Policing Amateur Frequencies


Written by Tony Stillman Flying Site Assistance Column As seen in the April 2018 issue of Model Aviation.

I have received quite a few telephone calls and emails concerning this topic since my March column was printed. I am happy to have AMA members contact me with questions or additional comments, so please, continue to communicate with me! Because of the additional questions I’ve received because of my article, I thought I should provide a little more information to help everyone better understand this issue. Keep in mind that typical frequency use by modelers that require licensing consists of RC transmitters used to control the aircraft using the following frequencies in the Amateur Radio Band: • 50 MHz (CH01–CH09) • 53 MHz (53.000 MHz–53.900 MHz) Typical FPV video transmitters operating on: • 5.8 GHz (5.650 GHz–5.925 GHz) It is important to know that in the FPV frequencies, there are video transmitters out there that operate beyond these frequency limits for 5.8 GHz. These systems are illegal for use in the US. Recently a US importer of such an item was fined by the FCC for importing and selling such. It is important that modelers verify what is legal and what is not before making a purchase and using a product, especially if the product is purchased from an overseas vendor. It might be that the product is legal in other countries, but not legal in the US. You can find a chart of frequencies and their use at: www.ntia.doc.gov/files/ntia/publications/2003-allochrt.pdf. It is also important to know that some 5.8 GHz video transmitters might be FCC Part 15 compliant, which means it is a low-power device and no license is required. In this case, there will be an FCC sticker on the video transmitter stating that it meets FCC Part 15 rules. Typically these are video transmitters with less than 1 milliwatt of output power and have a nonreplaceable transmitter antenna. All others would require an Amateur Radio License to operate. Following is a section of AMA Document 580 that is designed to give direction to modelers concerning FPV operation and licensing requirements.

System Licensing Guidance for FPV Flight

“Radio Controlled (RC) model aircraft must use frequencies approved by the FCC for transmitting radio frequency (RF) signals to control the model aircraft’s flight path in the National Airspace [System] (NAS). If the model aircraft utilizes an FPV system to transmit video signals/images from an onboard camera to a ground based receiver, the transmission frequency used must also be approved by the FCC. “If, out of the box, your FPV system (on 5.8 GHz) has an FCC sticker stating that it meets Part 15, then you can legally use the system without an amateur (Technician) FCC license. If you modify that system in any way—or your system doesn’t have a Part 15 sticker—then you will be required to carry an amateur FCC license. “Part 15 of the FCC code pertains to ‘out of the box low power output units that must not interfere with other systems and must accept all interference.’ The units are certified as stand-alone systems and all components of that system are certified together, meaning that any modification including attachments, cords, internal components, and associated batteries must conform to, and be of the same specification as, the original unit. Otherwise it is considered ‘modified’ and no longer certified, and the user must hold at least an amateur Technician license from the FCC. “AMA’s position and guidance to its members is that all equipment must be FCC certified where required. The responsibility of conforming to FCC certification is up to the owner/user of that equipment. The certification requirement is mandated by federal regulation and falls under the FCC’s jurisdiction of the FCC. As such, AMA leaves enforcement of the regulation to the federal government.” I hope this helps answer some of the questions that you might have. If not, please feel free to contact me by email at fsac@modelaircraft.org, or give me a call at (765) 287-1256, extension 230. Now, get out there and do some flying! -Tony Stillman fsac@modelaircraft.org


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4 comments

Wow! The non-replaceable TX antenna bit is tricky.

I'd also say that, if you buy something that has FPV capabilities to it (like the Inductrix FPV+ or FPV Pro or Torrent, which state SPECIFICALLY on the package that you need to have a HAM license in order to operate the video transmitter in North America, understand that it is not just to absolve the manufacturer of the license, it is because you need to have a HAM license! And honestly, they're not that hard to get. I studied loosely for a month, passed my HAM test, and now I'm good for the next 10 years. It's easier than arguing and fighting about it should someone from the FCC come out to a drone course and want to fine you for not having a license.

Good article but I would like to add a few things. Other legal FPV video transmitter frequencies are 900 MHz, 1280 MHz, 1258 MHz and 2.4 GHz with an amateur radio technician licence. A common RC control frequency used by FPV pilots outside of 2.4 GHz is 433 MHz. You can use 433 MHz for control up to 500 mw with an amateur radio technician licence. Ham Test Online is a great web site to help prepare for an amateur radio license exam. I hope this information helps. John

The Frequency chart link is a bit old. There is a more current version of the Frequency chart (2016) found here - https://www.ntia.doc.gov/files/ntia/publications/january_2016_spectrum_wall_chart.pdf

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