FCC rules for homebuilt low power transmissions

Any old or new electronic projects on the go
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Tobe
Posts: 665
Joined: 16 Feb 2018, 06:19
Location: Varberg or Stockholm, Sweden

FCC rules for homebuilt low power transmissions

Post by Tobe »

Just some legal issues around Low Power Transmission which affects our conversion and buildings of transmitters. I mention here the FCC rules but in most aspects it is the same with CE certification aspects around homebuilt


Home-Built Transmitters that are Not for Sale Hobbyists, inventors and other parties that design and build Part 15 transmitters with no intention of ever marketing them may construct and operate up to five such transmitters for their own personal use without having to obtain FCC equipment authorization. If possible, these transmitters should be tested for compliance with the Commission's rules. If such testing is not practicable, their designers and builders are required to employ good engineering practices in order to ensure compliance with the Part 15 standards. Section 15.23 Home-built transmitters, like all Part 15 transmitters, are not allowed to cause interference to licensed radio communications and must accept any interference that they receive. If a home-built Part 15 transmitter does cause interference to licensed radio communications, the Commission will require its operator to cease operation until the interference problem is corrected. Furthermore, if the Commission determines that the operator of such a transmitter has not attempted to ensure compliance with the Part 15 technical standards by employing good engineering practices then that operator may be fined up to $10,000 for each violation and $75,000 for a repeat or continuing violation. Section 15.5 47 U.S.C. 503 Operating a prototype of a product that is ultimately intended for market is not considered "personal use." Thus, a party that designs and builds a transmitter with plans to mass produce and market a future version of it must obtain an experimental license from the FCC in order to operate the transmitter for any purpose other than testing for compliance with the Part 15 technical standards. Information on experimental licenses may be obtained from the contact point listed in the Additional Information section of this bulletin. FCC authorization is not required in order to test a transmitter for compliance with the Part 15 technical standards.

This means basically that you will have to be officially the builder and it's the same that applies if you modify your commercial transmitter with a 2,4 GHz module.
nRF24L01 modules are within spec for the FCC if you choose the right channels in the software to stay within frequency. I have tested a few modules with a laboratory Spectrum Analyzer, and they are right on the money, and I would call it good engineering practices.

To be noted that if you use an FCC already approved module:

One of the relevant regulations—Part 15, section 15.23(a)—seemed to give people to build this kind of equipment together, so long as ”good engineering practices” were used but there is a "but" because in another section, 15.204(c), says, ”A transmitter may be operated only with the antenna with which it is authorized.” Confused? The clarification from the FCC, the regulation on home-built devices applied only to things that were built from scratch, not to modifications of FCC-certified radio equipment.

As I understand it, encoder/decoder that we make and its software is to be considered "homebuilt" but the RF module has to be considered commercial if it has not been built from scratch meaning that it has to be used w/o mods including the antenna that was used for certification.
Attachments
FCC - rules for low power transmissions.pdf
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Cheers,

Tobe
GarydNB
Posts: 282
Joined: 15 Feb 2018, 23:12

Re: FCC rules for homebuilt low power transmissions

Post by GarydNB »

They'll be saying you can only operate radios is you're double vaxed next!
Tobe
Posts: 665
Joined: 16 Feb 2018, 06:19
Location: Varberg or Stockholm, Sweden

Re: FCC rules for homebuilt low power transmissions

Post by Tobe »

To be able to enjoy our hobby it is a privilege, not a right and as any privilege's it can be taken away with a flick of a finger, like it or not!
..and if you can*t beet them you have to join them. Unfortunately we are already suffering limitations in our hobby due of people that have crossed the line so at this stage is more a matter to keep what we still have left.
So my message is simple, please follow the rules and if you absolutely feel the need to break them don't get caught because we will all suffer from it as one case in the media could be enough!
Cheers,

Tobe
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