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A TV is not a suitable replacement for a video output. It can only be used for a
short period of time and is particuarly suseptabler to nearby interferance. The TV
can also damage other equipment.
2.5.3 Audio signal input
The audio port is a BNC connection.
As the input impedance is high, the tone arm must be active.
The audio signal line should be strong and away from any electro magnetic
Interference and with a credible connection which should avoid false signals and
joint welding and oxidation. High voltage current should be especially avoided.
2.5.4 Audio signal output
Commonly the output parameter of a DVR audio signal is greater than 200mv
1KΩ(BNC) which can connect a low impedance earphone and active sound box
or other audio output equipments through a power ampliier. If the sound box and
the tone arm can not be isolated, a howling phenomena is often experienced.
Here are some methods to deal with this phenomena.
1).
Adopt a better directional tone arm.
2).
Adjust the sound box volume to below the threshold that produces the
howling phenomena.
3).
Use itment materials that absorb the sound to reduce the relection of the
sound.
4).
Adjust the layout of the sound box and the tone arm.
2.6 Speed dome connections
1).
Connect the 485 lines of the speed dome with the DVR 485 interface.
2).
Connect the video line with the DVR video input.
3).
Connect the speed dome to a power supply and switch on.
R485
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