Go to FCC.gov
FCC Logo - Return to the FCC Home Page  
  Media Bureau

  



 

      Basic Signal Leakage Performance Report (FORM 320)

FCC Form 320 contains a snapshot of the interference potential to aircraft communications and navigation over a cable system's distribution plant. Cable operators have the option of performing either the ground based CLI (10 log I infinity or 10 log I3000) or airspace measurement, in either case the test result should show compliance with the basic signal leakage criteria outlined in 47 CFR Section 76.611. The test equipment used must be capable of measuring leaks of 20 v/m @ 3 meters or its equivalent, and the test frequency must be within the VHF aeronautical band of 108-137 MHz or a frequency in which the results can be correlated to that band. The test signal used shall carry an average power equal to the average power level of the strongest carrier on the system. The accompanying exhibits shall include a list of all aeronautical frequencies used (Exhibit A) and information on the test measurements including a list of all leaks 50v/m or greater detected for ground based measurements, (Exhibit B) or information on airspace tests (Exhibit C).

If you have any questions about the Form 320, please call (202) 418-7000.

     Commonly Asked CLI and Form 320 Questions
     Click Here for On-Line CLI Calculations
     Click Here for to file Form 320 electronically

SRC="http://www.fcc.gov/images/fcclogowords.gif"

CLI example; This gif is an part of an example CLI calculation,
and the only simple way to display it is with a picture file.
This information will not, therefore, be accessible to some browsers.
If this is the case, please contact the 
Engineering and Technical Services Division for assistance at (202) 418-7000.
CLI example continued; This gif is an part of an example CLI calculation, and the only simple way to display it is with a picture file.  This information will not, therefore, be accessible to some browsers.  If this is the case, please contact the Engineering and Technical Services Division for assistance at (202) 418-7000.






CLI example 2; This gif is an part of an example CLI calculation, and the only simple way to display it is with a picture file.  This information will not, therefore, be accessible to some browsers.  If this is the case, please contact the Engineering and Technical Services Division for assistance at (202) 418-7000.


CLI example 2 continued; This gif is an part of an example CLI calculation, and the only simple way to display it is with a picture file.  This information will not, therefore, be accessible to some browsers.  If this is the case, please contact the Engineering and Technical Services Division for assistance at (202) 418-7000.


    

    




For comments or questions pertaining to Engineering Division web pages, send e-mail to the Media Bureau, Engineering Division Webmaster at: Walid.Kassem@fcc.gov. Questions can also be answered by calling the FCC's National Call Center, toll free, at 1-888-Call FCC (1-888-225-5322).

Skip FCC Footer and Contact InfoFederal Communications Commission
445 12th Street SW
Washington, DC 20554
More FCC Contact Information...
Phone:  1-888-CALL-FCC (1-888-225-5322)
TTY:  1-888-TELL-FCC (1-888-835-5322)
Fax:  1-866-418-0232
- Privacy Policy
- Website Policies & Notices
- Required Browser Plug-ins
- Freedom of Information Act