ASTEL TR 101 User manual

TR 101
VIDEO TWISTED-PAIR RECEIVER
OPERATING INSTRUCTIONS v1.0

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CONTENTS
Preface........................................................................................................................................................ 3
Features ...................................................................................................................................................... 3
Block diagram.............................................................................................................................................. 3
Principle of operation................................................................................................................................... 3
Controls and connectors ............................................................................................................................. 4
Connections ................................................................................................................................................ 5
Installation ................................................................................................................................................... 6
Appearance................................................................................................................................................. 8
Specifications .............................................................................................................................................. 8
This unit is produced to comply with Directive
89/336/EEC.

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PREFACE
The video twisted-pair receiver TR 101 is a
correction amplifier with symmetrical input and the
standard asymmetrical video output. It is mounted
in ABS casing. The numerous trimmers help to
adjust the input impedance, symmetry, linear gain
and rough or fine gain adjustment at different
frequencies. There are LED1 and LED2 which
indicate the power-on and the video signal error in
the video input of the receiver.
FEATURES
•small dimensions
•AC/DC power supply
•low power consumption
•over-voltage protection
•max. +60 dB gain at 5 MHz
BLOCK DIAGRAM
PRINCIPLE OF OPERATION
The input stage enables the setting of the input
impedance and symmetry.
The minimal high frequency gain is 6 dB and the
high frequency attenuation should be switched-on
at short distances.
The next two stages enable the linear gain
adjustment and the square-wave response
adjustment. There follow the filter stages with
sixteen switches and their adequate elements for
the fine adjustment with total gain from +6 to +60
dB.
In the end there are the low-pass filter and the
clamping circuit with the indication of power-on
(the green LED) and the video-signal-error
indication (the red LED).
With the help of the output stage the standard
video output with the impedance of 75 ohm is
achieved.
The power is supplied by connecting to the AC or
DC power supply unit.

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CONTROLS AND CONNECTORS
(1) AC/DC POWER SUPPLY
Power supply terminal block connector.
(2) TC 4
LF-III fine adjustment trimmer.
(3) LED 1
Red LED for video signal error indicator.
(4) TC 3
MF-III fine adjustment trimmer.
(5) LED 2
Green LED as power-on indicator.
(6) VIDEO OUTPUT
Video output terminal block connector.
(7) TP 3
Linear gain adjustment trimmer.
(8) TWISTED-PAIR INPUT
Twisted-pair terminal block connector.
(9) TP 1
Input impedance adjustment trimmer.
(10) TP 2
Symmetry adjustment trimmer.
(11) J 1
HF attenuation (short distance) jumper.
(12) TC 1
HF gain adjustment trimmer.
(13) TP 4
LF gain adjustment trimmer.
(14) SW1-SW16
LF/MF/HF gain switches.
(15) TC 2
HF-III fine adjustment trimmer.

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CONNECTIONS
•Be sure to switch-off the power supply unit
before connecting to other equipment.
•Also refer to the instruction manual of the
equipment to be connected.

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INSTALLATION
(1) Set the trimmer TP2 to the middle position.
(2) Set the trimmer TP3 to the middle position.
(3) Set the trimmer TP4 to the left.
(4) Switch-off SW1-SW15, SW16 switch-on.
(5) Set TC1, TC2, TC3 and TC4 to the minimal capacitance.
(6) In the Table 1 select the CABLE (insulation, impedance ZL, loss a5MHz /km)and calculate the cable loss
a5MHz. (see Example 1 and Example 2)
(7) Set the trimmer TP1 - measure with ohm-meter between Aand B.
Adjust resistance between Aand Bto achieve cable impedance ZL. (RAB = ZL)
(8) Switch-on the adequate switches (Table 1) to compensate the cable loss a5MHz.
In the SECTION I or SECTION II only one group of switches (10dB or 20dB) can be switched-on in the
same time. (see Example 1 and Example 2)
(9) Connect the power supply unit (AC or DC) to the K1.
(10) Connect the video monitor to the video output K2.
(11) Connect the twisted-pair cable to the K3.
(12) Switch-on the power supply units.
LED2 (green) lights, power supply is switched-on.
If there is a video signal at the input, LED1 (red) doesn’t light.
(13) Switch-on the video monitor.
(14) Check the positive video input signal between Aand ⊥.
(15) Check the negative video input signal between Band ⊥.
(16) Set the output video signal to 1 Vpp - trimmer TP3.
(17) Do the fine adjustment with TC2, TC3, TC4, correct the sync. pulse with TP4, TC1. (Fig. 1)
(18) If adjustment with TC2, TC3, TC4 is not possible, switch-on SW13, SW14, SW15 and do the fine
adjustment.
(19) Set the minimal disturbance - trimmer TP2.
(20) Correct the output video signal to 1 Vpp - trimmer TP3.
(21) If there is too much noise in the signal (gain adj. >50 dB at 5 MHz), set the pre-emphasis to +10 dB in
the video twisted-pair transmitter.
(22) If a <6 dB (short distance), SW1-SW15 switch-off, SW16 switch-on, jumper J1 set to −6 dB and do the
fine adjustment.

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adjusted sync. pulse TP4 adjustment TC1 adjustment
Fig. 1: Sync. pulse correction
Table 1
CABLE
SECTION I (SW1-SW6)
SECTION II (SW7-SW12)
TYPE INSULATION ZL/Ωa5MHz/km 10 dB 20 dB 10 dB 20 dB
Ppaper 150 51 dB 2 4 1 2 6 8 10 7 8 12
Ppaper 125 35 dB 2 4 6 1 2 5 8 10 12 7 8 11
Ppaper 125 33 dB 2 4 6 1 2 4 5 8 10 12 7 8 10 11
Ppaper 125 30 dB 2 4 6 1 2 4 5 8 10 12 7 8 10 11
YPVC 90 65 dB 2 4 6 1 2 4 5 8 10 12 7 8 10 11
YPVC 100 40 dB 2 4 6 1 2 3 5 8 10 12 7 8 9 11
2Y,2YF PE 130 40 dB 2 4 6 1 2 5 8 10 12 7 8 11
2Y,2YF,02Y PE 135 30 dB 2 4 6 1 2 4 5 8 10 12 7 8 10 11
2Y,2YF,02Y PE 135 24 dB 2 4 5 1 2 3 4 5 6 8 10 11 7 8 9 10 11 12
02Y PE 140 21 dB 2 4 5 1 2 3 4 5 6 8 10 11 7 8 9 10 11 12
Example 1:
Cable specifications: ZL=125 Ω, a5MHz/km=30 dB, paper insulation, cable length L=500 m.
(1)a5MHz=a5MHz/km x L=15 dB
(2)In Table 1 find column 10 dB in SECTION I or in SECTION II.
Switch-on the switches 2, 4 and 6 or 8, 10 and 12 (page 5).
(3)Do the fine adjustment (+5 dB) with TC1, TC2, TC3, TC4 and TP4.
Example 2:
Cable specifications: ZL=100 Ω, a5MHz/km=40 dB, PVC insulation, cable length L=1000 m.
(1)a5MHz=a5MHz/km x L=40 dB
(2)In Table 1 find column 20 dB in SECTION I and in SECTION II.
Switch-on the switches 1, 2, 3, 5, 7, 8, 9, and 11 (page 5).
(3)Do the fine adjustment with TC1, TC2, TC3, TC4 and TP4.
Note:
•It is not necessary to keep the instructions in Table 1 strictly in the practical use.

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APPEARANCE
SPECIFICATIONS
Video input :0.12 - 2 Vpp (TP3)
Input impedance :45 Ω- 175 Ω(TP1)
Video output :1 Vpp, 75 Ω
Freq. response :50 Hz - 5 MHz (-3 dB)
Disturbance reduction :>70 dB, 50 Hz (TP2)
Gain adjustment :+6 dB...+60 dB at 5 MHz (SW1-SW16, TC, TP)
Noise :-50 dB at +40 dB gain adj.
-47 dB at +60 dB gain adj.
Power supply :24 V, AC/DC, 100 mA max.
Input protection :noble-gas filled surge arrester, zener diodes
Power supply protection :varistor
Indicators :LED2 (green) - power-on
LED1 (red) - video-signal-error
Casing :ABS
Dimensions :160(W) x 55.5(H) x 100(D) mm
Protection :IP - 65 (VDE)

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