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Title 47 › Chapter I › Subchapter A › Part 15 › Subpart A › Section 15.23 Home-built devices

§15.23 Home-built devices.

(a) Equipment authorization is not required for devices that are not marketed, are not constructed from a kit, and are built in quantities of five or less for personal use.

(b) It is recognized that the individual builder of home-built equipment may not possess the means to perform the measurements for determining compliance with the regulations. In this case, the builder is expected to employ good engineering practices to meet the specified technical standards to the greatest extent practicable. The provisions of §15.5 apply to this equipment.

You could take a device, that was not marketed as a MURS device and modify it to comply with MURS rules.

Making a device does not require a licence, from what I've read or I couldn't find it. If the device is a DIY device it's a Home-built Device. It depends on the interpretation of "marketed device". Not sure if this has ever been challenged.

So technically. Depending on how the FCC interprets "marketed device" as per section 15.23.

Even if that is not true, you could technically build a radio transceiver from scratch under those pretences and have it comply with MURS and transmit without a license.

I think? I'd rather have someone more knowledgeable chime in. Please? Strictly on FCC rules.

Loophole? Or did I miss a FCC section somewhere?

"This isn't a question about having a license or not to broadcast/transmit." It's a question on whether a build at home is a work around for a device that is normally required by manufactures the be qualified to sell as a qualified MURS device being used as MURS device for personal use as in Section 15.23.

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Part 15 is a very convoluted document. Reading only one section and trying to apply it to a specific case is not a good practice. One section may seemingly grant broad authority but another section will squash the potential application. You will find sections on home brewing, power limits, authorized frequencies, authorized emission types, and authorized applications. To properly interpret a specific possibility, you must examine all sections of part 15. Often you will find that all other sections seemingly allow your desired outcome but one section will specifically prohibit it. This is the case with your MURS homebrew application.

Part 15 does not authorize any MURS type transmissions as made clear by the following that specifically disallows voice transmissions on MURS frequencies. A MURS receiver would be permitted, however. This is the only reference in part 15 that covers the MURS band with regard to allowed uses and emission types:

§15.231   Periodic operation in the band 40.66-40.70 MHz and above 70 MHz.

(a) The provisions of this section are restricted to periodic operation within the band 40.66-40.70 MHz and above 70 MHz. Except as shown in paragraph (e) of this section, the intentional radiator is restricted to the transmission of a control signal such as those used with alarm systems, door openers, remote switches, etc. Continuous transmissions, voice, video and the radio control of toys are not permitted. Data is permitted to be sent with a control signal. The following conditions shall be met to comply with the provisions for this periodic operation:

(1) A manually operated transmitter shall employ a switch that will automatically deactivate the transmitter within not more than 5 seconds of being released.

(2) A transmitter activated automatically shall cease transmission within 5 seconds after activation.

(3) Periodic transmissions at regular predetermined intervals are not permitted. However, polling or supervision transmissions, including data, to determine system integrity of transmitters used in security or safety applications are allowed if the total duration of transmissions does not exceed more than two seconds per hour for each transmitter. There is no limit on the number of individual transmissions, provided the total transmission time does not exceed two seconds per hour.

(4) Intentional radiators which are employed for radio control purposes during emergencies involving fire, security, and safety of life, when activated to signal an alarm, may operate during the pendency of the alarm condition

(5) Transmission of set-up information for security systems may exceed the transmission duration limits in paragraphs (a)(1) and (a)(2) of this section, provided such transmissions are under the control of a professional installer and do not exceed ten seconds after a manually operated switch is released or a transmitter is activated automatically. Such set-up information may include data.

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You can make one. However, as noted by others here, its power output must be FAR weaker than a legal MURS transceiver that you can buy.

In other words, it'll be almost useless for ordinary purposes, unless you live right next to a MURS repeater (do they exist?).

There are FCC laws about type acceptance. Once you exceed a certain power level, those laws override your reference about low power home-made or modified transmitters for MURS.

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    $\begingroup$ I added a link and quote to the question $\endgroup$
    – Phil Frost - W8II
    Commented Sep 11, 2017 at 20:18
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    $\begingroup$ The output power in part 15 is the maximum power allowed for authorized modes and uses. Part 15 only allows MURS frequencies to be used for control purposes with those power levels. Voice transmissions on MURS are specifically prohibited under part 15. $\endgroup$
    – Glenn W9IQ
    Commented Sep 13, 2017 at 1:28

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