The Audemat MC3 is a device which originated in Bordeau, France. It eventually became the French standard for Modulation and Field Strength measurement.

The box is so rich in features that it is difficult to know where to start! It has a high quality receiver (there is an AM or FM version), a GPS receiver, an external interface for synchronizing when readings are taken, has built-in RDS or DARC decoding, and is calibrated to provide reference readings of RF field strength.

The power of the unit is in the software that comes with the Audemat. Typically, a laptop computer is used to connect to the serial port of the Audemat, and all useful data is funneled into the laptop for storage and manipulation. The data rate can be as high as 115,200 baud, depending on the measurement requirements.

There are many displays available. The choice of the display is determined by the need. For example, an X-Y display is probably best for showing the difference between multiple stations along a traveled route. A route map would be best to visually see where the signal variations appear. The coverage can be overlaid on an actual map.

Measurements can be made on the composite levels, pilot, SCAs, left channel, right channel, L-R, L+R, a multipath calculation, RDS text information, and even whether or not the subcarrier is synchronized to the pilot.

A mechanical device is attached to the vehicle being used for the measurements, which uses an optical sensor to send pulses to the Audemat to determine measurement increments. This results in a consistent number of measurements per mile instead of other systems, which usually measure in timed increments.

GoldenEar is an option which allows an audio recording to be synchronized with the logging of measurement points along the route, so that a subjective judgment can be made of the impact of variations in signal strength or multipath on signal quality. Audemat also calculates a signal quality index number ranging from 1 to 5, which helps in troubleshooting a coverage issue.

As technology moves along, it will have to be upgraded. For example, the demo unit was unable to detect the difference between a signal with the USADR test signal and one without it.

The Audemat can be purchased for approximately $24,000. With GoldenEar, the package sells for $27,000. The upgrade from the base package is about $5,000, so it is better if you decide early on that option. For more information, contact Dan Rau at 978-392-2110, or e-mail him at d.rau@audemat.com.