Promax PROMAX-10 Premium User Manual

Page 1

USER’S MANUAL. PROMAX-10 Premium

TABLE OF CONTENTS

1 GENERAL...............................................................................................................1

1.1 Description........................................................................................................ 1

1.2 Specifications....................................................................................................2

2 SAFETY RULES.....................................................................................................9

2.1 Generals ..........................................................................................................9

2.2 Descriptive Examples of Over-Voltage Categories..........................................11

3 INSTALLATION.....................................................................................................13

3.1 Power supply ..................................................................................................13

3.1.1 Battery charge ..........................................................................................13

3.1.2 Recommendations for using the battery....................................................14

3.2 Installation and start-up...................................................................................14

3.2.1 Contrast adjustment ..................................................................................14

4 OPERATING INSTRUCTIONS..............................................................................15

4.1 Description of the controls and elements.........................................................15

4.2 Operating instructions.....................................................................................17

4.2.1 Global configuration menu ........................................................................19

4.2.2 SCAN operating mode..............................................................................22

4.2.2.1 SCAN mode configuration...................................................................23

4.2.3 CHANNEL-FREQUENCY operating mode................................................24

4.2.3.1 Channel tuning....................................................................................24

4.2.3.1.1 Video carrier + V/A + C/N measurement.......................................24

4.2.3.1.2 Audio carrier measurement and demodulation..............................25

4.2.3.1.3 CSO-CTB distortion products measurement.................................25

4.2.3.1.4 Power and C/N ratio measurement of digital channels (DVB-C /

DVB-T / DAB)...............................................................................27

4.2.3.1.5 Constellation Diagram representation, Bit Error Rate (BER) and Modulation Error Ratio (MER) measurement in digital channels. ..29

4.2.3.1.6 Configuration of QAM signal measurement using edit channel plan....29

4.2.3.2 Frequency tuning and configuration....................................................30

4.2.3.3 CHANNEL-FREQUENCY mode configuration....................................33

4.2.4 SPECTRUM ANALYSER operating mode................................................34

4.2.4.1 SPECTRUM operating mode. .............................................................34

4.2.4.2 MAX operating mode..........................................................................35

4.2.4.3 MIN operating mode...........................................................................36

4.2.4.4 TRANSIENT DETECTOR operating mode..........................................36

4.2.4.5 SPECTRUM ANALYSER mode configuration.....................................37

4.2.5 TILT operating mode.................................................................................38

4.2.5.1 TILT mode configuration.....................................................................38

4.2.6 DATALOGGER operating mode................................................................39

4.2.6.1 Datalogger configuration.....................................................................41

4.3 Connection to a Computer or Printer............................................................... 42

Englis h

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USER’S MANUAL. PROMAX-10 Premium

CABLE TV ANALYSER

PROMAX-10 Premium

1 GENERAL

1.1 Description

The

Datalogger, Scan, Tilt, Spectrum Analyser, Transient Detector Analyser analogue and digital 862 MHz

(CATV) and

in the whole frequency band, very useful to check a possible input s aturation of some broadband demodulators.

measurements:

and stored, each with carrier levels, C/N and V/A ratios, channel power or MER of up t o 140 channels. The measurements obtained may be checked, transferred to a PC or printed at any time.

PROMAX-10

which makes it an excellent tool for the installation and maintenance of

range, which includes

wireless cable TV

The

PROMAX-10

As a

Level Meter

Analogue channels

Digital channels DVB-C, DVB-T and DAB

The

Datalogger

Premium

television signal reception/distribution syst ems working in the

Premium

- Video carrier level measurement

- Carrier / Noise ratio measurement (C/N)

- Video / Audio ratio measurement (V/A)

- CSO and CTB Intermodulation distortion measurement

- Channel power measurement by integration

- Carrier / Noise ratio measurement (C/N)

- Bit Error Rate (BER) measurement

- Modulation Error Ratio (MER) measurement

- Graphical representation of DVB-QAM signals Constellation

Diagram.

function allows up to 55 loggers or measurements t o be taken

is seven functions in one instrument,

FM radio, community TV systems

(MMDS) including the

incorporates the power level measurem ent f unction

, the

PROMAX-10

sub-band

Premium

, and

(MATV),

(return path).

enables the following

Level Meter

Cable Digital

5 to

cable TV

Englis h

operating mode, the channels present on the band in a bar-graph display. The span and reference level are user definable. A moving marker shows the exact level of each specific channel.

difference in levels between any four previously defined pilot frequency channels, in order to obtain a qualitative measurement on band equalisation.

05/2004 Page 1

Scan

operating mode, the screen shows, both graphically and numerically, the

Tilt

PROMAX-10

Premium

indicates the level of all

Page 3

USER’S MANUAL. PROMAX-10 Premium

As a

Spectrum Analyser

it provides the analysis of the entire band, with a span defined by the user from 1 to 100 MHz. Furthermore, it is possible to alter the reference level, and to detect and maintain the

INGRESS

measurements.

The

Transient Detector

mode, permits to count the number of impulsive

maximum

and

minimum

values for

interferences in the return path and with a level higher than a threshold defined by the user. The maximum frequency range is from 5 to 100 MHz.

In designing the

PROMAX-10 Premium

, special attention was given to building a multi-purpose, accurate, yet easy-to-use instrument. A simple key board gives direct access to the various operating modes and, once in them, any measurement parameter can be easily changed using the rotary selector/button.

In addition, it has an

RS-232C

terminal for connecting to a printer or computer

for producing reports on the measurements obtained.

The instrument is powered by means of an internal rechargeable battery. All these functions have been brought together in one instrument weighing only

half a kilo. The ergonomic, sturdy design makes the

PROMAX-10 Premium

a worki ng

tool without parallel.

1.2 Specifications

TUNING Tuning range Tuning mode Channel plan

Resolution Indication Channel frequency offset

From 5 to 862 MHz. By channels or by frequency. 10 channel plans, each one with a maximum of 140 channels. Factory start-up channel plans: CCIR, EIA, OIRL, JAP2, UK, FCC, STD2L, AUST

(1)

. 10 kHz. Graphic LCD with back lighting.

2 MHz (10 kHz resolution).

POWER LEVEL MEASUREMENT Measuring range Bandwidth Resolution Accuracy

From 70 to 120 dBµV (From 10 dBmV to 60 dBmV From 5 to 862 MHz 1 dB

3 dB (From 5 to 40 °C)

(2)

LEVEL MEASUREMENT Measurement

Analogue channels Digital channels

Video carrier level measurement. Power measurement in the channel bandwidth by integration method.

Measuring range

Page 2 05/2004

From 25 to 120 dBµV. (From -35 dBmV to 60

(2)

dBmV)

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USER’S MANUAL. PROMAX-10 Premium

Maximum input level

From 5 to 862 MHz DC to 60 Hz

120 dBµV. (60 dBmV 60 V DC or RMS

(2)

Reduction of the measurement range depending on the number of channels.

Up to 10 channels From 11 to 20 channels From 21 to 50 channels From 51 to 80 channels

Readout

110 dBµV. 107 dBµV. 103 dBµV. 101 dBµV. Digital in dBµV, dBmV or dBm and analogue through a graphic bar. 1 dB resolution

IF bandwidth Input impedance Audible indicator

230 kHz ± 50kHz 75

Ω

Tone which varies with the signal level.

Accuracy

Analogue channels

Digital channels

2 dB (from 0 to 40 °C) for negative video

modulation

3 dB (from 0 to 40 °C) for 8 MHz bandwidth

(3)

channels.

DIGITAL SIGNALS MEASUREMENT MER (Modulation error ratio)

Measurement range Accuracy

22 dB to 34 dB for 64 QAM.

2 dB

BER (Bit error rate) Measured before RS decoding

Measurement range

Constellation Diagram

10 E-2 to 10 E-8 DVB-QAM signals (Annex A/B/C) and DOCSIS / Euro-DOCSIS

Lock range Symbol rate

Measurement range

Datalogger

-10 dBmV to 60 dBmV

1000 to 7200 Msym/s

for 16/64/256 QAM For each digital channel, the level and the MER can be stored. (BER for data dumping to printer or transfer to PC)

Modulation type

16/32/64/128/256 QAM ITU J1 annex A/C and 64/256 QAM ITU J1 annex B.

Bandwidth Frequency tuner

8 MHz

62.5 kHz.

Englis h

VIDEO / AUDIO RATIO MEASUREMENT Measurement Measurement range

(ANALOGUE CHANNELS) Ratio of video to audio carrier levels. From 0 to 40 dB

Audio subcarrier frequency

Variable

Accuracy

Including the OP-010-E option, otherwise the margin is from 1000 to 7000.

4-9 MHz. ± 2 dB (from 5 to 40 °C) for FM audio carrier

(4)

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USER’S MANUAL. PROMAX-10 Premium

CARRIER / NOISE RATIO MEASUREME NT Measurement

Analogue channels

Ratio between carrier level and the channel's noise level.

Digital channels

Ratio between the channel power and the noise level. The frequency where noise is measured is user definable in absolute or relative value. In the relative mode, the unit takes as defaul t frequency

Measurement range

Analogue channels

(5)

offset the value BW/2 + 0.5 MHz. 40-50 dB for input level between 60 and 70 dBµV.

> 50 dB for input level > 70 dBµV.

Digital channels

Accuracy

> 30 dB for input level > 60 dBµV.

2 dB (45 – 862 MHz) ± 3 dB (5 – 45 MHz)

CSO & CTB INTERMODULATION PRODUCTS MEASUREMENT

(ANALOGUE CHANNELS)

CSO

Ratio of the peak level of the video carrier to the peak of the distortion products of second order beat. Measured at four frequencies user definable.

Measuring frequencies

User definable from -2.50 to -0.50 MHz and from

0.50 to 2.50 MHz. (Default values -1.50, -0.50, 0.50 and 1.50 MHz).

CTB

Ratio of the peak level of the video carrier to the peak of the distortion products of third order beat. Measured at the carrier frequency or, approximately mode, in a channel previously defined by the user.

DATALOGGER FUNCTION Max. number of loggers Number of channels/logger

55 140

Measurements

Analogue channels Digital channels

Level, C/N and V/A. Channel power and MER. (BER for data dumping to printer or transfer to PC).

SCAN Span

Variable: 10, 30, 100, 300 MHz and full band (from 5 to 862 MHz, according to the channel plan).

Power detection Reference level

Forward band (45 to 862 MHz). Variable from 60 to 120 dBµV in 10 dB steps.

TILT Indication Analysed band

Numerical and by level bar. Forward (45 to 862 MHz) or Return path (5 t o 100 MHz).

Number of pilots Pilots frequency Pilots resolution

Page 4 05/2004

4 per band. From 5 to 862 MHz. 10 kHz.

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USER’S MANUAL. PROMAX-10 Premium

SPECTRUM ANALYSER Span Reference level Analysed band

Detector Bandwidth Resolution

Peak detector

Span 100 MHz Span 50 MHz Span 30 MHz Span 15 MHz Span 5 MHz Span 1 MHz

Average detector

Span 30 MHz Span 15 MHz Span 5 MHz Span 1 MHz

TRANSIENT DETECTOR

Detection threshold Detection range Readout

AUDIO Demodulation

Output

From 1 to 100 MHz (1, 5, 15, 30, 50, 100 MHz). Variable from 60 to 120 dBµV in 10 dB steps. Forward (45 to 862 MHz) or Return path (5 to 100 MHz). Peak or average. 230 kHz.

900 kHz. 450 kHz. 280 kHz. 140 kHz. 50 kHz. 10 kHz.

280 kHz. 140 kHz. 50 kHz. 10 kHz.

From 20 to 60 dBµV in steps of 1 dB. From 5 to 100 MHz maximum. Number of detected transitory in the measuring time. Present detected level and maximum detected level in the time of the measurement.

AM / FM / LEVEL (variable tone according to the signal level). Internal speaker / external headphones.

Englis h

POWER SUPPLY LNB Input Output Voltage Current Protection

POWER SUPPLY NiMh battery

Low battery indication Autonomy

Automatic power-off Battery charge Equipment consumption

By external power supply. By input signal connector. 24 V nominal (25 V max.). 500 mA max. Current limiter.

7.2 V – 1.4 Ah. Graphic indication on the display:

Approximately 3 hours (30 % on / off excepting measurements of MER / BER). Power-off after approximately 10 minutes of non-use. By fast internal charger.

13.5 W.

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USER’S MANUAL. PROMAX-10 Premium

Mains to charger adapter

230 V / 50-60 Hz / 13.5 V DC minimum (EUROPE and other countries).

ENVIRONMENTAL CONDITIONS

This equipment could be used on the following environmental conditions, in these conditions the specifications could also be applied:

Altitude Temperature range Maximum relative humidity

Up to 2000 metres. From 5 °C to 40 °C. 80 % (up to 31 °C), decreasing lineally up to 50% at 40ºC.

MECHANICAL FEATURES Dimensions Weight

70 W (90 on the display) x 218 H x 50 D mm. 825 g. (including battery and holster).

(1) Under request carried out at the factory. (See option OP-010-61) (2) Because of safety reasons, the maximum input power over the entire band is

limited up to 120 dBµV. The equivalent power level for a group of channels of similar levels is related with the input power level over the entire band according t o the following expression:

LT = L+10 log N (LT: total level , L: mean level of one channel, N: number of channels present).

For higher input power levels, the use of an external attenuator of 20 dB is recommended. There may be certain frequencies where the symbol "<" appears at levels higher than 25 dBµV (maximum 28 dB). This is due to the aut omatic correction of the frequency response. The value measured remains correct, although the accuracy becomes ±3 dB

(3) For the positive video modulation (L standard) it can vary from 0 to -2 dB among

white and black image.

(4) For the AM audio carrier (L standard), it can vary from 0 to -3 dB below the V/A

value.

(5) See appendix E

INCLUDED ACCESSORIES

AL-012 EUROPE and other countries 230 V / 50-60 Hz mains adapter

(basic version only).

AL-022 USA and CANADA 120 V / 50-60 Hz mains adapter (only with

the OPT-010-1). AL-032 UK 230 V / 50-60 Hz mains adapter (only with the OP-010-2). AL-042 Australia 240 V/50-60 Hz mains adapter (only with the OP-010-3) AL-052 Japan 100 V / 50-60 Hz mains adapter (only with the OP-010-4). AA-012 Car cigarette lighter adapter cable. DC-239

PROMAX-10 Premium

Carrying case. DC-286 Carrier belt. AD-057 F/female - F/female input adapter. AD-058 F/male - F/female rapid adapter. CC-030 F/male - F/male (1m) coaxial cable. DC-284 Rubber holster.

Page 6 05/2004

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USER’S MANUAL. PROMAX-10 Premium

OPTIONS

OP-010-1 Substitute mains adapter by AL-022. OP-010-2 Substitute mains adapter by AL-032. OP-010-3 Substitute mains adapter by AL-042. OP-010-4 Substitute mains adapter by AL-052. OP-010-61 Change channel plan. (Carried out under request in the

OP-010-E Extension of SYMBOL RATE measurement range.

OPTIONAL ACCESSORIES

AD-055 F/female - BNC/female adapt er. AD-056 F/female - IEC/female adapter. CI-023 Portable serial printer. CC-208 Data transfer cable to PC or printer. RM-010 Remote control software for AT-20C 20 dB attenuator.

factory).

PROMAX-10 Premium

Englis h

Page 9

USER’S MANUAL. PROMAX-10 Premium

2 SAFETY RULES

2.1 Generals

Use this equipment connected

at ground potential

only to devices or systems with their common

This equipment can be used in

Pollution Degree 2

Use the mains adapter in

Degree 1

When using some of the following accessories

ensure safety.

Observe all

Use this instrument under the

The user is not authorised to manipulate inside the instrument:

On the Maintenance paragraph the proper instructions are given.

Follow the

environments. It is for

Power adapter Car cigarette lighter adapter

Any other change on the equipment should be carried out by qualified personnel.

cleaning instructions

environments.

Over-Voltage Category II

specified ratings

Over-Voltage Category I

INDOOR USE

both of supply and measurement.

specified environmental conditions

described in the Maintenance paragraph.

use only the specified ones

installations and

Pollution

Englis h

Page 10

Symbols related with safety:

USER’S MANUAL. PROMAX-10 Premium

DIRECT CURRENT ALTERNATING CURRENT DIRECT AND ALTERNATING GROUND TERMINAL

PROTECTIVE CONDUCTOR

FRAME TERMINAL

EQUIPOTENTIALITY

ON (Supply)

OFF (Supply)

DOUBLE INSULATION (Class II protection)

CAUTION (Risk of electric shock)

CAUTION REFER TO MANUAL FUSE

Page 10 05/2004

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USER’S MANUAL. PROMAX-10 Premium

2.2 Descriptive Examples of Over-Voltage Categories

Cat. I Cat. II Cat. III Cat. IV

Low voltage installations isolated from the mains. Portable domestic installations. Fixed domestic installations. Industrial installations.

Englis h

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USER’S MANUAL. PROMAX-10 Premium

3 INSTALLATION

3.1 Power supply

The NiMh rechargable battery. Before taking any measurement, the user should make sure that the battery is fully charged (use the mains adapter supplied with the instrument).

PROMAX-10

Premium

is a portable instrument powered by a built-in 7.2 V

3.1.1 Battery charge

The instrument has a 230 V / 50-60 Hz, mains adapter, for use in EUROPE and other countries, to power or to charge the instrument. (See accessories to request other types of adapters).

There are two different situations on battery charge:

1) With the instrument stopped, on having connected the external power adapter,

begins a cycle of fast load which duration will depend on the battery state. For an empty battery this time will be of 2.5 h. approximately. The charge indicator of frontal panel will remain illuminated during this period. On having finished the battery charge the indicator will be illuminated blinking to indicate that a maintenance charge takes place.

2) With the instrument working, when connecting the power adapter, this one feeds

the instrument and provides a maintenance charge, remaining illuminated the charge indicator. The MER / BER measurements produce a light discharge of the battery in spite of the external power adapter being connected.

ATTENTION When stopping the instrument is reinitiated a charge

process. It is for that reason recommendable to discharge the

battery using in strumen t without ex ternal power ad apter to make complet e the ch arge / discha rge pr oces s.

Englis h

ATTENTION The charge system of PROMAX-10 Premium

incorporates a security system that does not allow the process charge from cer tain temperature limit, be gining the maintenance charge instead.

CAUTION Before using the power adapter, make sure that the

adapter is suitable for the mains voltage.

Figure 1.- PROMAX-10

Premium

adapter connection.

and mains

Page 13

USER’S MANUAL. PROMAX-10 Premium

3.1.2 Recommendations for using the battery

In case of anticipating a long period of inactivity for the equipment it is recommended to store it with the battery discharged.

When the equipment starts the operation after a long period of inactivity to follow next steps:

Put to charge the instrument with the external adapter.

•

If it starts on the maintenance mode (indicator flashing) wait for the pass to the

•

charging mode (indicator lighting permanently). Start up the equipment, assuring that the function AUTO POWER OFF is OFF, the

•

indicator will stand permanently lighted and it will stay in this condition during a period of time about 10 to 14 hours.

Use the equipment in normal way, reason why after one to three whole cycles of charge/discharge, depending on the time and temperature of inactivity, the battery will have been reconditioned.

3.2 Installation and start-up.

The

PROMAX-10

A fully charged battery can power the equipment for more than three hours. When the low battery indicator appears on the display (

recharged.

When a fully discharged battery is installed, it is possible that, due to residual charges, the automatically disconnect before the low battery indicator appears on the display.

PROMAX-10

Premium

has been designed for use as portable equipment.

), the battery must be

Premium

may start up. In this case, the instrument will

3.2.1 Contrast adjustment

When turning on the pushed, on the display will appear the mess age '

the rotary selector

display contrast to get the best viewing according to working conditions. The new contrast value is held when the unit is turned off and when battery is removed.

Page 14 05/2004

', then turning the rotary selector [9] it is possible to adjust the

PROMAX-10

Premium

, if the on/off key [16] is held

CONTRAST ADJUSTMENT - Turn

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USER’S MANUAL. PROMAX-10 Premium

4 OPERATING INSTRUCTIONS

4.1 Description of the controls and elements

Front panel

Englis h

Figure 2.-

[1] F-F (or F-BNC or F-IEC) adapter.

Maximum input voltage level 60 VAC rms /50-60 Hz. [2] "F" male base connector. [3] Graphic display with back lighting. [4] DC power adapter external input. [5] Volume control. [6] Keyboard. 7 keys for function selection.

Front panel.

Page 15

[7] Loudspeaker. [8] Connection to computer or printer.

specific connection cable.

CC-208

Do not connect any cable other than that supplied by the manufacturer, otherwise the instrument may suffer serious damage.

[9] Rotary selector / Pu sh button.

USER’S MANUAL. PROMAX-10 Premium

keyboard.

and the

TRANSIENT DETECTOR

[10]

Selects the

[11]

Selects the

[12]

Selects the

[13]

Selects the

Figure 3.- PROMAX-10 Premium

CHANNEL - FREQUENCY

operating mode.

SCAN

operating mode.

TILT

operating mode.

SPECTRUM ANALYSER

operating modes.

Page 16 05/2004

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USER’S MANUAL. PROMAX-10 Premium

[14]

Access to global configuration menu of the unit.

[15]

Selects the be taken, visualised, printed or transferred to a PC automatically.

[16]

On/Off key. [17] LNB exterrnal supply indicator. [18] Battery charge indicator.

CONFIGURATION

DATALOGGER

menus specific to each operating mode and to the

operating mode. Enables multipl e measurements to

4.2 Operating instructions

The

PROMAX-10 Premium

The

CHANNEL-FREQUENCY

, the Carrier/Noise ratio (

level

audio carrier demodulation for channel and the Modulation Error ratio (

Diagram

intermodulation distortion. The

DATALOGGER

performed and memorised for subsequent checking, transfer to PC or printing. It can perform and store up to 55 obtained measurements or loggers in the memory. Each logger carries out level, C/N, V/A, channel power or MER measurements on the channels activated in the channel plan (up to a maximum of 140 channels).

The

SCAN

the chosen frequency band in a bar-graph display. The span and the reference level may be selected through the rot ary selector. In addition, a moving marker shows the numeric level of any specific channel . This mode also permits to define the pilot channels, used for the TILT measurement (only in the forward band).

This key permits to accede to 2 operating modes: The

SPECTRUM ANALYSER

entire band in two parts: return path or sub-band (5 to 100 MHz) and forward band (5 to 862 MHz). The span is user definable between 1 and 100 MHz. In addition, it is possible to change the reference level, and

minimum

and the Carrier/Noise ratio (

power

for

digital

operating mode shows the signal level of all channels present on

levels may be detected and held for INGRESS measurements.

has 6 independent operating modes:

operating mode measures the video carrier

), the Video/Audio ratio (

C/N

analogue

channels. It also permits to measure the

operating mode enables multi ple measurements to be

mode provides a spectrum analysis over the

channels; as well as measuring the

), the Bit Error rate (

C/N

) and represent the

MER

) and activates

V/A

Constellation

CSO

maximum

and

BER

CTB

and

)

Englis h

Page 17

USER’S MANUAL. PROMAX-10 Premium

In the

TRANSIENT DETECTOR

mode, the

PROMAX-10 Premium

operates as a transitory counter in the return path. The level detection threshold and the frequency margin are user definable.

The

operating mode shows on the display, both graphically and

TILT

numerically, the level difference between any four channels, previously defined as pilot channels, in order to obtain information about band equalisation. This function can be applied to the forward band and to the return path, independently.

To access any operating mode, simply press the corresponding key. The parameters relative to a particular operating mode can be modified through

the

configuration menu associated to the mode

. In order to accede to the

configuration menu associated to a particular operating mode, simply press the

CONFIG

the second page it is necessary to press the

key [14]. Some modes have more than one configuration page, to accede to

CONFIG

key again. The general parameters of configuration (selecting/editing the channel plan, measurement units, language, etc.) can be changed through the acceded by pressing again the

CONFIG

key [14]. To leave a configuration menu, just

Global Configuration Menu

, to which it is

press the key of the operating mode you wish to accede.

Figure 4.- PROMAX-10 Premium

Page 18 05/2004

configuration menus.

Page 18

USER’S MANUAL. PROMAX-10 Premium

4.2.1 Global configuration menu

In order to accede to the global configuration menu, from any operating mode (SCAN, CH-FR, SPECT, etc.), you must press the

CONFIG

time that presses this key accedes to the configuration menu relative to the mode in use, which can have more than one page). The global configuration menu consists of two pages (attached figure shows the first one), to switch from one to the other simply press the

CONFIG

In order to modify the state of a given parameter, you must turn the rotary selector [9] until this one appears shaded and next press it, then the value of the parameter will appear shaded and turning the selector a new value will be able to be defined. Finally, to validate the new state, press the rotary selector [9] again.

The first page of the global configuration menu permits to modify the following parameters:

a) CHANNEL PLAN

It allows you to choose the active channel plan between the 10 channel plans that unit can store (CCIR, EIA, FCC, etc.).

b) EDIT CHANNEL PLAN.

When selecting this field and pressing the rotary selector, the unit accedes to the active

CHANNEL PLAN

[14] key repeatedly (the first

[14] key.

Figure 5.-

Global configuration. 1/2.

Englis h

The attached figure shows an example of channel plan. The first line shows the name of the channel plan ( offset (

5.50 MHz

units of measurement (

in the figure), the audio carrier

CCIR

), the modulation type (FM) and the

). Next line shows the

dBµV

head of the columns that constitute the channel plan: the first column ( channel and the second one (

) shows the name of each

CHAN

) the associated

FREQ

Figura 6.-

Editing a channel plan.

frequency, in MHz. The third column (BW) defines channel bandwidth, in MHz. The fourth column (ON) activates or deactivates the channel and the fifth ones (

DIG

) defines

if the channel is analogue or digital.

In the case of defining the channel as digital, the configuration page of parameters relative to QAM measurement will be accessed directly (see section

4.2.3.1.6).

The maximum number of channels in a channel plan is of 140.

The activation (ON) / deactivation (OFF) of the channels affects to the followi ng operation modes:

CH-FR, SCAN

and

DATALOGGER

. When a channel has been deactivated, this one will not be able to be tuned nor to be measured. This property allows to make agile the operation of the

PROMAX-10

Premium

, because it allows to

activate only those channels in which we are interested.

Page 19

USER’S MANUAL. PROMAX-10 Premium

The Edit Channel Plan function allows to automatically activate all the channels defined in the channel plan by means of the right of select

we select ON, all the channels of the plan will be activated, otherwise, if we

ALL

all channels will be deactivated. In order to activate / deactivate a particular

OFF

field on the third line. When to the

ALL

channel, turn the rotary selector [9] until this one appears s haded and then press it, t he cursor will jump to the ON column, then turning the selector it will be possible to activate it (it appears a cross) or to deactivate it (it does not appear a cross).

By means of the Edit Channel Plan function also it is possible to define channels as

analogue

l. To do this, turn the rotary selector [9] until the channel

digita

that you wish to modify appears shaded and then press it twice, the cursor will jump to the

column, then turning the selector it will be possible to define it as digital

DIG

(appears a cross, channel C04 in the example of the previous figure) or as analogue (it does not appear a cross). In the case of selecting it as digital it is possible to accede directly to the digital channel configuration. In order to return to the Edit Channel Plan function press the

CONFIG

[14] key.

To modify the rest of characteristics of the channel plans it is necessary to have the

software (optional accessory).

RM-010

c) UNITS

The

PROMAX-10 Premium

and

dBm

permits to select the level units between

dBmV, dBµV

d) TIME

To enter the time select the TIME field and press the rotary selector. Firstly, turn the rotary selector to change the minutes field. Next press the select or again to modify the hours and finally press it once again to confirm the new time.

e) DATE

To enter the date select the DATE field and press the rot ary selector. First c hange the year field, then the month and finally the day.

The parameters which may be modified on the second page of the global configuration menu of the unit are as follows:

Figure 7.-

Global configuration. 2/2.

f) AUTO POWER OFF

This field permits to activate (ON) or deactivate (OFF) the POWER-OFF function. When this function is ON, the unit automatically turns off when it has remained inactive for a period of 10 minutes.

g) BEEP

This function permits to activate (ON) or deactivate (OFF) the

Premium

beeper. When it is on, it sounds on pressing any key or when turning the

PROMAX-10

rotary selector in order to alert the user.

Page 20 05/2004

Page 20

USER’S MANUAL. PROMAX-10 Premium

h) LANGUAGE

This field permits to select the language between: ESPANOL, FRANÇAIS, ENGLISH and DEUTSCH.

i) EXTERNAL UNITS POWER SUPPLY (VLNB)

By means of the necessary to feed external units (MMDS antennas Multichannel Multipoint Distribution Service in case of terrestrial television without cable the signal input connector.

This voltage will have to be provided externally by the power input [4] and to be included in the margin from 21 to 25 V, in opposite case the instrument will not al low to activate this function, displaying the message " configuration.

PROMAX-10 Premium

it is possible to provide the voltage

) by

Error VEXT

wireless cable

" at the moment of the

The activation or deactivation of process next:

- Press repeatedly the key the configuration menu.

- Turn the rotary selector until appears shaded line

- Press the rotary selector to activate the selection. Turning the rotary selector, this one goes successively of

- Finally, to press the rotary selector to activate the configuration changes.

When surpassing the maximum LNB current consumption the output feeding will be deactivated and reactivate again the LNB voltage, after solving the cause of malfuction, it must be access again to the instrument configuration according to the sequence previously described.

Before using the LNB feeding function make sure of absence of other power supplies in the measurement/power supply connector like DC / AC voltages.

The entrance of external voltages when trying to feed from the PROMAX-10

Premium, can produce damages in the implied equipment.

To leave the global configuration menu, just press the key of the operating mode you wish to accede.

The lower line of the screen shows the (2.32 in previous figure).

LED

CONFIG

) from frontal will blink during a minute. In order to

LNB

takes place according to the described

VLNB

until acceding to the second screen of

VLNB

to ON.

OFF

of the unit

version

control software

ATTENTION

IMPORTANT

Englis h

Page 21

4.2.2 SCAN operating mode

USER’S MANUAL. PROMAX-10 Premium

The

operating mode shows, in a single screen, the signal level of all the

SCAN

active channels in the channel plan by means of a bar-graph. In addit i on, the exact level of any particular channel may be measured by simply placing the marker over it (only analogue channels).

To access to this operating mode, press the

key [11]. The top line of the

SCAN

screen will display the channel name (C44), the tuned frequency (655.25 MHz) and the level (65 dBµV) of the channel the m arker is over. The marker can be moved by turning the rotary selector [9].

Figure 8.-

SCAN mode,

full span

The channel is selected when it is shaded.

To change the

span

(shown bandwidth), press the rotary select or [9] (the span field is activated) and then turn it. The span is variable from the entire band (full span) to 10 MHz in the following steps:

10, 30, 100, 300 MHz y

full span

Figure 9.-

SCAN mode,

span 100 MHz

By pressing the rotary selector [9] again, you can change the reference level, in other words, on turning the rotary selecter [9] the graph is displaced vertically.

To modify the tuned channel, press the rotary selector [9] again, the channel field will be activited and then turning the rotary selector you will be able to

Figure 10.-

Ref. 90 dB

SCAN mode,

change it.

The attached figure shows an horizontal line at 45 dBµV. This line allows to est ablish judgements of channel level acceptance easily. To activate and define this reference line see the

(section 4.2.2.1).

Page 22 05/2004

Scan configuration

Figure 11.-

reference line at 45 dBµV.

SCAN mode with

Page 22

USER’S MANUAL. PROMAX-10 Premium

In the case of having activated the broadband power detection function (

MEAS -> ∑PWR

mode (See section 4.2.2.1), on the display

SCAN

PROMAX-10

) in the configuration menu of

Premium

will appear the total

POWER

power level on the instrument RF input. See the attached figure.

This parameter indicates the total power that is being transmitted by the connec ted coaxial cable to the

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in the band from 5 to 862 MHz.

Figure 12.-

detection function.

SCAN mode, power

pilots in

The

TILT

operating mode also allows channels to be programmed for use as

SCAN

operating mode, in the forward band (see sect ion 4.2.5 TILT operating

mode).

IMPORTANT

In the SCAN operating mode, all channels are considered as analogue, as a consequence digital channels power must be measured always from the CHANNEL-FREQUENCY operating mode.

4.2.2.1 SCAN mode configuration

In the SCAN operating mode, pressing the

CONFIG

for this mode.

THRESHOLD, REFERENCE LINE MEASUREMENT

the rotary selector [9] until it appears shaded and next press the selector, then the value of the parameter will appear shaded and turning the selector you will be able to modify its value. Finally, to validate the new value, press the rotary selector [9] again.

a) THRESHOLD

b) REFERENCE LINE

c) POWER MEASUREMENT

key [14] will access the configuration menu

This menu permits to change three parameters:

and

. To accede to any of them, turn

POWER

Figure 13.-

SCAN configuration menu.

It defines the minimum level to show channel on the display (OFF or between 21 and 120 dBµV). If the threshold is deactivated (OFF), on the SCAN representation will appear all the active channels of the channel plan with a level higher than 20 dBµV. Otherwise, if we define a level f or the THRESHOLD parameter, channels with a level lower than the threshold value will not be displayed.

It permits to activate or to deactivate (OFF) a reference line on the SCAN graph (between 21 and 120 dBµV). This reference line allows to establish judgements of channel level acceptance just with a glance at the SCAN screen.

It allows to define if the measurement of the power is carried out on the channel bandwidth ( 862 MHz (

) indicates by the MARKER or over the full band between 5 and

CHAN

∑

PWR

Englis h

Page 23

USER’S MANUAL. PROMAX-10 Premium

IMPORTANT

To leave the SCAN operating mode configuration menu, just press the key of the operating mode you wish to access.

4.2.3 CHANNEL-FREQUENCY operating mode

The

CHANNEL-FREQUENCY

operating mode provides the following

measurements:

Analogue channels

: - Video carrier level

- Carrier / Noise (C/N) ratio

- Video / Audio (V/A) ratio

- CSO-CTB intermodulation distortion measurement

Digital channels

: - Channel power by measurements integrati on

- Carrier / Noise (C/N) ratio

- Bit error rate (BER)

- Modulation error ratio (MER)

- Constellation Diagram

To access to this mode of operation, press the

tuning modes

: by

channel

or by

frequency

. When pressing the

key [10]. There exist two

CH-FR

key [10], if the

instrument is in this mode allows the switching from channel tuning to frequency tuning.

4.2.3.1 Channel tuning

4.2.3.1.1 Video carrier + V/A + C/N measurement

If the tuned channel has been defined as analogue by means of the Edit Channel Plan function (see section 4.2.1 Global Configuration Menu), the

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one shown in the attached figure.

The tuned channel (C69 in the figure) appears in the higher left hand corner; t his may be changed by turning the rotary selector [ 9]. At its right appears the frequency (855.25 MHz) and the active channel plan (CCIR in the figure).

will display a screen as the

Figure 14.-

measurement

V/A and C/N Level

Below is shown the

video carrier level, VIDEO Carrier

(80 dBµV in the example). The units of measurement may be changed using the Global Configuration Menu (section 4.2.1). At the bottom, a bar-graph displays the level with a resolution of 1 dB.

Also the

ratios between the video and the audio carriers (V/A)

video carrier and noise (C/N)

are shown. The example in previous figure shows a

and

the

channel with a Video/Audio ratio of 16 dB and a C/N ratio of 54 dB.

Page 24

USER’S MANUAL. PROMAX-10 Premium

4.2.3.1.2 Audio carrier measurement and demodulation

For the

demodul a te an audi o s i gn al an d sho w it s characteristics (level and frequency

, press the rotary selector [9] again.

offset)

In the attached figure, the audio carrier level (

) is 64 dBµV and the frequency offset is 5.50

Carrier

MHz ( F). It also shows if the audio (whether Level, FM or AM) is activated (a speaker appears) or not (no icon appears). To change the audio carrier offs et ( F) and the audio modulation (Level, FM or AM) accede to the Channel-Frequency configuration menu (section 4.2.3.3).

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AUDIO

Figure 15.-

Audio demodulation

and measurement.

4.2.3.1.3 CSO-CTB distortion products measurement

The active devices present in the distribution systems, when working in its nonlinear zone, generate interferent signals, called distortion products, that can fall within the video bandwidth. From a certain level this interference becomes visible on t he TV image.

The distortion products of greater level and which usually fall within the channel bandwidth are those of second and third order beats.

The level of the video carrier to the peak of the distortion products of second order beat, produced by the rest of channels. The ratio is expressed in dB and can be resembled to a C/N measurement as it is desired to be maximum.

Similarly, the of the video carrier to the peak of distortion products of t hird order beat, which s how up at the same frequency as the video carrier.

distortion (Composite Second Order) is defined, as a ratio of the peak

CSO

, Composite Triple Beat, is defined as a ratio of the peak level

CTB

Englis h

In order to obtain these measurements, the carriers of the channel plan that is desired to transmit, must be present in the network and the measurements must be carried out for each one of the channels of the system.

Second order beats show up within the channel, around the video carrier, but as the relative position of the video carrier in all the c hannels can be di fferent, it is difficult to determine where they are going to appear, as a consequence we would hav e to be made a sweep within all the channel. The measurement automatically at four frequencies around the video carrier (-1.5, -0. 5, +0. 5 and +1.5 MHz). These frequencies can be modified by the user, see Channel- Frequency mode configuration menu (sect i on 4.2. 3. 3).

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Premium

performs this

Page 25

USER’S MANUAL. PROMAX-10 Premium

Figure 16.-

The

PROMAX-10

(that is to say, the

Interpretation of the CSO and CTB measures.

Premium

ratio that has minor value) accompanied of the frequency offset

CSO

displays as

value the worst measurement

CSO

for which it has been obtained (for example, in the figure previous at +0.5 MHz).

The

measurement is performed equivalently to the

CTB

. If all the channels

CSO

that are transmitted have the video carrier at the same position within the channel, t hen the reason, that the

beat will show up at the same frequency as the video carrier. It is for that

CTB

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Premium

makes this measurement at the same frequency as the video carrier and, as consequence, to make this measurement it is necessary to possible to turn off the carrier at the head-end, the

the video carrier of the channel we want to analyse. If it is not

turn of f

PROMAX-10

Premium

allows, like

approach, to make this measurement at one of the free adjacent channels (see section

4.2.3.3. Channel-Frequency mode configuration).

MEASURING METHOD

When pressing the rotary selector

[9] again, we will accede to the

CSO-CTB

distortion products measuring screen. First of all it will appear the message

CARRIER. PRESS TO MEASURE

REMOVE

. That is to say, once the video carrier level on which it is desired to make the measurement appears on the screen, you must press the rotary selector [9] in order that the unit retains the carrier level and comes to

Figure 17.-

CSO and CTB

measurement.

calculate the CSO and CTB ratios; next you must turn off the video carrier of the channel you want to make the measurement (at the right of the CTB measurement will appear the message

Carrier OFF

The display will show the level of the video carrier (80 dBµV in the previous figure) and the ratio has been obtained) and the

according to the equipment has detected the absence or not of carrier).

ratio (accompanied by the frequency offset for which the minimum

CSO

ratio (with the message

CTB

Carrier OFF

Carrier

The lower part of the screen shows the 4 measures made for the estimation of the CSO value.

Page 26

USER’S MANUAL. PROMAX-10 Premium

If the rotary selector [9] is pressed again, the unit will return t o the measurement screen of the video carrier + V/A +C/N (paragraph 4.2.3.1.1).

4.2.3.1.4 Power and C/N ratio measurement of digital channels (DVB-

C / DVB-T / DAB).

When the tuned channel has been defined as digital by means of the Edit Channel Plan f unction (see section 4.2.1 Global Configuration Menu) a screen as shown in the attached figure will appear. This screen shows the digital example) together with its related channel bandwidth (

ratio (C/N

in the case of analogue channels, a bar-graph represents the channel power, with a resolution of 1 dB.

In order to measure digital channels correctly, previously, the channel must be defined as digital (see Edit Channel Plan function at section '4.2.1 Unit Global Configuration) and, if necessary, the CHANNEL BW parameter should be redefined by means of the Channel-Frequency configuration menu. When a channel has been defined as digital, the PROMAX-10 Premium tunes it at its central frequency.

Digital channels power measurement is carried out by means of an integration method. The

) in sections of 230 kHz (4 by each MHz approximately) and measures the

contribution of each one to the total power of the channel. This way, a very exact measurement is obtained, specially in the case of degraded channels, because the channel flatness is had in consideration.

CHANNEL POWER

= 8.0 MHz) and the

=17 dB). At the bottom of the screen, as

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Premium

(40 dBµV in the

Carrier/Noise

divides the bandwidth of the c hannel (

Figure 18.-

Measuring a digital

channel.

VERY IMPORTANT

CHANNEL

Englis h

Figure 19.-

The and the noise power. The user can define the frequency where the noise power must be measured. Two possibilities exist:

C/N ratio

Measuring the power of a digital channel by integration.

measurement shows the ratio between the digital channel power

Page 27

I. Absolute method

USER’S MANUAL. PROMAX-10 Premium

Selecting in the Channel-Frequency configuration menu the parameter as

, the equipment will interpret the

FREQ

NOISE FREQ.

NOISE MODE

value as the frequency where the noise power measurement must be done. Naturally the user must be sure that the

NOISE FREQ.

value corresponds with a free channel.

II. Relative method

Selecting in the Channel-Frequency configuration menu the

NOISE MODE

parameter as F, the unit will make the measurement of noise at the frequency obtained to add to the tuning frequency (channel central frequency) the value defined for the

NOISE FREQ.

parameter. The

= BW/2 + 0.5 MHz

, where BW is the channel bandwidth defined in the channel plan,

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takes by default

NOISE FREQ.

thus for example, if it is desired to measure the C/N ratio of a digital channel with a bandwidth (BW) of 8 MHz,

NOISE FREQ.

will take as value 4.5 MHz. The ChannelFrequency configuration menu (paragraph 4.2.3.3) allows the user to redefine this parameter; when tuning a new channel the equipment will return to assign to

the default value.

FREQ.

NOISE

The following figure shows that when making C/N measurements in t he relative method (∆F), it is essential to bear in mind the presence of adjacent channels; otherwise, the noise could be confused with the signal of another channel.

Figure 20.-

Example of digital channels spectrum.

Taking as example the previous figure, if we suppose that for the channels that appear in the figure it has defined a bandwidth of 8 MHz, in the relative mode of measurement the

. Note that this method can cause erroneous measures in the measurement of the

MHz

channels

D24

For

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and

D24

D25

it is advised to configure

will take as value for

NOISE FREQ = -4.5 MHz

NOISE FREQ. = 4.5

and to verify if the measurement increases. In case a channel has two adjacent channels (for example channel

NOISE FREQ.

between

Page 28 05/2004

) it is recommended to select the absolute mode and to assign to the

D25

parameter a frequency corresponding to a free channel (for example

D26

and

D27

Page 28

USER’S MANUAL. PROMAX-10 Premium

4.2.3.1.5 Constellation Diagram representation, Bit Error Rate (BER)

and Modulation Error Ratio (MER) measurement in digital channels.

Once obtained the measurement on tuned channel as well as the representation for the

. (See appendix H 'Principle of QAM modulation. The Constellation Diagram').

The screen like the one of the attached figure. On it besides the also appears the type of for the digital signal appendix G 'Measurement of the modulation digital ratio (MER)'), the represented quadrants (

carries out a new measurement. If the selector rotary is pressed t wo times, it is acceded again to the screen of

quadrants), goes to only a quadrant e.g.: Q1, pressing again CH-FR [10] obtains an extended representation (zooming x4) e.g.: Q1 Z. Pres s CH-FR [10] to return afresh to the

Q1-4 mode.

PROMAX-10

) and the type of detected codification (

Q1-4

When pressing again the rotary selector

Figure 21.- Constellation Diagram representation and

BER and MER measurement in a digital channel.

When pressing the CH-FR [10] from Q1-4 (graphical representation in four

Power and C/N ratio measurement

DVB-QAM

(BER)

Power and C/N ratio measurement

digital signal can be obtained pressing the rotary selector

Premium

QAM

, after some seconds for calculation, will show a

modulation, the symbol rate (SR), the error rate obtained

, the modulation error ratio measurement (

Constellation Diagram

MPEG2

, the

BER

Constellation diagram

, the

PROMAX-10

(section 4.2.3.1.4).

and

graph

) (see

MER

Premium

MER

Englis h

In order to change the quadrant, from Q1-4 press and keep pressed the CH-FR [10] key until a quadrant frame selec tor will appear and slide it by means of the rotary selector [9], locate it in the wished quadra nt and finally loose the CH-FR [ 10] to set the new quadrant for representing.

4.2.3.1.6 Configuration of QAM signal measurement using edit

channel plan.

From the edit channel plan it’s possible to access directly to the followi ng page of the configuration menu of the parameters relative to this mode, for the tuned channel.

Page 29

USER’S MANUAL. PROMAX-10 Premium

The parameters which may be changed and their margins are shown in the following table. To change a given parameter turn the rotary selector [9] until the field i s activated (it will appear shadowed) and then press. The value of the parameter will be activated and may be changed by turning the rotary selector. When the value you want appears, press the rotary selector [9] to validate it.

Figure 22.-

Configuration of digital

signal measurement.

DESCRIPTION PARAMETERS VALUES

System (according to country) QAM Modulation Symbol Rate

Attenuation Channel frequency Offset

(*) Remark:

Including the OP-0 10- E opt ion , ot her wi se the marg in is fr om 10 00 to 700 0.

ANNEX ITU-T

MODULATION

SYMBOL RATE

ATTN.

∆

FCH

DVB, B, C

16, 32, 64, 128, 256

1.000 to 7.200

(*)

Auto or from 0 to 60 dB.

(Steps of 10 in 10)

From - 2.00 to 2.00 MHz

IMPORTANT

To leave the configuration menu, just press the key of the operating mode you wish to access.

4.2.3.2 Frequency tuning and configuration

When in operating mode, pressing again the [10] key switches

tuning by frequency by frequency mode

receiver with a resolution of 10 kHz in the 5 to 862 MHz band. In this mode you may tune to any

signal within the band, including leakage pi lots, telephone and communications signals. To change tuning simply press the rotary selector [9] until the digit you want to change is underlined and then turn the rotary selector [9]. The channel number will appear to the left of the tuning frequency, as long as it corresponds to an active channel.

a) Measurement functions

When the measure the signal level being represented on a graphical bar. Simultaneously, this i s indicated by the loudspeaker which emits a tone that varies with the measured level.

The access to the measurem ent functions from the operation mode when the instrument operates in for the

analogue

CHANNEL-FREQUENCY

CH-FR

tuning by channel

and vice versa. In the

the instrument becomes a

PROMAX-10

digital channels

Premium

, is described in the following figure.

tuning

Figure 23.-

Level signal measurement.

works in frequency tuning, it allows to

CHANNEL-FREQUENCY

channel tuning

frequency tuning

Page 30

USER’S MANUAL. PROMAX-10 Premium

Figure 24. -

Access to the measurement functions, CH-FR operation mode.

The measurements when operating in frequency tuning are identical to the described ones for the channel tuning operation (See section “4.2.3.1 Channel tuni ng”).

b) Configuration

When the

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Premium

works in the FREQUENCY-TUNING operating mode, pressing the

CONFIG

key [14] will access the first page of the configuration menu of the parameters relative to this mode.

Figure 25.-

CH-FR configuration 1/2.

Page 31

USER’S MANUAL. PROMAX-10 Premium

The parameters, which may be changed, and their margins are shown in t he following tables. To change a given parameter turn the rotary select or [9] until the field is activated (it will appear shadowed) and then press. The value of the parameter will be activated and may be changed by turning the rotary selector. When the value you want appears, press the rotary selector [9] to validate it.

DESCRIPTION PARAMETER VALUES

Carrier type

MODE FREQ

ANL: Analogue

DIG: Digital Frequency steps (

Only digital channels

FREQ STEP

)

CHANNEL BW

From 0.01 to 10.00 MHz

From 0.3 to 9.9 MHz Digital channel bandwidth

(

Only digital channels

) Frequency where noise is measured in the C/N measurement.

(

Only digital channels

) Noise measuring mode.

NOISE FREQ.

NOISE MODE FREQ

± 99.9 MHz (relative mode).

5.00 MHz to 862.00 MHz absolute mode.

(Absolute): Noise level is measured at the frequency defined by

NOISE

FREQ.

(Relative): The value

BW/2

defined by

NOISE FREQ.

added to the tuning frequen cy.

(

Only ANL mode

CTB measurement mode (

Only ANL mode

FCS01

∆

(

Only ANL mode

FCS02

∆

(

Only ANL mode

FCS03

∆

(

Only ANL mode

FCS04

∆

System (according to country) QAM Modulation Symbol Rate

Attenuation

)

CTB SHOWED IN CH

FCS01

∆

FCS02

∆

FCS03

∆

FCS04

∆

ANNEX ITU-T

MODULATION

SYMBOL RATE

ATTN.

or free channel

From ± 0.5 to ± 2.50 MHz

From ± 0.5 to ± 2.50 MHz DVB, B, C

16, 32, 64, 128, 256

1.000 to 7.000 Auto or from 0 to 60 dB.

(Steps of 10 in 10)

The parameters

SYMBOL RATE

Page 32 05/2004

are changed digit by digit, starting at the lowest weight.

FREQ. STEP, CHANNEL BW, NOISE FREQ., ∆FCSO

Page 32

USER’S MANUAL. PROMAX-10 Premium

REMARK

: When switching from frequency to channel, if the tuned frequency does not

correspond to any channel, the

PROMAX-10 Premium

will search for the channel nearest to this frequency and will stay tuned to this channel. This operation may take a few moments.

4.2.3.3 CHANNEL-FREQUENCY mode configuration

CHANNEL-FREQUENCY

when the instrument works in channel tuning, pressing the

CONFIG

key [14] will access the first page of the confi guration menu of the parameters relative to this mode.

The parameters which may be changed and their margins are shown in the following table. To change a given parameter turn the rotary selector [9] until the field is activated (it will appear shadowed) and then press. The value of the parameter will be activated and may be changed by turning the rotary selector. When the value you want appears , press the rotary selector [9] to validate it.

DESCRIPTION PARAMETER VALUES

(

Only analogue channels

)

Audio modulation

(

Only analogue channels

)

Audio carrier offset (

Only digital channels

)

Digital channel bandwidth (

Only digital channels

) Frequency where noise is measured in the C/N measurement.

(

Only digital channels

) Noise

measuring mode.

Channel frequency Offset

mode,

Figure 26.-

AUDIO MODE

AUDIO FREQ.

CHANNEL BW

NOISE FREQ.

NOISE MODE FREQ

∆

FCH

CH-FR configuration 1/2.

FM: Audio FM AM: Audio AM LV: The loudspeak er emits

a tone whose frequency varies according to the received signal level.

OFF: Audio deactivation. From 4.00 to 9.00 MHz

From 0.3 to 9.9 MHz

± 99.9 MHz (relative mode).

5.00 MHz to 862.00 MHz absolute mode.

(Absolute): Noise level is measured at the frequency defined by

NOISE

FREQ.

(Relative): The value

∆F

defined by

NOISE FREQ.

is added to the tuning frequency.

From - 2.00 to 2.00 MHz

Page 33

USER’S MANUAL. PROMAX-10 Premium

The parameters

AUDIO FREQ., CHANNEL BW

and

NOISE FREQ.

are

changed digit by digit, starting at the lowest weight.

To accede to the second page of the configuration menu, press

CONFIG

[14]

key again.

The

CTB SHOWED

parameter allows to define the method of measurement for the CTB.

IN CH

(within the channel) is the suitable method whenever the carrier of the channel in study can be turned off. If it is not possible, as approach, any other channel (free) can be defined for the measurement of the CTB.

Parameters

and

∆FCS04

PROMAX-10

∆FCS01, ∆FCS02, ∆FCS03

Figure 27.-

allow to modify the frequencies where the CSO is measured (the

Premium

admits values from -0.5 to -2.50 and from 0.5 to 2.5 MHz).

CH-FR configuration 2/2.

These parameters are modified digit to digit, beginning by the one of smaller weight.

tuning (

Finally,

PROMAX-10

parameter allows to set the frequency offset for the channel

∆

FCH

Premium

admits values from –2.00 to 2.00 MHz).

IMPORTANT

To leave the configuration menu of the CHANNEL-FREQUENCY mode, just press the key of the operating mode you wish to access.

4.2.4 SPECTRUM ANALYSER operating mode.

Pressing the key the unit switches to the SPECTRUM ANALYSER mode. This function has 4 different operating modes (SPECT, MAX, MIN and TRANS), which are selectable through the spectrum mode configuration menu (see section 4.2.4.5).

4.2.4.1 SPECTRUM operating mode.

In the

SPECTRUM

analysis of the band; the span and the reference level are variable. The spectral analysis can be done in the spectrum configuration menu (section 4.2.4.5); this menu also allows to select the

detector

used for the representation of the spectrum between

The marker frequency is displayed in the higher left hand corner of the screen (650.00 MHz) and, to its right, the frequency signal level (34 dBµV). To alter the marker frequency turn the rotary selector [9].

mode, the

forward band

PROMAX-10

or in the

return path

Premium

peak

Figure 28.-

provides a spectral

as it is selected in the

and

average

SPECT mode.

Page 34

USER’S MANUAL. PROMAX-10 Premium

By pressing the rotary selector [9] you can alter the

between 1 MHz and

span

100 MHz.

Frequency tuning resolution varies according to the span selected, as shown in the following table.

Figure 29.-

SPECT mode, span reduction.

DETECTOR SPAN

PEAK

100 MHz (full span in the

return path)

50 MHz 450 kHz 30 MHz 275 kHz 15 MHz 135 kHz

5 MHz 45 kHz 1 MHz 10 kHz

AVERAGE

30 MHz 280 kHz 15 MHz 140 kHz

5 MHz 50 kHz 1 MHz 10 kHz

By pressing the rotary selector [9] again the reference level may be modified.

Pressing the rotary selector [9] a second time will activate the tuning frequency field of the marker, being possible to tune new frequencies.

The attached figure shows an horizontal line at 45 dBµV. This line allows to identify levels over a reference of our interest easily. The activation and definition of this

reference line

is carried out on the

spectrum analyser configuration menu.

FREQUENCY

RESOLUTION

Figure 30.-

modification.

Figure 31.-

900 kHz

Reference level

Reference line.

4.2.4.2 MAX operating mode.

The SPECTRUM operating mode also permits to be configured as (MAXIMUM INGRESS). This option is selected on the Spectrum Configuration menu (section 4.2.4.5). In the

mode, the

MAX

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screen the maximum measured level through a dotted line.

maximum hold

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holds on the

Figure 32.-

MAX mode.

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USER’S MANUAL. PROMAX-10 Premium

This measurement is used to be carried out on the

path and permits to

return

detect intermittent interferences.

Since on this operation mode the

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holds on the screen the maximum measured value (through a dotted line), after making several measurements over the band, it will be possible to detect impulsive type interferences. It is advised to previously define a reference line which actuates as a maximum noise threshold (30 dBµV on previous figure).

4.2.4.3 MIN operating mode.

This measurement permits to detect permanent channel interferences that in an other way could remain masked because of the variable nature of the signal. It is interesting in analogue channel measurements as well as in digital channel.

To select this representation mode you must select the INGRESS (see section 4.2.4.5. Spectrum mode configuration menu).

In this operating mode it is advised to select the

Average detector

4.2.4.5. Spectrum mode configuration menu).

Figure 33.-

MIN mode. First scan.

Figure 34.-

Previous figures show an example of this measurement over a digital channel. Left figure corresponds to the first sweep. After several sweeps (right figure) an interference is seen at the centre of the channel, which previously remain masked by the noisy nature of the signal.

mode, MINIMUM

MIN

(see section

After several scans.

4.2.4.4 TRANSIENT DETECTOR operating mode

IMPORTANT

The Transient detector mode is only operative in the return path.

The TRANSIENT DETECTOR mode allows to count the number of transitory with a level higher than a certain threshold. The threshold is defined by the user (between 20 and 60 dBµV) as well as the detection frequency range.

The frequencies on which the detector acts (the higher frequency can be reduced by means of the

parameter on the configuration menu).

FREQ.

The lower line ( the detector is active.

Page 36 05/2004

field shows the margin of

SCAN

) shows the time since

TIME

STOP.

Figure 35.-

Transient detector mode.

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USER’S MANUAL. PROMAX-10 Premium

The level defined by the mode (section 4.2.5.5).

dotted line shows the detection threshold (REF. LINE) whereas the continuous line indicates the maximum detected level.

COUNTER

To initialize the TIME and COUNTER fields, press the

In the lower part of the screen it appears a bar that shows present level, a

field shows the number of impulses that have exceeded the

REF. LINE

parameter in the configuration menu of the SPECT

SPECT

[13] key.

4.2.4.5 SPECTRUM ANALYSER mode configuration

Pressing the access the parameter configuration menu for the

SPECTRUM

To change the value assigned to one parameter, turn the rotary selector [9] until its field is activated (this will appear shadowed) and t hen press. The value of the parameter will be activated and may be changed by turning the rotary selector. When the value you want appears, press the rotary selector [9] to validate it.

The parameters that can be modified through this menu are:

a) BAND

It selects the analyzed band between:

b) MODE

It selects the representation mode:

CONFIG

function.

RETURN PATH FORWARD

SPECT MIN MAX TRANS

key [14] will

Figure 36.-

Sub-band spectrum (5 to 100 MHz). Band from 45 to 862 MHz.

Instantaneous value. Minimum values held (MIN INGRESS). Maximum values held (MAX INGRESS). Transient detector. Only operative in the return path.

SPECT mode configuration.

Englis h

c) DETECTOR (Only for the SPECT, MAX and MIN modes)

It selects the used detector between:

PEAK AVERAGE

In the

d) REF. LINE

It permits to activate / deactivate and to define the reference line level in 1 dB

steps from 20 to 120 dBµV (dBµV units). This line appears on the spectrum

representation and also it is the threshold value for the impulses detection in the

TRANSIENT mode (only if its value is under 60 dBµV).

e) STOP. FREQ

It defines the maximum frequency for the transient detection.

mode the detector used is always

TRANS

PEAK

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IMPORTANT

To leave the configuration menu of the SPECT mode, just press the key of the operating mode you wish to access.

4.2.5 TILT operating mode.

The

operating mode displays on-screen, graphically and numerically, the

TILT

difference in level between any four frequencies previously defined as pilots. This function provides a quantitative measurement about band equalisation.

This function can be applied to forward and to the return paths, according to is defined in the TILT mode configuration menu (section 4.2.5.1 Tilt mode configuration).

To access this mode of operation press the

key [12]. The screen will

TILT

show a bar-graph of the four pilot chann els and the difference in level (TILT) between the upper pilot and the lower pilot (- 5 dB in the example). When the pilots are not present or it s level is lower than 20 dBµV, the message ‘

NO PILOTS

rotary selector [9] the reference level may be modified.

’ will appear. Turning the

igure 37.-

TILT mode.

The pilots may be defined in two ways:

a) By frequency

Using the TILT configuration menu. See section 4.2.5.1 Tilt mode configuration.

b) By channel

From the

(only pilots in the forward band). mode. In order to do this:

SCAN

1. Place the marker over the channel you want as low pilot.

2. Press the

key [11], and the message ‘

SCAN

PILOT 1: PRESS TILT

will appear at the bottom of the screen.

3. Keeping the message ‘

PILOT 1 ENTERED

key [11] held down, press the

SCAN

’ will appear as confirmation.

key [12], and a

TILT

Repeat the steps 1 to 3 for the 3 following pilots.

’

4.2.5.1 TILT mode configuration.

Pressing the

CONFIG

access to the first page of the configuration menu.

To change a given parameter turn the rotary selector [9] until the field is activated (this will appear shadowed) and then press. The value of the parameter will be activated and may be changed by turning the rotary selector. When the value you want appears , press the rotary selector [9] to validate it.

Page 38 05/2004

[14] key will

Figure 38.-

TILT configuration. 1/2

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a) BAND

It permits to select between the

RETURN PATH

mode (5 to 100 MHz).

FORWARD

mode (45 to 862 MHz) and the

b) F. PILOT 1

It defines a frequency belongi ng to the forwar d band (from 45 to 862 MHz) where the first measurement of level will be done. This paramet er, and the res t of pilots, is defined digit by digit, by pressing repeatedly and turning the rotary selector.

c) F. PILOT 2

It defines the second pilot frequency belonging to the forward band.

d) F. PILOT 3

It defines the third pilot frequency belonging to the forward band.

e) F. PILOT 4

It defines the fourth pilot frequency belonging to the forward band. To accede to the second page of the

TILT configuration menu, press the

CONFIG

key again. This screen permits to define the frequencies of the pilots belonging to the return path (from 5 to 100 MHz). As in previous screen, the frequencies are defined digit by digit.

Figure 39.-

TILT configuration 2/2

IMPORTANT

To leave the configuration menu of the TILT mode, just press the key of the operating mode you wish to access.

4.2.6 DATALOGGER operating mode.

The

LOGGER

Carrier/Noise ratio and the Video/Audio ratio (the latter only in the case of analogue channels) as well as the power channel and MER measurements of each active channel in the channel plan (see paragraph Channel Plan editor at section 4.2.1. Unit Global Configuration). These measurements are stored in the memory so that they can be subsequently viewed, printed or transferred to a PC. The store up to 55 obtained channels or loggers in the memory, with a maximum of up to 140 analysed channels in each.

When pressing the key, a screen similar to the one of the attached figure will appear. The first line shows the logger number (i.e. 53 in the attached fi gure) followed by the date it was acquired (only if MEASURE funct ion was executed on that logger previously). Below, the different functions you can perform from this operating

mode are shown:

function permits to automatically measure the level, the

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and

[16]

Figure 40.-

LOGGER function. Initial menu.

LOGGER

VIEW, MEASURE

will

Englis h

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USER’S MANUAL. PROMAX-10 Premium

On the bottom of the display appears present time and date. To modify them see section 4.2.1 Global Configurat i on Menu.

To accede to any of the di fferen t f ields of the initial screen of the LOGGER funct ion , turn the rotary selector [9] unt il it i s act i vated (i t appe ars shadowed) and next press it .

First of all you must select the logger on which you want to perform any function: turn the rotary selector unt il the

LOGGER NUMBER

field is shadowed and press it. Then turning the rotary selector, select the desired logger (from 0 to 54) and finally press it again to validate. The acquisition date appears under the logger number (only if you have taken measurements on this logger).

To carry out a logger acquisiti on you must select the

MEASURE

function, for this purpose turn the rotary selector [9] and when this field appears s hadowed press it , in this way you will accede to the logger. Next press again the rotary selec tor [9] in order t hat t he

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makes all the measurements defined in the LOGGER configuration menu over all the ac tive channels of the channel plan (s ee Edit Channel Plan function at section 4.2.1 Global configuration menu).

IMPORTANT

The processing of channels as analogue or digital and the parameters to make the measures (the frequency of the audio carrier for the analogue channels and the frequency offset for the noise measure of the digital channels C/N ratio) will correspond with the configuration of the equipment at the time of carrying out the measurement.

To return to the initial menu of the LOGGER function press the

LOGGER

To check the measurements stored in a specific logger select the

VIEW

key.

option:

The first line shows the channel plan (CCIR in the example), the audio carrier offset (5.50 MHz), the audio demodulation (FM) and the units of measurement (dBµV). The second line shows the logger number (53 in the attached figure) and the headings of the measurements (V,

and

V/A

shown in the following format: first column s hows the

). The measurements taken are

C/N

Figure 41.-

Viewing a logger.

channel, the D indication on its right means it has been defined as digital (see Edit Channel Plan function at section 4.2.1 Global configuration menu), the second column shows the level (analogue channels) or the channel power (digital c hannels), the third the V/A ratio (analogue channels) an the fourth the C/N ratio (analogue c hannels) or MER (digital channels). Turning the rotary selector [9] you can see the rest of channels.

The time and date when measurements were taken appear at the end of the list of measurements, in the following order: hour:minute:second and month:day:year. To return to the initial menu of the LOGGER FUNCTION press

To print the stored measurement select the

LOGGER

key.

field, previously consult

section 4.3 Connecting to a computer or a printer.

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LOGGER NUMBER 10 DATE: 08:55 21-03-2004 CHANNEL PLAN: CCIR

AUDIO: 5.50 MHz (FM) UNITS: dBuV THRESHOLD: OFF NOISE FREQ.: BW/2

CHAN FREQ V V/A C/N C23 487.25 76 14 52 C25 503.25 53 9 33 C27 519.25 81 16 55 C29 535.25 59 13 39 C31 551.25 78 16 44 C34 575.25 67 11 45 C37 599.25 54 7 34 C38 607.25 57 14 >37 C39 615.25 62 18 >42 C41 631.25 71 14 43 C43 647.25D 43 13 C14 70 MER = 33

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BER = 8.8E-6

Figure 42.-

Example of print.

4.2.6.1 Datalogger configuration.

From the LOGGER mode, when pressing the

CONFIG

to the configuration menu. This menu permits to modify the parameters. To accede to them turn the rotary selector and once the parameter we want to change is appears shadowed, press it; then turning it its value will be modified. Finally press it again to validate the new value.

a) THRESHOLD: It activates / deactivates the measurement threshold.

This parameter allows to carry out the logger function in an agile way, by activating only those measures we consider signific ative. In the higher than 20 dBµV). On the other hand, when a level is defined, only those channels with a level higher than the measured.

b) MEASURES: It defines the types of measurements to be made.

This parameter allows to select the measurements that are desired to made between:

key [14] we will accede

THRESHOLD

mode (deactivated) all measurements are taken (with a level

OFF

and

MEASURES

Figure 4.3.-

Logger configuration menu.

THRESHOLD

Englis h

value will be

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USER’S MANUAL. PROMAX-10 Premium

ANALOGUE CHANNELS DIGITAL CHANNELS

Carrier /

Noise

Ratio

Power MER BER

Yes

LEVEL / POWER

AV - C/N / MER

AV-CN / MER-

BER

(*) Note:

The

Level

Yes - - Yes - -

Yes Yes Yes Yes Yes -

Yes Yes Yes Yes Yes

measurements represent an increase of the data acquisition time.

BER

Audio /

Video Ratio

IMPORTANT

To leave the configuration menu of the DATALOGGER mode, just press the key of the operating mode you wish to access.

4.3 Connection to a Computer or Printer.

The

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Premium

for data transfer, by means of the connection cable model

Do not connect any cable other than that supplied by the manufacturer, otherwise serious damage may be caused to the equipment.

1) Prior to connecting the equipment to a PC, disconnect both from their respective power supplies.

2) Connect the end of the connection cable corresponding t o t he

Premium

to connection [8] and the other end to the serial port of your

computer or printer.

permits the connection to a PC or to a serial printer

CC-208

PROMAX-10

(

Once the computer or printer have been connected, select on the

Premium

the

LOGGER

operation mode. If

function is selected data will be

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dumped to the remote unit through the serial port.

The communication parameters used by the

PROMAX-10

Premium

, and which

therefore must be defined on the remote unit (PC or printer) are the following:

Rate Data bits Parity Stop bits

Page 42 05/2004

19200 bauds 8 bits None 1

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USER’S MANUAL. PROMAX-10 Premium

The remote control software

from a computer the following options:

1) CHANNELS PLAN PROCESSOR: Modify, add or delete channel plans.

2) CONFIGURATION: Permits to modify all the configuration parameters.

3) DATALOGGER: Permits to edit and to save all the measurement contained in a logger.

4) UPDATE: Allows to update the

PROMAX-10 Premium

(optional accessory) permits to carry out

RM-010

software version.

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USER’S MANUAL. PROMAX-10 Premium

5 MAINTENANCE

This part of the manual describes the maintenance procedures and the location

of faults.

5.1 Instructions for returning by mail

Instruments returned for repair or calibration, either within or outwit the guarantee period, should be forwarded with the following information: Name of the Company, name of the contact person, address, telephone num ber, receipt (i n the c ase of coverage under guarantee) and a description of the problem or the service required.

5.2 Method of maintenance

The method of maintenance to be carried out by the user consists of cl eaning the cover and changing the battery. All other operations should be carried out by authorised agents or by personnel qualified in the servicing of instruments.

5.2.1 Cleaning the cover.

CAUTION

Do not use scented hydrocarbons or chlorized solvents. Such products may attack the plastics used in the construction of the cover.

The cover should be cleaned by means of a light solution of detergent and water applied with a soft cloth. Dry thoroughly before using the system again.

CAUTION

To clean the contacts, use a dry cloth. Do not use a wet or damp cloth.

CAUTION

Do not use for the cleaning of the front panel and particularly t he viewf inders, alcohol or its derivatives, these products can attack the mechanical properties of the materials and diminish their useful time of life.

5.3 Components which user can not replace

5.3.1 Not replaceable fuses by user

To be replaced by qualified personnel. Its position identifier and characteristics are:

F001: FUS 0.5 A T 125 V F002: FUS 2.5 A T 125 V

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USER’S MANUAL. PROMAX-10 Premium

APPENDIXES

APPENDIX A.- MEASUREMENT OF THE VIDEO CARRIER LEVEL (CL)

-ANALOGUE CHANNELS-

A) Negative Video Modulation (PAL/NTSC)

The measurement of the video carrier level is carried out taking the modulation peak as the measurement value, this being the maximum value of the signal during the line synchronism. The system requires a minimum length of time in order t o make this measurement, since it has to detect the peak of the modulated signal.

Figure 44.-

The typical values between which the video carrier level fluctuates are:

- In the transmission line: From 70 to 100 dBµV (From 10 to 40 dBmV)

- In the user’s terminal: From 60 to 80 dBµV (From 0 to 20 dBmV)

B) Positive Video Modulation (SECAM)

On this type of modulation, the line synchronism is defined by a minimum carrier level. The maximum signal level (measurement point) is variable in time, and it is a function of the picture that is being transmitted. It could vary from 10 dB among white and black image; nevertheless white signals, Video I nsertion Test (VIT), are t ransmitted in the sweep pulses, which reduce this margin to 4 dB approximately.

Due to this fact, and the small duration of the VIT, when we measure levels of SECAM signals, it is advisable to add 2 dB to the quantity showed on the displ ay, in order to obtain a more accurate measurement in its average value.

Measurement of the video carrier level.

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APPENDIX B.- MEASUREMENT OF THE ADJACENT CHANNEL LEVEL

-ANALOGUE CHANNELS-

The user can obtain the ratio between the video carrier amplitudes of two adjacent channels.

−

)dB(CC

2LV1LV

Figure 45.-

Measurement of the adjacent channel level.

Differences of more than 3 dB between carriers of adjacent channels may cause problems of interference in reception.

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APPENDIX C.- MEASUREMENT OF THE VIDEO / AUDIO RATIO

-ANALOGUE CHANNELS-

)dB(AVA/V

−=

It permits to measure the ratio between the video carrier and the audio carrier amplitudes.

Although this process depends on the standard used, it is usual to consider that a properly transmitted PAL channel should have a sound subcarrier 13 dB below the video carrier.

Englis h

Figure 46.-

These specifications ensure that there is no interference in the same or the adjacent channel.

Video / Audio ratio measurement.

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APPENDIX D.- CARRIER TO NOISE RATIO (C/N)

-ANALOGUE CHANNELS-

The Carrier to Noise ratio is a signal quality measurement. The noise power depends on the measurement filter bandwidth, in analogue TV it is usual to refer the noise level to a bandwidth of 5 MHz (this is the case of the

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Premium

is desired to know the C/N measurement for a different bandwidth (BWx), the following correction should be applied.

Starting from the C/N definition:

NCN/C

−=

BWBW

where C: Video carrier level N

: Noise power referred to a BWx measurement bandwidth

BWX

and as the noise power referred to BWx could be related with the noi se power referred to 5 MHz according to:

log(10NN

MHz5BW

)

MHz5

the C/N ratio referred to a noise measurement bandwidth BWx should be expressed as:

). If it

BWx

log(10NCNCN/C

MHz5

−=−−=−=

10PROMAXMHz5BWBW

−

BWx

log(10N/C)

)

mhZ5

That is to say, the factor 10 log (BWx / 5 MHz) should be subtracted to the

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Premium

readout.

There exist some standards that determine the minimum C/N value for an installation. In general, greater values than 40 dB are considered as good quality signals. Under 40 dB snow should appear on the TV screen.

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APPENDIX E.- CARRIER / NOISE RATIO MEASUREMENT (C/N)

Englis h

Figure 47.-

Example

Suppose that the video carrier level for an analogue channel, is of 10 dBmV,

from the diagram we can deduce that the measurement range is of 48 dB.

Thus, if when we carry out the measurement the C/N ratio is 54 dB the display

will show C/N > 48 dB.

On the other hand, if C/N=42 dB we will see on the display C/N = 42 dB.

C/N ratio measuring range.

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APPENDIX F.- CARRIER TO NOISE RATIO FOR 64-QAM DIGITAL

CHANNELS (C/N).

For a 64-QAM DBV-C digital signal with a bandwidth of 8 MHz, the C/N ratio must be better than 20 dB. Measurements lower than this value will correspond to signals with a no acceptable quality.

Justification and example

The basic parameter which describes the quality of a digital signal i s the ratio of the number of erroneous bits to the total number of bits transmitted. This parameter is known as BER (Bit Error Rate).

The DBV Group (Digital Video Broadcasting) defines a 'quasi error free transmission' (ETR290 Measurements Group ETR 290) as that with less than 1 error event per transmission hour. For a 64 QAM DBV-C transmission, the pre-FEC error (Forward Error Correction) must be <1.E-4.

In digital transmissions, as there is not one carrier, it is better t o speak in Eb/ No terms. The relation between Eb/No and the C/N is given by the following equation:

)dB(N/C

)M(log

*Rlog(*10)dB(

)

Where:

E b = Energy per bit N o = Noise power in a 1 Hz bandwidth R s = Symbol rate M = Number of points of the constellation

BW = Bandwidth

For DVB-C, 64 QAM, Rs=6.875 Mbaud, BW=8 MHz,

C/N (dB) =Eb / No (dB) + 7.12.

For a BER of 1E-4, Eb/No ≈ 16 dB. Therefore C/N ≈ 23 dB.

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APPENDIX G.- MEASUREMENT OF THE MO DULATION ERROR RATIO

(MER).

Analogue and digital carriers are very different i n terms of the signal c ontent and the power distribution over the channel. Therefore need to be measured differently.

The amount of distortion in a system is related to the total power of all of the carriers making accurate power measurements critical for optimum performance.

Instruments such as signal level meters that are designed to measure only analogue carriers will not accurately measure digital carriers.

Modulation error ratio ( Signal/Noise ( of the error power to the average power in an ideal at least 4 or 5 dB of margin from the system degradation. (noise) impairments, such as system noise and the second and third order beats ( and noise.

failure of the digital system. Unlike analogue systems where you can see degradations in Carrier/Noise ( to the point of system failure.

). This measurement takes in account not only amplitude noise, but also phase

CTB

Determining the

MER

) measurement used in analogue systems.

S/N

measurements are useful for early detection of non-transient

MER

of a signal is a key part of determining the margin from

MER

) performance, a poor

C/N

is defined as follows, expressed in dB:

log20

), used in digital systems is analogous to

MER

signal. Ideally you should have

QAM

where significant errors occur, to allow for

MER

is not noticeable on the picture right up

MER

magnitudeerrorRMS

represents the ratio

MER

)dB(

CSO

magnitudesymbolaverage

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05/2004 Page 53

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RMS Error Magnitud e

Ideal Symb ol

Average Symbol Magnitude

64 QAM

Figure 48.-

Modulation error ratio (

set decoders require better than

23 dB MER

)

MER

to operate. To allow for system degradation, a margin of at least 3 or 4 dB is preferred. However, decoders require better than Typically the maximum

was chosen as the preferred measurement for cable TV because of it’s

MER

28 dB MER

displayed on portable analysers is about

MER

similar to the analogue Carrier/Noise (

to operate with margins of

34 dB

) measurement expressed in dB that most

C/N

people from cable industry are familiar with.

QAM 256

at least.

3 dB

set

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APPENDIX H.- PRINCIPLE OF QAM MODULATION.

THE CONSTELLATION DIAGRAM

The modulation process implies to transfer the informat ion cont ained in a s ignal to a high frequency carrier. Modulation consisting of two carriers each one of the same frequency , one called I (in phase) and another out of phase 90° called Q (quadrature).

Each one of them is modulated in amplitude and phase by a portion of the digital input signal. The two modulated signals are combined then and they are transmitted as a single waveform. The receiver only needs to invert the process for generating a digital output that can be processed to produce images or anot her useful information also.

The number of levels used in the modulation of each carrier determines the number of possible symbols and, consequently, the number of bits that can be transmitted in a certain bandwidth. The

16 QAM, 32 QAM, 64 QAM, 128 QAM

For example, if four amplitude levels are applied to each one of the carriers, each signal could reach the value of -3.0, -1.0, +1.0, +3.0 at a given instant in time, so we have 16 possible combinations. This is known as exposition to four amplitudes, it allow us to generate 8 states for each carrier and 64 possible combinations (

64 QAM

, in concrete uses modulation in quadrature

QAM

standard allows 5 types of modulation:

DVB-C

and

256 QAM

16 QAM

. Extending the previous

These digital signals can be visualized graphically by means of the

Constellation Diagram

carrier (signal I or signal in phase) we would obtain the image in figure 49.

. If one imagines on an axis the possible states of the first

Figure 49.-

Figure 50.-

Signal I states

Signal Q states

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Figure 50 shows the other signal (Q in quadrature) on a vertical axis to consider the 90° phase change.

Figure 51.- I-Q

states combination

Figure 51 shows the combination of these two signals. This image constitutes the Constellation Diagram of the modulated digital signal.

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APPENDIX I.- FREQUENCY OFFSET ADJUSTMENT FOR TUNING

ANALOGUE AND DIGITAL CHANNELS.

It is possible to introduce an offset of the tuning central frequency for the channels defined in each channel plan using the it is possible to adapt the measures to irregular tunings, due t o small displacements on channel central frequencies that are defined by the standard channel plan.

parameter (± 2 MHz). Therefore,

∆

FCH

Figure 52.-

Taking as example the previous figure, if we suppose that in the configuration parameters of the digital channel (CH-33) a frequency offset equals to 1 MHz has been defined for the channel tuning frequency (∆FCH = -1MHz), although the central frequency corresponding to channel 30 (569 MHz) does not match with the defined one for the current CCIR channel plan (CH-33, 570 MHz), it will be possible to take measures corresponding to the Docsis normative for the standard FCC channel plan (CH-30, 569 MHz) with no need to modify the current channel plan or to ent er a new one.

Frequency offset on the tuning central frequency.

Englis h