A broadband reference signal source Model CGO-505 Comb Generator is for quick EMC site testing. It radiates signals up to 1000 MHz with a 1 MHz step size. 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.