Amateur Radio for Smart People
K5HRA 
What is the current flowing through a 24-ohm resistor connected across 240 volts? [T5D09] A. 24,000 amperes B. 0.1 amperes C. 10 amperes D. 216 amperes Get out your calculators, because this is a cut-and-dried case of needing to use Ohm’s law. Ohm’s law defines the relationship beteween voltage, current, and resistance in a circuit. … Read more
Well, I thought I’d get the HF “Go kit” out, set up and make a few contacts for this year’s Winter Field Day. While I did just that, I failed to make any contacts at all… but I’ll get to that in a minute. First, what’s “Winter Field Day” all about anyway? Well, much like … Read more
What is the peak-inverse-voltage across the rectifier in a half-wave power supply? A. One-half the normal peak output voltage of the power supplyB. One-half the normal output voltage of the power supplyC. Equal to the normal output voltage of the power supplyD. Two times the normal peak output voltage of the power supply [G7A04] To … Read more
What information is traditionally contained in a station log? [G2D09] A. Date and time of contactB. Band and/or frequency of the contactC. Call sign of station contacted and the signal report givenD. All of these choices are correct When keeping logs for your station, you need certain pieces of information for the contact, or QSO … Read more
Which of the following electronic components can amplify signals? [T6B05] A. Transistor B. Variable resistor C. Electrolytic capacitor D. Multi-cell battery The answer is, as luck would have it, A. Transistor. The transistor is probably the miracle of 20th century technology. It’s an amplifier, a switch, and so much more. None of the other components … Read more
Which of the following is an advantage of using a Schottky diode in an RF switching circuit rather than a standard silicon diode? [G6A06] A. Lower capacitance B. Lower inductance C. Longer switching times D. Higher breakdown voltage First off, we need to know the difference between a Schottky diode and a standard silicon diode. … Read more
What is the ability to store energy in an electric field called? [T5C01] A. Inductance B. Resistance C. Tolerance D. Capacitance Hate to say it, but this is basically a definition question. The answer is D. Capacitance. The easy way to remember this is just think about capacitors, the devices that actually store the electric … 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
Which of the following connectors would be a good choice for a serial data port? [G6B12] A. PL-259 B. Type N C. Type SMA D. DE-9 The answer is D. DE-9. Now, wait a minute! I thought that was a DB-9 serial port connector?! Well, technically no. The “B” refers to the size of the … Read more
If an ammeter calibrated in amperes is used to measure a 3000-milliampere current, what reading would it show? [T5B06] A. 0.003 amperes B. 0.3 amperes C. 3 amperes D. 3,000,000 amperes Don’t panic! This is a simple question about unit conversions, nothing more. Remember your definitions of metric prefixes. Milli means one one-thousandth, or 0.001. … Read more
