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E2E01 What is a common method of transmitting data emissions below 30 MHz? / A. DTMF tones modulating an FM signal / B. FSK/AFSK / C. Pulse modulation / D. Spread spectrum
E2E02 What do the letters FEC mean as they relate to digital operation? / A. Forward Error Correction / B. First Error Correction / C. Fatal Error Correction / D. Final Error Correction
E2E03 How is Forward Error Correction implemented? / A. By the receiving station repeating each block of three data characters / B. By transmitting a special algorithm to the receiving station along with the data characters / C. By transmitting extra data that may be used to detect and correct transmission errors / D. By varying the frequency shift of the transmitted signal according to a predefined algorithm
E2E04 What is indicated when one of the ellipses in an FSK crossed-ellipse display suddenly disappears? / A. Selective fading has occurred / B. One of the signal filters has saturated / C. The receiver has drifted 5 kHz from the desired receive frequency / D. The mark and space signal have been inverted
E2E05 How does ARQ accomplish error correction? / A. Special binary codes provide automatic correction / B. Special polynomial codes provide automatic correction / C. If errors are detected, redundant data is substituted / D. If errors are detected, a retransmission is requested
E2E06 What is the most common data rate used for HF packet communications? / A. 48 baud / B. 110 baud / C. 300 baud / D. 1200 baud
E2E07 What is the typical bandwidth of a properly modulated MFSK16 signal? / A. 31 Hz / B. 316 Hz / C. 550 Hz / D. 2 kHz
E2E08 Which of the following HF digital modes can be used to transfer binary files? / A. Hellschreiber / B. PACTOR / C. RTTY / D. AMTOR
E2E09 Which of the following HF digital modes uses variable-length coding for bandwidth efficiency? / A. RTTY / B. PACTOR / C. MT63 / D. PSK31
E2E11 What is the Baudot code? / A. A code used to transmit data only in modern computer-based data systems using seven data bits / B. A binary code consisting of eight data bits / C. An alternate name for Morse code / D. The International Telegraph Alphabet Number 2 (ITA2) which uses five data bits
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