From Carol Milazzo KP4MD/W6, ARRL Sacramento Valley Section Manager :
Keep Our Digital Transmissions Legal on 60 Meters Posted January 29, 2017
Our decreasing solar activity and residential antenna restrictions have attracted increasing numbers of radio amateurs to operate CW and weak signal digital modes on our lower HF frequencies including 60 meters. The five frequency channels that US amateur radio operators share on a secondary basis with US federal government users on 60 meters (5 MHz) pose unique requirements for CW and digital operators. As explained on http://www.arrl.org/60m-channel-allocation, US radio amateur emissions on our 60m channels must be precisely centered in the center frequency of each assigned channel, that is, 5332.0, 5348.0, 5358.5, 5373.0 or 5405.0 kHz. Thus, for example, a CW signal on channel 3 (USB Dial frequency 5357.0 kHz) must be precisely on 5358.5 kHz. The same ARRL page explains that all digital emissions must also be centered in the channel center.
This may appear unreasonable to radio amateurs because a 2.8 kHz channel can accommodate many digital and CW transmissions simultaneously, and requiring multiple stations to operate on the same exact frequency would result in mutual interference. The National Telecommunications and Information Administration (NTIA) explains this requirement in https://ecfsapi.fcc.gov/file/7021871884.pdf which states: “Allowing multiple emissions within the necessary bandwidth of the widest authorized modes (2.8 kHz) increases the possibility of harmful interference from secondary amateur stations to primary federal stations, and would make it more difficult for a federal station to identify an interfering amateur station. In addition, NTIA is concerned about the aggregate equivalent isotropically radiated power from multiple amateur stations transmitting within a single 2.8 kHz channel. Accordingly, NTIA requests that 47 C.F.R. Section 97.303(h) continue to require that amateur stations transmit only on the five center frequencies allocated to the amateur service.” (See http://www.arrl.org/what-the-fcc-rules-say-97-303-h)
Many A, K, N and W call signs have been transmitting WSPR mode outside the authorized 60 meter center channel frequencies. Many US WSPR transmissions are now being observed on 5288 kHz, a completely unauthorized frequency for US radio amateurs.
Each licensee has the final responsibility for the lawful operation of his or her station. Unfortunately, the increasing automation in our radios has apparently accustomed some to falsely assume that the radio will correct for operator carelessness and ignorance of regulations. Our cooperation with NTIA requirements is essential for our continued access to the 60m channels and for possible future access to the new ITU worldwide 60 meter allocation at 5351.5 to 5366.5 kHz. (See http://www.arrl.org/news/view/arrl-asks-fcc-to-allocate-new-5-mhz-band-retain-channels-and-current-power-limit and http://www.arrl.org/news/fcc-invites-comments-on-arrl-petition-to-allocate-new-5-mhz-band). Please be aware of these requirements if you intend to or currently operate CW or digital modes on our shared 60m allocations. Our Amateur Auxiliary is documenting this matter and hopes to raise its awareness in the wider amateur radio community.
-Carol Milazzo, KP4MD