In what it calls an “extremely urgent complaint” to the Federal Communications Commission (FCC), ARRL, the national association for Amateur Radio, has targeted the interference potential of a series of audio/video transmitters used on unmanned aircraft systems (UAS) and marketed as amateur radio equipment.
As explained in a press release from the group, a Jan. 10 letter to the FCC from the ARRL said the transmitters use frequencies intended for navigational aids, air traffic control radar, air route surveillance radars, and global positioning systems.
“This is, in ARRL’s view, a potentially very serious interference problem, and it is respectfully requested that the products referenced … be investigated and removed from the marketplace immediately and that the importers be subjected to normal sanctions,” the letter says.
“These video transmitters are being marketed ostensibly as amateur radio equipment,” the letter continues, “but of the listed frequencies on which the devices operate, only one, 1280 MHz, would be within the amateur radio allocation at 1240-1300 MHz.”
Even then, ARRL said, operation there would conflict with a channel used for radio location.
ARRL said the use of 1,040 MHz and 1,080 MHz, which would directly conflict with air traffic control transponder frequencies, represents the greatest threat to the safety of flight. The use of 1,010 MHz, employed for aeronautical guidance, could also be problematic, according to the group.
ARRL cited the Lawmate transmitter and companion 6 W amplifier as examples of problematic devices being marketed in the U.S. Each costs less than $100 and carries no FCC identification number, the group says.
“[T]he target market for these devices is the drone hobbyist, not licensed radio amateurs. The device, due to the channel configuration, has no valid amateur radio application,” the letter continues. “While these transmitters are marked as appropriate for amateur use, they cannot be used legally for amateur radio communications.”
In the hands of unlicensed individuals, the transmitters could also cause interference to amateur radio communication in the 1.2 GHz band, ARRL says.
In “Exhibit A” of the letter – “Illegal Drones Threaten Public Safety” – the group noted that some of the UAS and associated equipment it has come across “are blatantly illegal at multiple levels.”
“Rated at six times over the legal power limit and on critical air navigation transponder frequencies, these devices represent a real and dangerous threat to the safety of flight, especially when operated from a drone platform that can be hundreds of feet in the air,” the group wrote.
The full letter to the FCC can be found here.