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 Stopping  Ground Loops

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Almost all cases of video noise and audio buzz in home theater systems can be traced directly to ground loops or poor grounding. Each component of a video or sound system produces its own ground internally. This ground is usually called the signal ground. Connecting devices together with the interconnecting cables can tie the signal grounds of many components together through the conductors in the cable. Ground loops occur when the grounds of the two units are also tied together in another place: via the electrical ground in the line cord or power strips. etc. These situations create a circuit through which current may flow in a closed "loop" from one unit's ground out to another units ground and back. At times this problem is caused by a SVideo component like a VCR or DVD player. Many times it is impossible to eliminate these currents entirely. When that happens Allen Avionics has the S-Video products to make your home theater experience better.



Description / Application

Size / Price


With Brackets

The S2000 SVideo Hum Eliminator can solve problems caused by ground loops in home theater. Can be used with any SVideo output from a VCR or DVD. Standard SVideo connectors wide bandwidths and 75 ohms. S2250 supplied with mounting brackets.

7.4 L x 4.3 W x 2.4 H



  With Brackets

The SVIT200 is a true video transformer.  Can be used with any SVideo output from a VCR or DVD. Useful in any mobile home application. Standard SVideo connectors wide bandwidths and 75 ohms. SVIT225 supplied with mounting brackets


7.4 L x 4.3 W x 2.4 H



Poor Picture Quality

Good Picture Quality

Is this the kind of picture you get on your new home theatre display? Moving black lines through the picture and generally poor quality images. Do you have Audio buzz coming from your speaker?

Some times these problems are caused by the interconnection of system components like Satellite or Cable systems, DVD players, VCR’S, Audio amplifiers and receivers. Internal grounding in one piece of equipment or a power or grounding loop problem can cause this type of distortion. When ground loops cause the problem we have some hints on how to find and fix it.

How to find and eliminate ground loops and prevent AC Hum.

For complex systems you may need to repeat the following steps starting with a different piece of equipment in various combinations to locate the problem and correct it. See figure 1.

#1 Strip the system down to the display and one Video or  Audio source. Disconnect any Satellite or cable system, DVD player, VCR, Audio Receiver etc.    

#2  Add one piece of equipment back at a time. Reconnect Cables, power and check for Humbars in the Video or Hum in the audio.

#3 Proceed until you find the offending component(s) that is causing the problem.

#4 Once you know what combination of components is responsible Allen Avionics Will probably have a Audio or Video Hum Eliminator you can insert  between the offending equipment and the rest of the system to permanently stop the Hum 

Allen Avionics has hum eliminators for S Video, NTSC, Composite, HDTV Analog (Y,PbPr or RGB), Component, Y R-Y B-Y.  They can be used with any brand of Audio or Video equipment.

For additional technical information or ordering information call our technical sales department at 516-248-8080.

You can also see us on the Web at www.allenavionics.com  

Email any questions you may have to sales@allenavionics.com


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Allen Avionics, Inc.
2727 Clinton Street
River Grove, IL  60171
Phone: (708)-453-3238
Fax: (708)-453-0297
E-Mail: Sales@AllenAvionics.com

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