ARRL Protests DRM Alaska Test - Radio World

ARRL Protests DRM Alaska Test

'There is a 100% certainty of severe, continuous, harmful interference ... to ongoing amateur radio operation at 7.1 to 7.3 MHz.'
Author:
Publish date:

A leading ham group has come forward to protest the test plans of Digital Aurora Radio Technologies, the company that has an experimental authorization to test Digital Radio Mondiale broadcasts at high latitudes.

The national association for amateur radio, the American Radio Relay League, says one of the frequencies on which DART would test will interfere with amateur broadcasts, and the ARRL has asked the Federal Communications Commission to modify or cancel the experimental license. But the company tells RW it won't operate in those frequencies. The FCC amended the license.

In 2009, DART proposes to test statewide transmission of DRM at high latitudes in the 5, 7 and 9 MHz shortwave bands; it hopes the tests, if successful, will lead to a terrestrial, high-frequency digital radio service for the state of Alaska.

The ARRL takes issue with testing on the 7.1 – 7.3 MHz portion of the band, which it says is heavily used within ITU Region 2, including Alaska, and "is allocated domestically exclusively to the amateur radio service." DART plans to test using a 20 kHz bandwidth digital emission at a transmitter output power of 100 kilowatts and an ERP of 600 kW within a radius of about 930 miles of Delta Junction, Alaska.

"There is a 100% certainty of severe, continuous, harmful interference from operation of the DART facilities as authorized by the commission to ongoing amateur radio operation at 7.1 to 7.3 MHz," says the ARRL in its petition, filed this week. It calls that portion of the 7 MHz band perhaps the most heavily used amateur HF band in the United States.

According to the grant for the CP and license, issued Oct. 7, operation is subject to prior frequency coordination with the SBE. On Oct. 24, the FCC issued an amended license that redefined one of the station's frequency ranges to eliminate conflict with the Amateur Radio Service. The amended license narrows the range to 7.30 to 7.60 MHz.

In response to queries Thursday evening from Radio World asking about this issue, company President Whit Hicks stated in an e-mail that DART would not operate in 7.1 to 7.3 MHz, to avoid any interference with amateur operators.

Related

Construction Begins for DRM Alaska Test Bed

DART has a two-year experimental authorization for coverage of Alaska with DRM signals in three of the lower shortwave bands around 5, 7 and 9 MHz. How much power it will take to accomplish that is unknown and something DART and the DRM Consortium hope to learn during testing.

DRM Expands Into FM Band

Members of the DRM Consortium plan to extend their system to operate on frequencies of up to 120 MHz, including FM broadcast frequencies in VHF band II, 87.5 to 108 MHz.