Amateur Radio for Smart People
What is used to control the attenuation of RF signals by a PIN diode? A. Forward DC bias current B. A sub-harmonic pump signal C. Reverse voltage larger than the RF signal D. Capacitance of an RF coupling capacitor [E6B11] This question from the new Amateur Extra question pool dives head first into the operation … Read more
What is a telecommand station in the amateur satellite service? A. An amateur station located on the Earth’s surface for communication with other Earth stations by means of Earth satellitesB. An amateur station that transmits communications to initiate, modify or terminate functions of a space stationC. An amateur station located more than 50 km above … Read more
Part of the Amateur Extra exam is meant to prepare you for the possibility of becoming a VEC or Volunteer Exam Coordinator, and so they want you to know and understand some of the mechanics of the exams themselves. So, here’s one: What is the minimum passing score on amateur operator license examinations? A. Minimum … Read more
Which of the following must be done to insure that a crystal oscillator provides the frequency specified by the crystal manufacturer? A. Provide the crystal with a specified parallel inductanceB. Provide the crystal with a specified parallel capacitanceC. Bias the crystal at a specified voltageD. Bias the crystal at a specified current A crystal oscillator … Read more
At what time of year is Sporadic E propagation most likely to occur? A. Around the solstices, especially the summer solsticeB. Around the solstices, especially the winter solsticeC. Around the equinoxes, especially the spring equinoxD. Around the equinoxes, especially the fall equinox Sporadic E Propagation refers to the phenomena where radio signals bounce off of … Read more
What is an advantage of Gray code in digital communications where symbols are transmitted as multiple bits? A. It increases security B. It has more possible states than simple binary C. It has more resolution than simple binary D. It facilitates error detection Firstly, what the heck is “Gray code” anyway? The reflected binary code … Read more
What is meant by circularly polarized electromagnetic waves? A. Waves with an electric field bent into a circular shapeB. Waves with a rotating electric fieldC. Waves that circle the EarthD. Waves produced by a loop antenna To answer this we need to understand what’s going on inside an electromagnetic (or EM) wave. In an EM … Read more
Which of the following HF digital modes uses variable-length coding for bandwidth efficiency? A. RTTYB. PACTORC. MT63D. PSK31 Now, I guess this answers my question about last weeks Extra question. Mainly why is it important. It’s important because it does matter in transmission efficiency. So which mode would be a good and efficient method of … Read more
What is one advantage of using ASCII code for data communications? A. It includes built in error correction featuresB. It contains fewer information bits per character than any other codeC. It is possible to transmit both upper and lower case textD. It uses one character as a shift code to send numeric and special characters … Read more
Within what distance must an amateur station protect an FCC monitoring facility from harmful interference? A. 1 mileB. 3 milesC. 10 milesD. 30 miles The answer is: A. 1 mile. Why? Because the FCC has said so, basically. In section 13 of Part 97. (b) A station within 1600 m (1 mile) of an FCC … Read more
