ASTEL TRR 101, Operating Instructions Manual

Page: 6 / 12

6
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 Z
L
, loss a
5MHz /km
) and calculate the cable
loss a
5MHz.
(see Example 1 and Example 2 )
(7) Set the trimmer TP1 - measure with ohm-meter between A and B .
Adjust resistance between A and B to achieve cable impedance Z
L.
(R
AB
= Z
L
)
(8) Switch-on the adequate switches (Table 1) to compensate the cable loss a
5MHz
.
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 A and
⊥
.
(15) Check the negative video input signal between B and
⊥
.
(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.