The Com 3 is a lightweight, compact service monitor for testing AM and FM transceivers. The internal battery, which is a standard feature of the Com 3, combined with the optional carrying case and low weight (13 lbs), make it ideal for field use. Utilizing specially designed micro powered oven circuits, warm -up time is minimal, providing maximum use of the battery. The frequency range is 100 KHz to 999.999 MHz in 500 Hz steps. Standard CTS tones as well as a 1 KHz tone can be generated. RF power is continuosly variable in five ranges from 0.1 ¡iv to 10,000 ¡j.v. The display is a seven digit LED type which will display frequencies generated or received, CTS off air, as well as being an audio and RF frequency counter. Deviation and frequency error are displayed on a 20 segment LED bargraph, which is easily visible from across the shop. An internal RF relay switches transmitted power greater than 500 mW to a rear panel mounted BNC connector. This protects the Com 3 from accidental keying and allows easy connection of an antenna, power meter, or dummy load.