I am a scanner geek.  Whenever I hear sirens, I run for my scanner to see what is going on.  A directory which shows me what frequencies are used by various organizations, so  I discovered the frequencies used by pilots to communicate with the tower.  The next time I flew, I pulled out my scanner and listened to the pilots talk to the Air Traffic Controllers.  While serving me coffee, a steward asked me what the scanner was, and I told her I was listening to the pilot communicate. She left, only to return a few minutes later, to tell me that the pilot wanted to speak with me.  I sheepishly went into the cockpit ( clearly this story predates September 11 ) and explained my actions to the pilot. 

The pilot explained he was concerned that my scanner would cause Electromagnetic Interference (EMI) that could interfere with his communications or navigation equipment.  It is similar to the reason why cell phone use is not permitted during flight.  In reality, he explained, cell phones and scanners are designed to strict standards, and it is very unlikely that they would generate enough EMI to interfere with the plane systems, but they are banned nonetheless in an abundance of caution, in light of the importance of communications and navigation in an airplane.  He was a good natured fellow, and told me I could continue listening, but I must agree to turn off my scanner if and when directed to do so by the Steward.  I agreed to those terms. 

So, what is this thing called EMI and how is it controlled?

Electromagnetic interference (EMI) can be caused when electrical flow produces a magnetic field which could impact nearby or connected equipment.  When designing a system, it is critical to understand and control EMI with the use of Electromagnetic Control ( EMC ) techniques so that the system works as intended, and so that it does not create problems for other nearby systems.  Controlling and understanding EMI is so important that the military has adapted strict guidelines to control both box level EMI requirements ( MIL-STD-461 ) and system level EMI requirements ( MIL-STD-464 ).  EMC testing is a critical part of system design, and should be rigorously conducted throughout the design process, both before and after the system is fielded in its intended environment.

Since EMC is a critical part of the design process in military systems, ATI will be offering a course called “EMI/EMC in Military Systems.”  In this course, you will learn:

• How to identify, prevent, and fix common problems
• Rules of Thumb to help you make quick design decisions
• EMI/EMC troubleshooting techniques
• MIL-STD-461 and MIL-STD-464 requirements
• EMI/EMC documentation requirements

This course will be available at ATI soon, but in the meantime, we will be offering a free, one-hour, lunchtime webinar where you will be able to meet our new Instructor, Ms. Karen Burnham.  During this webinar at 12:30 Eastern on May 19, Karen will give an overview of EMI/EMC in Military Systems, and will describe in more detail the contents of her upcoming course.

To register for the Free Webinar, please go to the registration page which can be found here.