Power Saving MDCL


Modulation-Dependent Carrier Level (MDCL) control technologies or algorithms, long used by international broadcasters operating high-powered AM transmitters to reduce transmitter power consumption, is now FCC approved for use by AM stations in the U.S.

Note: to implement MDCL technology, AM licensees must notify the FCC using Form 338 per 47 CFR 73.1560. In April 2013, the NRSC provided a new AM MDCL Usage Guideline; see NRSC-G101.

MDCL is FREE On NX Series

Nautel has provided MDCL power-saving technology as a free, standard pre-installed software feature (vs. optional circuit board) in all NX Series transmitters.

NX Series

Enabling MDCL on your NX transmitter only takes a moment, using Nautel’s Advanced User Interface (AUI):

  • Select Menu | Presets | Analog Settings
  • Click Dynamic Carrier Control dropdown
  • Pick an option*
  • Click Load

*All provide significant power savings—we recommend AMC for minimal audible impact

XR Series

  • Systems operating with HD Radio® technology: Contact Nautel Customer Service to upgrade your Exporter Plus software to include the MDCL package.
  • Systems using an older version Exporter or NE-IBOC (AM) unit: It may be necessary to upgrade to an Exporter Plus; contact your Nautel Sales Rep for pricing.
  • Systems NOT using HD Radio technology: An external DCC (Dynamic Carrier Control) unit is required. Installation is simple and cost is minimal; contact your for pricing.

ND Series & XL Series

  • Systems operating with HD Radio technology: Contact Nautel Customer Service to upgrade your Exporter Plus software to include the MDCL package.
  • Systems NOT using HD Radio technology: Some upgrades are required: 1) replace the RF Drive and PDM boards in the exciter section of the transmitter; 2) install an interface board to connect to the DCC unit; 3) install, in a separate rack, and connect the DCC unit. Pricing is on a case-by-case basis, contact Nautel Customer Service.

Additional Power Savings

Overall efficiency of the NX25 and NX50 is typically 88% or better. NX100 and above achieve 90% efficiency.

This means less energy is wasted as heat, which reduces cooling and ventilation costs. Savings can amount to tens of thousands or even hundreds of thousands of dollars over the life of your transmitter depending on its size and your local power rates.

MDCL Station Examples

MDCL Operation Is a Winner for High-Power AM, Radio World
Crawford Sees ‘Very Tangible Savings’ With MDCL, Radio World
Crawford Saving Money With MDCL, Radio World
KSPN Is Running MDCL in L.A., Radio World 01/06/2012
A Break for Your AM Station’s Power Bill, Radio World 9/13/2011