How to Scan an RF for Cell Phone Signals

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An RF scanner can help you detect nearby cell phones.

RF stands for radio frequency. It's what cell phones use to transmit their signals. Cell phones can sometimes be used to secretly eavesdrop on conversations when hidden in a room where people are talking. If you would like to know if someone is using a cell phone to listen in on you, one way is to use an RF scanner to detect the transmission.


Step 1

Purchase a radio frequency scanner. These are available at most online spy and gadget stores (see Resource links). Costs vary, depending on your needs.

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Step 2

Turn on your scanner and place it on a nearby table. Make a call from your cell phone while standing next to the scanner. It will start beeping rapidly. This is the sound you are looking for to see if there is a mobile phone nearby. Turn your cell phone off.


Step 3

Move your scanner around the room. You might get a steady slow beep to show that the machine is turned on and operating. However, this doesn't mean that there is a cell phone in the room. If the beep becomes much more rapid, then there is likely a cell phone nearby.

Step 4

Sweep the room thoroughly by dividing it into quarters and checking each section completely. If you find a transmitting mobile phone, turn it off so it can no longer eavesdrop on your conversations.


If you find a hidden cell phone that is being used to eavesdrop on your conversation, notify the authorities immediately.