broadcast medium
TRANSCRIPT
BROADCASTINGBROADCASTING
ENGR. PHIL U. LOMBOYENGR. PHIL U. LOMBOY
BROADCASTING
The process of transmitting information (voice, music or video signal) by radio or
through television for reception by the general public.
BROADCASTING
“To send out in all directions”
AM BROADCASTINGAM BROADCASTINGINTERNATIONAL INTERNATIONAL BROADCASTIINGBROADCASTIING
VERTICALLY POLARIZEDVERTICALLY POLARIZEDHORIZONTAL POLARIZEDHORIZONTAL POLARIZEDOMNIDIRECTIONALOMNIDIRECTIONAL
UNIDIRECTIONALUNIDIRECTIONAL
HF: 3 – 30 MHzHF: 3 – 30 MHz
GROUNDWAVEGROUNDWAVESKYWAVESKYWAVE
MF: 300 – 3000 kHzMF: 300 – 3000 kHz
VERTICALLY POLARIZEDVERTICALLY POLARIZED
TYPES OF BROADCASTING SYSTEM
TV BROADCASTINGTV BROADCASTINGFM BROADCASTINGFM BROADCASTING
SPACE WAVESPACE WAVE
HORIZONTAL POLARIZEDHORIZONTAL POLARIZED
VHF: 30 – 300 MHzVHF: 30 – 300 MHz
CIRCULARLY POLARIZEDCIRCULARLY POLARIZED
SPACE WAVESPACE WAVE
VHF & UHF: 300 – 3000 MHzVHF & UHF: 300 – 3000 MHz
CIRCULARLY POLARIZEDCIRCULARLY POLARIZED
TYPES OF BROADCASTING SYSTEM
2. What is the process of sending voice, speech, music or image intended for reception by the general public?
a. Navigationb. Telephonyc. Broadcastingd. Mixing
REVIEW QUESTIONS
1. Term in communications which means “ to send out in all directions”.a. Announceb. Broadcastc. Transmitd. Media
3. Short wave broadcasting operates in what band?a. MFb. HFc. VHFd. VLF
4. The transmitting antenna for an AM broadcast station should have a _____ polarization.a. verticalb. horizontalc. circulard. elliptical
REVIEW QUESTIONS
5. What broadcasting service must use directional antennasa. AMb. FMc. International broadcastd. TV
6. What type of broadcast service might have their antennas on top of hills?a. FMb. AMc. TVd. a and c
REVIEW QUESTIONS
AM BROADCASTING
PARAMETERSPARAMETERS Int’l StandardInt’l StandardRP StandardRP Standard
Broadcasting Band 535 – 1605 kHz525 – 1705 kHz
Frequency Band Medium frequencyMedium frequency
Channel Width 10 kHz9 kHz
Station Spacing 40 kHz36 kHz
Max no. of channels 107118
IF - Rx 455 kHz455 kHz
Fc Tolerance +/- 20 Hz+/- 20 Hz
PARAMETERSPARAMETERS
Type of Emission A3E (DSBFC)A3E (DSBFC)
Modulation AMAM
Receiver SuperheterodyneSuperheterodyne
Antenna Polarization
VerticalVertical
Type of Propagation
Ground waveGround wave
Radiation Pattern OmnidirectionalOmnidirectional
AM BROADCASTING
Int’l StandardInt’l StandardRP StandardRP Standard
CHANNEL NUMBERCHANNEL NUMBER CARRIER FREQUENCYCARRIER FREQUENCY
1 531 kHz
2 540 kHz
3 549 kHz
… …
… …
131 1701 kHz
AM BROADCASTING ALLOCATIONS
AREAAREA LOW BANDLOW BAND
525 – 918 kHz525 – 918 kHz
Metro Manila 10 kW
Metro Cebu 10 kW
Other Areas 5 kW
MIDDLE MIDDLE BANDBAND
919-1312 kHz919-1312 kHz
HIGH BANDHIGH BAND
1313-1705 kHz1313-1705 kHz
20 kW 30 kW
20 kW 30 kW
10 kW 15 kW
LUZON
VISAYAS
MINDANAO
DZ../DW..
DY..
DX..
Call Signs
AM BROADCASTING ALLOCATIONS
a. PRIMARYa. PRIMARY
The signal is not subject to interference nor fading
b. SECONDARYb. SECONDARY
The signal is subject to some fading but there is no objectionable co-channel interference
c. INTERMTTENTc. INTERMTTENT
The signal is subject to some fading and interference
SERVICE AREA
PARTS OF A BROADCAST DAY
BROADCAST DAYBROADCAST DAY RP LOCAL TIMERP LOCAL TIME
DAY TIME 6 am – 6 pm
NIGHT TIME 6 pm – 6 am
EXPERIMENTAL PERIOD
12 mn – 5 am
TYPES OF TRANSMITTER
MAIN TRANSMITTERMAIN TRANSMITTER
Power rating: 1 kW
ALTERNATE TRANSMITTERALTERNATE TRANSMITTER
Same power rating and frequency stability as that of the main transmitter
Must be co-located with the man transmitter
Used when the main transmitter failed or there are some modifications to be made with it
AUXILIARY TRANSMITTERAUXILIARY TRANSMITTER
Co-located or not co-located
Operating power may be less but never greater than the authorized power of the regular main transmitter
Use during emergencies
Emergency Broadcast System ( EBS)Emergency Action Notification (EAN)Emergency Action Termination (EAT)
TYPES OF TRANSMITTER
AM ANTENNA SYSTEM
ANTENNA SITE SELECTIONANTENNA SITE SELECTION
Location in relation to the population to be served and other communications installed
Conductivity of the soil at and immediately adjacent to the site
Conductivity of the path between the site and the target area
ANTENNA DESIGN CONSIDERATIONSANTENNA DESIGN CONSIDERATIONS
The transmitting antenna system shall be vertically polarized and shall radiate an effective field of not less than that of a 60-degree vertical
radiator
The antenna, antenna lead-in, and counterpoise shall be installed so as not to present hazard
AM ANTENNA SYSTEM
REVIEW QUESTIONS
1. One of the main considerations in the selection of antenna site for AM isa. conductivity of the soilb. height of the terrainc. elevation of the sited. Accessibility
2. The part of broadcast day from 6 PM to 6 AM local timea. day timeb. night timec. bed timed. experimental period
3. What are the frequency limits of the AM broadcasting band?a. 88 – 108 kHzb. 500 – 1600 kHzc. 300 – 3000 kHzd. 535 – 1605 kHz
4. What is the frequency tolerance for the RF carrier in the standard AM radio broadcast band?
a. Zerob. + / - 20 Hzc. + / - 10 Hzd. + / - 20 kHz
REVIEW QUESTIONS
5. What is the channel width of an AM station?a. 5 kHzb. 10kHzc. 50 kHzd. 20 kHz
6. Standard AM intermediate frequencya. 355 kHzb. 455 kHzc. 525 kHzd. 625 kHz
REVIEW QUESTIONS
7. Standard AM bandwidtha. 9 kHzb. 10 kHzc. 12 kHzd. 15 kHz
8. What is the allowable bandwidth of commercial AM radio in the US?a. 10 kHzb. 30 kHzc. 20 kHzd. 15 kHz
REVIEW QUESTIONS
9. What broadcast stations use vertical antennas on flat ground?a. AMb. FMc. TVd. Short wave
10. The center to center spacing between two adjacent stations in the Philippine AM BC banda. 9 kHzb. 200 kHzc. 36 kHzd. 800 kHz
REVIEW QUESTIONS
11. The operating power of the auxiliary transmitter shall not be less than _____ % or never greater than the authorized operating power of the Main Transmitter.a. 5b. 10c. 15d. 20
12. It is a resistive load used in place of an antenna to test a transmitter under normal loaded conditions without actually radiating the transmitter’s output signal.a. Auxiliary Txb. Main Txc. Secondary Txd. Artificial Antenna
REVIEW QUESTIONS
13. Marshy land is an ideal location for AM transmitters becausea. it optimizes ground conductivityb. it increases antenna heightc. it reduces reflectiond. it enhances radio wave propagation
14. Service area of broadcast stations having a ground field of 1 mv/meter.a. Primary Service Areab. Secondary service Areac. Tertiary Service Aread. Intermittent Service Area
REVIEW QUESTIONS
15. Service area of broadcast stations without any interference but with fading or intermittent variations on intensitya. Primary Service Areab. Secondary Service Areac. Tertiary Service Aread. Intermittent Service Area
16. Service area of broadcast stations that is subject to fading and interference.a. Primary Service Areab. Secondary service Areac. Tertiary Service Aread. Intermittent Service Area
REVIEW QUESTIONS
17. One of the broadcast transmission auxiliary servicesa. Remote Pickupb. STLc. Communications, Coordination and Controld. All of these
18. An AM broadcast station in Metro Manila operating at 594 kHz has a maximum power of
a. 5 kwb. 10 kwc. 15 kwd. 30 kw
REVIEW QUESTIONS
FM BROADCASTINGFM BROADCASTING
FM BROADCASTING
PARAMETERSPARAMETERS RP STANDARDRP STANDARD
Broadcasting Band 88 – 108 MHz
Frequency Band VHF
Channel Width 200 kHz
Station Spacing 800 kHz
Max no. of channels 100
Max no. of stations 25
IF - Rx 10.7 MHz
PARAMETERSPARAMETERS RP STANDARDRP STANDARD
Carrier Freq Tolerance +/- 2000 Hz
Type of Emission F3E (mono) F8E (stereo)
Modulation FM
Receiver Superheterodyne
Type of Propagation Space wave
Antenna Polarization Horizontal/circular
FM BROADCASTING
CHANNEL CHANNEL NUMBERNUMBER
CARRIER FREQUENCYCARRIER FREQUENCY
1 88.1 MHz
2 88.3 MHz
3 88. 5 MHz
… …
… …
100 107.9 MHz
FM BROADCASTING ALLOCATIONS
CLASSES OF FM STATION
CLASSCLASS TX POWERTX POWER
A 10 kW – 25 kW
B 1 kW – 10 kW
C --
ERPERP HEIGHT ABOVE HEIGHT ABOVE AVERAGE TERRAINAVERAGE TERRAIN
< 125 kW < 2000 ft
< 30 kW < 500 ft
< 1 kW --
D < 10 W -- --
FM BROADCAST FREQUENCY ALLOCATION
FMn = FM1 + (n – 1) BW
FM = channel frequency in MHz
FM1 = frequency of the 1st FM channel = 88.1 MHz
n = channel number
BW = channel bandwidth = 200 kHz
FM BROADCAST FREQUENCY ALLOCATION
PRE-EMPHASIS
US 75 usec
EUROPE 150 usec
TIME CONSTANTS
DE-EMPHASIS
DOLBY 25 usec
FM STEREO BROADCASTING
Two audio signals (L and R) are mixed to provide two new signals. The first is the sum of the input channels (L+R), and
the second is the difference of the two (L-R).
The sum channel (L+R) is modulated directly in the
baseband assignment between 50 Hz and 15
kHz
The difference signal (L-R) is DSBSC modulated in the 23 to 53 kHz slot about a stereophonic subcarrier of 38 kHz.
PARAMETERSPARAMETERS RP STANDARDRP STANDARD
Pilot subcarrier 19 kHz +/- 2Hz
Stereophonic subcarrier 38 kHz (2nd harmonic of pilot subcarrier
Stereophonic subcarrier suppression level
< 1% modulation of the main carrier
FM STEREO BROADCASTING
Subsidiary Communications Authorization (SCA)
Licensed system which has the purpose of providing background music for public buildings.
2. Remote pick-up Broadcast Stations
Stations in this service are to be used for the transmission of aural programming materials and associated cues and data.
3. Communications, Coordination and Control
Link
FM STEREO BROADCASTING
Broadcast Transmission Services
Stations in this service are to be used as relay of aural programming materials
from studio to transmitter and between fixed facilities
in other locations.
1. Studio-to Transmitter Link (STL)
1. Standard emission for FM broadcasta. A3Eb. C3Fc. F3Ed. B8E
2. Frequency deviation of standard FM broadcasta. 25 kHzb. 50 kHzc. 75 kHzd. 100 kHz
REVIEW QUESTIONS
3. FM broadcast guard banda. +/- 10 kHzb. +/- 15 kHzc. +/- 25 kHzd. +/- 30 kHz
4. FM broadcast pilot subcarriera. 8 kHzb. 19 kHzc. 38 kHzd. 41 kHz
5. FM broadcast frequency tolerancea. 1 kHzb. 2 kHzc. 5 kHzd. 10 kHz
6. FM broadcast time constant for Pre-emphasisa. 55 usecb. 75 usecc. 68 usecd. 81 usec
REVIEW QUESTIONS
7. The class of FM station, which has an authorized radiated power not exceeding 125 kw.
a. Class Ab. Class Bc. Class Cd. Class D
8. An FM broadcast station, which has an authorized transmitter power not exceeding 10 kw and ERP not exceeding 30 kw.
a. Class Ab. Class Bc. Class Cd. Class D
REVIEW QUESTIONS
9. A class of FM station which is limited in antenna height of 500 ft above average terrain.
a. Class Ab. Class Bc. Class Cd. Class D
10. The class of FM station used for educational purposesa. Class Ab. Class Bc. Class Cd. Class D
REVIEW QUESTIONS
11. The class of FM station used for non-commercial and community service purposes.
a. Class Ab. Class Bc. Class Cd. Class D
12. The first channel in the FM broadcast band has a center frequency of
a. 88 MHzb. 88.1 MHzc. 88.3 MHzd. 108 MHz
REVIEW QUESTIONS
13. Maximum ERP allowed for Class A FM stationa. 250 kwb. 200 kwc. 150 kwd. 125 kw
14. Standard FM bandwidtha. 200 kHzb. 500 kHzc. 800 kHzd. 850 kHz
REVIEW QUESTIONS
15. What is the deviation ratio for commercial FM?a. 1b. 2c. 5d. 10
16. What is the radio transmission of two separate signals, left and right, used to create a multidimensional effect on the receiver?
a. SCAb. Stereo systemc. Pilot transmissiond. Monophonic transmission
REVIEW QUESTIONS
17. The frequency spectrum of the stereophonic signala. 67 kHzb. 59.5 to 74.5 kHzc. 19 to 38 kHzd. 30 to 53 kHz
18. FM broadcast receivers in the 88 – 108 MHz have an IF nominally ata. 455 kHzb. 10.7 MHzc. 15 MHzd. 500 kHz
REVIEW QUESTIONS
19. How many commercial FM broadcast channels can fit into the bandwidth occupied by a commercial IV station?
a. 10b. 20c. 30d. 40
20. The carrier frequency tolerance for FM broadcastinga. +/- 25 kHzb. +/- 2 kHzc. +/- 20 kHzd. +/- 30 kHz
REVIEW QUESTIONS
21. Where is de-emphasis added in a stereo FM system?a. before the matrix at the Txb. before the matrix at the Rxc. after the matrix at the Txd. after the matrix at the Rx
22. Where is pre-emphasis added in a stereo FM system?a. before the matrix at the Txb. before the matrix at the Rxc. after the matrix at the Rxd. after the matrix at the Tx
REVIEW QUESTIONS
23. An additional channel of multiplex information that is authorized by the FCC for stereo FM radio stations to feed services such as commercial free programming to selected customers.
a. STLb. SCAc. EBSd. EIA
24. The normal frequency for an SCA subcarrier is ______ KHz.a. 67b. 76c. 38d. 19
REVIEW QUESTIONS
25. A monoaural FM receiver receives only the ____ signal of a stereo multiplex transmission
a. L + Rb. L – Rc. Both a and bd. 67 kHz
REVIEW QUESTIONS
TELEVISIONTELEVISION
“to see at a distance”
TELEVISION BROADCASTINGTELEVISION BROADCASTING
The science of transmitting rapidly changing pictures from one point to
another by means of electrical signals.
DEFINITIONS
1. STUDIO OR OUTSIDE THE STATION
2. PICTURE AND SOUND TRANSMITTER
COMPONENTS OF A COMPLETE TV BROADCASTING SYSTEM
COMPONENTS OF A COMPLETE TV BROADCASTING SYSTEM
3. MEDIUM (COAXIAL CABLE / FIBER OPTIC CABLE
4. A NUMBER OF RECEIVERS
STL – STUDIO TO TRANSMITTER LINK
ENG – ELECTRONIC NEWS GATHERING
ACRONYMS
SNG – SATELLITE NEWS GATHERING
SEG – SPECIAL EFFECTS GENERATOR
EFP – ELECTRONIC FIELD PRODUCTION
ACRONYMS
DIPLEXERDIPLEXER
A special coupling device that permits the transmission of both
audio and video signals using one antenna system.
VSB – VESTIGIAL VSB – VESTIGIAL SIDEBANDSIDEBAND
To conserve electromagnetic spectrum, it produces only
the full USB and only a portion of the LSB
DEFINITIONS
MONOCHROMEMONOCHROME
Shades of black, gray and white
COLORCOLORRed, green and blue
TV BROADCAST TV BROADCAST CHANNELCHANNEL
The band of frequencies assigned for the transmission of the picture and
sound signals.
TV BROADCASTING FREQUENCY ALLOCATION
CHANNEL CHANNEL NUMBERNUMBER
FREQUENCY FREQUENCY RANGE (MHz)RANGE (MHz)
1 44 - 50
54 - 60
60 - 66
66 - 72
76 - 82
6 82 - 88
4
3
5
2
174 - 180
180 - 186
186 - 192
192 - 198
198 - 204
204 - 210
210 - 216
7
12
10
9
11
8
13
ANALOG COLOR TV SYSTEMS IN THE WORLD (ASPECT RATIO, 4:3)
UPPER VHF – CHANNELS 7 - 13
UHF – CHANNELS 14 - 83
FLOWER = 6N + 132
FLOWER = 6N + 386
470 – 890 MHz
TV BROADCASTING STANDARDS
PARAMETERSPARAMETERS RP STANDARDRP STANDARD
Broadcasting Band 54 – 890 MHz
Ch 2 to 4 (54 – 72 MHz) VHF Low
Ch 5 to 6 (76 – 88 MHz)
Ch 7 to 13 (174 – 216 MHz) VHF High
Ch 14 to 83 (470 – 890 MHz) UHF
Channel width 6 MHz
Baseband Freq Video: 0 – 4 MHz Audio: 50 Hz – 15 kHz
PARAMETERSPARAMETERS
Max no. of stations 25 stations
Picture IF: 45.75 MHz
Sound IF: 41.25 MHz
Picture Carrier: +/- 1000 Hz
Color Carrier: +/- 10 Hz
Sound Carrier: +/- 1000 Hz
Fc Tolerance
IF - Rx
CircularPolarization
TV BROADCASTING STANDARDS
RP STANDARDRP STANDARD
PARAMETERSPARAMETERS
Type of Emission Video: C3E
Audio: F3E (mono)
Multi-channel TV Sound (stereo)
Audio : FM
Video: AM / Vestigial Sideband
Receiver Superheterodyne
Type of Propagation Space wave
Modulation
TV BROADCASTING STANDARDS
RP STANDARDRP STANDARD
STANDARDS FOR ANALOG TV SYSTEM
PARAMETERSPARAMETERS American , NTSCAmerican , NTSC
No. of lines/frame 525
No. of lines/field 262 ½ (odd/even)
No. of frames/sec 30
Field frequency 60 (59.94) Hz
Line frequency 15,750 (15,735.36) Hz
Channel width 6 MHz
Video bandwidth 4 MHz
European, PALEuropean, PAL
625
312 ½ (odd/even)
25
50 Hz
15,625 Hz
7 MHz
5 MHz
PARAMETERSPARAMETERS American, NTSCAmerican, NTSC
Color Subcarrier 3.58 MHz
Sound System FM
Max Sound Deviation + / - 25 kHz
Intercarrier Frequency
4.5 MHz
European, PALEuropean, PAL
4.43 MHz
FM
+ /- 50 kHz
5.5 MHz
STANDARDS FOR ANALOG TV SYSTEM
SCANNINGSCANNING
The process of analyzing successively according to a
pre-determined method, the light values of picture elements constituting the
total picture area
INTERLACED SCANNING INTERLACED SCANNING PATTERNPATTERN
Odd fields first then even fields; from left to right; then from top to bottom
SCANNING
HORIZONTAL SCANNING FREQUENCY : 15,750 Hz
VERTICAL SCANNING FREQUENCY : 60 Hz
Progressive scan differs from interlaced scan in that the image is displayed on a screen by scanning each line (or row of pixels) in a
sequential order rather than an alternate order, as is done with interlaced scan.
PROGRESSIVE SCANNING PATTERNPROGRESSIVE SCANNING PATTERN
SCANNING
SYNCHRONIZATIONSYNCHRONIZATION
Keeps the transmitter and receiver scanning in step with each other
Rectangular pulses
SYNCHRONIZATION
HORIZONTAL SYNC FREQUENCY : 15,750 Hz
VERTICAL SYNC FREQUENCY : 60 Hz
Occur during blanking time when no picture information is sent (blacker than black region)
EQUALIZATIONEQUALIZATION
Serves to maintain continuous flow of sync information to the horizontal scanning system.
EQUALIZATION
EQUALIZING PULSE FREQUENCY : 31,500 Hz
Occur before and after each V sync pulse
BLANKINGBLANKING
Prevents the electron beam from reaching the screen, thus retraces
(flyback) are made invisible.
BLANKING
HORIZONTAL BLANKING FREQUENCY : 15,750 Hz
VERTICAL BLANKING FREQUENCY : 60 Hz
NEGATIVE TRANSMISSIONNEGATIVE TRANSMISSION
As the signal increases, the picture becomes
darkerCOMPONENTS OF A COMPONENTS OF A COMPOSITE VIDEO COMPOSITE VIDEO
SIGNALSIGNAL
Picture (video)
DEFINITIONS
Lowest amplitudes are the whitest color
Blanking pulses
Sync (H and V)
a. BRIGHTNESSa. BRIGHTNESS
Overall or average intensity of illumination which determines the background level in the
reproduced picture
b. CONTRASTb. CONTRAST
Difference in intensity between black and white parts of the reproduced picture
PICTURE QUALITIES
c. DETAILc. DETAIL
Depends on the number of picture elements that can be produced within
the frame.
d. COLOR LEVELd. COLOR LEVEL
The color should vary the picture from no color to pale and medium
colors up to vivid intense color.
Also known as Resolution or Definition
PICTURE QUALITIES
e. HUEe. HUEThe color of the object
f. ASPECT RATIOf. ASPECT RATIO
The ratio of the width to the height of the picture frame.
g. VIEWING DISTANCEg. VIEWING DISTANCE
Standard: 4:3
4 to 8 times the picture height
SPECIAL FACILITIES IN CAMERA ASSEMBLY
5. IRIS CONTROL5. IRIS CONTROL
Level of illumination
6. MECHANICAL FOCUS6. MECHANICAL FOCUS
Cw / ccw or lock to a scene
7. VIEWFINDER7. VIEWFINDER
To find a sample of the material
SPECIAL FACILITIES IN CAMERA ASSEMBLY
1. INTERCOMMUNICATION1. INTERCOMMUNICATION
2. MULTIPLE LENS TURRET2. MULTIPLE LENS TURRET
Collection of different lenses
3. TALLY LIGHTS3. TALLY LIGHTSMounted on camera housing ;
“on air”
4. PAN / TILT CONTROLS4. PAN / TILT CONTROLS
Up/down; left/right; zoon in/out
1. PHOTOEMISSION1. PHOTOEMISSION
Liberation of electrons from a material under the influence of illumination
2. PHOTOCONDUCTION2. PHOTOCONDUCTION
Changes of conductivity of a surface due to illumination
METHODS OF PRODUCING AN IMAGE WITHIN THE TUBE
3. PHOTOVOLTAIC ACTION3. PHOTOVOLTAIC ACTION
Generation of voltage due to chemical or physical changes
induced by illumination
1. LIGHT TRANSFER 1. LIGHT TRANSFER CAPABILITYCAPABILITY
Ratio of brightness variations in the reproduced image to the
brightness variations in the original scene
2. SPECTRAL RESPONSE2. SPECTRAL RESPONSE
Same as the eye; colors are rendered in their proper tones
CHARACTERISTICS OF CAMERA TUBES
3. SENSITIVITY3. SENSITIVITY
Unit: Lumen; output photosignal per incident illumination
4. DARK CURRENT4. DARK CURRENT
Small amount of signal current flowing in the
output circuit even in the absence of illumination on the faceplate of the tube.
5. LAG CHARACTERISTIC5. LAG CHARACTERISTIC
Inability of the photosensitive layer in the pick up tube to
follow faster changes in illumination.
6. RESOLVING POWER6. RESOLVING POWER
Resolution power
CHARACTERISTICS OF CAMERA TUBES
The light image is transformed into an electronic image, which can then be read from the back of the target by a
beam of electrons.
HOW CAMERA TUBES WORK
In a camera tube pickup device, the front of the tube contains a layer of photosensitive material called a target.
The lens of a camera focuses light from a
scene onto the front of the camera tube, and
this light causes changes in the target
material.
This varying voltage is the electronic television signal.
HOW CAMERA TUBES WORK
The beam of electrons is produced by an electron gun at the back of the camera tube.
The beam is controlled by a system of electromagnets that make the beam
systematically scan the target material.
Whenever the electron beam hits the bright parts of the electronic image on the target material, the tube emits a high voltage, and when the beam hits a dark
part of the image, the tube emits a low voltage.
TYPES OF CAMERA TUBES
1. NIPKOW DISK1. NIPKOW DISK
A photoelectric tube is used with a rotating wheel
punched with small holes spiraling in toward the
center to scan the picture elements.
2. IMAGE DISSECTOR 2. IMAGE DISSECTOR / ICONOSCOPE/ ICONOSCOPE
The first all electric pick up device.
3. IMAGE ORTHICON3. IMAGE ORTHICON
Indicates the linear relation between light input and
signal output; highly sensitive but relatively large
and expensive.
TYPES OF CAMERA TUBES
4. FLYING SPOT SCANNER4. FLYING SPOT SCANNER
The spot of light from the screen of the CRT is used as the light source to
scan a film slide
5. VIDICON5. VIDICON
Most widely used; a very small camera tube of relatively simple construction, a photoconductive target plate and an electron gun.
Image plate is made up of Antimony Trisulfide
TYPES OF CAMERA TUBES
6. PLUMBICON (PHILIPS)6. PLUMBICON (PHILIPS)
Similar to the Vidicon except that the image plate is made of Lead Oxide (PbO)
7. SATICON (HITACHI, LTD)7. SATICON (HITACHI, LTD)
The image plate is made of Selenium, Arsenic and Tellurium.
8. SILICON VIDICON8. SILICON VIDICON
A Silicon semiconductor junction is used for the target material; extremely high sensitivity for low light applications.
TYPES OF CAMERA TUBES
9. CHALNICON (TOSHIBA)9. CHALNICON (TOSHIBA)
The target is a multilayer arrangement consisting of Tin Oxide,
Cadnium Selenide and Arsenic Trisulfide; very high sensitivity.
10. NEWVICON (MATSUSHITA ELECTRIC)10. NEWVICON (MATSUSHITA ELECTRIC)
The target is made of Amorphous Zinc Selendie layer backed by
Antimony Trisulfide.
TYPES OF CAMERA TUBES
CHARGE COUPLED DEVICE
A charge-coupled device (CCD) is a light-sensitive integrated circuit that stores and displays the data for an
image in such a way that each pixel (picture element) in the image is converted into an electrical charge the intensity of
which is related to a color in the color spectrum
CHARGE COUPLED DEVICE
In a CCD, the light from a scene strikes an array of photodiodes arranged on a
silicon chip.
Photodiodes are devices that conduct electricity when they are
struck by light; they send this electricity to tiny capacitors.
The capacitors store the electrical charge, with the amount of charge
stored depending on the strength of the light that struck the photodiode.
The CCD converts the incoming light from the scene into an electrical
signal by releasing the charges from the photodiodes in an order that
follows the scanning pattern that the receiver will follow in re-creating the
image.
CHARGE COUPLED DEVICE
CRITERIA FOR COMPATIBILITYCRITERIA FOR COMPATIBILITY
1. The color TV system must transmit and be capable of receiving a luminance signal which is either identical to a monochrome transmission or
easily converted to it.
2. Must use the same 6 MHz bandwidth
3. Must transmit the Chrominance information in such a way that it is sufficient for adequate color
reproduction but easy to ignore by a monochrome receiver.
COLOR TV SYSTEM
1. LUMINANCE1. LUMINANCE
Indicates the amount of light intensity, which is perceived by
the eye as brightness.
Contains all information required to construct a black and
white picture from the signal
Where: R – Red video signal
G – Green video signal
B – Blue video signal
PRIMARY COLOR SIGNALS
Y = 0.30R + 0.59G + 0.11BY = 0.30R + 0.59G + 0.11B
2. CHROMINANCE2. CHROMINANCE
Term used to combine both hue (amplitude of C signal) and saturation (phase angle)
Is the 3.58 MHz color subcarrier with quadrature
modulation by I and Q color signals
a. IN-PHASE CHROMINANCEa. IN-PHASE CHROMINANCE
Color video signal transmitted as amplitude modulation of the 3.58 MHz C signal
The only color video signal with bandwidth of 0 to 1.3 MHz
I = 0.60R – 0.28G – 0.32BI = 0.60R – 0.28G – 0.32B
The positive polarity of the I signal is orange while the negative polarity is cyan
CHROMINANCE SIGNALS
b. QUADRATURE PHASE CHROMINANCEb. QUADRATURE PHASE CHROMINANCE
Color video signal that modulates the 3.58 MHz C signal in quadrature with the I signal
with bandwidth of 0 to 0.5 MHz
Q = 0.21R – 0.52G + 0.31BQ = 0.21R – 0.52G + 0.31B
The positive polarity of the Q signal is purple while the negative polarity is yellow green
CHROMINANCE SIGNALS
ANALOG COLOR TV SYSTEMS IN THE WORLD (ASPECT RATIO, 4:3)
NTSC
National Television Standards Committee (American)
Phase Alteration
by Line (British, German)
PAL
Sequential Color and Memory (French)
SECAM
SIMILARITYSIMILARITY
They separate the luminance and chrominance information and transmit the chrominance information in the form of 2 color difference signals which
modulate a color subcarrier frequency transmitted within the sideband of the luminance signal.
DIFFERENCEDIFFERENCE
COLOR TRANSMISSION STANDARDS
The processing of the chrominance information
NTSC – subcarrier frequency is amplitude modulated
PAL – subcarrier frequency is phase modulated
SECAM – subcarrier frequency is frequency modulated
COLOR COMBINATIONS
GREEN + RED =
GREEN + BLUE =
BLUE + RED =
GREEN + BLUE + RED =
YELLOW
MAGENTA
CYAN
WHITE
Retransmit the signals of TV broadcast station by
frequency conversion and amplification without
significantly altering any characteristic except the
amplitude and frequency.
1. TRANSLATORS1. TRANSLATORS
OTHER TV SERVICES
2. CATV – CABLE TELEVISION2. CATV – CABLE TELEVISION
A communications system that gathers local , remote, playbacks and satellite signals and sent by
coaxial cables to the subscribers.
OTHER TV SERVICES
A. HEADENDA. HEADEND
The main hub of the CATV system where the signals from all sources originate, then processed, amplified and distributed to the subscribers.
PARTS OF THE CATV SYSTEM
B. OUTSIDE PLANTB. OUTSIDE PLANT
Part of the CATV system that provides the distribution of the TV signals from the head end to the paying subscribers.
C. SUBSCRIBER PREMISE EQUIPMENTC. SUBSCRIBER PREMISE EQUIPMENT
The end of the line of the CATV system, where the cable signals were delivered from its origin to the subscriber.
3. MATV – MASTER ANTENNA TELEVISION3. MATV – MASTER ANTENNA TELEVISION
The means by which many apartments, houses, hotels, schools and other multi-unit buildings distribute TV and FM signals to a number of
receivers.
OTHER TV SERVICES
DIVISIONSDIVISIONS
1. Head end
2. Distribution System
A. HEADENDA. HEADEND
Normally consists of an antenna installation to receive the desired signals, processing equipment to filter the signals and remove
interference, and a distribution amplifier to amplify the signals to the level required to provide an adequate signal to every receiver in the
system.
PARTS OF THE MATV SYSTEM
B. DISTRIBUTION SYSTEMB. DISTRIBUTION SYSTEM
Provides a clean signal to the sets by isolating each receiver from the system and by delivering the proper amount of signal to each set
4. CCTV – CLOSED CIRCUIT TELEVISION4. CCTV – CLOSED CIRCUIT TELEVISION
A TV system that operates on a closed loop basis; CCTV images are only available to those connected to
the closed loop.
OTHER TV SERVICES
Applications: educational, business, industry, medicine, traffic control,
surveillance
Components: Camera and lens, Coaxial cables, Monitors, Video
Cassette/Tape Recorders
This process produces much clearer picture and sound quality than analog systems, similar to the
difference between a compact disc recording (using digital technology)
and an audiotape or long-playing record.
DIGITAL TELEVISION
A device that receives, decodes, and displays digital
video broadcasts (in both high-definition and standard-
definition formats) for consumer viewing.
Digital television uses technology that records,
transmits, and decodes a signal in digital form—that is, as a
series of ones and zeros.
It also permits additional features to be embedded in signals including program and consumer information as well as interactivities.
There are three types of broadcast digital television (DTV), each with progressively better picture and sound
quality:
TYPES OF DIGITAL TELEVISION
Digital technology is being developed that
will offer sharper pictures on wider
screens, and HDTV with cinema-quality
images. High-Definition TV (HDTV)
Standard-Definition TV (SDTV)
Enhanced-Definition TV (EDTV)
480i
480 lines by 720 pixels wide, displayed in interlaced format.
Committee established by the FCC to define new standards for publicly regulated broadcast television in the United States
Advanced Television Systems Committee (ATSC)
STANDARD DEFINITION TELEVISION
It has a 4:3 or 16:9 aspect ratio, 29.97-Hz frame rate, as defined by
the ATSC standard.
High-definition television (HDTV) image that is 480 vertical lines by 720 horizontal pixels displayed in
progressive format
480p
ENHANCED DEFINITION TELEVISION
It has a 4:3 or 16:9 aspect ratio, 59.94 Hz, 29.97 Hz, and 23.98 Hz
frame rates, as defined by the ATSC standard
HIGH DEFINITION TELEVISION
High-definition video formats that have 16:9 aspect ratio. Generally refers to 1080i or 720p images.
1,080 vertical lines by 1,920 horizontal
pixels wide, displayed in an
interlaced format.
It has a 16:9 aspect ratio, 29.97 Hz frame
rate,
1080i 720 vertical lines by
1,280 horizontal pixels wide, displayed in
progressive format.
It has a 16:9 aspect ratio, 59.94 Hz, 29.97
Hz, and 23.98 Hz frame rates,
720p
Many flat panel TVs use liquid-crystal display (LCD) screens that make use of a
special substance that changes properties when a small electric current
is applied to it.
LCD technology has already been used extensively in laptop computers.
LCD television screens are flat, use very little electricity, and work well for small,
portable television sets.
FLAT PANEL TELEVISION
Flat panel TVs made from gas-plasma displays can be much larger.
In gas-plasma displays, a small electric current stimulates an inert gas
sandwiched between glass panels, including one coated with phosphors
that emit light in various colors.
While just 8 cm (3 in) thick, plasma screens can be more than 150 cm (60
in) diagonally.
FLAT PANEL TELEVISION
1. TV channels 7, 9, 11 and 13 are known asa. mid band UHFb. low band UHFc. high band VHFd. low band VHF
2. Picture frames are repeated at the rate of ____ per seconda. 30b. 60c. 525d. 2
REVIEW QUESTIONS
3. The number of scanning lines is _____ per framea. 262.5b. 30c. 525d. 60
4. The number of fields is ______ per frame.a. 30b. 60c. 525d. 2
5. The number of scanning lines is _____ per field.a. 262.5b. 30c. 525d. 2
6. The number of scanning lines is _____ per second.a. 15750b. 60c. 30d. 525
REVIEW QUESTIONS
7. The horizontal line scanning frequency is ______ Hz.
a. 15750b. 60c. 30d. 525
8. The vertical field scanning frequency is ______ Hz.
a. 15750b. 60c. 30d. 525
9. Video signal amplitude determines the picture quality calleda. contrastb. brightnessc. resolutiond. color saturation
10. Light is converted to video signal by the _____ tube.a. pictureb. camerac. cathode rayd. scanning
REVIEW QUESTIONS
11. Video signal is converted to light by the ______ tube.a. pictureb. camerac. cathode rayd. Scanning
12. The bandwidth of a TV channel is _____ MHz.a. 6b. 4.5c. 2.5d. 12
13. How many international commercial AM broadcast channels can fit into the bandwidth occupied by a commercial TV station?
a. 100b. 200c. 125d. 600
14. The type of modulation on the picture carrier signal is
a. AMb. FMc. PMd. PCM
REVIEW QUESTIONS
15. The type of modulation on the sound carrier signal isa. AMb. FMc. PMd. PCM
16. The assigned band for channel 3 is _____ MHz.a. 54 – 60b. 60 – 66c. 66 – 72d. 76 – 82
17. The difference between the picture and the sound carrier frequencies for channel 7 is ______ MHz.a. 6b. 4.5c. 2.5d. 3.58
18. Scanning in the receiver is timed correctly by _____ pulses.a. scanningb. blankingc. syncd. equalizing
REVIEW QUESTIONS
19. Retraces are not visible because of _____ pulses.a. scanningb. blankingc. syncd. Equalizing
20. Black on the picture tube screen results from _____ beam current.a. 0b. 1c. 100d. Maximum
21. The color subcarrier frequency is approximately ____ MHz.a. 6b. 4.5c. 2.5d. 3.58
22. _____ is the device that prevents aural RF from entering the video transmitter and vice versa.a. diplexerb. duplexerc. modulatord. demodulator
REVIEW QUESTIONS
23. The amount of color saturation in the picture depends on the amount of _____ signal.a. chrominanceb. luminancec. contrastd. Hue
24. In TV broadcasting in the Philippines, the aspect ratio of the picture frame isa. 4:3b. 4:1c. 2:1d. 3:1
25. The black and white or monochrome brightness signal in TV is calleda. RGBb. Color subcarrierc. Luminanced. Chrominance
26. Color TV is made possible through the combination of the primary colors ofa. white, red and greenb. blue, yellow and greenc. red green and blued. red white and blue
REVIEW QUESTIONS
27. How many electron beams actually leave the electron gun of a single gun color CRT?
a. 1b. 2c. 3d. 1/3
28. Which of the following is not a requirement for a color TV signal?
a. compatibility with black and white receivers
b. within 6 MHz bandwidthc. simulate a wide variety of colorsd. functional with Baron super antenna
29. Radio spectrum is conserved by using ______ modulation for the video and TV signals.a. vestigialb. amplitudec. phased. Frequency
30. The TV receiver picture IF is 45.75 MHz and the sound IF is _____ MHz.a. 41.25b. 45.75c. 54.75d. 57.55
REVIEW QUESTIONS
31. Which of the following camera tubes has minimum lag?
a. Vidiconb. Plumbiconc. Saticond. Iconoscope
32. The camera tube that uses selenium, arsenic and tellurium.
a. Plumbiconb. Vidiconc. Saticond. Silicon Vidicon
33. In a standard commercial TV broadcast, the picture carrier signal is located _____ above the lower end frequency of the channel.a. 0.75 MHzb. 0.25 MHzc. 4.2 MHzd. 1.25 MHz
34. Special effects and production switching are done by the a. CCUb. ENGc. SEGd. Sync Gen
REVIEW QUESTIONS
35. The hue 180 degrees out of phase with red isa. cyanb. yellowc. greend. Magenta
36. Greater peak to peak amplitude of the 3.58 MHz chrominance signal indicates morea. whiteb. yellowc. hued. saturation
37. The difference between sound carrier and color subcarrier isa. 4.5 MHzb. 1.25 MHzc. 0.92 MHzd. 0.25 MHz
38. Mixing green and blue light in TV systems result toa. cyanb. yellowc. magentad. white
REVIEW QUESTIONS
39. In television, the color with the most luminance is
a. Greenb. Bluec. yellowd. Red
40. When the colors Magenta and Yellow are mixed, the resultant color is
a. Redb. Whitec. Blued. green
41. The three complementary colors area. white, yellow, cyanb. black, white, grayc. yellow, magenta, cyand. violet, indigo, fushcia
42. Which of the following consists of two of the three primary colors in TV signal?
i. red ii. violet iii. yellow iv. bluea. i and iib. ii and iiic. iii and ivd. i and iv
REVIEW QUESTIONS
43. Suppose the signal from a color camera has R = 0.8, G = 0.4 and B = 0.2, where 1 represents the maximum signal possible. Determine the value at the luminance signal.
a. 0.498b. 0.254c. 0.1325d. 1.4
44. In the previous problem, calculate the chrominance signal.a. 0.305b. 0.304c. 0.498d. 0.022
REVIEW QUESTIONS
45. Equalizing TV pulses are sent during a. horizontal blankingb. vertical blankingc. horizontal retraced. Sync
46. Mechanism or device which enables the TV camera to move in lateral and tilting motion.a. panning deviceb. scannerc. tiltingd. pan/tilt device
REVIEW QUESTIONS
47. The ____ ensures that the electron beam will strike the correct phosphor dot on the TV screen.
a. Coatingb. aperture maskc. Diplexerd. Duplexer
48. What is the return of the electron beam in a CRT from right to left or from bottom to top?
a. Relayb. Flybackc. Utilizationd. resolution
49. The form of scanning used in TV emissions
a. right to leftb. Negativec. Positived. Interlaced
50. What is the process of placing the chrominance signal in the band space between portions of the luminance signal?
a. Interlacingb. Fittingc. Sneakingd. interleaving
REVIEW QUESTIONS
51. The components of a composite video signal are:
a. chroma signalb. blanking pulsec. sync pulsed. all of these
52. It is the quality of the TV picture after imperfections.
a. aspect ratiob. utilization ratioc. A1d. Monochrome
53. How far above the video carrier is the sound carrier in a TV transmission?a. 0.25 MHzb.4.5 MHzc. 10 MHzd. 6 MHz
54. How far above the lower limit of a TV channel is the video carrier located?a. 0.25 MHzb. 1.25 MHzc. 4.5 MHzd. 5.75 MHz
REVIEW QUESTIONS
55. If a TV broadcast station is operating on Channel 5 (low edge is 76 MHz), the frequency of the video carrier isa. 77.25 MHzb. 77.5 MHzc. 80.5 MHzd. 82.2 MHz
56. Addition of 0.59 green, 0.3 red and 0.11 blue signals from a color TV camera produces thea. Q signalb. I signalc. Y signald. IQ signal
57. What is the frequency of RPN 9’s color subcarrier?a. 187.25 MHzb. 190.38 MHzc. 187.52 MHzd. 190.83 MHz
58. Identify the equation for the In-phase component of the Chroma signala. 0.21R – 0.52G + 0.31Bb. 0.3R + 0.59G + 0.11Bc. 0.6R – 0.28G – 0.32Bd. 0.59R + 0.3G + 0.11B
REVIEW QUESTIONS
59. Defined as the smallest area of a TV image that can be transmitted within the parameters of the system.a. pixelb. fieldc. framed. Image
60. Which is a color filter?a. aquadagb. dichroic mirrorc. phosphor screend. diplexer
61. A widely recognized TV standard that originated from Germany.a. NTSCb. SECAMc. PALd. MAC
62. The picture quality derived from getting the square root of the sum of the squares of the I signal magnitude and Q signal magnitude.a. resolutionb. huec. purityd. brightness
REVIEW QUESTIONS
63. A third symbol which represents television.a. Ab. Cc. Dd. F
64. Which type of photoconductive tube is used by vidicons?a. Antimony Trisulfideb. Lead Oxidec. Selenium Alloyd. Zinc Selenide
65. What are the three separate signals derived from a matrix in a color TV transmitter?a. Y, I and Qb. P, D and Qc. M, N and Od. R, S and T
66. What is the phase difference between the I and Q color signal carriers?a. 0 degreesb. 45 degreesc. 60 degreesd. 90 degrees
REVIEW QUESTIONS
67. The colors at the vertices of the color triangle are referred to asa. primaryb. whitec. desaturatedd. all of these
68. At what position on the color triangle will saturated yellow be located?a. between red and blueb. between red and greenc. between blue and greend. at the center
69. Is the most common technique where apartment houses, hotels, schools, condominiums and multi-unit buildings distribute TV and FM signals to a number of receivers, using a single head-end.
a. CCTVb. CATVc. MATVd. Antenna
70. The source point for service on the CATV network.a. Hubb. Head endc. Trunk Amplifierd. Line Extender
REVIEW QUESTIONS
71. Which of the following is the first component of any MATV system to receive broadcast signals?
a. Filterb. LNAc. RF amplifierd. Antenna
72. An emissive flat panel display where light is created by phosphors excited by a plasma discharge between two flat panels of glass.
a. LCDb. Plasma Displayc. CRTd. HDTV
REVIEW QUESTIONS
73. What is the aspect ratio for HDTV systems?
a. 4/3b. 9/7c. 19/6d. 16/9
72. A certain HDTV television has 480 x 640 resolution with progressive scanning, then the HTV is
a. 480ib. 480pc. 640id. 640p
REVIEW QUESTIONS
75. HDTV is a digital TV system that allows higher resolution, what is the resolution if the HDTV is 720i?
a. 1280 x 720 interlacedb. 1280 x 720 progressivec. 720 x 1280 interlacedd. 720 x 1280 progressive
Phil Lomboy po, Phil Lomboy po,
59 NA PO TAYO, KAPUSO.59 NA PO TAYO, KAPUSO.