What Is Tone Lock™ Squelch?

Answer: The adjustable squelch setting, discussed in our previous Question of the Week post, should not be confused with Tone Lock™ squelch, which is an advanced feature found on some Audio-Technica wireless systems. Although Tone Lock squelch cannot be adjusted, both adjustable squelch and Tone Lock squelch work together to achieve satisfactory audio. Tone Lock squelch mutes the audio only, permitting any radio frequency (RF) energy on the frequency to show on the “RF” bar-meter of the receiver. If the system features Tone Lock squelch, it will prevent radio frequency interference (RFI) from being heard in your audio system when your transmitter is turned off. However, if the transmitter is turned on and the user is operating on a frequency that is unavailable/incompatible, then it is possible that you will hear the RFI in your audio system. Tone Lock squelch also opens/unmutes only when the correct/compatible transmitter is detected by the receiver, reducing the possibility of audible interference when the transmitter is turned off. This is accomplished by a tone that is embedded in the signal sent by the transmitter. This tone, often referred to as the Pilot Tone, must be present before the receiver will allow the audio to be processed. As a result, transmitters and receivers from the same Series must be used together, and should not be used with components from other Audio-Technica wireless systems (unless specified otherwise), nor should the user try to pair transmitters or receivers from other manufacturers. In other words, if an ATW-T310bC transmitter is turned on and broadcasting at 541.500 MHz, and the corresponding ATW-R3100bC receiver is also turned on and set to 541.500 MHz, the squelch detection circuit will unmute and allow the audio to pass through. However, if that T310bC transmitter is turned off, the receiver will become muted and audio shall not pass through. We hope this two-part look at squelch – adjustable squelch and Tone Lock squelch – has answered any questions you may have had on the subject. But, as always, if you require further assistance, please feel free to contact our Audio Solutions Department. And be sure to join us next time for another “Question of the Week”!