There really isn’t much to say about a modulation meter, as it’s name describes what it does perfectly – Modulation meters measure degrees of modulation in a modulated signal.
Essentially, this meter is used to check the depth of modulation on an AM signal, and the level of deviation on an FM signal. Using these measurements ensures a transmitter is within allowed tolerances and specifications.
The Racal-Dana Models 9008 modulation meters overcome the disadvantages of manually tuned units and provide a simple, unambiguous means of measuring peak, trough, and mean modulation depth of AM signals, or positive, negative, and mean deviation of FM signals.
Automatic tuning and amplitude levelling guarantee measurement accuracy without relying on the personal skill of the operator. These features together with an easy-to-read meter, color-coded front panel markings, and straight forward controls allow the unskilled operator to make precision measurements with confidence.