I know this isn’t exactly about ham radios and that almost any ham radio operator that reads this will think it was a waste of their time because they already knew this, but for those readers who are not active in the ham radio hobby, this may prove to be a useful post.

Almost everyone has had at least some experience with FRS radios, you know, the hand-held 14 or 22 channel walkie talkies that are available in every department and sporting goods store in the country. It seems that almost every one of those radios that is manufactured has somewhere around 38 “privacy codes” as they are called. The package will boast “836 channel combinations” and make the purchaser feel like they are getting a lot from a little device.

In reality, there are still only as many channels as the radio has without figuring in the “privacy codes” which actually do nothing for privacy. If there were 12 people on the same channel and each with different “privacy codes” programmed in, only one of them would be able to transmit at a time or the transmission would just become garbled because all of them would be transmitting on the same frequency and interfering with each other. So this does nothing to create more “channels” for multiple users.

If those same 12 people did take turns talking one at a time, none of them would be able to hear any of the others because of the “privacy codes” which are nothing more than CTCSS tones. CTCSS stands for continuous tone-coded squelch system which means that the radio emits a sub-audible tone at a given frequency in parallel to each transmission that makes the receiving radio receive it if they are using the same tone, and block it out if they have a different tone set.

While thus far, it would seem that these tones are doing their job at keeping people from hearing the transmissions of your group unless they know what tone you are using, but there is one factor that has not been accounted for. The “privacy tones” on a radio can be turned off.

When these tones are turned off, the radio will not transmit any tone when you talk on it (and not be heard by people using the tones), but it will also not require a tone to receive a transmission and any tone that is received will be ignored. This means that if I tune in to the same channel that the 12 people before were using and turn my tones off, I will be able to hear everything that is said by any of the 12 (if they talk one at a time) even though they will be unable to hear each other.

These tones do serve a good purpose of the members of your group not having to hear the members of another group if you do happen to be on the same channel. This can be useful so that you don’t hear things you might not care about when in an area saturated with other people using FRS radios. The only privacy provided is that you don’t hear them, it doesn’t mean that they can’t hear you. Keep this in mind next time you use the “privacy tones” on your FRS radio.