🚀 SYSTEM MIGRATED TO ZETTELKASTEN
This repository has been converted into a Zettelkasten Knowledge System to allow for better cross-referencing and modular study.
- 📖 Read the Study Guide: A linear, book-like version generated from the notes. Best for sequential studying.
- 📂 Enter Zettelkasten: Browse the raw atomic notes, explore connections, and see the knowledge graph.
The Zettelkasten (German for "Slip Box") method organizes knowledge into small, atomic notes that are linked together. It is best viewed using Obsidian, a powerful knowledge base tool that works on top of a local folder of Markdown files.
- Atomic Notes: Each file covers one specific concept (e.g., Ohm's Law, Dipole Antenna).
- Connections: Notes link to related concepts (e.g., Dipole links to Impedance and Resonance), mimicking how the brain works.
- Maps of Content (MOC): Index files (like the Master Index below) that organize notes into topics.
The old hierarchical documentation has been moved to docs_archive/ for reference but is no longer the primary source.
This repository serves as a preparation checklist for the Dutch HAM radio exam (RZAM-F).
Structure: Follows the official Dutch CBR exam requirements (Eindtermen).
Language: English, with key Dutch terms in parentheses (...).
Content: Enriched with detailed explanations, formulas, and concepts from the UK Full Licence syllabus to provide a deep study guide.
📂 Open Master Index - A comprehensive list of all topics.
- 0.1 Mathematical Skills
- Standard Form / Scientific Notation: Manipulating powers of 10.
- Prefixes:
- Formulas: Rearranging equations.
- Logarithms & Decibels:
- Logarithms: Inverse of exponentiation (10^2 = 100 -> log(100) = 2).
- Decibel (dB): Logarithmic unit for ratios.
- Power Ratio: dB = 10 * log(P_out / P_in).
- Voltage/Current Ratio: dB = 20 * log(U_out / U_in).
- Trigonometry (Goniometrie):
- Sine & Cosine: Fundamental for AC analysis.
- Phase: Shift between waveforms.
- Radians: Natural unit of angle. 360 degrees = 2 * pi radians.
- Pythagoras Theorem: a^2 + b^2 = c^2. (Used for Impedance Z = sqrt(R^2 + X^2)).
- Graphs: Interpreting linear and logarithmic scales.
Eindterm 1: Electricity, Electromagnetism, and Radio Theory (Elektriciteitsleer, elektromagnetisme en radiotheorie)
- Atomic Structure:
- Nucleus (Kern): Protons (+) and Neutrons (neutral).
- Shell (Schil): Electrons (-).
- Ion: Atom with net charge (gained or lost electrons).
- Materials:
- Conductors (Geleiders): Low resistance, free electrons (e.g., Copper, Silver, Gold).
- Semiconductors (Halfgeleiders): Conductivity between conductor and insulator (e.g., Silicon, Germanium).
- Insulators (Isolatoren): High resistance (e.g., Glass, Ceramic, Plastic).
- Basic Quantities:
- Charge (Q, Coulomb): 1 C ≈ 6.24 x 10^18 electrons.
- Current (I, Ampere): Flow of charge (Q) per time (t). Formula: I = Q / t
- Direction: Technical direction (Plus to Minus) vs Electron flow (Minus to Plus).
- Voltage (U, Volt): Potential difference. Energy per charge.
- Resistance (R, Ohm): Opposition to current flow.
- Specific Resistance (Soortelijke weerstand, rho):
- rho = Specific resistance of material (Ohm-meter).
- l = Length (m).
- A = Cross-sectional area (m^2).
- Ohm's Law (Wet van Ohm):
- Kirchhoff's Laws (Wetten van Kirchhoff):
- First Law (Current/Stroom): Sum of currents entering a junction = Sum of currents leaving.
- Second Law (Voltage/Spanning): Sum of EMFs = Sum of potential drops in a closed loop.
- Power (Vermogen) & Energy:
- Power Formula: P = U * I (or P = I^2 * R, or P = U^2 / R). Unit: Watt.
- Energy Formula: W = P * t. Unit: Joule or Watt-hour.
- Battery Capacity: measured in Ampere-hours (Ah).
- Measurements: Voltage (Parallel), Current (Series), Resistance.
- Voltage Source Properties:
- EMF (Bronspanning/EMK): Voltage generated by the source.
- Internal Resistance (Ri): Resistance inside the battery/source.
- Terminal Voltage (U_klem): U_klem = E - (I * Ri). Voltage drops under load.
- Short Circuit Current: I_short = E / Ri.
- Combinations:
- Series: Voltages add up, Internal resistance adds up.
- Parallel: Capacity adds up, Voltage remains the same (identical cells only).
- Concept: Force field between charged plates.
- Field Strength (E): E = U / d (Voltage / distance). Unit: V/m.
- Formulas:
- Capacitor: C = epsilon_0 * epsilon_r * A / d.
- Force on Charge: F = Q * E.
- Shielding (Afscherming): Faraday Cage (conductive enclosure blocks static electric fields).
- Concept: Field around current-carrying wires and coils.
- Right-hand grip rule.
- Shielding: Using high-permeability materials (e.g., Mu-metal) to divert magnetic flux. Low resistance (Copper) does NOT shield magnetic fields well.
- Radio Waves: Combination of Electric (E) and Magnetic (H) fields at right angles.
- Velocity: c is approx 300,000,000 m/s (in vacuum).
- Relationship: v = f * lambda (Velocity = Frequency * Wavelength).
- Polarisation (Polarisatie): Defined by the orientation of the E-field (Horizontal, Vertical, Circular).
- Parameters:
- Amplitude (U_max): Peak voltage.
- Effective/RMS Value (U_eff): DC equivalent heating effect.
- Period (T): Time for one cycle (seconds).
- Frequency (f): f = 1 / T (Hertz).
- Phase: Relative timing between two waves (measured in degrees or radians).
- Wavelength (lambda): lambda = c / f. (Distance a wave travels in one period).
- Angular Frequency (omega): omega = 2 * pi * f (radians/second).
- Instantaneous Voltage: u(t) = U_max * sin(omega * t + phi).
- Square Wave (Blokgolf): Fundamental frequency + odd harmonics (3f, 5f, 7f...). Amplitudes decrease as 1/n.
- Triangle Wave (Driehoeksgolf): Fundamental + odd harmonics. Amplitudes decrease as 1/n^2.
- Sawtooth (Zaagtand): Contains both even and odd harmonics.
- Fourier Analysis: Any complex periodic wave is a sum of sine waves (Fundamental + Harmonics).
- DC Component: Average voltage level.
- Noise (Ruis):
- Thermal Noise: Pn = k * T * B (k=Boltzmann, T=Kelvin, B=Bandwidth).
- Shot Noise: Generated in PN junctions.
- Atmospheric (QRN): Static, Lightning.
- Man-made (QRM): Machinery, Electronics.
- Noise floor increases with bandwidth and temperature.
- Analogue:
- CW (Morse): Keying the carrier on/off. Narrow bandwidth (~50-150 Hz).
- AM (Amplitude Modulation):
- Modulation Depth (Modulatiediepte, m): Ratio of audio amplitude to carrier amplitude (m = U_audio / U_carrier). m=1 (100%) is max.
- Sidebands (Zijbanden): Lower Sideband (LSB) and Upper Sideband (USB).
- Bandwidth: B = 2 * f_max_audio.
- Power: P_total = P_carrier * (1 + m^2 / 2).
- At 100% mod: Sidebands contain 1/3 of total power (1/6 each).
- PEP (Peak Envelope Power) = 4 * P_carrier (at 100% mod).
- SSB (Enkelzijband, EZB): Carrier and one sideband suppressed.
- Sideband Selection: USB vs LSB depends on IF design / Frequency convention.
- Efficiency: All power useful. Bandwidth ~2.4 - 2.7 kHz.
- FM (Frequency Modulation) / PM (Phase Modulation):
- Deviation (Frequentiezwaai, Delta f): Max frequency change from center.
- Modulation Index (m): m = Delta f / f_mod.
- Bandwidth (Carson's Rule): B = 2 * (Delta f + f_max_audio).
- Valid for beta >= 1 (Wideband FM).
- For NBFM (beta < 1), spectrum is narrower.
- NBFM (Narrow Band): B ~ 12.5 kHz.
- Pre-emphasis / De-emphasis: Boosting high audio frequencies before transmission and reducing them after reception to improve S/N.
- Capture Effect: Stronger signal suppresses weaker co-channel signal.
- Improves noise immunity.
- Makes FM unsuitable for weak-signal work.
- Digital:
- Baud vs Bit rate:
- Baud (Bd): Symbol rate (changes per second).
- Bit rate (bps): Information rate. Bit rate = Baud * bits_per_symbol.
- Types:
- ASK: Amplitude Shift Keying.
- FSK: Frequency Shift Keying (RTTY).
- PSK: Phase Shift Keying (BPSK, QPSK).
- QAM: Quadrature Amplitude Modulation (Amplitude + Phase).
- Coding:
- Baudot (CCITT-1): 5-bit code (32 characters). Used in RTTY.
- ASCII (CCITT-5): 7 or 8-bit code.
- Parity: Error check bit.
- Baud vs Bit rate:
- Decibels (dB): Logarithmic ratio.
- Power Ratio: 10 * log(P2 / P1)
- Voltage Ratio: 20 * log(U2 / U1)
- Impedance Matching (Aanpassing): Max power transfer occurs when Source Impedance = Load Impedance.
- PEP (Peak Envelope Power): Average power of one RF cycle at the crest of the modulation envelope.
- ADC / DAC: Analogue to Digital / Digital to Analogue.
- Sampling: Taking snapshots of voltage.
- Nyquist Theorem: Sample rate must be at least 2x the highest frequency component (fs > 2 * f_max) to avoid aliasing.
- Aliasing: False signals created if sampling is too slow.
- Quantisation: Assigning a digital value to the sample. Leads to Quantisation Noise (resolution error).
- Filters: Anti-alias filter (before ADC) and Reconstruction filter (after DAC).
- Function: Limits current, dissipates heat.
- Unit: Ohm.
- Types: Fixed, Variable, Thermistors (NTC/PTC).
- Color Code: 4-band code for value and tolerance.
- E-Series: Standard values (E12, E24).
- Function: Stores charge in electric field.
- Formula: C depends on Area, Distance, Dielectric.
- Reactance (Xc): 1 / (2pi f C).
- Types: Ceramic, Electrolytic (Polarized), Variable.
- Function: Stores energy in magnetic field.
- Self-Induction: Back EMF opposes current change (Lenz).
- Reactance (Xl): 2pi f L.
- Factors: Turns squared (N^2), Core material (mu).
- Ratio: Voltage proportional to turns; Impedance proportional to turns squared.
- Cores: Laminated iron (LF), Ferrite/Toroid (HF).
- Losses: Eddy currents, Hysteresis, Copper loss.
- Diodes: Rectifier, Zener, Varicap, LED.
- Transistors:
- BJT: NPN/PNP. Current controlled.
- FET: JFET/MOSFET. Voltage controlled. High Input Z.
- Configurations: Common Emitter/Source (Gain), Follower (Buffer).
- Vacuum Tubes: Triode, Tetrode, Pentode.
- Op-Amps: High gain, differential input. Inverting/Non-inverting modes.
- Logic Gates: AND, OR, NOT, NAND, NOR, XOR.
- Flip-flops: Memory elements.
- Crystals: Piezoelectric effect. High stability (TCXO, OCXO).
- Resonant Circuits (LC):
- Series LC:
- Impedance Minimal at resonance (Z = R_loss).
- Acts as Acceptor/Suction circuit (Zuigkring).
- Below f0: Capacitive. Above f0: Inductive.
- Parallel LC:
- Impedance Maximal at resonance (High Z).
- Formula (High-Q approx): Z_dyn = L / (C * R_series).
- Acts as Rejector/Blocking circuit (Sperkring).
- Below f0: Inductive. Above f0: Capacitive.
- Resonant Frequency: f0 = 1 / (2 * pi * sqrt(L * C)).
- Series LC:
- Filter Types:
- Low Pass (LPF), High Pass (HPF), Band Pass (BPF), Band Stop (Notch).
- Q-Factor (Kwaliteitsfactor):
- High Q -> Sharp peak -> Narrow Bandwidth.
- Bandwidth B = f0 / Q.
- Crystal Filter: Very High Q (thousands), very narrow bandwidth.
- Mechanical Filter: Used in IF stages, very high Q (hundreds), narrow bandwidth, physically vibrates.
- Ceramic Filter: Piezoelectric, medium Q, IF stages.
- Decibels in Filters:
- -3dB Point: Cut-off frequency (Half Power point, Voltage x 0.707).
- -60dB Point: Used to define Shape Factor (-60dB BW / -6dB BW).
- Rectification:
- Half-wave (1 diode), Full-wave centre-tap (2 diodes), Bridge (4 diodes).
- Smoothing: Large capacitor to reduce Ripple (Rimpel).
- Capacitor charges to U_peak, discharges during gaps.
- Stabilisation:
- Zener: Simple parallel regulator. Series resistor R = (U_in - U_zener) / (I_zener + I_load).
- Series Regulator: Zener ref + Transistor (Emitter follower) for higher current.
- Integrated Circuits: 78xx (Positive), 79xx (Negative).
- Switch Mode (SMPS): High efficiency, small, but creates RF noise (EMC).
- PWM: Pulse Width Modulation controls output voltage.
- Coupling Methods:
- RC Coupling: Resistor + Capacitor. Audio/Wideband. Cheap.
- LC/Choke Coupling: Higher efficiency for RF. DC voltage on collector = V_supply.
- Transformer: Impedance matching, isolation. Used in RF and Push-Pull.
- Operating Characteristics:
- Load Line (Belastingslijn): Graphical line on characteristic curves representing the load. Intersection with device curve is the Operating Point (Werkpunt).
- Dissipation: Heat loss (P = U_ce * I_c). Must stay within the Dissipation Hyperbola (Safe Operating Area).
- Feedback (Terugkoppeling):
- Negative Feedback (Tegenkoppeling): Reduces gain, reduces distortion, increases bandwidth. (e.g., unbypassed emitter resistor).
- Positive Feedback (Meekoppeling): Increases gain, reduces bandwidth. Used in oscillators and regenerative receivers.
- Classes:
- Class A: Conducts 100% (360 deg). Bias in middle of linear range. High linearity, low efficiency (max 25% with resistor, 50% with transformer).
- Class B: Conducts 50% (180 deg). Bias at cut-off. Push-pull needed to avoid Crossover Distortion. Efficiency max 78.5%.
- Class AB: Conducts >50% but <100%. Compromise between A and B. Reduced crossover distortion.
- Class C: Conducts < 50%. Pulses. High efficiency (>80%). RF PA only (requires output tank circuit to restore sine wave).
- Distortion: Harmonic (multiples of freq), Intermodulation (mixing of two freqs).
- AM Detector: Simple Diode (Envelope detector).
- Product Detector: For SSB/CW. Mixes incoming signal with BFO (Beat Frequency Oscillator) to recover audio.
- FM Detector: Discriminator, Ratio Detector.
- Condition: Barkhausen criterion (Loop gain = 1, Phase shift = 0 or 360 degrees). Positive Feedback.
- LC Oscillators:
- Meissner: Inductive coupling (transformer feedback).
- Hartley: Inductive voltage divider (Tapped coil).
- Colpitts: Capacitive voltage divider.
- Butler: Crystal oscillator variant with improved stability.
- Clapp: Variation of Colpitts with series capacitor for better frequency stability.
- Crystal Oscillators: Piezoelectric effect. High Q, high stability.
- Pierce: Crystal between Base and Collector (or Gate/Drain). Acts as inductor.
- Overtone: Crystal vibrates at odd harmonic (3rd, 5th). Requires LC tank to select overtone.
- Temperature Compensation: TCXO (Compensated), OCXO (Oven Controlled).
- VCO: Voltage Controlled Oscillator. Uses Varicap (Capaciteitsdiode) to tune frequency.
- Phase Noise: Jitter in time domain = noise sidebands in freq domain. Critical for digital modes and receiver selectivity.
- Components:
- Reference Oscillator: Stable crystal oscillator.
- Phase Detector (Fasevergelijker): Compares reference phase with VCO phase. Output is Error Voltage.
- Loop Filter (LDF): Low pass filter to smooth error voltage. Determines lock speed and stability.
- VCO: Voltage Controlled Oscillator. Frequency adjusted by error voltage.
- Divider: Divides VCO frequency for comparison (in synthesizers).
- Use: Frequency synthesis (stable variable frequency), FM demodulation, FM generation.
- Operation: Non-linear device combining f1 and f2.
- Output: Sum (f1+f2) and Difference (f1-f2), plus originals and harmonics.
- Image Frequency (Spiegelfrequentie): Unwanted signal that mixes to the same IF.
- Mitigation: High IF or Double Conversion (Dubbelsuper), Preselection filters.
- Sampling:
- Nyquist-Shannon Theorem: Sample rate must be > 2 * f_max_signal to avoid aliasing.
- Aliasing: High frequencies masquerading as low frequencies. Blocked by Anti-Alias Filter (Low Pass) before ADC.
- ADC / DAC: Analogue-to-Digital / Digital-to-Analogue Converters.
- Quantisation Noise: Noise due to finite bit resolution (rounding errors).
- DDS (Direct Digital Synthesis): Generating sine waves from a lookup table + DAC. Fast switching, high resolution.
- FFT (Fast Fourier Transform): Convert Time domain signals to Frequency domain (Spectrum display).
- Digital Filters:
- FIR (Finite Impulse Response): Stable, linear phase.
- IIR (Infinite Impulse Response): Feedback used, potential instability, acts like analog filter.
- Series/Parallel: Formulas for R, C, and L.
- Voltage Divider: Potentiometer principles.
- RC and RL: Tau = RC or L/R.
- Charge/Discharge: 63% at 1 Tau.
- Types: LPF, HPF, BPF, Notch.
- LC Circuits: Series (Acceptor) vs Parallel (Rejector).
- Selectivity: Q-factor, Crystal/Mechanical filters.
- Rectification: Half-wave, Full-wave, Bridge.
- Smoothing: Reservoir capacitor.
- Stabilisation: Zener, Linear regulator, SMPS (Switch mode).
- Classes: A, B, AB, C. Efficiency vs Linearity.
- Feedback: Negative (Stability) vs Positive (Oscillation).
- Distortion: Harmonic, Intermodulation.
- Oscillators: Hartley, Colpitts, Crystal, VCO.
- Detectors: Envelope (AM), Product (SSB/CW), Discriminator (FM).
- Mixers: Sum and Difference frequencies. Image frequency.
- PLL: Phase Locked Loop for synthesis.
- TRF (Rechtuit): Simple, poor selectivity.
- Regenerative: High gain/selectivity, unstable.
- Direct Conversion: Simple for SSB/CW, audio issues.
- Mixing: RF + LO = IF.
- Image Frequency: Major disadvantage.
- Double Conversion: High 1st IF (Image), Low 2nd IF (Selectivity).
- AGC: Automatic Gain Control.
- AM: Envelope detector.
- SSB/CW: Product detector (needs BFO).
- FM: Discriminator, Ratio Detector, PLL.
- Sensitivity: SINAD, Noise Figure.
- Selectivity: Bandwidth, Shape Factor.
- Dynamic Range: Blocking, Intermodulation (IP3).
- S-Meter: S9 = 50 uV.
- CW: Oscillator -> Buffer -> PA.
- FM: VCO (Direct) or Phase Mod (Indirect). Multipliers.
- SSB: Audio -> Bal Mod -> Filter -> Mixer -> PA.
- Controls: VOX, ALC, Speech Processing.
- Linearity: Required for SSB/AM (Class A/AB).
- Efficiency: Class C for FM/CW.
- Filtering: LPF to suppress harmonics.
- Matching: ATU.
- Dipole: Half-wave, center-fed.
- Vertical: Ground plane, radials.
- Directional: Yagi-Uda (Beam), Quad.
- Other: End-fed, Loop, Dummy Load.
- Gain: dBi vs dBd.
- Power: ERP vs EIRP.
- Radiation Resistance: Efficiency factor.
- Pattern: Front-to-Back ratio, Beamwidth.
- Types: Coax (Asymmetric) vs Open Wire (Symmetric).
- Velocity Factor: Signal speed in cable.
- Transformation: Quarter-wave lines invert impedance.
- SWR: Standing Wave Ratio.
- Balun: Balanced to Unbalanced (Choke vs Transformer).
- ATU: Antenna Tuning Unit (matches TX to line).
- EM Waves: E and H fields.
- Polarization: Horizontal/Vertical.
- Inverse Square Law: Power loss with distance.
- Ground Wave: LF/MF, follows earth.
- Sky Wave: HF, ionospheric refraction.
- Line of Sight: VHF/UHF. Radio Horizon.
- Tropospheric: Ducting, Scatter.
- Layers: D (Absorbs), E, F1/F2 (Reflect).
- Solar Cycle: Sunspots, SFI.
- Frequencies: MUF, LUF, Critical Frequency.
- Fading: QSB causes.
- HF Bands: 160m to 10m properties.
- VHF/UHF: 6m, 2m, 70cm usage.
- Propagation: Day vs Night, Solar Max vs Min.
- Analogue: Moving coil, Sensitivity (kOhm/V), Loading effect.
- Digital: High input impedance, ADC.
- Technique: Voltage (Parallel), Current (Series), Resistance (Isolated).
- Oscilloscope: Time domain (Voltage vs Time). Amplitude, Period.
- Spectrum Analyzer: Frequency domain (Amplitude vs Frequency). Harmonics, Bandwidth.
- SWR Meter: Forward/Reflected power. Calibration.
- Frequency Counter: Gate time, Accuracy.
- Dip Meter: Measuring resonant frequency of unpowered circuits.
- Dummy Load: Non-inductive 50 Ohm load for testing.
- Receiver Overload: Blocking (Desensitization).
- Mixing Products: Intermodulation (
$2f_1 - f_2$ ), Cross-modulation. - Audio: LFD (Audio Rectification). "Donald Duck" SSB, Clicks.
- Transmitter: Chirp, Key Clicks, Splatter.
- Emissions: Harmonics, Spurious, Phase Noise.
- Immunity: Poor shielding, Pin 1 problem.
- Paths: Radiated vs Conducted (Mains, Coax shield).
- Filtering: LPF (TX), HPF (TV/Radio), Mains Filter.
- Ferrites: Common Mode Chokes (clamp-on/ring).
- Decoupling: Capacitors on audio lines.
- Body Effects: 10mA (Let-go), 30mA (Respiratory), 75mA (Fibrillation).
- Mains: Live (Brown), Neutral (Blue), Earth (Green/Yellow).
- Protection: Fuse (Fire), RCD (Shock, 30mA).
- Risks: Heating (Eyes/Testes), RF Burns.
- SAR: 0.08 W/kg (Public), 0.4 W/kg (Occupational).
- Distance: Calculation based on EIRP.
- Classes: Class I (Earthed), Class II (Double Insulated), Class III (SELV).
- Lightning: Disconnect antennas.
- Chemical: Lithium batteries, Beryllium Oxide (Toxic dust).
- Beryllium Oxide (BeO): White ceramic in power transistors. Toxic dust if broken.
- Lead: In solder. Wash hands.
- Etchants (Etsmiddelen): Ferric Chloride etc. Corrosive.
- Lightning: Disconnect antennas during storms.
- Phonetic Alphabet: Spelling callsigns (Alfa, Bravo...).
- Q-Codes: QTH (Location), QSL (Confirm), QRM (Interference), etc.
- Abbreviations: CQ, 73, DX, DE.
- RST System: Readability, Strength, Tone.
- Emergency: SOS (CW), MAYDAY (Voice). Do not obstruct genuine emergency traffic.
- ITU: Radio Regulations, Regions (NL = Region 1).
- CEPT: Harmonisation (T/R 61-01 Guest op).
- IARU: Amateur interests, Band plans.
- HAREC: Exam standard.
- Registration: RDI. Classes N and F.
- Call Signs: Prefix (PA-PH, PI, PD) + Suffix.
- Identification: Every 10 mins.
- Definition: Non-commercial, self-training.
- Status: Primary vs Secondary (must not cause interference).
- Emission Classes: A1A (CW), J3E (SSB), F3E (FM).
- Laws: Telecommunicatiewet.
- Social: Be polite, helpful, tolerant.
- Operating: Listen before transmitting. Use minimum power.
- Emergency: DARES. Know when to help and when to stay clear.
Special thanks to the VRZA (Vereniging van Radio Zend Amateurs) for their comprehensive course material which served as a primary resource for the detailed expansions in this guide.