Amazon Is Selling FM Transmitters That Illegally Broadcast for Miles
FM transmitters shipped and sold by Amazon violate FCC field strength rules, while claiming compliance.
Tests of FM transmitters sold and shipped by Amazon show signal strength far exceeding FCC Part 15 limits — in some cases capable of broadcasting for miles, despite being marketed as compliant consumer devices.
You may be familiar with the FM transmitters commonly used to broadcast music around a home or car; these innocuous devices have been around for decades. They operate under the FCC’s Part 15 exemption for low-power radio — no license required.
These limits exist because radio spectrum is finite. Excessively powerful transmitters can overwhelm licensed broadcasts and interfere with critical communications, including aviation, emergency services, and public radio. Part 15 allows personal use while preventing disruption of the broader spectrum.
However, a recent breed of inexpensive, high-power transmitters have cropped up from Chinese manufacturers, far exceeding the strength limits of the Part 15 exemption. The sub-$100 Retekess TR508 advertises nearly 1000ft of range — 5x the distance of a typical Part 15 transmitter. In my testing, the device reached a range of one mile, even in an urban setting.
The Amazon Retekess listing claims legal operation and compliance, listing a real FCC identification number. If this device is breaking the law, how did it obtain certification?
An FCC ID does not signify blanket legality. It indicates that a device, in a specific configuration, was tested and found compliant under laboratory conditions. Crucially, manufacturers control the configuration submitted for testing.
Buried within a settings menu, the TR508 features a “low power” mode that reduces its range to roughly 200 feet — consistent with Part 15 limits. In other words, the device can operate legally, but only if manually configured to do so.
Neither Amazon’s product listing nor the user manual disclose this distinction. The transmitter is advertised as both extended-range and FCC-compliant, yet ships by default in a high-power configuration that exceeds Part 15 limits. As a result, thousands of customers may be operating the device unlawfully without realizing it.
When reached for comment, Retekess shifted regulatory responsibility to their supplier and halted shipments of the device: “Our product’s FCC certification is provided by our supplier. After receiving your email, we immediately contacted our compliance department to address this issue … Regarding current stock, we have informed the supplier that we will return all stock and request that they must arrange to conduct all necessary testing. We have also stopped sending new inventory to the warehouse.”
Retekess isn’t alone — there are even more egregious offenders currently available from Amazon. The $180 NIORFNIO 15W Fm Transmitter advertises up to 2.5 miles of range while claiming legal FCC operation.
Though the FCC has not aggressively pursued the use of these devices so far, the stakes are real. The recent PIRATE Act stiffens the penalties for violating the rules; up to $120,000 per day. An unlicensed station out of New Jersey recently earned itself a nearly $1 million fine.
As transmitter capability becomes cheaper and more accessible, a regulatory gray market has emerged — with manufacturers exploiting technical loopholes, platforms distributing the devices, and consumers left unaware of the legal risks.
Amazon was notified of the compliance concerns and the manufacturer’s shipment halt. As of publication, the company has removed listings for Retekess transmitters. However, other, more powerful units from different manufacturers remain available for sale.