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 completes and electronically submits form FCC Form 338, AM Station MDCL Notification. The electronic filing process is explained in the February 18, 2016 Public Notice.
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.
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.