Skip to main content
Electronic Theatre Controls Inc

Using a Radio (Walkie-Talkie) Near My ETC Equipment Causes it to Behave Strangely


Using a portable radio transmitter (sometimes called a walkie-talkie) near a piece of ETC equipment causes the equipment to behave abnormally. The manner of abnormality can range from screens flickering or turning off, processors crashing, to units ceasing to function until power cycled.

Explanation of Issue

Many ETC products use components that operate with high frequency signals.  Radios also operate at high frequency and can create large Electromagnetic Interference (EMI) disruptions as they are operated. These EMIs can be directly or indirectly related to the frequencies of the other components operating at high frequency as well as the harmonics, quarter and half wavelengths of the base frequency. Often, the power of the transmitter, regardless of the frequency in use, is enough to cause a disruption in the operation of the component also operating at high frequency.


  1. Move the radio transmitter further away from the device impacted.

Why can't ETC just provide a list of frequencies to avoid?

When it comes to disruptions, the consideration of the base frequency, quarter wavelength, half wavelength, and the harmonics of all of the above would render a list that is not only impractical, but would not tell the full story. Simply avoiding a frequency can sometimes help, but more often than not, the power of the radio transmitter and the proximity to the device are enough to cause widespread disruptions that are not avoidable.

  • Was this article helpful?