Amateur Radio Honor

Vocational Activities

Requirements

  1. Correctly receive and send no fewer than 5 words per minute, for 5 minutes, using the International Phonetic Code and the Q Code (25 five-letter words minimum, 25 correct consecutive letters).

    Answer: Practice the International Phonetic Code (Alpha, Bravo, Charlie...) and the Q Code (QSL=confirmation, QTH=location, QRZ=who is calling). Use an HT radio, walkie-talkie or simulator app. Goal: send and receive 25 five-letter words in 5 minutes without consecutive errors. — The Q Code was standardized in 1909 by the Berlin international conference — 3-letter abbreviations (QRM=interference, QSY=change frequency) save time and cross language barriers; it is still used by aviation, the navy and amateur radio operators all over the world in modern times.

  2. Explain at least 8 rules that regulate the activities of radio operators.

    Answer: Eight rules: have an ANATEL/LABRE license, use the call sign, operate only on authorized bands, keep a logbook, no commercial purposes, no interfering with others, no offense/politics, and use international codes (Q and phonetic). — In Brazil, LABRE (the Brazilian Amateur Radio League) has accredited amateur radio operators since 1934 — the system of classes A, B and C requires written and practical Morse Code exams for advanced levels, regulated by ANATEL's Resolution 449/2006 even today.

  3. Explain the terms below and state which equipment is used for measurement:
    • Electrical energy
    • Electric current
    • Electric power

    Answer: 1) Electrical energy: it is the electrical work performed, that is, the capacity to produce work from electricity. It is measured in kilowatt-hours (kWh) by the energy meter (electricity meter). 2) Electric current: it is the orderly flow of electric charges (electrons) through a conductor. It is measured in amperes (A) by the ammeter. 3) Electrical power: it is the amount of energy consumed or supplied per unit of time, calculated by P = V x I (voltage times current). It is measured in watts (W) by the wattmeter. — James Watt (1736-1819), a Scottish engineer, gave his name to the unit of power — his revolutionary steam engine defined the concept of mechanical power that was later adapted for electricity; 1 horsepower (HP) is equivalent to approximately 746 electrical watts.

  4. What are the abbreviations for:
    • Greenwich Mean Time
    • Megacycles
    • Continuous wave
    • Amplitude modulation
    • Frequency modulation
    • Kilocycles
    • Eastern Standard Time

    Answer: 1) Greenwich Mean Time: GMT, the worldwide time reference. 2) Megacycles: MHz (megahertz) — the term megacycles has now been replaced by megahertz. 3) Continuous Wave: CW, a transmission mode in Morse code. 4) Amplitude Modulation: AM. 5) Frequency Modulation: FM. 6) Kilocycles: kHz (kilohertz) — the term kilocycles has been replaced by kilohertz. 7) Eastern Standard Time: EST. — GMT was officially replaced by UTC (Coordinated Universal Time) in 1972 as the worldwide reference — UTC uses cesium atomic clocks and is more precise than the astronomical observation of mean time at Greenwich, the standard today in telecommunications.

  5. Give the algebraic formula of Ohm's Law and its usefulness.

    Answer: Ohm's Law: V = R × I (Voltage = Resistance × Current). Equivalents: I=V/R and R=V/I. Usefulness: to calculate any of the 3 electrical quantities knowing the other 2; to size resistors, predict current in circuits and protect electronic equipment against overload. — Georg Simon Ohm published the law in 1827 after being a poor secondary-school teacher in Germany — his discovery was rejected for decades by the German academy, and he was only recognized internationally in 1841 by the Royal Society of London with the Copley Medal.

  6. Explain the following terms:
    • Amplification
    • Modulation
    • Detection
    • Attenuation

    Answer: 1) Amplification: increasing the intensity (power or amplitude) of an electrical signal without altering the information it carries, using valves or transistors. 2) Modulation: varying a characteristic of the carrier wave (amplitude in AM, frequency in FM) according to the information signal, so that the message can travel through the air. 3) Detection (demodulation): extracting the original information back from the received wave, separating the useful signal from the carrier. 4) Attenuation: the natural reduction of signal intensity along the path, caused by distance, obstacles and cable resistance. — Modulation was invented by Reginald Fessenden in 1906 — the first transmission of modulated audio on radio on Christmas Eve that year; before, only Morse code pulses were transmitted, and this innovation paved the way for all modern AM/FM radios in the world.

  7. What is the relationship between a fundamental frequency and its second, third or fourth harmonic?

    Answer: Harmonics are integer multiples of the fundamental frequency. 2nd harmonic = 2× the fundamental; 3rd = 3×; 4th = 4×. E.g.: fundamental 100Hz → 2nd=200Hz, 3rd=300Hz, 4th=400Hz. Unwanted harmonics in radio cause interference in other stations. — Harmonics are an acoustic-electrical phenomenon studied since Pythagoras (6th century BC) in musical strings — in radio, poorly designed transmitters emit harmonics that pollute other frequencies, which is why amateur radio operators must use filters to suppress these spurious emissions, by regulation.

  8. Can any transmission be made without the station's identification?

    Answer: NO. Every transmission must include the call sign registered with ANATEL/LABRE at the beginning, at the end and every 10 minutes. Operating without a call sign is a crime, with a fine, suspension of the license and seizure of the equipment. — In Brazil, ANATEL's Resolution 449/2006 defines that the call sign is composed of a prefix + digit + suffix (e.g.: PY1ABC = Brazil region 1 ABC) — operating without identification constitutes clandestine transmission, violating the Telecommunications Law and potentially resulting in high fines.

  9. At what intervals should the amateur station transmit its call sign (CQ)?

    Answer: The CQ call sign (general call) should be repeated every 30 seconds during the search for contacts. The station's call sign is mandatory at the beginning, at the end and every 10 minutes throughout the communication, in accordance with ANATEL standards. — CQ is an abbreviation of the French 'sécu' (security/attention) — used worldwide since 1904 to call any station willing to respond; 'CQ DX' seeks international contacts and 'CQ DE PY1ABC' indicates that the call comes from station PY1ABC, the current standard.

  10. What is the function of the RFI (radio frequency interference) filter? Explain how a radio frequency can suffer interference.

    Answer: The RFI filter eliminates electromagnetic interference in the signal. Origins of the interference: nearby motors and power supplies, storms, stations on adjacent frequencies, and spurious harmonics from the radio itself. — RFI filters use capacitors and inductors in LC circuits to suppress unwanted frequencies — a principle discovered by Heaviside in 1885; modern filters use ferrite (a magnetic core) attached to the cables of electronic equipment such as printers and PC power supplies.

  11. Explain the function of the following components:
    • RF modulator
    • Amplifier
    • Rectifier
    • Filter

    Answer: 1) RF modulator: encodes (inserts) the information into the radio-frequency carrier wave, generating the modulated signal that will be transmitted. 2) Amplifier: increases the power or amplitude of the signal, both in transmission (to reach farther) and in reception (to make weak signals usable). 3) Rectifier: converts alternating current (AC) into direct current (DC), an essential stage of the power supplies that feed the equipment. 4) Filter: separates the desired frequencies from the unwanted ones, letting only the useful band pass and eliminating noise and interference. — The rectifier was invented by Karl Ferdinand Braun in 1874 — laureate of the Nobel Prize in Physics in 1909 along with Marconi for the development of radio; his galena crystal valve was the basis of the first commercial radio receivers in 1920 around the world.

  12. Explain what parasitic oscillations (feedback) are.

    Answer: Parasitic oscillations are unwanted electromagnetic vibrations generated by positive feedback in amplifiers: part of the output signal returns to the input, generating self-sustainment and noise. They cause whistling, distortion or burnout of the equipment. — The Larsen effect is the classic example of acoustic feedback — when a microphone picks up sound from its own speaker, the sound amplifies indefinitely; discovered by the Dane Søren Larsen in 1911, the principle is also applied in radio to identify oscillations.

  13. What should the power be for the valves that supply energy to an amateur radio operator's antenna?

    Answer: Power: 100-1500W depending on the class (Brazil: A=1500W, B=1000W, C=100W). The limit is regulated by ANATEL. Exceeding it causes interference and burnout of the equipment. — The first audio transmission on radio used only 50W, made by Reginald Fessenden in 1906 — today amateur radio operators can use up to 1500W with an advanced license, and commercial (broadcast) stations reach 100kW; power defines the range and clarity of the communication.

  14. Explain the term 'solid state' in amateur radio.

    Answer: Solid state: equipment with transistors instead of vacuum tubes. They are smaller, lighter, more efficient and durable. They replaced tubes in amateur radio starting in the 1960s. — The transistor was invented in 1947 by John Bardeen, Walter Brattain and William Shockley at Bell Labs — the 1956 Nobel Prize in Physics; within 30 years it replaced tubes in almost all the world's electronic equipment, being the basis of modern chips today.

  15. Why are rectifiers and filters necessary in the plate power supply system when operated from alternating current? What are the regulations in your area that govern amateur radio operators?

    Answer: 1) Why rectifiers and filters are necessary in the plate power supply when operating from alternating current (AC): the radio's electronic circuits need stable direct current (DC). The rectifier converts the AC from the mains into pulsed DC; the filter smooths this pulsed DC, removing the ripple and delivering pure, constant DC. Without rectification and filtering, the voltage would oscillate, causing hum/noise in the transmission, malfunction and even burnout of the components. 2) Regulations governing amateur radio operators in your area: in Brazil, the activity is regulated by ANATEL (the National Telecommunications Agency), including the Amateur Radio Service Regulation (Res. 449/2006), which requires a license and call sign, defines the classes (A, B, C) and the authorized bands/powers; LABRE (the Brazilian Amateur Radio League) represents and guides amateur radio operators. — ANATEL's Resolution 449/2006 replaced the previous regulation from 1989 and standardized the 3 Brazilian license classes (A, B, C) with different powers and bands — LABRE exams include theory and Morse code for modern advanced classes.