Study materials for class N: Regulations, Operations, and Technology

I. PART: REGULATIONS (Legislative framework)

1. Definitions and basic terms

• Amatérska služba: A radiocommunication service intended for self-education, mutual communication, and technical study, conducted by amateurs (licensed individuals) who are interested in radio technology purely as a personal hobby and without financial interest.

• Amatérska družicová služba: Same definition, but uses space stations (satellites) for signal transmission.

• Amatérska stanica: A set of transmitting and receiving equipment (including antennas and accessories) necessary for the operation of the amateur service.

2. International rules (ITU and Regions)

• Článok 25 Rádiokomunikačného poriadku ITU: States that amateur radio broadcasting must be conducted in a language understandable to others (clear speech), prohibits the broadcasting of music, advertisements, and coded messages (except for technical abbreviations).

• ITU Regióny: Svet je rozdelený na tri regióny. Slovensko patrí do Regiónu 1 (Europe, Africa, Russia, Middle East). Region 2 includes America, Region 3 Asia and Oceania. Differences are mainly in frequency allocations (e.g., the 7 MHz band is wider in Region 2).

European cooperation (CEPT and ECC)

• Odporúčanie ECC (05)06: Defines 'Novice Radio Amateur Licence' (Class N). It allows amateur radio operators with this class to temporarily transmit in other CEPT countries that have adopted this recommendation without the need to apply for a local license (usually up to 3 months). When transmitting abroad, the prefix of the respective country is added before the own call sign (e.g. OE/OM3XXX in Austria).

4. Licensing process in Slovakia

• Povoľovací orgán: Office for Regulation of Electronic Communications and Postal Services (Regulatory Office).

• Žiadosť o povolenie: Can be submitted by a natural person (from 14 years old with the consent of a legal representative) or a legal entity. A certificate of successful examination must be attached to the application.

• Triedy operátorov: * Trieda N (Novice): Entry level with limited power and bands.

  • Trieda E (Extra): Full license (HAREC). Transition from N to E requires successful completion of an additional exam on more advanced techniques and regulations.

• Platnosť povolenia: Standardly 10 years, it is possible to apply for an extension. The license expires upon the death of the holder, revocation by the authority (in case of gross violation), or expiration.

5. Operational provisions and log

• Zodpovednosť: The holder is responsible for the operation of the station. A legal entity must designate a responsible operator.

• Staničný denník (Log): Mandatory document. It must contain: date, time (UTC), frequency (band), type of operation, call sign of the counterpart station, and transmitted/received report (RST). Today, electronic format is preferred.

• Zakázané vysielanie: It is prohibited to broadcast messages for third parties (except in emergency situations), to use vulgar expressions, to play music, or to disrupt other services.

6. Technical parameters of class N (SK)

In class N, selected segments of bands are allowed (e.g. part of 80m, 40m, 20m, 15m, 10m on HF and entire bands 2m and 70cm on VHF). Maximálny výkon je limitovaný (zvyčajne 100 W on selected HF bands and lower power on VHF/UHF according to the current general authorization).

II. PART: OPERATION (The Art of Communication)

1. Spelling table (International)

For an amateur radio operator, it is essential to master the ICAO phonetic alphabet:

• A – Alfa, B – Bravo, C – Charlie, D – Delta, E – Echo, F – Foxtrot, G – Golf, H – Hotel, I – India, J – Juliet, K – Kilo, L – Lima, M – Mike, N – November, O – Oscar, P – Papa, Q – Quebec, R – Romeo, S – Sierra, T – Tango, U – Uniform, V – Victor, W – Whiskey, X – X-ray, Y – Yankee, Z – Zulu.

2. Q-codes and abbreviations

• QSO: Connection

• QTH: Station (location)

• QRG: Frequency

• QRM: Interference from other stations

• QRN: Atmospheric noise (static crackle)

• QSL: Confirmation of connection (card)

• QSY: Change of frequency

• 73: Greeting (Respectfully)

3. Identification and call signs

• Štruktúra: Prefix (krajina, napr. OM for Slovakia), Number (region, e.g. 3), Suffix (1 až 3 písmená, napr. ABC). Celá značka: OM3ABC.

• Identifikácia: The station must identify itself at the beginning and end of the connection, and every 10 minutes during longer sessions.

4. RST System (Report)

Used to assess signal quality:

• R (Readability – zrozumiteľnosť): 1 (unintelligible) to 5 (completely intelligible).

• S (Strength – sila): 1 (very weak signal) to 9 (extremely strong).

• T (Tone – tón, len pri CW): 1 (very bad) to 9 (pure tone).

• Príklad: "You are giving me a report 59" means that I hear you excellently.

5. Propagation of radio waves

• Krátke vlny (KV): Odrážajú sa od ionosféry (layers D, E, F1, F2). This allows for connections beyond the horizon (DX). Quality depends on the 11-year solar activity cycle. Lower bands (80m) work better at night, while higher bands (20m, 10m) work better during the day.

• Veľmi krátke vlny (VKV): Šíria sa priamo (priama viditeľnosť). Dosah zvyšujú prevádzače (repeaters) umiestnené na kopcoch. Špeciálne podmienky: Tropo (inverzia v atmosfére), Es (sporadic E layer – reflections in summer over long distances), Aurora (odraz od polárnej žiary).12

III. PART: ELECTRICAL ENGINEERING (Basics and safety)34

1. Basic quantities and Ohm's law56

In electrical engineering, we work with the relationship between voltage, prúdom a odporom.

Ohm's law is a fundamental physical law of electrical engineering that expresses the relationship between voltage, current, and resistance in an electrical circuit. The law states that the electric current flowing through a conductor is directly proportional to the voltage and inversely proportional to the resistance.

Basic formula:

U = R × I

Derived formulas:

• I = U / R (current)
• R = U / I (resistance)

Where:

• U – voltage (volt, V)
• I – current (ampere, A)
• R – resistance (ohm, Ω)

This law applies to ohmic conductors at constant temperature and is named after the German physicist Georg Simon Ohm.

P is power in watts. For class N, it is important to know how to calculate, for example, the required current for a source if we know the power and voltage (typically 13.8 V).

2. Components and their functions

• Rezistor: It resists current, reduces voltage.

• Kondenzátor: Stores electric charge, blocks direct current but allows alternating current (high frequency). Unit: Farad [F].

• Cievka (Indukčnosť): Resists alternating current. In combination with a capacitor, it forms ladený obvod (rezonančný obvod), ktorý určuje frekvenciu rádia.

• Dióda: Allows current to flow in only one direction (used in rectifiers).

• Tranzistor: Basic element for amplifying signals or generating oscillations (oscillator).

3. Amateur radio station (Blocks)

• Receiver (Superheterodyne): Signál z antény sa v zmiešavači zlúči so signálom z oscilátora, čím vznikne medzifrekvencia, ktorá sa ľahšie zosilňuje a filtruje pred detekciou (demoduláciou) na zvuk.

• Vysielač: Microphone amplifier -> Modulator (inserts voice into carrier wave) -> Driver -> Power amplifier (PA) -> Low pass filter (to suppress harmonics) -> Antenna.

4. Antennas and lines

• Dipól: The simplest half-wave antenna ($L = 142,5 / f$ [MHz]).

• yagi: Directional antenna with elements (radiator, reflector, directors) that focuses energy in one direction (gain).

• SWR (PSV): Pomer stojatých vĺn. Meria sa SWR metrom. Ideálna hodnota je $1:1$. Hodnota nad $3:1$ can damage the transmitter because the energy is not transferred to the antenna but returns back to the radio as heat.

• Koaxiálny kábel: The most common feed with impedance $50$ Ohmov.

5. Interference (EMC)

Rádioamatér musí dbať na to, aby nerušil TV, rozhlas alebo susedov. Príčinou môže byť harmonické vyžarovanie (the transmitter also transmits at multiples of the frequency). The solution is filters (low-pass) and quality shielding.

6. Safety and protection

• Zásah prúdom: Nebezpečný je už prúd nad 30 mA is already dangerous. In devices (especially older tube devices), voltages are hundreds of Volts. Kondenzátory môžu ostať nabité aj po vypnutí zariadenia!

• Uzemnenie: The station must be properly grounded for safety and to reduce interference.

• Blesky: Antény sú bleskozvody. Počas búrky vždy disconnect antenna connectors from devices and remove them outside the building (or ground them outside).