Amateur Extra license study guide

Who this guide is for

This guide is for General licensees going for Amateur Extra. Element 4 is the most technical exam: about half the questions cover circuits, components, signals and antennas, often with math. Plan for more study time than the earlier exams.

A simple study plan

1. Take one practice exam first to get a baseline. Start the practice test.
2. Read this guide topic by topic, starting with your lowest-scoring topics.
3. Drill each topic in study mode until you get most questions right, reading every explanation.
4. Take full practice exams until you pass several in a row with room to spare, then book your exam.

Many candidates spend one to three months on Extra. Learn the math formulas first; they unlock many questions.

What Amateur Extra adds

Amateur Extra licensees have every U.S. amateur privilege on every band, including the Extra-only segments at the bottom of 80, 40, 20 and 15 meters, which are popular for working rare DX stations. Extra licensees can also serve as Volunteer Examiners for all three license exams.

The exam blueprint

Your exam has one question from each of the 50 groups. The number of exam questions per topic is fixed:

E1: Commission Rules 6 exam questions · 68 in pool

Key facts to know

• Band-edge math: USB extends above and LSB below the displayed carrier, so keep the full signal width inside the band (for example, a 2.8 kHz USB data signal must be at or below 14.1472 MHz).
• LF/MF bands: 2200 meters is limited to 1 W EIRP and 630 meters to 5 W EIRP; you must notify the Utilities Technology Council and may operate after 30 days unless told you are within 1 km of PLC systems.
• Spurious emissions below 30 MHz must be at least 43 dB down. Spread spectrum is permitted only above 222 MHz. North of Line A, 420 to 430 MHz is off-limits.
• Space operation: space stations, beacons and telecommand stations may transmit one-way; telecommand to space stations may be encrypted; model craft telecommand is limited to 1 W.
• Exams: VECs maintain the question pools; VEs are accredited by a VEC; three VEs must certify results; a VE may not examine relatives; non-compliant candidates have their exam terminated.
• International: CEPT and IARP permits allow operation abroad; Canadians may operate in the U.S. under their own license terms. A remote station must stop within 3 minutes if its control link fails.

Official question groups in E1

• E1A: Frequency privileges; signal frequency range; automatic message forwarding; stations aboard ships or aircraft; power restriction on 630- and 2200-meter bands
• E1B: Station restrictions and special operations: restrictions on station location; general operating restrictions; spurious emissions; antenna structure restrictions; RACES operations
• E1C: Automatic and remote control; band-specific regulations; operating in and communicating with foreign countries; spurious emission standards; HF modulation index limit; band-specific rules
• E1D: Amateur Space and Earth stations; telemetry and telecommand rules; identification of balloon transmissions; one-way communications
• E1E: Volunteer examiner program: definitions; qualifications; preparation and administration of exams; reimbursement; accreditation; question pools; documentation requirements
• E1F: Miscellaneous rules: external RF power amplifiers; prohibited communications; spread spectrum; auxiliary stations; Canadian amateurs operating in the US; special temporary authority

Practice E1 questionsSee all 68 E1 questions

E2: Operating Procedures 5 exam questions · 60 in pool

Key facts to know

• Satellites: the mode is the uplink/downlink band pair; inverting transponders reverse the spectrum; limit uplink power to share the transponder; geostationary satellites appear fixed in the sky.
• Television: NTSC frames have 525 interlaced lines; analog TV uses vestigial sideband; SSTV encodes brightness as tone frequency and identifies its mode with a VIS code; DVB-T uses QAM and QPSK.
• Contesting and DX: Cabrillo is the contest log format and ADIF the log exchange format; contests avoid 30 meters; DX stations often work split; give your full call sign once or twice in a pileup.
• Weak-signal modes: FT8 cycles are 15 seconds; MSK144 is for meteor scatter; Q65 is for EME and can average multiple cycles; JT65 uses multitone AFSK.
• APRS uses AX.25 packets in UI frames, relayed by digipeaters; a WIDE3-1 path requests three hops with one remaining.
• Other digital: PACTOR can transfer binary files; PSK31 uses variable-length Varicode; direct FSK shifts the VFO itself; ALE radios scan for their call sign.

Official question groups in E2

• E2A: Amateur radio in space: amateur satellites; orbital mechanics; frequencies and modes; satellite hardware; satellite operations
• E2B: Television practices: fast-scan television standards and techniques; slow scan television standards and techniques
• E2C: Contest and DX operating; remote operation techniques; log data format; contact confirmation; RF network systems
• E2D: Operating methods: digital modes and procedures for VHF and UHF; APRS; EME procedures; meteor scatter procedures
• E2E: Operating methods: digital modes and procedures for HF

Practice E2 questionsSee all 60 E2 questions

E3: Radio Wave Propagation 3 exam questions · 39 in pool

Key facts to know

• EME: stations up to about 12,000 miles apart can work via the Moon; path loss is lowest at perigee; libration fading is fluttery and irregular.
• Meteor scatter uses E-region trails and works best from 28 to 148 MHz. Tropospheric ducts, often over water, carry microwave signals 100 to 300 miles.
• Transequatorial propagation reaches up to about 5,000 miles, best in the afternoon or early evening, on paths crossing the geomagnetic equator.
• Chordal hop refracts between ionospheric layers without touching ground, reducing loss. Sporadic E peaks around the summer solstice during daylight. Long-path is most common on 40 and 20 meters.
• Space weather: solar flares cause short-term blackouts; rising A or K indices mean geomagnetic disturbance; a southward Bz worsens conditions; X-class is the strongest flare; G5 is an extreme storm.
• The VHF/UHF radio horizon is about 15 percent beyond the geographic horizon. VOACAP models HF propagation.

Official question groups in E3

• E3A: Electromagnetic Waves and Specialized Propagation: Earth-Moon-Earth (EME) communications; meteor scatter; microwave tropospheric and scatter propagation; auroral propagation; daily variation of ionospheric propagation; circular polarization
• E3B: Transequatorial propagation; long-path propagation; ordinary and extraordinary waves; chordal hop; sporadic-E mechanisms; ground-wave propagation
• E3C: Propagation prediction and reporting: radio horizon; effects of space-weather phenomena

Practice E3 questionsSee all 39 E3 questions

E4: Amateur Practices 5 exam questions · 63 in pool

Key facts to know

• Test equipment: spectrum analyzers show amplitude vs frequency; digital scopes are limited by sample rate and can alias; compensate a probe with a square wave; a prescaler divides frequency for a counter.
• Vector network analyzers: calibrate with short, open and 50-ohm loads; S11 is input reflection (SWR) and S21 is forward gain.
• Receiver performance: -174 dBm is the theoretical noise in 1 Hz; noise figure compares receiver noise to that minimum; widening bandwidth from 50 Hz to 1,000 Hz raises the noise floor about 13 dB.
• Dynamic range: blocking dynamic range is measured to 1 dB of compression; third-order intercept compares IMD products to the input; reciprocal mixing comes from local oscillator phase noise; roofing filters help.
• Link math: received level = transmit power + gains - losses; margin = received level minus (sensitivity + required signal-to-noise ratio).
• Noise: noise blankers remove impulse noise; DSP reduces many noise types; ferrite chokes and line filters suppress conducted noise; switch-mode supplies create carriers at regular intervals.

Official question groups in E4

• E4A: Test equipment: analog and digital instruments; spectrum analyzers; antenna analyzers; oscilloscopes; RF measurements
• E4B: Measurement technique and limitations: instrument accuracy and performance limitations; probes; techniques to minimize errors; measurement of Q; instrument calibration; S parameters; vector network analyzers; RF signals
• E4C: Receiver performance: phase noise, noise floor, image rejection, minimum detectable signal (MDS), increasing signal-to-noise ratio and dynamic range, noise figure, reciprocal mixing; selectivity; SDR non-linearity; use of attenuators at low frequencies
• E4D: Receiver performance characteristics: dynamic range; intermodulation and cross-modulation interference; third-order intercept; desensitization; preselector; sensitivity; link margin
• E4E: Noise and interference: external RF interference; electrical and computer noise; line noise; DSP filtering and noise reduction; common-mode current; surge protectors; single point ground panel

Practice E4 questionsSee all 63 E4 questions

E5: Electrical Principles 4 exam questions · 49 in pool

Key facts to know

• Resonant frequency f = 1 / (2π√(LC)). Series resonance gives minimum impedance (equal to R); parallel resonance gives maximum impedance and minimum input current.
• Q and bandwidth: half-power bandwidth = f / Q. Higher Q means narrower bandwidth and higher internal voltages. For a parallel circuit, Q = R / X.
• Time constant: one RC time constant charges a capacitor to 63.2 percent or discharges it to 36.8 percent.
• Phase: in a capacitor current leads voltage by 90 degrees; in an inductor voltage leads current. In a series RLC circuit, angle = arctan((XL - XC) / R).
• Notation: rectangular form puts resistance on the X axis and reactance on the Y axis (capacitive is -j); polar form uses magnitude and angle. Admittance is the inverse of impedance; susceptance (B) is its imaginary part.
• Real power is consumed only in resistance; reactive power is stored and returned. Skin effect raises resistance at RF, and short leads matter at VHF and above.

Official question groups in E5

• E5A: Resonance and Q: characteristics of resonant circuits; series and parallel resonance; definitions and effects of Q; half-power bandwidth
• E5B: Time constants and phase relationships: RL and RC time constants; phase angle in reactive circuits and components; admittance and susceptance
• E5C: Coordinate systems and phasors in electronics: rectangular coordinates; polar coordinates; phasors; logarithmic axes
• E5D: RF effects in components and circuits: skin effect; real and reactive power; electrical length of conductors

Practice E5 questionsSee all 49 E5 questions

E6: Circuit Components 6 exam questions · 68 in pool

Key facts to know

• Semiconductors: N-type has excess electrons, P-type has holes (from acceptor impurities). GaAs and GaN suit microwave frequencies. FETs have very high input impedance; a silicon BJT is on at about 0.6 to 0.7 V base-emitter.
• Diodes: Zener for constant voltage, Schottky for low forward drop and fast VHF/UHF mixing, varactor as a voltage-controlled capacitor, PIN for RF switching and attenuation.
• Logic: CMOS has the lowest power and switches at about half the supply voltage; tri-state outputs add a high-impedance state; comparators use hysteresis to avoid noise chatter.
• Crystals are piezoelectric and modeled as a series RLC with a parallel capacitance. Ferrite cores need fewer turns; powdered iron is more temperature stable; brass cores reduce inductance; toroids contain the field.
• MMICs typically have 50-ohm inputs and outputs, connect with microstrip, and get power through a resistor or choke on the output. Surface-mount parts have the least parasitic effects.
• Optoelectronics: optoisolators (LED plus phototransistor) isolate control circuits from AC lines; photoconductors drop in resistance under light; silicon solar cells give about 0.5 V.

Official question groups in E6

• E6A: Semiconductor materials and devices: semiconductor materials; bipolar junction transistors; operation and types of field-effect transistors
• E6B: Diodes
• E6C: Digital ICs: families of digital ICs; gates; programmable logic devices
• E6D: Inductors and piezoelectricity: permeability, core material and configuration; transformers; piezoelectric devices
• E6E: Semiconductor materials and packages for RF use
• E6F: Electro-optical technology: photoconductivity; photovoltaic devices; optical sensors and encoders; optically isolated switching

Practice E6 questionsSee all 68 E6 questions

E7: Practical Circuits 8 exam questions · 99 in pool

Key facts to know

• Digital: flip-flops are bistable and divide by 2 (four divide by 16); astable multivibrators free-run; monostables switch for a set time; know the NAND, OR and XNOR truth tables.
• Amplifiers: Class AB conducts 180 to 360 degrees; Class D and other switching amplifiers are efficient but need output filters; Class C distorts SSB. Know common-emitter bias (figure E7-1).
• Filters: Chebyshev has passband ripple and a sharp cutoff; elliptical adds stop-band notches; repeater duplexers use cavity filters; VHF/UHF radios often use helical filters.
• Power: linear regulators vary a pass element (figure E7-2); switchmode regulators vary duty cycle; a Zener provides the reference; series regulator dissipation = (Vin - Vout) x Iout.
• DSP and SDR: sample at least twice the highest frequency; 10 bits resolve 1 mV in 1 V; an FFT converts time to frequency; decimation needs an anti-alias filter; more FIR taps give a sharper filter.
• Op-amps have very high input and very low output impedance; inverting gain = -RF / R1 (figure E7-3). Oscillators: Colpitts (capacitive divider), Hartley, Pierce (crystal); PLLs and DDS synthesize frequencies.

Official question groups in E7

• E7A: Digital circuits: digital circuit principles and logic circuits; classes of logic elements; positive and negative logic; frequency dividers; truth tables
• E7B: Amplifiers: class of operation; vacuum tube and solid-state circuits; distortion and intermodulation; spurious and parasitic suppression; switching-type amplifiers
• E7C: Filters and matching networks: types of networks; types of filters; filter applications; filter characteristics; impedance matching
• E7D: Power supplies and voltage regulators; solar array charge controllers
• E7E: Modulation and demodulation: reactance, phase, and balanced modulators; detectors; mixers
• E7F: Software defined radio fundamentals: digital signal processing (DSP) filtering, modulation, and demodulation; analog-digital conversion; digital filters
• E7G: Operational amplifiers: characteristics and applications
• E7H: Oscillators and signal sources: types of oscillators; synthesizers and phase-locked loops; direct digital synthesizers; stabilizing thermal drift; microphonics; high-accuracy oscillators

Practice E7 questionsSee all 99 E7 questions

E8: Signals and Emissions 4 exam questions · 48 in pool

Key facts to know

• Fourier analysis shows a square wave is a sine wave plus odd harmonics. An n-bit ADC encodes 2ⁿ levels; dither reduces quantization noise; flash ADCs are fast enough for SDRs.
• FM modulation index = deviation / modulating frequency; deviation ratio = maximum deviation / highest modulating frequency (5 kHz / 3 kHz = 1.67).
• Multiplexing: OFDM uses many orthogonal subcarriers; FDM splits data by frequency; TDM shares time slots. QAM modulates two carriers 90 degrees apart, shown on a constellation diagram.
• Bandwidth: CW is about 4 x WPM; FT8 is about 50 Hz; FSK bandwidth = baud + 1.2 x shift. Baud equals symbol rate. A more efficient code raises data rate without more bandwidth.
• Codes: Gray code changes one bit at a time; Baudot uses 5 bits with letters/figures shifts; ASCII supports upper and lower case; parity detects some errors; ARQ requests retransmission.
• Spread spectrum: direct sequence shifts carrier phase with a fast bit stream; frequency hopping changes frequency pseudorandomly. Slow CW rise and fall times prevent key clicks; idle PSK IMD should be -30 dB or better.

Official question groups in E8

• E8A: Fourier analysis; RMS measurements; average RF power and peak envelope power (PEP); analog/digital conversion
• E8B: Modulation and demodulation: modulation methods; modulation index and deviation ratio; frequency- and time-division multiplexing; orthogonal frequency-division multiplexing (OFDM)
• E8C: Digital signals: digital communication modes; information rate vs. bandwidth; error correction; constellation diagrams
• E8D: Keying defects and overmodulation of digital signals; digital codes; spread spectrum

Practice E8 questionsSee all 48 E8 questions

E9: Antennas and Transmission Lines 8 exam questions · 93 in pool

Key facts to know

• ERP/EIRP: add antenna gain, subtract all losses in dB, then convert (150 W with a net +2.8 dB is about 286 W ERP). dBd = dBi - 2.15. Antenna efficiency = radiation resistance / total resistance.
• Patterns: read beamwidth, front-to-back and front-to-side ratios from plots (figures E9-1 and E9-2). The far field is where the pattern stops changing with distance. Method of Moments models wires as segments.
• Arrays: two verticals 1/2 wavelength apart fed in phase give a broadside figure-eight; 180 degrees out of phase give end-fire; 1/4 wavelength apart fed 90 degrees out of phase give a cardioid.
• Wire antennas: folded dipole about 300 ohms; Zepp is end-fed half-wave; extended double Zepp is 1.25 wavelengths; terminating a rhombic makes it unidirectional; seawater improves low-angle vertical radiation.
• Loading and matching: center loading is most efficient on short whips; loading narrows bandwidth; gamma, hairpin, stub and quarter-wave Q-section matches (100 to 50 ohms needs about 71 to 75 ohms).
• Transmission lines: velocity factor depends on the dielectric; a shorted 1/4-wave line looks open and a shorted 1/2-wave line looks shorted; Smith charts plot resistance circles and reactance arcs. Beverages and small loops are receiving and DF antennas.

Official question groups in E9

• E9A: Basic antenna parameters: radiation resistance, gain, beamwidth, efficiency; effective radiated power (ERP) and effective isotropic radiated power (EIRP)
• E9B: Antenna patterns and designs: azimuth and elevation patterns; gain as a function of pattern; antenna modeling
• E9C: Practical wire antennas; folded dipoles; phased arrays; effects of ground near antennas
• E9D: Yagi antennas; parabolic reflectors; feed point impedance and loading of electrically short antennas; antenna Q; RF grounding
• E9E: Impedance matching: matching antennas to feed lines; phasing lines; power dividers
• E9F: Transmission lines: characteristics of open and shorted feed lines; coax versus open wire; velocity factor; electrical length; coaxial cable dielectrics; microstrip
• E9G: The Smith chart
• E9H: Receiving antennas: radio direction finding (RDF) techniques; Beverage antennas; single- and multiple-turn loops

Practice E9 questionsSee all 93 E9 questions

E0: Safety 1 exam question · 12 in pool

Key facts to know

• RF exposure at a neighbor's home must stay below the uncontrolled (general population) MPE limits. Limits are most restrictive from 30 to 300 MHz.
• At shared sites, each transmitter producing 5 percent or more of its MPE limit where the total is exceeded shares responsibility. High-gain microwave antennas can create high exposure.
• SAR measures the rate at which the body absorbs RF energy. Separate E and H field limits apply below 300 MHz. An 80-meter station must always be evaluated.
• Tower safety: 100 percent tie-off means at least one lanyard attached at all times; attach lanyards to tower legs, and shock-absorbing lanyards above head level. Ground rods dissipate lightning charge.

Official question groups in E0

• E0A: Safety: RF radiation hazards; hazardous materials; grounding

Practice E0 questionsSee all 12 E0 questions

Formulas worth memorizing

Frequently asked questions