Comb Generators Model CGO-520 is a broadband EMC reference signal source for quick EMC site testing. It radiate signals up to 4.5 GHz at 20 MHz frequency steps. EMC labs calibrate their radiated emissions test sites, instrumentation and accessories at least once a year. The calibration procedures are elaborate and time consuming. However, calibration does not prevent equipment malfunction in between calibration period such as damaged receivers, broken cables, poor connections, bad antenna, etc. Monitoring a few frequencies regularly on the Comb Generator's broadband radiated output can verify the entire setup quickly and efficiently. Any potential problems with the test setup can be detected before it causes erroneous results. It is powered by a rechargeable NimH battery pack. It has circular shape for more uniform radiated output. It is supplied with two detachable antennas.