product specifications

New Products

audio isolation products

prices & ordering info

ordering info

Literature downloads

trade shows and conventions

contact us

frequently asked questions


Empire State Filter Co.ís line of hum eliminators, also referred to as a humbucker or a ground loop eliminator, is designed to remove interference created by long cable runs, 60 cycle power demands, grounding noise, and magnetic coupling. Normal voltage differences between system grounding points cause small AC power currents to flow through video cables. At power frequencies, a voltage drop of only 7mV peak can cause a visible hum bar. 

How a hum eliminator works:  60 cycle hum - ground loop current - only flows on the shield of a coaxial video cable. This current will produce a magnetic field in the iron core of the hum eliminator and create an inductor, or choke. The high impedance of this choke - in the ground path - effectively eliminates the 60 cycle hum from passing through the unit. The video signal, on the center conductor, is shielded from this impedance - by the cable's shield - and passes through the unit unaffected.

The major advantage using a hum eliminator over an isolation transformer is high bandwidth. The low-frequency response extends to DC avoiding an effect, seen on waveform analyzers, called field-rate tilt and the high-frequency response of 100 MHz or more make these units suitable for high-definition and projection systems. These units are passive devices which remove induced hum while being transparent to the video signal.

Single channel units are designed for composite signals, multi-channel units can be used either for multiple composite signals, component, YCbCr, or RGB  plus sync signals. Other models are also available with internal audio ground loop isolators to remove both audio and video interference. 

Our use of quality materials in the manufacture of these products will assure you that you're getting the best hum eliminator possible. Click on the buttons to the left of the screen to browse the website for product and purchasing information.

Remember, you can always call us toll free and speak to an engineer to find the right product for your application.

  Add me to your Favorites list





Empire State Filter Co., Inc.   85-7 Air Park Drive 1521 Ocean Avenue Unit A6   Ronkonkoma, NY   11779
  Phone: 631-471-2980   888-345-8370   Fax: 631-471-3490

©2002 Empire State Filter Co., Inc.   1559 Lincoln Avenue, Holbrook, NY   11741
  Phone: 631-589-0950   888-345-8370