Promax GV-698 User manual

TV SIGNAL GENERATOR
GV-698
1 GENERAL
1.1 Description
The GV-698 TV signal generator is a multi-standard, multi-system unit with
advanced functions. It has been designed using the most modern technology resulting
in great reliability and reduced consumption. Its modular structure makes it highly
versatile and permits rapid access to all its components. Starting from base modules,
it is possible to increase the applications of the instrument by adding modules if
desired.
The GV-698 is particularly suitable for those industrial sectors that require
high-quality pictures such as adjustment and analysis lines, production studios,
technical assistance services, etc. In addition, being easy to operate, it is indispensable
in the training of video technicians.
The GV-698 operates in accord with the CCIR/OIRT recommendations for the
colour systems PAL-SECAM and FCC for the NTSC system and may provide a
modulated signal for practically all the transmission standards presently in use. The
video is equipped with 32 pattern charts to analyze the picture visually or with an
oscilloscope. For geometric adjustments, the electronic circle can be inserted in all the
charts.
To detect defects in the tuning circuits and IF amplifier stages, the GV-698 has
a complete radio-frequency modulator, its principal characteristics being:
- Frequency range from 37 to 865 MHz
- Synthesized frequency output
- Tuning by channels or by frequency (in steps of 50 kHz)
- Attenuation of output RF signal up to 50 dB (in steps of 10 dB)
The VTR (Video Text Recorder) function is available to check the functioning
of video tape recorders, particularly the functions of "still", stepped image, heads
position, etc.
Microprocessor control, the presentation of information on a wide illuminated
alphanumeric display and the incorporation of a single rotary selector for all the
functions results in simple and easy operation. The functions controlled are:
- Selection and display of RF by channel or by frequency
- Selection of the colour system and sound standard
- Selection of the output chart
- Storage of up to 32 different programs is possible. Each program
(chart/system-sound standard/frequency or RF channel) may be stored or
retrieved at any time.
Internal (1 kHz/3 kHz) or external modulation of sound is possible. For a
superior analysis of the video and sound signal, there are push–buttons for cancelling
or including certain basic functions, such as:
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- Independent cancellation of the colour subcarrier and of the burst
- Inclusion of the electronic circle
- Cancellation of the interlace in the video signal
- Cancellation of the sound subcarrier
- Selection of stereo or dual sound
- Independent cancellation of L and R sound
- Cancellation of the TELETEXT and VPS signal
- Selection of the information to transmit in the VPS signal
On the front panel there is an adjustable composite video output and an RF
output with an attenuator of up to 50 dB. In addition, numerous auxiliary inputs and
outputs increase the possibilities of the instrument considerably. These supplementary
connectors are located on the rear panel:
-S–VHS output
- R, G and B (or G plus synchronisms) outputs
- Composite synchronisms output
- Synchronisms output for an oscilloscope
- L and R sound input
- In the Euroconnector:
- Composite video output
- R, G, B (or G plus synchronisms) outputs
- L and R sound inputs and outputs
- Video input (external signal modulation)
The GV-698 has a series of functions which may be optionally included (see
the list of versions and options under item 1.2 of the specifications). The GV–698/11
version includes all these functions.
- Generator module of the TELETEXT and VPS signals. During recent years,
there has been a growing acceptance of TELETEXT on the part of users,
and the majority of television sets incorporate it. With the GV-698, it is
possible to generate 8 pages in two languages, which can be selected from
the television set (by number or by means of the FLOF or FASTEXT
function), with different combinations of graphics and text in 1.0 and 1.5
levels which permit the verification of all the decoding functions.
The VPS signal (Video Program Service) is an information signal, which is
emitted by television channels during a program, that may activate or stop
the users' video recorders if they are equipped with this feature. This
eliminates the problems caused by changes in the programming to be
recorded.
- Generator module of the stereo/dual (Zweiton) signal either generates a
second sound carrier to be used as a second mono sound channel, or
provides the right channel stereo information. This signal, like the main
carrier, may be modulated by an external signal.
- Generator module of the NICAM signal for PAL G and I. The demand for
better quality sound in television systems has resulted in the appearance of
digital coding of sound. This module enables the testing of equipment which
has this feature.
On request by the customer, the logotypes can be custom-programmed to
personalize the source of the image.
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1.2 Specifications
The values indicated with tolerances are guaranteed by the manufacturer, those
without are to be nominally expected within a group of identical instruments.
Specifications are valid 10 minutes after switching on.
TV SYSTEM
System PAL/SECAM NTSC
RF Standard B,G,H,D,K,K1,I,L M
No. of lines/frame 625 525
Field frequency 50 Hz 60 Hz
Line frequency 15625 Hz 15734 Hz
Horizontal synchronism
Line period (1/fH)64 µs ± 100 ns 63.56 µs ±100ns
Front porch 1.6 µs ± 100 ns 1.59 µs ± 100 ns
Synchronism 4.8 µs ± 100 ns 4.77 µs ± 100 ns
Blanking 12 µs ± 100 ns 11.12 µs ±100ns
Vertical synchronism
Frame period 20 ms ± 100 ns 16.68 ms ± 100 ns
(H = 64 µs) (H = 63.56 µs)
Blanking 25 H + 12 µs 21 H + 11.12 µs
Duration of impulse of:
Pre-equalization 2.5 H 3 H
Equalization 2.5 H 3 H
Post-equalization 2.5 H 3 H
Scanning of picture Selectable: Interlaced ratio 2:1
Not interlaced
PAL (B,G,H,D,I) colour subcarrier
Frequency 4.43361875 MHz <± 30 ppm (10ºC to 40ºC)
Burst duration 2.4 µs (10 ± 1 period of Fsc)
Burst position 5.6 µs ± 100 ns from the line previous
synchronism flank.
Phase ± 135ºreferred to the U axis with the sequence
Line Frame
1 2 3 4
Even - - + +
Odd + + - -
Amplitude error ± 5 %
Phase error ± 3 %
Burst amplitude ON/OFF, selectable
Subcarrier amplitude ON/OFF, selectable
NTSC (M) colour subcarrier
Frequency 3.579545 MHz <± 30 ppm (10ºC to 40ºC)
Burst duration 2.38 µs (10 ± 1 period of Fsc)
Burst position 5.56 µs ± 100 ns from the line previous
synchronism flank.
Phase - 180ºreferred to the U axis
Amplitude error ± 5 %
Phase error ± 3 %
Burst amplitude ON/OFF, selectable
Subcarrier amplitude ON/OFF, selectable
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SECAM (B,G,H,D,K,K1,L) colour subcarrier (Version /3,/5,/11)
Subcarrier frequency For = 4.406250 MHz ± 2 kHz
(sinc. fH)Fob = 4.250000 MHz ± 2 kHz
Identification pulses
Frame (position) Line 7 to 15 in odd fields
Line 320 to 328 in even fields
Frequency Dr = 4.756250 MHz ± 35 kHz
Db = 3.900000 MHz ± 35 kHz
Frame Selectable ON/OFF with interlace button
Line Selectable ON/OFF with burst button
Chrominance signal
Amplitude D'r = -1.9 (E'r - E'y)
D'b = 1.5 (E'b - E'y)
Precorrection of chrominance Bell filter
Central frequency
of Bell filter 4.286 MHz ± 0.020 MHz
DISPLAY Digital, 16 characters, with chart, TV
standard/sound system, channel and
frequency (5 digits) indications. Program
indicated in the Store/Recall mode.
RADIO–FREQUENCY OUTPUT
Range covered 37 to 865 MHz (synthesized)
Tuning By frequency: in steps of 50 kHz
By channels: CCIR (FCC Version /1,/6,/8)
Store/recall 32 programs
Frequency indicator 5 digits
Output amplitude 90 dBµV ± 3 dB
Attenuation 50 dB (in steps of 10 dB)
Impedance 75 Ω
Connector BNC
VIDEO MODULATION
Modulation type AM, double side band
Modulation index 85% (internal modulation)
VIDEO OUTPUT
Impedance 75 Ω
Amplitude Variable from 0 to 1.2 V
Nominal value 1 V
Polarity Positive
Coupling Direct coupling
Blanking cont.lev. 0 V (nominal)
Connector BNC or Euroconnector
Y–C (S–VHS) OUTPUT COMPONENTS
Impedance 75 Ω
Amplitude 0.7 V (max. white level luminance)
0.3 V (colour burst)
Connector S–VHS
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R–G–B OUTPUTS
Impedance 75 Ω
Amplitude 0.7 Vpp
G synchronisms 0.3 Vpp (selectable ON/OFF)
Connector BNC or Euroconnector
SYNCHRONISMS OUTPUT
Impedance 75 Ω
Amplitude 2.0 Vpp
Polarity Positive or negative (selectable)
Connector BNC
OSCILLOSCOPE TRIGGER OUTPUT
Impedance 75 Ω
Amplitude 2.0 Vpp vertical, 1.5 Vpp horizontal
Connector BNC
SOUND OUTPUT
Impedance 1 kΩ
Amplitude 0.4 Vpp
Connector Euroconnector
VIDEO INPUT
Impedance 10 kΩ
Coupling Direct coupling
Connector Euroconnector
EXTERNAL L.F. SOUND INPUT
Impedance 100 kΩ
Amplitude Max. 0.5 Vpp
Bandwidth 100 Hz to 15 kHz
Connector DIN 41524 or Euroconnector
SOUND MODULATION (MULTISTANDARD–MONO)
Carrier
(sinc. fH)ON/OFF selectable
Frequency 4.5 MHz (M)
5.5 MHz (B,G,H)
6.0 MHz (I)
6.5 MHz (D,K,K1,L)
Video/sound
carrier ratio 13 dB
Type of modulation Int. FM (1 kHz) (M,B,G,H,D,K,K1,I)
(selectable) Ext. FM
AM (L)
FM modulation
Pre-emphasis 50 µs (B,G,H,D,K,K1,I)
75 µs (M)
Modulation deviation 30 kHz (in FM)
Modulation index 50 % (in AM)
MODULATION OF STEREO/DUAL SOUND (ZWEITON) (OPTIONAL, OPT-698-2)
Carrier ON/OFF selectable
Sinc. fHCarrier 1 Carrier 2
Frequency 5.5 MHz 5.7421875 MHz
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Video/sound
carrier ratio 13 dB 20 dB
Type of modulation Int. FM (1 kHz) int. FM (3 kHz)
(selectable) Ext. FM Ext. FM
Max. 0.5 Vpp Max. 0.5 Vpp
Pre-emphasis 50 µs 50 µs
Modulation deviation 30 kHz 30 kHz
Mode
Dual LR
Stereo (L+R)/2 R
Detection mode
Pilot frequency 54.6875 kHz (3.5*fH)
Modulation AM
Modulation index 50 %
Identif. frequency 274.1 Hz (fH/57) dual
117.5 Hz (fH/133) stereo
MODULATION OF NICAM SOUND (OPTIONAL, OPT-698-4)
Carrier ON/OFF selectable
PAL B,G, L 5.850 MHz <± 30 ppm
PAL I 6.552 MHz <± 30 ppm
Carrier ratio
video/sound 20 dB (B,G,I), 26 dB (L)
Modulation 4QPSK
Modes Mono, dual, stereo
Internal sources
Channel 1 1 kHz, ON/OFF selectable
Channel 2 3 kHz, ON/OFF selectable
Sound reserve flag ON
Signal coding 32 samples/block
16 blocks.
Transmission speed 728 kbits/s
Pre-emphasis In accord with CCITT Rec. J17
Spectrum form 40% roll-off cosine (PAL B,G,)
100% roll-off cosine (PAL I)
TELETEXT GENERATOR (LEVEL 1.0 & 1.5) AND VPS (OPTIONAL, OPT-698-3)
Teletext ON/OFF selectable
(sinc. fH)
Frequency 6.9375 MHz (444*fH)
Transmission mode NRZ (no return to zero)
Data lines From 11 to 15 and 19 to 22 in odd fields
From 324 to 329 and 332 to 335 in even fields
Content 8 different pages (two languages sent
consecutively).
VPS ON/OFF selectable
Frequency 5.0 MHz
Transmission mode Biphase
Data line 16 odd field
Content Selectable through change of chart apart from
the functions stop, start and standby which are
selected through the keyboard.
"0" Level Black level
"1" Level 66% ± 5% of the white level
Connector Signal output together with the composite
video by BNC and Euroconnector.
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LOGOTYPE GENERATOR
Window position Charts A1 and A4 (logotypes)
Charts A3 and C1 (VTR)
VIDEO TEST RECORDER (VTR)
VTR format 8-position mobile rectangle
Velocity 1 position per image field
POWER SUPPLY
Mains voltage AC 110-125-220-230-240 V ± 10% 50-60 Hz
Power consumption 20 W
OPERATING ENVIRONMENTAL CONDITIONS
Altitude Up to 2000 m
Temperature range From 5 to 40 ºC
Maximum relative humidity 80% (up to 31 ºC), decreasing lineally up to
50% at 40 ºC.
MECHANICAL FEATURES
Dimensions W.288 x H.102 x D.247 mm
Weight 3 kg
ACCESSORIES INCLUDED
90901207 BNC/TV coaxial cable CC-07
90901105 Mains cable CA-05
0 FS0060 1A F 250 V spare fuse
VERSIONS
90206980 GV-698 NTSC/PAL CCIR channels
90206981 GV-698/1 NTSC/PAL FCC channels
90206982 GV-698/2 NTSC/PAL OIRT channels
90206983 GV-698/3 SECAM/NTSC/PAL CCIR channels
90206985 GV-698/5 SECAM/NTSC/PAL OIRT channels
90206986 GV-698/6 NTSC/PAL N FCC channels
90206988 GV-698/8 NTSC/PAL M FCC channels
90206989 GV-698/11 Complete SECAM/NTSC/PAL. Includes options
-2 ZWEITON, -3 TELETEXT & VPS, -4 NICAM.
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OPTIONS
90296981 OPT-698-1 Special logotype programming
90296982 OPT-698-2 ZWEITON sound
90296983 OPT-698-3 TELETEXT, VPS
90296984 OPT-698-4 NICAM sound
NOTE:According to I.E. PROMAX's information the NICAM sound transmission system
has by now been adopted by the following countries:
NICAM B/G NICAM I NICAM L
Spain United Kingdom France
Portugal South Africa
Sweden Ireland
Norway Hong Kong
Denmark
Iceland
Finland
Singapore
New Zealand
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2 SAFETY RULES
* Use this equipment connected only to devices or systems with their common at
ground potential.
* This is a class I equipment, for safety reasons plug it to a supply line with the
corresponding ground terminal.
* This equipment can be used in CATEGORY II installations and Pollution Degree
1 environments.
* When using some of the following accessories use only the specified ones to
ensure safety.
Power cord
* Observe all specified ratings both of supply and measurement
* Remember that voltages higher than 60V DC or 30V AC rms are dangerous
* Use this instrument under the specified environmental conditions
*The user is only authorized to carry out the following maintenance operations:
To replace the mains fuse of the specified type and value
To replace the logo EPROM
On the Maintenance paragraph the proper instructions are given. Any other
change on the equipment should ve carried out by qualified personnel.
*The Measure negative is at ground potential
*Do not obstruct the ventilation system
* Follow the cleaning instructions described in the Maintenance paragraph
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* Symbols related with safety:
DIRECT CURRENT
ALTERNATING CURRENT
DIRECT AND ALTERNATING
GROUND TERMINAL
PROTECTIVE CONDUCTOR
FRAME TERMINAL
EQUIPOTENTIALLITY
ON (Supply)
OFF (Supply)
DOUBLE INSULATION PROTECTED
(Class II Protection)
CAUTION
(Risk of electric shock)
CAUTION REFER TO ACOMPANYING DOCUMENTS
FUSE
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3 INSTALLATION
3.1 Power requirements
This equipment requires a mains power source of 110-125-220 or 230/240 V
AC 50 to 60 Hz. Mains operating voltage can be selected at the rear panel.
Figure 1.- Selection of mains voltage.
1.- Pull out the fuseholder lid.
2.- Set the proper fuse for the desired mains voltage.
3.- Insert the fuseholder lid so the [ A ] pointer faces the desired mains voltage
display [ B ].
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CAUTION:
THE EQUIPMENT IS FACTORY SET FOR 220 V OPERATING VOLTAGE.
BEFORE SWITCHING ON THIS INSTRUMENT, SET THE VOLTAGE
SELECTOR TO THE PROPER POSITION AND BE SURE THAT THE FUSE
VALUE IS ACCORDING TO THE MAINS VOLTAGE.
FUSE TYPE SHOULD BE: 5 x 20 mm., 250 V.
0.5 A F FOR 220, 230 and 240 V
1 A F FOR 110 and 125 V
AVOIDING THIS DIRECTIONS COULD DAMAGE THE EQUIPMENT
3.2 Grounding
In order to guarantee safe operation of the GV-698, a suitable connector is
provided on the rear panel for connection to GROUND (Mains Connector [35]).
ATTENTION
Any equipment manufactured with a power supply connected to the chassis
and which is to be connected to the GV-698 must be supplied with an
adequate isolating transformer. Non-observance of this norm may cause
damage to the instrument and/or produce damage to the operator.
3.3 Installation and start-up
The equipment is prepared for use as desk–top equipment.
After having selected the power supply voltage, the equipment may be
connected to the mains and switched on by activating the mains switch [1].
The equipment's highest level of performance is obtained at about 10 minutes
after switching on. This period stabilizes the components sensitive to the thermal
gradient.
ATTENTION
For correct operation of the GV-698, ensure, when connecting the equipment
to an external instrument, that the impedances are correctly matched (see item
1.2 of specifications), otherwise incorrect operation may result.
E.g.: in the case of connection to a TV with a balanced R.F. input of 300
Ω
impedance, an impedance adaptor model A-75/300 GV or similar should be
used.
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4 OPERATING INSTRUCTIONS
4.1 Control description
Figure 2.- Front panel.
[1] LINE. Mains switch
[2] Row indicator
[3] Column indicator
[4] STO, RCL. Memory selector (recall/store)
[5] SEL. Rotary function selector (chart/system–standard/channel–frequency)
[6] Alphanumeric display
[7] TUNE SELECT. Rotary selector
[8] 10. 10 dB attenuator
[9] 20. 20 dB attenuator
[10] 20. 20 dB attenuator
[11] RF . RF output
[12] START. VPS signal information (start/stop) selection button
[13] PRG. VPS signal information (program/standby) selection button
[14] TXT/VPS OFF. Teletext and VPS signal suppression button
[15] R OFF. R channel suppression button (stereo sound/dual)
[16] L OFF. L channel suppression button
[17] DUAL. Stereo or dual sound mode selection button
[18] OFF. Sound carrier suppression button
[19] IL. OFF. Interlace suppression button
[20] CIRC. Circle addition button
[21] OFF. Colour suppression button
[22] BURST OFF. Burst suppression button
[23] LEVEL. Video output level control
[24] VIDEO . Video output connector
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Figure 3.- Rear panel.
[30] SYNC . Synchronisms output
[31] TRIG. SCOPE . Composite signal output for oscilloscope trigger
[32] R . R signal output
[33] G . G signal output
[34] B . B signal output
[35] Mains input
[36] EURO-AV. Euroconnector connector
[37] SYNC. G. G synchronisms ON/OFF selector
[38] . S–VHS output
[39] POLARITY. Synchronisms output polarity selector
[40] LF MODULATION . External LF input connector
[41] SOUND. Internal/external LF selector
4.2 Using the GV-698
This section explains how to use the GV–698 including the operation of the
keyboard, the composite video signal, the radio-frequency output and a detailed
description of the information appearing on the display.
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4.2.1 Selection of TV standard
Figure 4.–Selection of TV standard and memory.
To select the desired TV standard follow the instructions below:
1) Press simultaneously the STO and RCL buttons corresponding to the group
[4]. The data presentation on the alphanumeric display will change: on the
left side the abbreviated denomination will appear, and on the right a
complete description of the equipment system at that moment.
2) Select the desired system by means of the TUNE SELECT rotary selector
[7]. The options available are shown on table 1.
3) By pressing the SEL button of the group [5] the process will be completed.
The alphanumeric display will return to its normal mode and the
abbreviation of the system selected will appear in the position corresponding
to indication of the system.
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ABBREVIAT.
DENOMIN. COMPLETE DENOMINATION CARRIERS SEPARATION
SOUND 1 SOUND 2
Pb PAL B/G/H 5.5 MHz -
Pi PAL I 6.0 MHz -
Pd PAL D/K 6.5 MHz -
Pz PAL ZWEITON 5.5 MHz 5.742 MHz
P# PAL I-NICAM 6.0 MHz 6.552 MHz
P* PAL G-NICAM 5.5 MHz 5.850 MHz
Sb SECAM B/G/H 5.5 MHz -
Sd SECAM D/K/K1 6.5 MHz -
Sl SECAM L 6.5 MHz (AM) -
Nm NTSC M 4.5 MHz -
EX VIDEO EURO-AV - -
Table 1
4.2.2 Storing a configuration
To store a configuration follow the instructions below:
1) Select all (chart/system–standard/channel–frequency) that which you wish
to store (see items 4.2.1, 4.2.5, 4.2.6 and 4.2.7).
2) Press the STO button corresponding to the group [4]. The LED situated
below the MEM position will light and the message "STO XX" on the display
will indicate that this option has been selected, "XX" indicating the number
of the memory currently selected.
3) Select the memory position in which you wish to store the information by
means of the TUNE SELECT [7] rotary selector.
4) Press the STO button again, by which the process will be completed.
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4.2.3 Retrieving a configuration
Take the following steps to retrieve the desired configuration:
1) Press the RCL button corresponding to the group [4]
2) The LED situated below the MEM position will light and the message "RCL
XX" on the display will indicate that this option has been selected, "XX"
indicating the number of the memory currently selected.
3) Select the memory position in which you wish to store the information by
means of the TUNE SELECT [7] rotary selector.
4) Press the RCL button again, by which the process will be completed.
The entire configuration stored (chart/system-standard/channel-frequency)
will be updated within the equipment.
4.2.4 Rotary selector
Figure 5.- Selection of the function of the rotary selector.
The TUNE SELECT [7] rotary selector incorporated in the GV-698 enables
selection of chart, system, standard, channel and frequency to be simply made.
The SEL button in the group [5] permits the selection of the function indicated
by the rotary selector. By pressing this button repeatedly, the information corresponding
to the type of chart, system, channel and frequency is successively selected. The LED
situated below each function is lit in order to indicate the selected function.
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4.2.5 Chart selection
Keep the SEL button corresponding to the group [5] pressed until the LED
situated below the PAT indication is lit. The chart selected will be displayed in this
position. Then turn the TUNE SELECT rotary selector [7] to move successively through
the 32 charts that can be presented by the video generator.
A column in letters (see column indicator [3]) and a row in numbers (see row
indicator [2]) will appear on the visual display. In order to enable pictures to be more
easily selected, these have been arranged into 8 columns (all related in their
performance).
- Groups A to E for colour and general adjustments
- Groups F to H for the adjustment of B/W parameters
4.2.6 Channel selection
Keep the SEL button corresponding to the group [5] pressed until the LED
situated below the CHANNEL indicator is lit. The selected channel will be displayed.
Then turn the TUNE SELECT rotary selector [7] and the channels stored in the
microprocessor will be consecutively selected. The channels appear arranged
according to frequency (standard TV and cable TV channels).
The television channels are indicated by "C" and a number. For instance, TV
channel 41 would be indicated as "C41". The cable TV channels, on the other hand,
are specified by an "S", for example "S11". The channels implemented depend on the
selected version (see list of versions in item 1.2 Specifications).
4.2.7 Frequency selection
Keep the SEL button corresponding to the group [5] pressed until the LED
situated below the FREQ. MHz. indicator is lit. The selected frequency will be
displayed. Then turn the TUNE SELECT rotary selector [7] and the frequency will
change in steps of 50 kHz.
NOTE: When the frequency does not correspond to a channel, the information
on the alphanumeric display will disappear.
4.2.8 Application of test pictures
Group A.- General analysis of the picture, combined pictures.
- A1 Monoscope 1 with possibility of insertion of logotypes
- A2 Colour bars / Blue with zero luminance
- A3 Monoscope 2 / VTR (Video Test Recorder) signal to analyze the
operation of videos.
- A4 Monoscope 3 with possibility of insertion of logotypes
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Group B.- Colour saturation control, tint control, etc.
- B1 Colour bars
- B2 Horizontal colour bars
- B3 Luminance/Colour bars/Multiburst/DEM
Composite chart for contrast control, tint control, definition and colour
demodulators.
- B4 Colour bars / Scale of greys
Saturation in optimal conditions for the adjustment of contrast and
brightness.
Group C.- Colour luminance control, R, G, B amplitude, seen on the screen.
- C1 White split 100% / VTR signal colour bars
- C2 Red split colour bars
- C3 Green split colour bars
- C4 Blue split colour bars
Group D.- Purity, noise and beam current control for R, G and B. R, G, B
outputs check.
- D1 Red raster
- D2 Green raster
- D3 Blue raster
-D4RGB
Group E.- Colour demodulator control, phase and delay line.
- E1 Antipal with split–field 50% luminance
Adjustment of phase, delay line and colour demodulators.
- E2 Axes and antipal
Adjustment of colour demodulators.
- E3 Colour bars / Multiburst
Verification of the video amplifier bandwidth.
-E4Delay
Chrominance and luminance delay check.
Group F.- Resolution, video response and linearity control.
- F1 Scale of greys
Video amplifier linearity (correct ratio between the values of the electronic
beam currents), whiteness control and adjustment, contrast and brightness
control.
- F2 Multiburst
Determination of the bandwidth of the video amplifier.
- F3 Chequer-board
Video amplifier low frequency response.
- F4 Window
Response to transients in the video signal, DC restoration circuit check
(clamping), and delay.
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Group G.- Focus control, geometry and matt supply.
- G1 100% white
Verification of the limiter circuit for the beam current, modulation adjustment
on videotapes, measurements of the signal/noise ratio.
- G2 black
Clamping check, measurements of the signal/noise ratio, adjustment of the
level of black.
- G3 50 Hz rectangular
Clamping circuits check.
-G4MAT
Very High Tension source control.
Group H.
- H1 Cross and rectangle
Aspect, geometry and centrality ratio.
- H2 Framed grid
Centered adjustment of the picture and overscanning.
- H3 Grill
Static and dynamic convergence adjustment, interline check.
-H4Points
Picture suitable for the adjustment of the focus voltage.
4.3 Function buttons which modify the composite video signal
Their effect may be observed at the outputs at which a composite video signal
is present (VIDEO output [24], EURO–AV Euroconnector [36] pin 19 and Y–C
output [38], and in the RF modulated signal (RF connector [11]).
- BURST OFF [22]: press this button to suppress the burst of the composite
video signal and enable the correct operation of the colour killer in the
receivers to be checked. In a correctly adjusted TV receiver no colour
appears on the screen if the burst is cancelled. Anomalous colorations may
be due to high gain in the amplifiers and some deficiency is likely to have
appeared at this stage.
When the SECAM system is selected, pressing this button eliminates the
line identification signal.
- OFF [21] (Chrominance): press this button to disable the chrominance.
It enables suppression of the colour subcarrier in the video signal in order
to analyze the luminance of the colour charts.
- CIRC. [20] (Electronic circle): press this button to activate the circle which
may be inserted in any chart and is particularly useful in geometric
adjustments.
NOTE: the insertion of the circle in the multiburst chart is not perfect, since
this signal does not pass through circuits which would limit its bandwidth. As
the circle in this chart does not provide any information of interest, it is
preferable not to insert it during definition studies.
05/96 GV-698