This quiz started out with the attack on Pearl Harbor and the radio frequencies used at the time, but it works out about the same as the attack on the Polish radio station that provided a pretext for invasion. The quiz topic then went on a long and twisting trail before settling on encoded messages. Enjoy!

T1D03 When is it permissible to transmit messages encoded to obscure their meaning?

A. Only during contests

B. Only when transmitting certain approved digital codes

C. Only when transmitting control commands to space stations or radio control craft

D. Never

G8C04 Which of the following describes Baudot code?

A. A 7-bit code with start, stop, and parity bits

B. A code using error detection and correction

C. A 5-bit code with additional start and stop bits

D. A code using SELCAL and LISTEN

E1D02 Which of the following may transmit encrypted messages?

A. Telecommand signals to terrestrial repeaters

B. Telecommand signals from a space telecommand station

C. Auxiliary relay links carrying repeater audio

D. Mesh network backbone nodes

Answers:

T1D03 = C [FCC Parts 97.211(b), 97.215(b), 97.113(a)(4)]

G8C04 = C

E1D02 = B [FCC Part 97.211(b)]