable, 20 m
Antenna cable, 50 m
Antenna cable, 130 m
Calibration certificate
with protocol
Calibration certificate
Hold-over aging/week
Extended warranty 3 years
Extended warranty 5 years
Printed Users Manual (PDF
file included as standard)

7-9 Ordering Information

Specifications

This page is intentionally left blank.

7-10 Ordering Information

Specifications

Chapter 8

Appendix

Antenna
Installation

Introduction

When installing an antenna for the satellite con

­trolled frequency standards GPS-12X, some
basic facts should be considered, relating to an

­tennas and radio reception properties. The theo

­retical and practical discussions below will
help you to make the right decisions.

Pendulum supplies satellite antennas and an an

­tenna mounting kit as well as cable assemblies
of different lengths. Other system components
that may be necessary to meet your require

­ments are readily available from vendors of
GNSS antenna equipment.

It is important to observe that deviations from
the recommended normal solution may se­verely impair the performance of the overall
system, unless the user has acquired the knowl­edge necessary to design a configuration of his
own. General guidelines to good system design
are given in this section of the handbook, but
the user is entirely responsible for adequate
performance in this case.

Available Options for
Antenna Installation

Option 01/00:

Option 01/90:

Option 01/50:

GPS antenna w. Type TNC
fem. connector

GLONASS/GPS antenna w.
Type TNC fem. connector

Antenna mounting kit for wall
or pole mounting.

Option 02: Antenna cable, 20 m (Opt.

02/20), 50 m (Opt. 02/50) and,
130 m (Opt. 02/130) with Type
TNC male connector at one
end and Type N male at the
other.

General Guidelines to Good
Antenna Location

The general rule that applies to all installations
working in or near the microwave frequency
bands is that it should be possible to see the
transmitter from the receiver antenna position.
When dealing with terrestrial radio communi

­cation it is a great advantage to place both the
transmitter antenna and the receiver antenna as
high as possible. The effective line-of-sight dis­tance increases with the square root of the
height above ground.

The satellite-based transmitters are, however,
moving targets in the sky and require in part
new rules of thumb. Moreover, you need at
least see more than two satellites simulta­neously, irrespective of the point of time, to get
stable time readings. The receiver can have
contact with 12 GPS or 16 GLONASS satellites
at the same time, but in practice three is enough
for timing purposes, when the receiver is sta

­tionary.

It is not certain that an elevated location is an
advantage, unless it is the only way to see as
much of the sky as possible including the hori

­zon in most directions. On the contrary, loca

­tion on the ground could be more efficient from
a technical point of view if you do not have to
consider certain negative factors like the risk of
physical damage and the influence of snow and
ice on the antenna efficiency.

Other conditions to be taken into account are
multi-path reception and interference from
high-frequency signal sources nearby. All these

8-2 Antenna Installation

Appendix

considerations could force you to find a place for
the antenna situated far from the receiver and
high above ground level. We will discuss these
matters presently, but the implication in brief is
that new system components may have to be in

­troduced, like low-loss coaxial cables and line
amplifiers.

Coping with Interference

There are mainly two sources of interference
that may affect the location of the antenna.
They will be treated below. Careful inspection
of the proposed site can often reveal the most
apparent ones.

n

Multi-path Reception

Reflections from metal surfaces nearby can
cause the wanted signal to enter the a ntenna
from two or more directions with more or less
equal strength. Then the phase relationship de­termines whether the resulting signal will be
amplified or attenuated. At worst it can vanish.
Since the GNSS satellites are not stationary the
conditions can be compared to the fading prob­lem on the shortwave bands. The directive sen­sitivity of the antenna resembles a hemisphere
with its base plane going horizontally through
the antenna, provided it is mounted vertically
on top of a mast. Therefore you must avoid lo

­cations near reflective surfaces beside or above
the antenna.

n

High-frequency Interference

Strong signal sources in the vicinity, like cellu

­lar radio transmitters, can cause interference or
saturation in the antenna amplifier. Even
though the systems do not operate at the same
frequency the problem has still been observed
from time to time and must not be neglected.

Standard Configuration

The majority of installations can do with the
standard configuration, consisting of one
satellite antenna, one 20-m antenna cable, and
the frequency reference itself, the GPS-12X. In
many cases, the distance between the antenna
and the receiver could be less than 20 m.
Normally excessive cable length is easy to tol

-

erate. Do not shorten the cable, unless abso

­lutely necessary, because the high antenna gain
of 36 dB requires the signal to be attenuated by
at least 6 dB before entering the receiver.

Deviations from the Standard
Configuration

n

General Principles

The system configurations that cannot directly
use the standard options provided by Pendulum
can be listed in different ways. One simple
method of classification used here is to isolate a
number of cases and treat them separately. If
several steps have to be taken to arrive at a solu­tion that satisfies all requirements, then it
should be possible to derive the individual
components from the list by means of combina­tion. The method is illustrated by some practi

­cal examples later in this chapter.

The most important design parameter is the ca

­ble loss at the receiving frequency. There are a
number of cable types to choose from, but for
the sake of simplicity one normal and one
low-loss type have been selected:

Cable type Attenuation per 100 m

Standard (RG-213)
Low loss (LMR400)

Approx 40 dB
Approx 17 dB

The common laboratory cable RG-58 has been
excluded, as its losses only allow relatively

8-3 Antenna Installation

Appendix

short distances between antenna and receiver. It
is more flexible, however, and might be utilized
with care, if you are fully aware of its charac

-

teristics.

Remaining parameters to consider are:

Antenna gain:
Guard band:
Total external gain at
the receiver input:

+36 dB (option 01)
±3 dB

+11dB … +33 dB

When designing your own antenna installation,
you must check that the gain at the receiver in

-

put is within limits according to the above ta

-

ble. That is, you must check that:

+ antenna gain

- total attenuation
+ total amplification

- guard band

+ antenna gain

- total attenuation
+ total amplification
+ guard band

³ +11 dB £ +33 dB

n

Case Classification

The distance between antenna and
receiver exceeds 20 m but not 55 m

–

Use a coaxial cable of type RG-213 or
cascade two or three pieces of option 02
by means of adapters. Note that normal
adapters are not weatherproof and should
be placed indoors. Normally there is little
to gain by using a low-loss cable in this
case, but see example #1 below. RG-213 is
more inexpensive and flexible.

The distance between antenna and
receiver exceeds 55 m but not 130 m

–

Use a low-loss coaxial cable of type LMR
400 or equivalent.

The distance between antenna and
receiver exceeds 130 m but not 245 m

–

Use a line amplifier with a nominal gain
of 20 dB plus low-loss coaxial cable of
type LMR 400 or equivalent. The ampli

-

fier must accept a fixed +5 V supply volt

­age fed through the central conductor of
the coaxial cable. The maximum input
power for linear operation should be at
least –6 dBm, and the noise figure should
be less than 2 dB.

The distance between antenna and
receiver is in the range 245-360 m

–

Use two cascaded line amplifiers (20 dB
each) plus low-loss coaxial cable of type
LMR 400 or equivalent.

Better protection against lightning
strikes needed

Lightning protection is a wide field and cannot
be covered more than superficially in this man­ual. If the building is situated in a risk area, a
general survey of the overall house protection
might be needed. Especially lightning rods near
the GPS antenna mounting mast should be in­spected. Make sure that the antenna is far from
being the highest point and, as a precaution,
ground the mounting mast as if it were part of
the ordinary lightning rod system.

There are several conditions that may call for a
separate lightning arrester to support the
built-in antenna protection.

–

The cable length outside the building ex

­ceeds
15 m.

–

An elevated antenna position with no effi

-

cient lightning rods nearby.

–

Areas where the frequency of thunder

-

storms is significantly higher than normal.

8-4 Antenna Installation

Appendix

–

Extra safety wanted due to sensitive and/or
expensive equipment being connected to
the GPS timebase system.

A lightning arrestor should be mounted inside
the building close to the cable entry point.

Harsh environmental conditions

Snow and ice on the surface of the antenna can
significantly reduce the effective sensitivity by
as much as 6 dB. You could, for instance, utilize
an electrically heated radome to house the an

­tenna unit, to avoid the attenuation effects of
this environmental influence.

Other weather conditions having negative in

­fluence on the system sensitivity are heavy rain
and fog. The attenuation effects are normally
covered by the 3 dB guard band, used in the cal­culations.

n

Four Practical Examples

Example 1

Requirements

Cable length:
Lightning arrester:
Climatic conditions:

52 m (5 m indoors)
yes
normal

Solution

The cable length indoors, i.e. after the lightning
arrester, must be at least 8 m, otherwise the pro

­tective function may not be guaranteed. So, you
have to make the cable 3 m longer indoors. The
effective cable length will be 55 m instead. This
is the upper limit for the standard RG-213 ca

­ble, under normal climatic conditions.

Calculation of total gain at the receiver input,
using a RG-213 cable with an attenuation of

0.40 dB/m (40 dB per 100 m), under normal
environmental conditions:

Antenna gain:
Cable loss:
Guard band:
Total gain:

+36 dB

-22 dB (-55 * 0.40)

-3 dB
+11 dB (36-22-3)

This gain figure is exactly at the lower permis

-

sible level at the receiver input.

Example 2

Requirements

Cable length:
Lightning arrester:
Climatic conditions:

55 m (50 m indoors)
no
snow and ice

Solution

The cable length 55 m is the upper limit for the
standard RG-213 cable, under normal environ-

mental conditions.

But snow and ice on the surface of the antenna
can attenuate the signal by 6 dB.

Let us calculate total gain at the receiver input
for a RG-213 cable, taking the snow and ice
factor into consideration:

Antenna gain:
Harsh weather:
Cable loss:
Guard band:
Total gain:

+36 dB

-6 dB

-22 dB (-55 * 0.40)

-3 dB
+5 dB (36-6-22-3)

The latter figure should be in the range 11 – 33
dB, so the additional 6 dB loss due to extreme
weather c onditions requires the use of a
low-loss cable, e.g. LMR400, having an attenu

­ation of 0.17 dB/m (17 dB per 100m). This
gives the following total gain:

8-5 Antenna Installation

Appendix

Antenna gain:
Harsh weather:
Cable loss:
Guard band:
Total gain:

+36 dB

-6dB

-9 dB (-55 * 0.17)

-3 dB
+18 dB (36-6-9-3)

This gain value is well within the acceptable
range.

Example 3

Requirements

Cable length:
Lightning arrester:
Climatic conditions:

130 m (120 m indoors)
no
normal

Solution

As this cable length suggests the use of a line
amplifier, let us check that the total gain at the
receiver input does not exceed the maximum
value allowed, +33 dB.

Antenna gain:
Amplifier gain:
Cable loss:
Guard band:
Total gain:

+36 dB
+20 dB

-22dB(-130*0.17)
+3 dB
+37 dB (36+20-22+3)

This calculation means that if the weather is
fine and the antenna gain is at its positive toler

­ance level, then the signal should be attenuated
by at least 4 dB to avoid overloading the re

­ceiver input. An external 6 dB attenuator di

­rectly on the input connector takes care of the
problem.

As the cable length outside the building is not
more than 10 m (limit 15 m) a lightning arrester
is not compulsory.

Example 4

Requirements

Cable length:

Lightning arrester:
Climatic conditions:

325 m (120 m in

­doors)
yes
snow and ice

Solution

This is a typical two-amplifier configuration. A
worst-case calculation using a LMR400 cable
gives:

Antenna gain :
Amplifier gain:
Cable loss:
Guard band:
Harsh weather:
Total gain:

+36 dB
+40 dB (+20 +20)

-55dB(-325*0.17)

-3 dB

-6 dB
+12 dB
(36+40-55-6-3)

In other words, 325 m is close to the upper limit
of the cable length, if the weather conditions
are much worse than average. Otherwise you
could expect another 35 m. It is not recom

­mended to cascade more than two amplifiers to
obtain even greater cable lengths due to the risk
of saturation or other non-linear behavior. If
need be, use a single, tuned amplifier designed
for the calculated total gain.

Since the cable length outside the building is
substantial, it is strongly recommended to use a
lightning arrester, even if the location of the an

­tenna is well protected from direct lightning
strikes. Induced high voltages must not be ne

­glected. Sensitive equipment without
over-voltage protection can easily be destroyed
in this way.

8-6 Antenna Installation

Appendix

Auxiliary Components on the
Market

This is a summary of system components that
may be necessary to complete an installation
tailored to your individual needs. These com

-

ponents are supplied by a large number of man

-

ufacturers worldwide.

If any of these parts have to be mounted out

-

doors, make sure they have an adequate tem

­perature range. They must also be specified as
weatherproof. Otherwise they have to be
housed in boxes that can withstand the local cli

­matic conditions.

n

Coaxial Cables

–

Used for transferring the RF signal from
the antenna unit to the receiver, sometimes
via other system components. Active de­vices like line amplifiers and the antenna
unit itself are also supplied with DC power
through this cable.

Only high-quality 50 W cables should be used,
preferably RG-213 for normal use and LMR
400 when long distances have to be bridged.

n

Coaxial Adapters

–

Used for interconnecting system compo

-

nents employing different connector stan

-

dards.

All major connector manufacturers also supply
a large variety of adapters. Note that most
adapters require additional protection if
mounted outdoors or in places with high hu

­midity.

n

Line Amplifiers

–

Used for compensation of cable losses.

Normally wide-band amplifiers with moderate
gain are used, but in special cases tuned
high-gain amplifiers may be more suitable, for

example when very long cable lengths are nec

-

essary.

Maximum two amplifiers can be inserted in the
signal path before the loss seen from the an

­tenna exceeds 6 dB. The distance between the
antenna and the first line amplifier should be as
short as possible and not more than about 35 m,
giving a loss of 35*0,17 » 6 dB, if a low-loss
cable is used.

If this basic rule is followed, the noise figure of
the total system is almost entirely set by the
first amplifier stage, in this case the active an

­tenna itself. The noise of the line amplifiers can
then normally be neglected.

n

Power Splitters

–

Used for dividing the signal from the an­tenna between two or more timing receiv­ers.

There are both passive and active splitters, the
latter often being line amplifiers with more than
one output. A passive power splitter has a fixed
insertion loss, for instance 6 dB with the resis­tive type, whereas the active types often have
no loss or even a low gain.

n

Attenuators

–

Used for adapting the signal level at the
input of the receiver input.

There are both fixed and variable attenuators
available.

n

Lightning Arresters

–

Passive devices for diverting over-voltages
to ground, thus protecting sensitive equip

-

ment connected to the output of the light

-

ning arrester.

Such a device should be mounted inside the
building close to the cable entry point. It re

­quires a good ground connection through a 4
AWG copper wire or a braided copper strap

8-7 Antenna Installation

Appendix

with the corresponding cross-section area. It
must be a minimum cable length of 8 m after
the lightning arrester to guarantee its proper
function.

Remember that the antenna and the lightning
arrester primarily protect the equipment later in
the chain. They may be destroyed themselves.
Consequently it is recommended to keep these
components as replacement parts, if minimum
downtime is important.

n

Mounting Masts

–

Used for securing the antenna unit. At the
same time the coaxial connectors are pro

-

tected from both mechanical and environ

-

mental influence.

Pipes with 1-14 UNS thread, suitable as masts,
can often be obtained from retailers selling boat
gear.

Pendulum offers the accessory option 01/50, an
antenna mounting kit for wall or pole mount­ing.

8-8 Antenna Installation

Appendix

Chapter 9

Inde x

Index

!

1pps/10MHzCheck .............5-3

1ppsOffset..................... 3-5

2.048/1.544 MHz Check ...........5-3

A

AlarmMenu .................... 3-6

AlarmOutputCheck ..............5-6

AlarmOutputs ...............3-6,7-4

Antenna (Option 01) ..............7-6

Antenna Cable (Option 02) .........7-6

Antenna Delay ..................3-5

Antenna Installation ...........2-7,8-2

AvailableOptions...............8-2

CaseClassification .............8-4

Deviations ....................8-3

Interference...................8-3

Location......................8-2

Protection against Lightning Strikes . 8-4

Standard Configuration ..........8-3

Appendix.......................8-1

Attenuators ..................... 8-7

Auxiliary Components .............8-7

B

BasicControls ..................3-2

BatteryReplacement .............6-3

C

Calibration .....................6-2

Cesium Standards ...............1-2

CheckList...................... 2-3

Coaxial Adapters ................8-7

CoaxialCables..................8-7

Connecting to a PC ...............2-7

Controls .......................7-6

D

DefaultMenu ...................3-4

DefaultMode ...................1-3

DimensionsandWeight............7-7

DisplayContrast.................3-7

E

Environmental Conditions ..........8-5

EnvironmentalData ..............7-7

External DC Supply (-48 V) .........7-5

F

Fan...........................7-7

FanControl.....................2-5

FanReplacement................6-3

9-2

Index

Fold-down Support ...............2-5

Front Panel .....................3-2

Front Panel Controls ..............5-3

Front Panel Outputs ...........3-7,5-3

Functional Description ............3-4

G

GNSSMenu....................3-5

GNSSReceiver .................7-6

GPS-12Monitor .................4-2

H

High-frequency Interference ........8-3

Hold-overMode ................. 1-3

I

Identification ....................2-3

Included Accessories .............7-8

Installation .....................2-4

InternalBackupBattery............7-5

Introduction.....................1-2

K

Keyboard and Indicator Test ........5-3

L

Language ......................3-7

LEDIndicator...................7-6

LightningArresters...............8-7

LineAmplifiers ..................8-7

Long-term Uncertainty ............3-4

M

Mounting Masts ................. 8-8

Multi-pathReception..............8-3

N

National Standards ...............1-3

O

Option 01 (Antenna) ..............7-6

Option 02 (Antenna Cable) .........7-6

Option 70B

3x10MHz+1x5MHz(spec.)......7-4

Check .......................5-3

Option 71B

10,5,1,0.1MHz(spec.).........7-4

Check .......................5-4

Option 72B

2x2.048 MHz + 2x2.048 Mbps (spec.)

...........................7-4

Check .......................5-4

Option 73B

4x13MHz(spec.)..............7-5

Check .......................5-4

Option 74B

2x1.544 MHz + 2x1.544 Mbps (spec.)

...........................7-5

Check .......................5-4

Option 77

-48VDC(spec.)................7-5

Check .......................5-4

Option 78 & Option 78/HS

Check .......................5-5

InternalBattery(spec.)...........7-5

Option 79/01

2 x 10 MHz Out & 1 pps I/O (spec.) . 7-6

Check .......................5-5

Optional Accessories .............7-9

Optional I/O Boards...............1-2

Options........................7-4

OrderingInformation..............7-8

OrientationandCooling............2-5

Oscillator Menu..................3-5

P

PC Connection ..................7-7

9-3

Index

PerformanceCheck ..............5-1

PowerConsumption..............7-7

PowerSourceMenu ..............3-6

PowerSplitters..................8-7

PowerSwitch...................2-4

Power-OnTest..................5-2

PracticalExamples...............8-5

Preface........................1-1

PreparationforUse...............2-1

Preventive Maintenance ...........6-1

R

Rackmount Adapter ..............2-5

Rear Panel ..................... 3-3

Rear Panel Outputs...............5-3

Recommended Test Equipment......5-2

Reference Outputs & Disciplining Input 7-6

S

SafetyInstructions ...............2-2

Specifications................... 7-1

Stability (spec.)

1ppsOutput ..................7-3

Frequency

Hold-over .......................7-3

LockedtoGNSS..................7-2

Standard Reference Outputs ........7-4

Supply Voltage ..................2-4

Symbols.......................2-2

T

TimeFormat....................3-7

TimeZone ..................... 3-7

U

Unpacking...................... 2-3

UserInterface...................3-4

UserOptions....................3-7

UsingtheControls................ 3-1

9-4

Index

Chapter 10

Service

Sales and Service Office

For additional product information, customer support and service, please contact

Pendulum at the following addresses:

II

Altaria Services Sp. z.o.o

ul.Lotnicza 37
80-297 Banino
Poland

Office

Address:

As above

Shipping Address:

As above

Phone:
Fax:

[phone]
[phone]

E-mail:

[e-mail]

Internet:

www.pendulum.se