And also, can anyone tell me how? Using Arduino or any other way ...

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    $\begingroup$ You ask if it is legal, but you don't say where you are. Every country has its own laws, although some are common across several countries. $\endgroup$
    – Scott Earle
    Dec 4, 2018 at 7:17
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    $\begingroup$ You should definitely ask the "how" question separately (but hint: since you want to do it, it seems the purpose is obfuscation, and that's illegal in amateur radio, as Glenn illustrates for the US, almost everywhere), so that that question would be off-topic here, but might be an interesting question on signals.stackexchange.com or electronics.stackexchange.com . However, these sites will require you to show more own research. $\endgroup$ Dec 4, 2018 at 12:54

1 Answer 1


In the US, the FCC prohibits this type of operation if the purpose is to obscure the meaning of your transmission.

97.113 Prohibited Transmissions

(4) ... messages encoded for the purpose of obscuring their meaning...

In response to filings on this topic, the FCC has made it clear that this prohibition includes encryption. The FCC has also illuminated in its orders, the intent of section 97.113:

... to help maintain the noncommercial character of the amateur radio service by prohibiting certain types of transmissions. The primary protection against exploitation of the amateur service and the enforcement mechanism in the amateur service is its self-regulating character...To ensure that the amateur service remains a non-commercial service and self-regulates, amateur stations must be capable of understanding the communications of other amateur stations.

There are exemptions to this for things such as space command codes, etc. but those are not applicable to your question.

A respondent to FCC proceedings on this topic made an insightful observation:

For governments around the world to permit amateur radio to continue, it must be perceived as harmless. The strength of harmlessness is destroyed by encryption.

You can use digital voice modes that are well published if the purpose is not to obscure the meaning of your transmission. One that has gained some interest for use on the HF bands is FreeDV that uses open source voice codecs and is free for use.


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