How to Detect Spy Devices

by Marshal M. Rosenthal

It's a sad truth that our privacy is invaded on a daily basis. Spy devices are small enough to be hidden almost anywhere, and they are nearly impossible to detect with the naked eye. This has led to the creation of special pens that can "hear" the radio frequencies (RF) that are used by spy devices. These spy detector pens are small enough to carry in your pocket, and their use will give you peace of mind that there is no spy device spying on you.

Power down any cell phones, pagers, or other electronic devices that you might be carrying. Press the button on the spy detector pen to turn it on and illuminate the LED on the top.

Slowly walk through the location holding the pen upright so that the LED is pointing straight up. Stop walking when the LED begins to blink.

Move slowly and walk in the direction that causes the LED on the spy detector pen to blink more rapidly.

Stop walking when the LED on the spy detector pen is blinking at its fastest rate. Search the location for the spy device that is hidden in the area where you are now standing.


  • check Hold the spy detector pen against your body so that you can maintain the way it is being held over a long amount of time.


  • close RF devices like cell phones and microwave ovens and even MP3 players can impair the function of the spy detector pen by creating false signals that mask the spy device's RF signal.

Items you will need

About the Author

Marshal M. Rosenthal is a technology maven with more than 15 years of editorial experience. A graduate of Brooks Institute of Photography with a Bachelor of Arts in photographic arts, his editorial work has appeared both domestically as well as internationally in publications such as "Home Theater," "Electronic House," "eGear," "Computer and Video Games" and "Digitrends."