Extra exam: operating procedures
Satellites, television modes, contesting, digital modes and operating in unusual conditions. 60 questions, 10 at a time, starting with ones you haven't seen.
Rules to remember10 key operating procedures rulesShow the rules
- An ascending pass is one where the satellite moves from south to north across the observer's sky; a descending pass goes north to south. (p. 21)
- An NTSC fast-scan frame contains 525 horizontal lines, sent as two interlaced fields. (p. 24)
- By band-plan convention, contests are not held on the WARC bands, which include 30 meters. (p. 26)
- MSK144 is designed for meteor scatter, packing data into the brief pings from meteor trails. (p. 28)
- Q65 is designed for very weak signals such as EME (moonbounce), with long sequences and averaging. (p. 28)
- APRS messages travel as AX.25 packet radio frames. (p. 29)
- FT4 uses four-tone continuous-phase frequency shift keying, which is what the 4 refers to. (p. 30)
- WSPR is a beacon mode that sends only call sign, grid and power, so it cannot be used for keyboard chats. (p. 30)
- FT8 runs in fixed 15-second transmit and receive periods. (p. 31)
- PSK31 uses Varicode, which gives common characters shorter codes and rare ones longer codes. (p. 31)
Taken from the explanations to checked practice questions; page numbers link to the official handbook.
Sample operating procedures questions
1.Which of the following digital modes is designed for meteor scatter communications?
- AWSPR
- BAPRS
- CHellschreiber
- DMSK144
Show the answer
✓ D. MSK144
MSK144 is designed for meteor scatter, packing data into the brief pings from meteor trails.
2.Which of the following types of modulation is used for data emissions below 30 MHz?
- APulse modulation
- BFSK
- CDTMF tones modulating an FM signal
- DSpread spectrum
Show the answer
✓ B. FSK
HF data emissions commonly use frequency shift keying, as in RTTY.
3.What is vestigial sideband modulation?
- AAmplitude modulation in which one complete sideband and a portion of the other are transmitted
- BNarrow-band FM modulation achieved by filtering one sideband from the audio before frequency modulating the carrier
- CSpread spectrum modulation achieved by applying FM modulation following single sideband amplitude modulation
- DA type of modulation in which one sideband is inverted
Show the answer
✓ A. Amplitude modulation in which one complete sideband and a portion of the other are transmitted
Vestigial sideband is AM in which one full sideband and only part of the other are transmitted.
4.How is an interlaced scanning pattern generated in a fast-scan (NTSC) television system?
- ABy scanning two fields simultaneously
- BBy scanning odd-numbered lines in one field and even-numbered lines in the next
- CBy scanning lines from left-to-right in one field and right-to-left in the next
- DBy scanning each field from bottom-to-top
Show the answer
✓ B. By scanning odd-numbered lines in one field and even-numbered lines in the next
Interlacing sends the odd-numbered lines in one field and the even-numbered lines in the next, combining two fields into one frame.