Compu-Video Systems CVDA-2 Manuel utilisateur
Thank you for purchasing one of our products. Please read this manual before using this
product. When using this product, always follow the instructions contained in this manual,
and pay attention to the safety information.
P.O. Box 749 Peekskill, NY 10566 Tel: (845) 737-7009 Fax: (845) 737-0426 Web: www.compuvideosystems.com
Do not expose this product to water, rain or moisture.
Doing this can result in electric shock or re.
Never take this product apart or try to modify it.
Doing so is very dangerous and could result in electric shock.
Do not store this product near open ame.
Do not use this product near open ame or place lit or ammable items, such as
candles, incense, ect., on it.
Do not place any containers lled with water or other liquids near this product.
Doing so could result in re or electric shock if the liquid spills and enters the product or
gets it wet. If a liquid spills near this product, unplug the product immediately.
Do not remove or insert the power supply with wet hands.
Doing so could result in electric shock.
Do not use the power supply in any of the following ways.
Doing so could result in re or electric shock.
Modifying or heating the power cable
Damaging the power cable
Bending or tugging on the power cable unnecessarily
Knotting or kinking the power cable
Setting heavy objects on the power cable
When moving this product , rst unplug the power supply from the outlet. Do not
tug the cable or move this product with the power supply plugged into the outlet.
Doing so could damage the cable, possibly resulting in re or electric shock.
To reduce the risk of electric shock, do not remove the cover.
No parts inside the product can be serviced by the user. If your product needs service
contact:
Compu-Video Systems Inc. at (845) 737-7009.
Usage Environment
Avoid using or storing this product in areas such as those listed below. Doing so could
damage the product or cause it to malfunction.
Areas exposed to heat or ames
Humid areas and areas where water is used
Handling this product
Do not drop or apply a strong force to this product or any included or connected parts.
Do not spill liquids around or inside this product or drop ammable objects around or
inside it.
Power Supply
Only use the supplied power supply which is designed specically for this product.
Do not allow the plug to come into contact with metal or water.
This Product is not designed for contact medical use
Do not use this product for medical applications that could result in patient contact.
The information in this manual is believed to be accurate. It is intended for professional
end users having the skills to evaluate and use the data properly. Compu-Video assumes
no liability in connection with damages incurred while using this product.
P.O. Box 749 Peekskill, NY 10566 Tel: (845) 737-7009 Fax: (845) 737-0426 Web: www.compuvideosystems.com
Mounting Location:
Model Mounting locations:
CVDA-2 As close to center of the two output feeds or at recieving end
for Ground Loop Blocking
Model # Of Inputs # Of Outputs Controls Special Features
CVDA-2 1 2 Gain, High Freq. Ground Loop
Isolation
INSTALLATION
The CVDA-2 is a light weight unit able to be mounted at any location. After the unit has
been placed, you can connect the power.
CONNECTING THE POWER
WARNING! The DC power cannot be from the same supply as the DC camera
or video source. It must be from an isolated source.
For the CVDA-2, Hum in a video picture can be caused by several things:
A) Ground loop
B) Camera
C) Power supply failure
D) Induced hum due to proximity of ac power feeds.
The CVDA-2 is designed to only reduce or eliminate ground loop hum
between two points and will have minimal to no effect on the other
types of distortion. If you have any splices or bare cables that may
be touching metal between the camera and the CVDA-2, isolate it with
tape so that it does not touch any other metal items.
Ground loops usually become visible when several cameras are connected together at a
switcher or a quad screen splitter. The problem also occurs when a camera is located in a
different “ground” plane than the monitor is located in. The hum or interference is caused by
the differences in ground voltages from each device mixing together. By using the CVDA-2
to isolate the signal and the ground, the problem is resolved. The CVDA-2 corrects the
ground-loop problem on the input side of a run, this still leaves a potential for a
ground-loop to occur between the 2 locations on the output side of the VDA. If this
problem should occur on one or both outputs simply add a GLB-ll to one of the 2
outputs.
P.O. Box 749 Peekskill, NY 10566 Tel: (845) 737-7009 Fax: (845) 737-0426 Web: www.compuvideosystems.com
SIGNAL ADJUSTMENTS
On the CVDA-2 there are openings on the side of the unit for the gain and high frequency
controls. Insert a small straight edge screwdriver to adjust. Connect a signal to the video
“in” of the unit. With an oscilloscope connected to the output and the output cable
terminated in 75 ohms, adjust the gain control so that the sync signal is 280mv or if a 1VPP
test signal is available, adjust the gain control for an overall level of 1VPP at the end of the
cable.
On the CVDA-2, the High Frequency control is adjusted for the sharpest picture desired.
Fig. 1
Control Locations
PLACEMENT IN SYSTEM
The CVDA-2 should be placed as near the end of a system as possible for ground loop
protection.
1) Disconnect the feed from the camera at the end by the monitor, switcher or VCR.
Connect the camera feed to CVDA-2 input. Connect one output to your monitor,
switcher or VCR. and verify that the hum is reduced or eliminated.
2) Adjust the video gain for the desired level
3) Adjust the High Frequency control for the sharpest possible picture.
GAIN High Frequency
Aligning The CVDA-2 Using The VST-1000
P.O. Box 749 Peekskill, NY 10566 Tel: (845) 737-7009 Fax: (845) 737-0426 Web: www.compuvideosystems.com
To align the CVDA-2 with out using an oscilliscope use the VST-1000, place the VST-1000
immediately after the CVDA-2. Using the gain or level adjustments on the CVDA-2 to match
the Gain / Level indicator box color to that of the Gain / Level xed reference bar box next to
it. Once that has been done do the same thing to the HF or High Frequency control box. If
the Variable indicator can not be turned “down” to match the reference box that is ok.
Camera DVR
View of what the boxes should look like after being properly adjusted.
P.O. Box 749 Peekskill, NY 10566 Tel: (845) 737-7009 Fax: (845) 737-0426 Web: www.compuvideosystems.com
Gain / Level
Indicator
Gain / Level
Fixed Reference Bar
High Frequency
Indicator
High
Frequency
Fixed
Reference Bar
VIDEO:
Inputs: Composite Video
Input Connectors: BNC
Input Level: 1vpp Into 75 Ohms
Input Impedance: 75 ohm +/-5%
Output: 2x Per Input
Output Connector: BNC
Output Impedance: 75 ohm +/-5%
Gain In/Out: +/-3dB Minimum
Diff Gain: <1%
Diff Phase: <1°
Frequency Response: 0-65mHz
Power / Supply Hum: <63dB
H Tilt: <1%
V Tilt: <1%
CCMR: Type. 60dB @ 4Mhz
High Freq. Boost: Type 0+/- 8dB
POWER REQUIREMENTS:
DC Operation: 12 to 18VDC Isolated Source
DC Power Draw: <1w
Power Connector: 1/8” Phono Plug
MECHANICAL:
Size: 1.75”W, 4”D, 1”H
Weight: <1.0 lbs
P.O. Box 749 Peekskill, NY 10566 Tel: (845) 737-7009 Fax: (845) 737-0426 Web: www.compuvideosystems.com
All Specications Subject To Change Without Prior Notication
P.O. Box 749 Peekskill, NY 10566 Tel: (845) 737-7009 Fax: (845) 737-0426 Web: www.compuvideosystems.com
P.O. Box 749 Peekskill, NY 10566 Tel: (845) 737-7009 Fax: (845) 737-0426 Web: www.compuvideosystems.com
NOTES
P.O. Box 749 Peekskill, NY 10566 Tel: (845) 737-7009 Fax: (845) 737-0426 Web: www.compuvideosystems.com
NOTES
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