Safe Frequencies for Audience Response System Keypads

Turning Technologies ResponseCards RF and ResponseCards RF LCD are very robust systems can be used without fear of interference from devices that emit radio frequency interference and commercial wireless technologies, including wifi (WLAN 802.11 b,g and g), even though the technologies exist within the 2.4 GHz band. If you really want to play it safe, there are several channels that you can use that are completely outside the range of frequencies used by common wireless devices.

Below is a chart that outlines the frequencies of the different WLAN, or Wi-Fi, channels in the United States. The lowest frequency is 2.401GHz and highest is 2.473GHz

Wifi Frequency Chart

2.401GHz – 2.473GHz corresponds to ResponseCard RF channels 1 through 73. There are a total of 82 possible channels that the ResponseCard can be set to. Each channel has a frequency width of 1 MHz or 0.001 GHz. By selecting a channel between 74 and 82, your audience response keypad will be completely outside the range of WLAN and able to operate with minimal risk of interference from wireless internet devices.

To avoid Bluetooth interference, your safe channels are 80, 81 and 82.

I just want to reiterate that I have been working with TurningPoint ARS software since 2005 and I have never experienced any transmission or interference issues during that except those caused by using foil labels on the receiver and keypads.

Related Document: Change the channel of the ResponseCard RF
Related Post: Change the RC channel away from the default channel

During my timer working at Turning Technologies, one of the jobs that I took on was trying to make the system fail due to RF interference, I couldn’t make it happen. Some of the ridiculous things that I tried included:

  • Placing the computer and receiver inches away from a high powered wireless access point
  • Voting with a ResponseCard that was near a wireless access point
  • Setting up the audience response system on top of a microwave that was running

If you have any crazy or extreme situations in which you’d like me to test the ResponseCards, submit it in the comments.

Related Posts:

Leave a Reply

Your email address will not be published. Required fields are marked *