Covers PCM pattern testing from 1 to 700 MHz. Built-in clock synthesizer with 1 kHz steps. This unit also has Options 21 & 22 and contains plug-in module M02966. Error Rate Measuring Equipment Receiver. Operating frequency 1 - 700 MHz. Include MH677A extends operating frequency to 1.4 GHz. Error Measurement: Error rate, number of error pulses, error interval (EI time is .01, .l or 1s, error free interval and frequency.