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AM broadcast station licensees may now employ energy-saving Modulation Dependent Carrier Level (MDCL) technologies.  These technologies are briefly summarized in the Commission's September 11, 2011 Public Notice.  AM stations employing Modulation Dependent Carrier Level (MDCL) control technologies to reduce power consumption may commence such operation without prior Commission authority, provided that: :

  • Within 10 days of commencement of MDCL operation, the AM station licensee must complete and electronically submit FCC Form 338, AM Station MDCL Notification.  Electronic filing of this simple form is required.
  • Use the ECFS' "Non-Docketed" filing form at https://www.fcc.gov/ecfs/filings/nodocket and select Form 338 in the drop down menu labelled "FCC Inbox".  Complete the remaining information and submit the form. 
  • To see what's asked for in the form, view the sample Form 338 (PDF).  This PDF cannot replace electronic filing.


See the First Report and Order, Further Notice of Proposed Rule Making, and Notice of Inquiry, Revitalization of the AM Service, MB Docket No. 13-249, adopted October 21, 2015, for a discussion of MDCL control technologies and Commission requirements for MDCL operation.  See also the February 18, 2016 Public Notice for the effective date of the MDCL rules.

A list of AM broadcast stations authorized to use MDCL technology, in Excel format, is available HERE.  This list is updated from time to time.

For more information on AM and FM radio broadcasting, please visit the Audio Division website, and the Broadcast Radio Links page.

FCC > Media Bureau > Audio Division.

Monday, August 24, 2020