E2E01

What is a common method of transmitting data emissions below 30 MHz?

1. FSK/AFSK

E2E02

What do the letters FEC mean as they relate to digital operation?

1. Forward Error Correction

E2E03

How is Forward Error Correction implemented?

1. By transmitting extra data that may be used to detect and correct transmission errors

E2E04

What is indicated when one of the ellipses in an FSK crossed-ellipse display suddenly disappears?

1. Selective fading has occurred

E2E05

How does ARQ accomplish error correction?

1. If errors are detected, a retransmission is requested

E2E06

What is the most common data rate used for HF packet communications?

1. 300 baud

E2E07

What is the typical bandwidth of a properly modulated MFSK16 signal?

1. 316 Hz

E2E08

Which of the following HF digital modes can be used to transfer binary files?

1. PACTOR

E2E09

Which of the following HF digital modes uses variable-length coding for bandwidth efficiency?

1. PSK31

E2E10

This question has been removed by the QPC

E2E11

What is the Baudot code?

1. The International Telegraph Alphabet Number 2 (ITA2) which uses five data bits

E2E12

Which of these digital communications modes has the narrowest bandwidth?

1. PSK31

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