PART 1: USING THE BH184 AS A VIDEO LAUNCH AMPLIFIER
INSTALLATION
Note 1: A Launch Amplifier is usually used in conjunction with a second video amplifier unit
installed at the monitor end of the cable run. For short cable runs up to about 300m the
BH184 unit may be used on its own.
Note 2: The BH184 unit will block telemetry signals – for video only.
The unit should be installed as close to the camera as is practical. The output cable of the
12V DC supply is connected to the spring-loaded connector labelled ‘12V DC’. Ensure the
positive wire is connected to the connector slot labelled ‘+’. The positive wire from the power
supply is marked with a light grey stripe. An LED in the top panel shows when power is
connected.
The video cable from the camera is connected to the BNC coax connector labelled ‘VIDEO
IN 75R’. The outgoing coax cable is connected to one of the two output coax connectors
labelled ‘VIDEO OUT 75R’. The unused output connector does not have to be terminated.
DIAGRAM 1 SHOWING A BASIC CCTV INSTALLATION
INCORPORATING A BH184 UNIT
(For clarity only one camera run is shown)
ADJUSTMENT
The BH184 unit is adjusted in the factory for Unity output so that an input signal of 1.0 Volt
peak to peak @75R will give an output signal of 1.0 Volt peak to peak @75R. For medium /
long cable runs it will be necessary to increase the output signal level. The BH184 unit has
two controls: one for signal amplitude (GAIN) and one for high frequency lift (HFL).
To increase the signal levels rotate the pots clockwise. If you are using the BH184 in
conjunction with a second amplifier unit, adjust the BH184 unit first.
The GAIN control will adjust the peak to peak amplitude of the video signal – this will
affect the brightness of the picture on the monitor.
The high frequency component of the video signal carries information on fine detail
and colour. For long cable runs the High Frequency Lift control may be set to
maximum if required.
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