NCTI ROC II BOOK II FINAL Test 1 When pressure testing a drop system to check for leakage, What must be done before applying the test signal? - ANSWER The technician must isolate the drop system from the hybrid fiber/coax (HFC) network by disconnecting the drop at the distribution tap.Why do some leakage detection systems utilize a leakage carrier modulated with a tagging signal? - ANSWER To avoid false detection of leaks.When all three sections of a pulse code modulator (PCM) are combined, what function can be performed? - ANSWER · As an analog-to-digital converter (ADC) What prevents the subcarriers in orthogonal frequency division multiplexing (OFDM) from interfering with each other? - ANSWER · The peak power of each subcarrier aligns with the minimum power of the adjacent subcarrier. 1 / 2
What two significant signals go into the mixer to create the intermediate frequency (IF)? - ANSWER · The RF signal frequency at the output of the front-end filter and the local oscillator (LO) signal.Which class of amplifier efficiency approaches, but never achieves, 100%? - ANSWER · Class D amplifier.What is the output waveform coming from a ferroresonant power supply? - ANSWER · A quasi-square wave.What instrument should be used to accurately measure the output voltage of a ferroresonant power supply? - ANSWER · A true root mean square (RMS) digital multimeter (DMM) What could a light dimmer with a silicon controlled rectifier (SCR) create in a customer premises? - ANSWER · Radio frequency interference (RFI).
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