Amateur Radio for Smart People
Digital modes are the topic of this week’s Amateur Extra exam question…. [E8C13] What is one advantage of using JT-65 coding? A. Uses only a 65 Hz bandwidth B. The ability to decode signals which have a very low signal to noise ratio C. Easily copied by ear if necessary D. Permits fast-scan TV transmissions … Read more
What does it mean when a CW operator sends “KN” at the end of a transmission? A. Listening for novice stations B. Operating full break-in C. Listening only for a specific station or stations D. Closing station now The answer is, C. Listening only for a specific station or stations. You would use this “word,” … Read more
What is the correct way to connect a voltmeter to a circuit? A. In series with the circuit B. In parallel with the circuit C. In quadrature with the circuit D. In phase with the circuit Well, first off lets just get rid of C. and D. Neither “in quadrature” or “in phase” really make … Read more
Ew, this sounds kind of gross, but this aspect of sideband modulation is on the test! [E2B06] What is vestigial sideband modulation? A. Amplitude modulation in which one complete sideband and a portion of the other are transmitted B. A type of modulation in which one sideband is inverted C. Narrow-band FM transmission achieved by … Read more
What part of a data packet contains the routing and handling information? A. Directory B. Preamble C. Header D. Footer The answer is C. Header. When dealing with data “packets”, no matter the type, there has to be a portion of data that contains information regarding what’s to be done with the data inside it. … Read more
What is the maximum power level that an amateur radio station may use at VHF frequencies before an RF exposure evaluation is required? A. 1500 watts PEP transmitter output B. 1 watt forward power C. 50 watts PEP at the antenna D. 50 watts PEP reflected power The answer to this question is C. 50 … Read more
Ah, another fine math problem from the Amateur Extra exam (don’t you just love these?) [E5D16] What is the power factor of an RL circuit having a 30 degree phase angle between the voltage and the current? A. 1.73 B. 0.5 C. 0.866 D. 0.577 awasdf This question is a bit tricky, because we have … Read more
What frequency range is occupied by a 3 kHz USB signal with the displayed carrier frequency set to 14.347 MHz? A. 14.347 to 14.647 MHz B. 14.347 to 14.350 MHz C. 14.344 to 14.347 MHz D. 14.3455 to 14.3485 MHz This is really just a question of simple addition, so don’t let all the numbers … Read more
Which type of modulation is most commonly used for VHF and UHF voice repeaters? A. AM B. SSB C. PSK D. FM The answer is D. FM, or Frequency Modulation. I’m not sure there is a technical reason for this, as any modulation would work just as well. Except PSK which really isn’t a modulation, … Read more
The Amateur Extra question of the week comes from the section on frequency allocations and amateur services… [E1D07] Which amateur service HF bands have frequencies authorized to space stations? A. Only 40m, 20m, 17m, 15m, 12m and 10m B. Only 40m, 20m, 17m, 15m and 10m bands C. 40m, 30m, 20m, 15m, 12m and 10m … Read more