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Since 2002, our specialists have begun to develop and produce devices for the processing and transmission of video signals at long distances by coaxial cable and twisted pair of wires.
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JSC “RD Alfa mikroelektronikas departaments”Maskavas 240, Riga LV-1063, Latvia
Phone:+371 67109 400Fax: +371 67109 498
Chief DesignerAleksander Maiborodaphone: +371 67109 [email protected]
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About the companyJoint Stock Company “RD ALFA Microelectronic Department” is an assignee of the Scientific Research Institute
of Micro Devices and “Invertor” plant in Riga, which in due time became part of the industrial corporation “Alfa”.During a period of 60-80 years, these enterprises were the leader in Eastern Europe in the field of analog and
analog-to-digital microelectronics.Founded in 1962, these enterprises may factually be considered as the pioneers in this electronic technique.The specialists of the institute and plant have accumulated significant scientific and industrial experience
in the analog and analog-to-digital fields of technology (Bi, Bi-FET, complementary Bi, CMOS, and Bi-CMOS), microcircuits, and the design and testing of microcircuits. At present, this scientific and industrial potential has been preserved at “RD Alfa md” in large measure.
The company’s quality management system has been certificated on compliance with the demands of ISO 9001:2000 by the firm “SGS Societe de Surveillance SA Systems&Services Certification”, Switzerland. Certificate CH05/0392 was received on May 18th, 2005.
The main directions of the company’s activities are the design and full-scale production of high-quality microcircuits for common use and airspace.
The company’s production includes:• Operational amplifiers;• Comparators;• Timers;• Analog-digital and digital-analog converters;• Circuits of general application for national economic enterprises;• Video-transmission systems for long distances.Since 2002, our specialists have begun to develop and produce devices for the processing and transmission of
video signals at long distances by coaxial cable and twisted pair of wires. Such devices were based on microcircuits of in-house design, which are in full-scale production at “RD ALFA Microelectronic Department”.
Our company is at present producing and selling different types of devices.Two sets of devices are well known:“Twist” - for the transmission of video signals by twisted pairof wires at distances up to 900 meters;“Twist - 2” - for the transmission of video signals by twisted pairof wires at distances up to 1800 meters.These produced products are continuously upgraded by adding new and useful functions in the light of the
experience of their exploitation by various large customers. Every year the company develops and produces two or three new products in this sphere.
PRODUCTS SELECTOR GUIDEModel Function Cable type Video
transmission distance
Frequencybandwidth
Cableequalisation
Video gain
Isolation output input
Clam Power supply
TWIST-T Video transmitter
Balanced Twisted Pair
900 meters 7 MHz 9 dB 0 dB AC 220 V +/- 15% with SCP OCP
TWIST-R Video receiver
Balanced Twisted Pair
900 meters (1800 meters TWIST-2T)
7 MHz 24 dB 8 dB Sync Tip AC 220 V +/- 15% with SCP OCP
TWIST-2T Video transmitter
Balanced Twisted Pair
1800 meters 7 MHz 48 dB 6 dB AC 220 V +/- 15% with SCP OCP
TWIST-4RC 4 channel video receiver
Balanced Twisted Pair
900 meters (1800 meters TWIST-2T)
7 MHz 24 dB 8 dB Sync Tip AC 220 V +/- 15% with SCP OCP
CAB - 2 Video amplifier
Unbalanced (Coaxial)
500 meters 7 MHz 12 dB 9 dB AC 220 V +/- 15% with SCP OCP
CAB - 3 Optical video isolator
Unbalanced (Coaxial)
500 meters 10 MHz 12 dB 9 dB Sync Tip AC 220 V +/- 15% with SCP OCP
VIDEONORM - 1 4 channel video signal normalizer
Unbalanced (Coaxial)
20 meters 7 MHz 0 dB Yes KeyedBlackLevel
AC 220 V +/- 15% with SCP OCP
TWIST-2NR 2 channel video receiver joint normalizer
Balanced Twisted Pair
900 meters (1800 meters TWIST-2T)
7 MHz 24 dB 8 dB KeyedBlackLevel
AC 220 V +/- 15% with SCP OCP
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“TWIST” SYSTEMEquipment for transmission of video signals through twisted pair of wires at distances up to 900 meters.
The “TWIST” system includes the following equipment:- “TWIST-T” transmitter, which converts a signal from the source (video camera) into a differential video signal. It is installed on the transmitting end of the video line.- “TWIST-R” receiver, which converts a differential video signal into a standard one. It is installed on the receiving end of the video line. When the “TWIST-T” transmitter on the transmitting end of the video line and the “TWIST-R” receiver on the receiving end of the video line are connected in a series, a black-and-white or color video signal is transmitted through the twisted pair of wires at distances of up to 900 meters.
The “TWIST- T” transmitter has a coaxial 75 ohm BNC input connector and differential outputs made in the form of a contact connector with 3 contacts. Two contacts are intended for connecting the twisted pair of wires to different phases, and the third contact is for the net ground wire. The “TWIST- R” receiver has a differential input for the twisted pairs in the form of a contact connector with 3 contacts. Two contacts are intended for connecting the twisted pair of wires to different phases, and the third contact is for the net ground wire. The coaxial 75 ohm BNC output connector is intended for the output of a standard video signal. The transmitter has a converter of a standard video signal into a differential video signal as well as a discrete frequency correction that pre-distorts a differential video signal, thus compensat-ing for high frequency losses in a long line. The transmitter has output protection from impulse pick-ups with the amplitude up to 120 V and the pulse width up to 100 ms, and also protection from constant differential voltage up to 24 V or voltage on a linear wire with relation to a common wire up to ±12 V. The receiver has an amplifier – a corrector providing compensation for signal losses in the cable and making correction for signal roll-off at high frequencies (discrete correction of signal frequency characteristics depending on the length of the video line, with accuracy up to 100 meters). The receiver has an input protection from impulse pick-ups with the amplitude up to 120 V and the pulse width up to 100 ms, and also protection from constant differential voltage up to 24 V or voltage on a linear wire with relation to a common wire up to ± 12 V. Both devices have a built-in power unit for AC power supply 220 V.The devices are intended for use outdoors (category IP54) and are made exclusively using integral circuits made by RD ALFA md, JSC. They are notable for small power consumption, reliability and simplicity of operation.
“TWIST-T”Parameter ValueTotal amplitude of input video signal 0,7-1,5 VResistance for coaxial input 75 OhmWave resistance of twisted pair of wires 100 OhmPass – band 7 MHzInput – output transfer rate number 1Discrete control of amplitude – frequency characteristic (at frequency 7 MHz)
0 – 6 - 9 dB
Ratio signal/noise 50 dBMax. useful current of transmitter 30 mASupply voltage (AV 50 Hz) 220-230 VSize of transmitter 110 x 60 x 67 mmWeight of transmitter 100 g.Max. distance of transmission 900 m.
“TWIST-R”Parameter ValueTotal amplitude of input video signal 0,7-3,0 VResistance for coaxial output 75 OhmWave resistance of twisted pair of wires 100 OhmPass – band 7 MHzInput – output transfer rate (controlled) 0,5-1,5Range of control of amplitude – frequency characteristic at frequency 5 MHz
0 –24 dB
Increment of control of amplitude – frequency characteristic at frequency 5 MHz
10
Common mode rejection of interference 40 dBMax. useful current of receiver 40 mASupply voltage (AV 50 Hz) 220-230 VSize of receiver 110 x 80 x 40 mmWeight of receiver 120 g.Max. distance of transmission* 900 m
*Losses in twisted pair at frequency 4 MHz not more than 4.1 dB at 100 m
Technical Characteristics
~220
V
IN OUT
TWIST-TTWIST PAR VIDEO
TRANSMMITER
TWIST-RTWIST PAR VIDEO
RECEIVER
~220
V
IN OUT
Designfeatures
Correction of video line length by one
switcher with discretion of 100
meters
Fixed sync-tip clamping of video
signal level
Built-in power supply source with electronic
protection
Case protecting from dust and
moisture
TWIST VIDEO TRANSMISSION AND DISTRIBUTION
Twist-T Twist-R
Camera
Maximum allowed voltages in video line ValueDifferential voltage on signal wires, not more than 24 VVoltage in signal wire with relation to common wire ± 12 VAmplitude of impulse voltage with width not more than 100 ms 120 V
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“TWIST – 2T” SYSTEMEquipment for transmission of video signals through twisted pair of wires at distances up to 1800 meters.
The “TWIST – 2T” system includes the following equipment:- “TWIST – 2T” transmitter, which converts a signal from the source (video camera) into a differen-tial video signal. It is installed on the transmitting end of the video line.- “TWIST – R” receiver, which converts a differential video signal into a standard one. It is installed on the receiving end of the video line. When the “TWIST – 2T” transmitter on the transmitting end of the video line and the “TWIST – R” receiver on the receiving end of the video line are connected in a series, a black-and-white or color video signal is transmitted through the twisted pair of wires at distances of up to 1800 meters.
The “TWIST – 2T” transmitter has a coaxial 75 ohm BNC input connector and differential outputs made in the form of a contact connector with 3 contacts. Two contacts are intended for connecting the twisted pair of wires to different phases, and the third contact is for the net ground wire. The “TWIST - R” receiver has a differential input for the twisted pairs in the form of a contact connector with 3 contacts. Two contacts are intended for connecting the twisted pair of wires to different phases, and the third contact is for the net ground wire. The coaxial 75 ohm BNC output connector is intended for the output of a standard video signal. The transmitter has a converter of a standard video signal into a differential video signal, and also two channels of discrete frequency correction that pre-distorts a differential video signal, thus compensating for high frequency losses of signal in a long line (discrete pre-distortions of a signal depending on the length of the video line, with accuracy up to 100 meters). The transmitter has output protection from impulse pick-ups with the amplitude up to 120 V and the pulse width up to 100 ms, and also protection from constant differential voltage up to 24 V or voltage on a linear wire with relation to a common wire up to ± 12 V. The receiver has an amplifier – a corrector providing compensation for signal losses in the cable and making correction for a signal roll-off at high frequencies (discrete correction of signal frequency characteristics depending on the length of the video line, with accuracy up to 100 meters). The receiver has input protection from impulse pick-ups with the amplitude up to 120 V and the pulse width up to 100 ms, and also protection from the constant differential voltage up to 24 V or the voltage on a linear wire with relation to a common wire up to ± 12 V. Both devices have a built-in power unit for AC power supply 220 V.The devices are intended for use outdoors (category IP54) and are made exclusively using integral circuits of RD ALFA md, JSC. They are notable for small power consumption, reliability and simplicity of operation.
“TWIST-2T’’Parameter ValueTotal amplitude of input video signal 0,7-3,0 VResistance for coaxial input 75 OhmWave resistance of twisted pair of wires 100 OhmPass – band 7 MHzInput – output transfer rate (uncontrolled) 2Range of regulation of differential amplitude – frequency characteristic at frequency 5 MHz
0 – 48 dB
Increment of control of amplitude – frequency characteristic at frequency 5 MHz
10
Ratio signal/noise 50 dBMax. useful current of transmitter 50 mASupply voltage (AV 50 Hz) 220-230 VSize of transmitter 110 x 60 x 67 mmWeight of transmitter 100 gMax. distance of transmission 1800m
“TWIST-R”Parameter ValueTotal amplitude of input video signal 0,7-3,0 VResistance for coaxial output 75 OhmWave resistance of twisted pair of wires 100 OhmPass – band 7 MHzInput – output transfer rate (controlled) 0,5-1,5Range of control of amplitude – frequency characteristic at frequency 5 MHz
0 –24 dB
Increment of control of amplitude – frequency characteristic at frequency 5 MHz
10
Common mode rejection of interference 40 dBMax. useful current of receiver 40 mASupply voltage (AV 50 Hz) 220-230 VSize of receiver 110 x 80 x 40 mmWeight of receiver 120 g.Max. distance of transmission* 1800 m
*Correction of video line length by one switcher with discretion of 100 meters
Technical Characteristics
~220
V
IN OUT
TWIST-TTWIST PAR VIDEO
TRANSMMITER
TWIST-RTWIST PAR VIDEO
RECEIVER
~220
V
IN OUT
1800m
Designfeatures
Correction of video line length with discretion of 100
meters
Fixed sync-tip clamping of video
signal level
Built-in power supply source
Case protecting from dust and
moisture
VIDEO TRANSMISSION AND DISTRIBUTION TWIST 2T
Twist-2T Twist-2R
Camera
Maximum allowed voltages in video line ValueDifferential voltage on signal wires, not more than 24 VVoltage in signal wire with relation to common wire ± 12 VAmplitude of impulse voltage with width not more than 100 ms 120 V
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TWIST-4RC VIDEO TRANSMISSION AND DISTRIBUTION
“TWIST-4RC”Receiver – converter with four channels for transmission of video signals through twisted pair of wires
The “TWIST-4RC” receiver with four channels includes:- Four separate receivers converting differential video signals sent from different video signal transmitters by twisted pair of wires into a standard video signal. It is installed on the receiving end of video lines. During connection of the “TWIST-T” (or “TWIST-2T”) transmitter in a series at the transmitting ends of video lines and connection of the “TWIST-4RT” receiver at the receiving end of four video lines, four black-and-white or color video signals are transmitted through the twisted pair of wires at distances of up to 900 (or 1800) meters.
Each of the four “TWIST-4RC” receiver channels has a differential input for the twisted pairs made in the form of a contact connector with 3 contacts. Two contacts are intended for connect-ing the twisted pair of wires to different phases, and the third contact is for the net ground wire. The coaxial 75 ohm BNC output connector is intended for the output of a standard video signal. Each of the four channels of the receiver has an amplifier – corrector, which provides compensation for signal losses in the cable and corrects the signal roll-off at high frequencies (discrete correction of signal frequency characteristics depending on the length of the video line with accuracy up to 100 meters). The receiver has protection of inputs from impulse pick-ups with the amplitude up to 120 V and the pulse width up to 100 ms as well as protection from the constant differential voltage up to 24 V or the voltage in a linear wire with relation to a common wire up to ± 12 V. The device has a built-in power unit for AC power supply 220 V.The device is intended for use indoors, and is made completely using integrated circuits of RD ALFA md, JSC. It is notable for small power consumption, reliability and simplicity of operation.
Technical Characteristics“TWIST-4RC”
Parameter ValueNumber of receivers 4Total amplitude of input video signal 0,7-3,0Resistance for coaxial output 75Wave resistance of twisted pair of wires 100Pass – band 7Input – output transfer rate (controlled) 0.5-2.0Range of control of amplitude – frequency characteristic at frequency 5 MHz 0 –24Increment of control of amplitude – frequency characteristic at frequency 5 MHz 10Common mode rejection of interference signal at frequency 5 MHz 40Max. useful current of receiver 170Supply voltage (AV 50 Hz) 220-230Size of receiver 240x150x45 mmWeight of receiver 420 gMax. distance of transmission* 900 or 1800 m **
* Losses in twisted pair at frequency 4 MHz not more than 4.1 dB at 100 m** On using transmitters “TWIST-2”
Designfeatures
Four video channels
High-quality transmission
of video signals through twisted pair of wires at distances up to
900 meters (with the transmitter
TWIST-T)
High-quality transmission
of video signals through twisted pair of wires at distances up to
1800 meters (with the transmitter
TWIST-2T)
Correction of video line length by one switcher with discretion of 100
meters
Built-in power supply source with electronic
protection
1 2 3 4
1 2
3 4
TwisT-T
TwisT-T
<1800 m
<900 m<300 m
Twist-T
Twist-T
BAlUN
Twist-4RC
TTP111VT
TwisT-2T
Twist-2T
Twistedpair line
Maximum allowed voltages in video line ValueDifferential voltage on signal wires, not more than 24 VVoltage in signal wire with relation to common wire ± 12 VAmplitude of impulse voltage with width not more than 100 ms 120 V
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VIDEO TRANSMISSION AND DISTRIBUTION CAB-2
Designfeatures
High-quality transmission
of video signal through coaxial
cable at distances up to 700 meters
Correction of video line length on two
frequencies
Adjustment of video signal level
Wide band of video signal gain up to
7 MHz
Built-in power supply source
Case protecting from dust and
moisture
Compensatory video amplifier “CAB-2”
The compensatory video amplifier “CAB-2” is intended for use in systems of video monitoring, for compensation of losses and correction of the amplitude-frequency characteristic of a cable coaxial connective line with length of up to 700 meters. The device allows for the correction of frequency distortions and losses in the coaxial cable, providing good matching of sources and receivers of the video signal. The device is recommended to be installed and connected at the end or at the beginning of the video line.
The device performs: Level control of full video signal in a range of 9 dB. Correction of the amplitude-frequency distortions of the coaxial cable at two bands on 3 and 6 MHz, thus providing the transmission of a video signal through the long coaxial cable maintaining vertical sharpness of no less than 520 lines. Matching of the output resistance of a video signal source with wave impedance of the cable line (= 75 Ohm) which excludes the appearance of the reflected signal. The “CAB-2” device has protection of input and output from impulse pick-ups with the ampli-tude up to 120 V and width up to 100 ms, as well as protection from dangerous voltage in a linear wire in relation to a common wire up to 24 V. The “CAB-2” device has a built-in power supply source, which supplies power from AC net 220 V.
Technical Characteristics“CAB-2”
Parameter ValueInput resistance 75 OhmOutput resistance 75 Ohm
Supply voltage (AV) 220 - 230 V
Control of gain ratio in range 0,5...1,5
Control of amplitude-frequency characteristic (at frequency 6 MHz) 10 dB
Control of amplitude-frequency characteristic (at frequency 3 MHz) 6 dB
Min. width of undistorted video impulse with amplitude 1 V at cable RG – 59U* length 500 meters
100 ns
Gain-bandwidth at 3 dB level at switched-off control of amplitude- frequency characteristic
7 MHz
Maximum allowed voltages in video line ValueVoltage in signal wire with relation to common wire ± 12 VAmplitude of impulse voltage with width not more than 100 ms 120 V
8
OPTICAL VIDEO ISOLATOR “CAB-3”Insulating video amplifier with optical isolator “CAB-3”
The high quality “CAB-3” insulating video amplifier with optic isolator is intended for provid-ing full isolation between sources of video signals and receiving gear for a video signal, such as monitors, projectors, and digital displays. “CAB-3” allows for the eliminatiion of well-known problems experienced by the installers of video monitoring systems such as background inter-ference from “ground current loops”, preventing the passage of dangerous constant current and other interferences that degrade the quality of the signal transmitted by video lines.
Technical Characteristics“CAB-3”
Parameter ValueInput resistance 75 OhmOutput resistance 75 OhmSupply voltage (AV) 220 - 230 VControl of gain ratio in range 0,5...2,0Control of amplitude – frequency characteristic (at frequency 5 MHz) 9 dBMin. width of undistorted video impulse with amplitude 1 V at cable RG – 59U* length 500 meters
100 ns
Gain-bandwidth at 3 dB level at switched-off control of amplitude-frequency characteristic
10 MHz
Suppression of background interference (50 – 100 Hz) 76 dB
*Losses in cable at frequency 5 MHz – 2.1 dB on 100
CAB-3 VIDEO TRANSMISSION AND DISTRIBUTION
Designfeatures
Output fully isolated from input
High linear transmission of
video signal
Wide band ofvideo signal gain
up to 10 MHz
Fixed sync-tip clamping of video
signal level
Built-in power supply source
OPTICAl VIDEO ISOlATOR “CAB-3”
~AC 220V
Camera
“CAB-3” as an active optic insulating device has high linearity and wide band for the passing video signal in comparison with devices with insulating transformers. The “CAB-3” insulating video amplifier with optic isolator has a coaxial 75 ohm BNC input connector which is isolated from the BNC output connector by optoelectronic transducer on a Hewlett Packard microcircuit with dielectric breakdown voltage > 3000 V. In the output part of the device, the regulation of the video signal amplification and fixed sync-tip clamping of its level are performed and the controlled correction of a video signal is made using the microcircuits of RD ALFA md, JSC. The “CAB-3” amplifier has input and output protection from impulse pick-ups with the ampli-tude up to 120 V and the pulse width up to 100 ms, as well as protection from the constant differ-ential voltage up to 24 V or the voltage in a linear wire with relation to a common wire up to ±12 V. The “CAB-3” amplifier has a built-in power unit for AC power supply 220 V. The amplifier is intended for use indoors (category IP50), and it is notable for small power consumption, reliability and simplicity of operation.
Maximum allowed voltages in video line ValueVoltage in signal wire with relation to common wire ± 12 VAmplitude of impulse voltage with width not more than 100 ms 120 V
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Fig. 1. Sample of “VIDEONORM-1” operation when transferring the test signal “checkered field”
incoming bad signal image and oscilogram Outgoing signal image and oscilogramAfter ViDEONORM-1 signal conditioning.
Device for video signal conditioning with four channels “VIDEONORM-1”
The “VIDEONORM-1” device is intended for the normalization of video signal levels in inputs of the commutation equipment of observation stations. The “VIDEONORM-1” device may solve well-known problems experienced by the installers of video security systems. Video signals from different cameras during their passage through long lines of transmission may be distorted heavily due to losses of constant signal components and the impinging of background interferences on the video signal. It leads to the synchroniza-tion skip of pictures in the input of switching facilities (multiplexers, monitors, video recording devices, etc.). Moreover, additional losses of video picture quality may appear in digital recording systems and in devices for data transfer in computer networks due to the non-conditioning of the signal. During the passage of video signals through “VIDEONORM-1” a constant component recov-ers in the video signal and thus the levels of video signals match with the input dynamic ranges of Analog-Digital Converters (ADC) in the computer circuit boards of video capture and of ADCs in digital video recording systems, so the fixed capture of the initial poor-quality video signal is reached. The fast clamping of the video signal level takes place only during moments of the sync pulses of video signal passages and filters out for video signal background interferences at low frequencies. See Figure 1. “VIDEONORM-1”, together with digital displays, significantly improves the quality of recording pictures due to the normalization of the video signal level and growth of the ratio Signal/Noise at the input of a video recording system. Especially effective application of “VIDEONORM-1” may take place during abrupt changes in observing objects of illumination. Such a situation may take place during changes in the time of day, and also during an abrupt change in the medium brightness of the picture in dome-shaped video cameras. Additionally, this device has an LED indication of the video signal presence in every channel. The video signal passes through “VIDEONORM-1” before it is sent to the computer circuit boards of video capture or to the inputs of digital video recording systems.
Technical Characteristics“VIDEONORM-1”
Parameter ValueInput resistance of channel 75 OhmOutput resistance of channel 2000 OhmTransfer ratio of channel at load 75 Ohm 1Maximal total amplitude of output voltage of channel 2,0 VMaximal total amplitude of input voltage of channel 2,0 VPass – band of channel 7,0 MHzSupply voltage (AV) 220 - 230 VUseful current 200 mANumber of channels 4Clamping ratio – Klock-on = ΔUsync1/ΔUsync2 * 20Size of distribution amplifier 240x160x50 mmWeight of distribution amplifier 550 g
* See Figure 2.
The “VIDEONORM-1’’ device is intended for indoor use (IP44). It is made completely using the integrated circuits of RD ALFA md, JSC and “National Semiconductor”. It is notable for small power consumption, reliability and simplicity of operation.
Fig. 2.
VIDEO TRANSMISSION AND DISTRIBUTION VIDEONORM-1
Designfeatures
Elimination of background
pick-ups
Fast clamping of “black” level
4 video channels
Indication of video signal presence
Maximum allowed voltages in video line ValueVoltage in signal wire with relation to common wire ± 12 VAmplitude of impulse voltage with width not more than 100 ms 120 V
10
“TWIST-2RN”Receiver converter with two channels for receiving video signals through twisted pair of wires with device for video signal conditioning
The “TWIST-2RN” receiver with two channels includes:- Two separate receivers converting differential video signals sent from different video signal transmitters through the twisted pair of wires into the standard video signal. It is installed on the receiving end of video lines. During the connection of the “TWIST-T” (or “TWIST-2T”) transmitter in a series at the trans-mitting ends of the video lines and connection of the “TWIST-4RN” receiver at the receiving end of four video lines, four black-and-white or color video signals are transmitted through the twisted pair of wires at distances of up to 900 (or 1800) meters.
Each of the two channels of the “TWIST-2RN” receiver has a differential input for twisted pairs made in the form of a contact connector with 3 contacts. Two contacts are intended for connect-ing the twisted pair of wires to different phases, and the third contact is for the net ground wire. The coaxial 75 ohm BNC output connector is intended for the output of a standard video signal. Each of the two channels of the receiver has an amplifier-corrector which provides compen-sation for signal losses in the cable and corrects the signal roll-off at high frequencies (discrete correction of signal frequency characteristics depending on the length of the video line, with accuracy up to 100 meters). The receiver includes the recovery scheme of constant components in the video signal, which works during moments of the passage of line sync pulses and provides for the filtration of low frequency interferences. The receiver has protection of inputs from impulse pick-ups with the amplitude up to 120 V and the pulse width up to 100 ms and protection from the constant differential voltage up to 24 V or the voltage in a linear wire with relation to a common wire up to ±12 V. The device has a built-in power unit for AC power supply 220 V. The device is intended for indoor use, and it is made using the integrated circuits of RD ALFA md, JSC and “National Semiconductor’’. It is notable for small power consumption, reliability, and simplicity of operation.
Technical Characteristics“TWIST-2RN”
Parameter ValueNumber of receivers 2Total amplitude of input video signal 0,7-3,0 VMaximal total amplitude of output video signal 2,0 VResistance for coaxial output 75 OhmWave resistance of twisted pair of wires 100 OhmPass – band 7 MHzInput-output transfer rate (controlled) 0,5-1,5Range of control of amplitude-frequency characteristic at frequency 5 MHz 0 –24 dBIncrement of control of amplitude-frequency characteristic at frequency 5 MHz 10Common mode rejection of interference 40 dBClamping ratio – Klock-on = ΔUsync1/ΔUsync2 *** 20Controlled level of video signal clamping -1 ÷ +2 VMax. useful current of receiver 70Supply voltage (AV 50 Hz) 220-230 VSize of receiver 240 x 160 x 50 mmWeight of receiver 550 gMax. distance of transmission 900 or 1800 m **
* Losses in twisted pair at frequency 4 MHz not more than 4.1 dB on 100 m** On using transmitters “TWIST-2T”*** See Figure 2 [p. 9]
TWIST-2RN VIDEO TRANSMISSION AND DISTRIBUTION
Designfeatures
Two video channels with fast clamping
of “black” level
High-quality noise- immune transmission of video signal
through twisted pair of wires at
distances up to 900 meters
Correction of video line length by
one switcher with discretion of 100
meters
Indication of video signal presence
Built-in power supply source with electronic
protection
1 2
1 2
TwisT-T
TwisT-T
<900 m
Normalized VideoTwistedpair line
Twist-T
Twist-T
Twist-2RN
Maximum allowed voltages in video line ValueVoltage in signal wire with relation to common wire ± 12 VAmplitude of impulse voltage with width not more than 100 ms 120 V
11
VIDEO MEASUREMENT VMD-1R
Portable signal testerfor measuring parameters of composite video signal for video surveillance systems VMD-1R
Functional application of VMD-1RThe portable diagnostic signal tester VMD-1R is an effective device intended for reducing time spent on the installation of video cameras, checking of video lines, and adjustment of correction equipment and registration of video signals’ which enables testing and finding failures in video surveillance systems without using an oscilloscope.
Operational principle of the signal testerThe signal tester processes the composite video signal, divides it into components, and mea-sures the range of each of them separately indicating the results in volts on the built-in LCD.VMD-1R is able to operate with PAL and NTSC video signals.
Technical Characteristics“VMD-1R”
The range of the values of video signal measurable parameters:
Us (270 mV ≤ norm ≤ 330 mV ) 100 – 600 mV
Ub (280 mV ≤ norm ≤ 390 mV ) 100 – 600 mVUmax (670 mV ≤ norm ≤ 770 mV ) 100 mV – 1,5 V
Uavr 100 mV – 1,5 V
Measuring errors (for the standard PAL):Us and Ub +/- 5 %Umax and Uavr +/- 10 %Input resistance 75 Ohm
Output resistance 75 Ohm
Error in clamping level +/- 50 mV
DC supply voltage 3 V
Supply current 150 mA
Dimensions 135 X 70 X 24 mm
Weight 160 g
Battery type 2 AA
Maximal input voltage, not more than +/- 20 V
Continuous operation time (without charging batteries 2 A 1800 mAH ) not less than 8 h
Designfeatures
Control of the operation course of video cameras, adjustment of the
autodiaphragmatic control system.
Measurement of video signal losses
in video signal transmission
lines and control of operation
of video signal transmission
and registration equipment.
Adjustment of video amplifiers and video signal
transmitters through twisted-
pair wire.
Normalization of video signal in the output of the signal tester
for persistent operating of LCD
monitors.
Measurable parameters Us – the range of sync pulse in the video signal. Ub – the range of color burst signal for color picture cameras.Umax – the peak rate of luminance signal range.Uavr – average (by half-frame) value of luminance signal range.
Additional functions of VMD-1R: The numeric value of the measured parameter is indicated on the LCD display along with the concordance of this parameter to the technical standard rate (Us = 314 = nor). The absence of the video signal is indicated as (No Video) on the LCD display. The value of the battery voltage (BAT = 2,72 nor) is indicated on the LCD display when the measuring mode is switched off. The supply of the video signal into the signal tester process is induced by the light-emitting diode Video.
Areas of application of VMD-1R:Control of the operation course of video cameras; adjustment of the auto-diaphragmatic control system.Measurement of video signal losses in video signal transmission lines and control of operation of video signal transmission and registration equipment. Adjustment of video amplifiers and video signal transmitters through twisted-pair wire. Normalization of video signal in the output of the signal tester for persistent operating of LCD monitors.
“TWIST-AUTO” SYSTEMEquipment for transmission of video signals through twisted pair of wires at distances up to 500 meters
The TWIST system includes the following equipment:- Active automatic TWIST-AUTO receiver, which converts a differential video signal into a standard one. It is installed on the receiving end of the video line.- Active TWIST-T transmitter, which converts a signal from the source (video camera) into a differen-tial video signal. It is installed on the transmitting end of the video line. When the TWIST-T transmitter on the transmitting end of the video line and TWIST-AUTO receiver on the receiving end of the video line are connected in series, a high-quality color video signal is transmitted through the twisted pair of wires at distance up to 500 meters.When the passive BALUN type receiver on the transmitting end of the video line and the automatic TWIST-R receiver on the receiving end of the video line are connected in series, a high-quality color video signal is transmitted through the twisted pair of wires at distance up to 300 meters.
The automatic TWIST-AUTO receiver has a differential input for the twisted pairs in the form of a contact connector with 3 contacts. Two contacts are intended for connecting the twisted pair of wires to different phases, and the third contact is for the net ground wire. The coaxial 75 ohm BNC output connector is intended for the output of a standard video signal.The automatic receiver has a converter of a differential video signal into a standard one, as well as a system of automatic correction of video line length, pre-distorting PAL or NTSC differential colour video signal in order to compensate high-frequency losses in the long line and the system of automatic adjustment of video signal level. The receiver has indication of video signal presence and automation operating. The receiver has an input protection from impulse pick-ups with the amplitude up to 300 V and the pulse width up to 100 ms, and also protection from constant differential voltage up to 50 V or voltage on a linear wire with relation to a common wire up to ± 25 V. The receiver has an input protection from impulse pick-ups with the amplitude up to 120 V and the pulse width up to 100 ms, and also protection from constant differen-tial voltage up to 24 V or voltage on a linear wire with relation to a common wire up to ± 12 V.TWIST- T transmitter has a coaxial 75 ohm BNC input connector and differential outputs made in the form of a contact connector with 3 contacts. Two contacts are intended for connecting the twisted pair of wires to different phases, and the third contact is for the net ground wire.The transmitter has a converter of a standard video signal into a differential video signal as well as a discrete frequency correction that pre-distorts a differential video signal thus compensating high frequency loses in a long line. The transmitter has output protection from impulse pick-ups with the amplitude up to 120 V and the pulse width up to 100 ms, and also protection from constant differential voltage up to 24 V or voltage on a linear wire with relation to a common wire up to ±12 V.Both devices have a built-in power unit for AC power supply 220 V.The devices are intended for use outdoors (category IP54) and are made exclusively using integral circuits made by MAXIM and RD ALFA md, JSC. They are notable for small power consumption, reli-ability and simplicity of operation.
TWIST-AUTO VIDEO TRANSMISSION AND DISTRIBUTION
Designfeatures
High-quality transmission
of video signals through twisted pair of wires at
distances up to 500 meters
Automatic correction of video line lenght for PAL
and NTSC video signals
Fast clamping of black level
Indication of the video signal presence and automation operating
Built-in power supply source with electronic
protection
~220
V
TWIST-TTWIST PAR VIDEO
TRANSMMITERTWIST-RAUDIO
~220
V
IN OUT
Twist-T Twist-R Audio
Autoadjustment
Camera
IN OUT
“TWIST-AUTO”Parameter ValueTotal amplitude of input video signal 0,5-2,5 VResistance for coaxial input 75 OhmWave resistance of twisted pair of wires 100 OhmPass – band 7 MHzInput – output transfer rate (automatically controlled) 1,5Range of control of amplitude – frequency characteristicat frequency 4.43 mHz (automatically controlled)
12 dB
Gain adjustment range (automatically controlled) 9 dBCommon-mode signal suppression 40 dBMax. useful current of receiver 60 mASupply voltage (AV 50 Hz) 220 - 230 VSize of receiver 110 x 80 x 40 mmWeight of receiver 120Max. distance of transmission 500 m
“TWIST-T”Parameter ValueTotal amplitude of input video signal 0,7-1,5 VResistance for coaxial input 75 OhmWave resistance of twisted pair of wires 100 OhmPass – band 7 MHzInput – output transfer rate number 1Discrete control of amplitude – frequency characteristic (at frequency 7 MHz)
0 – 6 - 9 dB
Ratio signal/noise 50 dBMax. useful current of transmitter 30 mASupply voltage (AV 50 Hz) 220-230 VSize of transmitter 110 x 60 x 67 mmWeight of transmitter 100 g.Max. distance of transmission 900 m.
Maximum allowed voltages in video line ValueDifferential voltage on signal wires, not more than 50 VVoltage in signal wire with relation to common wire ± 24 VAmplitude of impulse voltage with width not more than 100 ms 300 V
RD ALFA DESIgN Of VIDEO SURVEIllANCE SySTEMS
Sigulda bobsleigh, luge,and skeleton track.Length: 1200m (16 curves),Height difference 120mConstruction made by“Verlan Ltd” and “RD ALFAMD JSC”.Video lines use externalmulti-pair cables; numberof video cameras 14.Length of video lines 1200mand 120m. Video transmissionequipment system“Twist” + “Videonorm”
Riga ShipyardTerritory area: 1 100 000 m2.Construction was made by “BISS Ltd” and “RD ALFAMD JSC”.Video lines use internaltelecommunication network; number of video cameras 16.Length of video lines2200m and 300m. Videotransmission equipmentsystem “Twist” + “Videonorm”.
Function block of video surveillance system Sigulda bobsleigh, luge,and skeleton track.
Contact infoJSC “RD Alfa mikroelektronikas departaments”Maskavas 240, Riga LV-1063, Latvia
Phone:+371 67109 400Fax: +371 67109 498
Chief DesignerAleksander Maiborodaphone: +371 67109 [email protected]