Possibly even “scrambled,” though in a primitive way. But to us – and possibly to the manufacturer – the word “coded” suggests a scheme by which parties expect to keep their messages absolutely indecipherable except to those to whom the key – the code – has been entrusted. Spy-novel stuff. Anyone trying to use voice inversion for real privacy would be in for an unhappy surprise.

The manufacturer might reasonably have concluded that a signal so easily recovered is not “coded,” as most people understand that term. Inverted, yes. The algorithm for the privacy feature, called “voice inversion,” is trivially simple: a circuit in the radio reverses the speech spectrum, exchanging high and low frequencies. Nothing else. The signal is not encrypted. No password or key is needed. The algorithm is well enough known to have its own Wikipedia article. The FCC notice that advised the manufacturer of the fine – a published document, available to anyone – has enough technical information for a skilled hobbyist to build a de-inverter. Those less skilled can buy a pre-built de-inverter on a chip. Or download free software that does the same thing. The FCC recently singled out one of these manufacturers for a $21,000 fine, claiming the radio was capable of sending what it called “coded messages.” Could the manufacturer reasonably have known in advance that the feature was unlawful? Several brands of GMRS radios come with a “voice privacy” feature that converts the speaker’s voice to gobbledygook. Any radio from any manufacturer with the same feature converts the voice back to intelligibility. The General Mobile Radio Service (GMRS) is a category of two-way radios, usually more powerful and of better quality than the little FRS “family radios” sold everywhere. Users must hold individual licenses from the FCC. The radios must be certified by the FCC for compliance with applicable rules. One of those rules prohibits GMRS users from sending “coded messages.”

Now the FCC’s enforcement arm claims the feature is a violation, and imposes a fine. FCC rules have the force of law. That means people who violate them are subject to a fine.īut suppose a company sells a product having a feature the rules do not plainly prohibit. Even a careful reader might not take the rules as alluding to this feature at all. The company might plausibly think its actions are perfectly okay. And, just to make it interesting, let’s suppose another part of the FCC had approved the same feature as being lawful.

Two way gmrs radio scrambler