5XJ General Study Guide
Complete preparation for the FCC Amateur Radio General License Exam
Welcome to the 5XJ General Study Guide
About This Guide: This comprehensive study material covers all topics on the FCC General Class Amateur Radio License exam. The General license grants you access to the world-famous HF bands where you can communicate globally. With proper study using this guide, you can be well-prepared to pass the exam.
35
Questions on Exam
75%
Pass Score Required
10
Major Topic Areas
What is the General License?
The General Class license is the intermediate amateur radio license in the United States. It grants operating privileges on all HF (High Frequency) amateur bands, greatly expanding your ability to communicate over long distances and around the world. General licensees also gain additional VHF/UHF privileges.
Progression of Amateur Radio Licenses
| License Class | Frequency Access | Typical Range |
|---|---|---|
| Technician | VHF/UHF (50 MHz and above) | Local to Regional |
| General | HF bands (1.8 MHz to 30 MHz) + VHF/UHF | Worldwide |
| Amateur Extra | All amateur frequencies | Worldwide + Advanced modes |
Why Upgrade to General?
- Access to worldwide HF propagation
- Participate in international DX (distant) contacts
- Enhanced VHF/UHF privileges
- Access to more modes and frequencies
- Participate in major contests and events
- Emergency communications worldwide
General Exam Overview
Exam Details:
- 35 multiple-choice questions
- 75% pass score required (26-27 correct)
- Covers FCC rules, operating procedures, and technical knowledge
- Focus on HF band operation and global communication
- Prerequisite: Must hold a valid Technician license
Table of Contents
- FCC Rules for General License
- HF Bands & Frequencies
- Operating Procedures (General)
- Advanced Circuit Theory
- Modulation & Transmission Modes
- Advanced Radio Wave Propagation
- HF Antenna Systems
- Test Equipment & Measurements
- Advanced Safety Considerations
- Practice Questions & Answers
Continue to the next section to begin your study. You can navigate using the menu on the left.
1. FCC Rules for General License
General License Privileges Overview
General Class licensees have significantly expanded operating privileges compared to Technicians. You gain access to most HF bands and additional VHF/UHF allocations, opening the world to your amateur radio operations.
General License Restrictions and Rules
Station Identification
Critical Rule: Same as Technician - Identify every 10 minutes and at the end of each transmission using your FCC call sign. No exceptions.
Maximum Power Output
- General licensees: Up to 1500 watts PEP on most bands
- Some bands have lower limits (typically listed in regulations)
- Always use minimum power necessary for effective communication
General HF Band Privileges
CW-Only HF Bands
All frequencies in these bands (General class privileges):
- 160-meter band: 1.800-2.000 MHz (CW only for General)
- 80-meter band: 3.500-3.750 MHz (CW only for General)
- 40-meter band: 7.025-7.125 MHz (CW only for General)
- 15-meter band: 21.025-21.200 MHz (CW only for General)
Phone (Voice) HF Band Segments
General class phone privileges (subset of bands):
- 80-meter: 3.775-3.890 MHz (SSB)
- 40-meter: 7.150-7.300 MHz (SSB)
- 20-meter: 14.225-14.350 MHz (SSB)
- 17-meter: 18.110-18.168 MHz (SSB)
- 15-meter: 21.275-21.450 MHz (SSB)
- 12-meter: 24.930-24.990 MHz (SSB)
- 10-meter: 28.400-29.700 MHz (SSB/FM)
RTTY and Data Mode Privileges
General licensees have access to digital modes on most HF bands including:
- RTTY (Radioteletype)
- PSK31
- FT8 and other digital modes
- Packet radio on HF
Operating Rules for General
Transmitting on Frequencies
- Only transmit within authorized frequency ranges
- Respect subband designations (CW, data, phone segments)
- Avoid interference to other operators
- Do not transmit music or sound effects
- No encrypted messages except authorized (satellite)
Remote Operation
General licensees may operate remotely via internet if authorized by the FCC. This allows you to control your station from anywhere in the world.
License Term and Renewal
- Initial term: 10 years
- Renewal period: 10 years
- Grace period for renewal: 2 years
- Can renew online through FCC ULS system
Upgrading Your License
After passing the General exam, you can upgrade by passing the Amateur Extra class exam. Extra class operators have access to all amateur radio frequencies and modes.
2. HF Bands & Privileges
Understanding HF Bands
HF (High Frequency) bands span from 1.8 MHz to 30 MHz. These bands enable long-distance communication through ionospheric propagation. The lower the frequency, generally the longer the distance possible (especially at night).
The Nine HF Amateur Bands
160-Meter Band (1.8-2.0 MHz)
- Lowest amateur band
- Best in winter at night (very long distances)
- Difficult daytime propagation
- Narrow bandwidth due to spectrum allocation
- Requires large antennas
80-Meter Band (3.5-4.0 MHz)
- Most popular evening/night band
- Excellent for regional and intercontinental DX
- Night mode: 600+ mile range common
- Daytime: Highly variable
- High noise levels
40-Meter Band (7.0-7.3 MHz)
- Available day and night
- Excellent for both local and DX
- Very popular band - usually crowded
- Good seasonal variation for DX work
20-Meter Band (14.0-14.35 MHz)
- Most popular daytime band
- Worldwide communication possible
- Often open during daylight hours
- Good for contests and pile-ups
- Excellent for DX hunting
17-Meter Band (18.068-18.168 MHz)
- Less crowded than 20 meters
- Similar propagation to 20 meters
- Good for quiet operating
15-Meter Band (21.0-21.45 MHz)
- Excellent for daytime DX
- Disappears at sunset
- Very crowded during sunspot maxima
- Good for international contests
12-Meter Band (24.89-24.99 MHz)
- Narrow allocation
- Similar to 15 and 10 meters
- Relatively quiet
10-Meter Band (28.0-29.7 MHz)
- Requires high sunspot activity for DX
- FM repeaters available
- Fast, dynamic propagation
- Good for local and regional work
6-Meter Band (50.0-54.0 MHz)
- Primarily VHF (line-of-sight)
- Occasional long-distance openings via Es (sporadic E)
- Popular for weak-signal SSB work
General Calling Frequencies
| Band | CW Calling | Phone Calling | Mode |
|---|---|---|---|
| 80m | 3.510 MHz | 3.860 MHz | SSB |
| 40m | 7.030 MHz | 7.230 MHz | SSB |
| 20m | 14.030 MHz | 14.260 MHz | SSB |
| 15m | 21.030 MHz | 21.360 MHz | SSB |
| 10m | 28.030 MHz | 28.360 MHz | SSB |
Band Characteristics by Time of Day
| Time | Best Bands | Distance |
|---|---|---|
| Sunrise/Sunset | 40m, 20m | 500-2000 miles |
| Daytime | 20m, 15m, 10m | Worldwide possible |
| Night | 160m, 80m, 40m | 500+ miles |
3. Operating Procedures (General)
HF Operating Conventions
Operating on HF bands follows well-established procedures developed over decades of amateur radio use. Following these conventions ensures clear communication and a friendly operating environment.
HF Communication Modes
CW (Continuous Wave / Morse Code)
- Narrow bandwidth: ~100 Hz
- Excellent for weak signal work
- Most efficient mode for long-distance
- Requires learning Morse code
- Speed: 5-60+ WPM
SSB (Single Sideband Voice)
- Bandwidth: ~2.7 kHz
- Most popular HF phone mode
- Lower power requirements than AM
- Two types: LSB (lower frequencies) and USB (higher frequencies)
Digital Modes
- RTTY: Radioteletype (170 Hz shift)
- PSK31: Phase Shift Keying (31 baud)
- FT8: Fast response digital mode for weak signals
- JT65/JT9: Weak-signal digital modes
- Packet: AX.25 protocol
DX Operating
What is DX?
DX means "distant communication" - contacting stations in far-away locations, typically in different countries. DX hunting is a popular amateur radio pursuit.
DX Etiquette
- Listen before calling
- Keep calls brief (2-3 times only)
- Wait your turn in a pile-up
- Respond on the DX station's frequency
- Not all DX stations accept all countries
Pile-Up Procedure
A "pile-up" occurs when many stations call a rare or sought-after station:
- Listen to the DX station's frequency first
- Note their frequency and any specific instructions
- Call at precisely the right moment (between contacts)
- Use minimal power and keep call short
- Listen for your call sign
- Once they respond, complete QSO quickly
Net Operating
What is an Amateur Radio Net?
A net is a scheduled on-air meeting on a specific frequency where operators can:
- Share information
- Coordinate emergency communications
- Participate in traffic nets
- Join hobby-related discussions
Net Operating Rules
- Listen on frequency before the scheduled start
- Check in on schedule (brief)
- Wait for the net control station (NCS) to call on you
- Keep transmissions brief and organized
- Don't interrupt net control
SSB Voice Operating Tips
Proper Microphone Technique
- Speak at normal conversational level
- Keep mouth 2-3 inches from microphone
- Avoid plosive sounds (P, B)
- Don't shout or whisper
- Maintain steady mic gain
Audio Quality Standards
Poor audio quality is a major complaint on HF. Use proper equipment and settings:
- Adjust mic gain properly (not too high/low)
- Avoid overmodulation (distortion)
- Check speech processor settings
- Use appropriate bandwidth (2.7 kHz for SSB)
- Keep receiver audio clean
Signal Reports on HF
RST Report System
| R (Readability) | S (Signal Strength) | T (Tone) |
|---|---|---|
| 1 = Unreadable 2 = Barely readable 3 = Readable with difficulty 4 = Readable 5 = Perfectly readable |
1 = Faint 2 = Very weak 3 = Weak 4 = Fair 5 = Fairly good 6 = Good 7 = Very good 8 = Excellent 9 = Extremely strong |
1 = Extremely rough 2 = Very rough 3 = Rough 4 = Modulated rough 5 = Modulated 6 = Slightly rough 7 = Nearly perfect 8 = Perfect 9 = Perfect |
Examples of RST Reports
"Your signal is 5-9-9" = Perfect readability, extremely strong, perfect tone
"Your signal is 4-7-6" = Readable with excellent strength but slightly rough tone
"Your signal is 3-5-3" = Readable with difficulty, fair strength, rough tone (needs adjustment)
"Your signal is 4-7-6" = Readable with excellent strength but slightly rough tone
"Your signal is 3-5-3" = Readable with difficulty, fair strength, rough tone (needs adjustment)
4. Advanced Circuit Theory
Oscillators and Frequency Generation
Crystal Oscillators
A crystal oscillator uses a piezoelectric quartz crystal to generate a precise, stable frequency. This is the foundation of all modern radio frequency generation.
Common Crystal Oscillator Circuits
- Colpitts: Capacitive voltage divider feedback
- Hartley: Inductive voltage divider feedback
- Pierce: Simple single-stage crystal circuit
Frequency Stability Factors
- Temperature drift (PPM/°C)
- Load impedance variations
- Supply voltage stability
- Crystal aging over time
Impedance Matching and Transmission Lines
Smith Chart Introduction
The Smith Chart is a graphical tool for solving transmission line and impedance matching problems. It allows visualization of:
- Reflection coefficient
- Standing wave ratio (SWR)
- Impedance transformations
- Quarter-wave and half-wave matching
Transmission Line Loss
Different cable types and frequencies result in different attenuation:
| Cable Type | Loss at 50 MHz (per 100 ft) | Loss at 450 MHz (per 100 ft) |
|---|---|---|
| RG-58 | 1.4 dB | 6.0 dB |
| RG-8 | 0.7 dB | 2.0 dB |
| LMR-400 | 0.6 dB | 1.3 dB |
| Ladder Line | 0.1 dB | 0.2 dB |
Amplifier Design Basics
RF Power Amplifier Considerations
- Class A: Maximum efficiency ~50%, linear
- Class B: Maximum efficiency ~78%, push-pull required
- Class C: Maximum efficiency ~90%, nonlinear (CW only)
- Class AB: Efficiency ~55-70%, good compromise
- Class D/E: Switching amplifiers, very high efficiency
Intermodulation Distortion (IMD)
IMD occurs when multiple signals in an amplifier interact, creating unwanted products on new frequencies. This causes interference to other stations.
Filters in RF Circuits
Filter Response Types
| Filter Type | Rolloff | Ripple | Application |
|---|---|---|---|
| Butterworth | -20 dB/decade/order | None | General purpose |
| Chebyshev | Steeper than Butterworth | Passband ripple | Steep rolloff needed |
| Elliptic | Steepest | Both bands | Minimum components |
Receiver Architecture
Superheterodyne Receiver
The superheterodyne (superhet) design is used in almost all modern radio receivers. Signal flow:
- RF input → RF amplifier → Mixer
- Local oscillator mixed with RF signal
- Creates intermediate frequency (IF)
- IF amplified with high gain
- Detector recovers information
Image Frequency
The "image" is an unwanted frequency that will also mix to the IF frequency. Modern receivers use IF filters to reject images.
5. Modulation & Transmission Modes
Understanding Modulation
What is Modulation?
Modulation is the process of encoding information (audio, data) onto a radio wave carrier by varying one of its properties: amplitude, frequency, or phase.
Amplitude Modulation (AM)
AM Characteristics
- Information in amplitude variation
- Bandwidth: ~10 kHz
- Susceptible to amplitude noise
- Simple to generate and demodulate
- Not commonly used in amateur radio (replaced by SSB)
Single Sideband (SSB)
Why SSB Over AM?
- AM transmits both sidebands (redundant) → waste power
- SSB suppresses one sideband → saves power
- SSB bandwidth: ~2.7 kHz (vs 10 kHz AM)
- More efficient use of spectrum
- Requires more complex receiver (product detector)
LSB vs USB
- LSB (Lower Sideband): Used on 160m, 80m, 40m below 10 MHz
- USB (Upper Sideband): Used on frequencies above 10 MHz
Generating SSB
Two main methods:
- Filter Method: Generate AM, then filter out unwanted sideband
- Phasing Method: Use phase relationships between carriers
Frequency Modulation (FM)
FM Characteristics
- Information in frequency variation
- Bandwidth depends on deviation (typically 5-15 kHz)
- Better noise immunity than AM
- Used on 10m and 2m repeaters
- More complex transmitter/receiver than AM
Carson's Rule
Bandwidth = 2 × (deviation + highest modulation frequency)
For example: FM with ±5 kHz deviation and 3 kHz audio:
BW = 2 × (5 + 3) = 16 kHz
For example: FM with ±5 kHz deviation and 3 kHz audio:
BW = 2 × (5 + 3) = 16 kHz
Digital Transmission Modes
RTTY (Radioteletype)
- Uses frequency shift keying (FSK)
- Shift: 170 or 850 Hz
- Baudrate: 45-300 baud
- Can transmit text and images
- Requires TNC or sound card interface
PSK31 (Phase Shift Keying)
- 31.25 baud rate
- Extremely narrow bandwidth (~31 Hz)
- Very weak-signal capable
- Computer required
- Popular for keyboard-to-keyboard QSOs
FT8 (Fast Turnaround 8-FSK)
- Designed for weak signals
- Very fast exchanges (8-second transmissions)
- Automatic sending of messages
- Requires computer/sound interface
- Controversial but very effective
JT65 and JT9
- Designed by Joe Taylor (K1JT)
- Extremely weak-signal capable
- Longer transmission cycles (60 seconds)
- Great for moonbounce and meteor scatter
- Requires computer with WSJT-X software
Bandwidth and Legal Considerations
Bandwidth Rules
FCC rules specify maximum bandwidth for each mode:
- CW: 150 Hz (or determined by keying)
- SSB: 2.7 kHz
- FM: 5 kHz (narrowband), 16 kHz (wideband)
- RTTY: 1 kHz
- Digital: Depends on mode
Emission Designators
FCC uses three-character designators for emissions:
| Designator | Meaning |
|---|---|
| A1A | CW (Morse code) |
| J3E | SSB (phone) |
| F3E | FM (phone) |
| F1B | RTTY |
| J2B | PSK digital |
6. Advanced Radio Wave Propagation
The Ionosphere in Detail
Ionospheric Layers
D-Layer (60-90 km):
E-Layer (90-150 km):
F1-Layer (150-200 km):
F2-Layer (200-400 km):
- Absorbs radio waves, especially at lower frequencies
- Exists only during daylight
- More absorptive during solar flares
E-Layer (90-150 km):
- Main reflection layer for medium-distance propagation
- Sporadic E (Es) clouds enable long-distance VHF
- Most stable during daylight
F1-Layer (150-200 km):
- Exists only during daylight
- Combines with F2 at night
F2-Layer (200-400 km):
- Primary layer for HF long-distance communication
- Controls MUF (Maximum Usable Frequency)
- Varies with time of day, season, and solar activity
The Solar Cycle
11-Year Solar Cycle
The sun's activity varies in approximately 11-year cycles. More sunspots mean:
- Higher ionospheric electron density
- Higher MUF values
- Better propagation on higher frequencies (15m, 10m)
- Longer skips on HF bands
Solar Activity Indices
| Index | Meaning | Effect on Propagation |
|---|---|---|
| Sunspot Number | Count of sunspots on solar surface | Higher = better HF propagation |
| Solar Flux (SFI) | Radio emission from sun at 2.8 GHz | Higher = better HF conditions |
| A-Index | Overall planetary magnetic disturbance | Lower = better propagation |
| K-Index | Real-time geomagnetic activity | Lower = better propagation |
Geomagnetic Disturbances
Geomagnetic Storms
Solar flares and coronal mass ejections create geomagnetic storms:
- Increased A and K indices
- Sudden absorption of radio waves
- Auroral propagation at high latitudes
- Rapid changes in MUF
Practical Propagation Predictions
Gray Line Propagation
The "gray line" is the terminator (boundary between day and night). Unique propagation properties make it excellent for DX:
- Low D-layer absorption
- Better F2-layer reflection
- Sunrise and sunset times critical
Backsatter Propagation
Radio waves can propagate backward (toward the transmitter) via the F2 layer.
Multihop Propagation
Signals may bounce multiple times off the ionosphere for very long distances (thousands of miles).
Propagation Tools and Resources
Prediction Tools
- VOACAP: Voice of America Coverage Analysis Program
- HF Propagation Forecast: Solar Terrestrial Dispatch predictions
- Proppy: Online propagation prediction tool
- WWV: NIST radio broadcasts solar data every hour
7. HF Antenna Systems
HF Antenna Basics
Antenna Length Calculations for HF
Half-Wave Dipole (feet) = 468 ÷ Frequency (MHz)
Quarter-Wave Vertical (feet) = 234 ÷ Frequency (MHz)
Examples:
40-meter dipole = 468 ÷ 7.15 = 65 feet
80-meter dipole = 468 ÷ 3.65 = 128 feet
Quarter-Wave Vertical (feet) = 234 ÷ Frequency (MHz)
Examples:
40-meter dipole = 468 ÷ 7.15 = 65 feet
80-meter dipole = 468 ÷ 3.65 = 128 feet
Dipole Antennas
Basic Dipole Configuration
- Total length ≈ ½ wavelength
- Typically horizontal ("wire antenna")
- Fed at center
- Impedance: ~70 Ω (resistive)
- Radiation pattern: Omnidirectional (broadside)
Radiation Pattern
A horizontal dipole's radiation pattern (viewed from end) is "figure-8" shaped:
- Maximum radiation broadside (perpendicular to wire)
- Null along the wire axis
- No radiation directly above or below
Angle of Radiation
The elevation angle affects range:
- Low angle (2-15°): Long-distance DX
- High angle (30-60°): Regional contact
- Very high (80-90°): Local "skip zone"
Vertical Antennas
Quarter-Wave Vertical
- Length: ¼ wavelength
- Mounted vertically
- Requires ground plane (radials)
- Omnidirectional pattern (360°)
- Low angle radiation (good for DX)
Radial Systems
Verticals require a ground plane made of radials:
- Ideal: 120 full-length radials
- Good: 32 or more radials ¼ wavelength long
- Acceptable: 4 radials at 90° spacing
- Better ground plane = better performance
Yagi Antennas
Yagi Array for HF
- Directional antenna (high gain)
- Three elements: Reflector, Driven element, Director
- More elements = higher gain
- Typical 2-element Yagi gain: 5-6 dBd
- Requires rotor for directional control
Advantages and Disadvantages
Advantages:
- High gain (front-to-back rejection)
- Excellent for DX (focuses signal)
- Can switch beam direction
Disadvantages:
- Requires rotor and boom structure
- Wind loading and ice loading concerns
- Expensive installation
- Requires significant height/space
Resonance and Tuning
Antenna Resonance
An antenna is most efficient when operated at or near its resonant frequency. Impedance is purely resistive at resonance.
Bandwidth Concepts
- Bandwidth is frequency range where SWR < 2:1
- Lower frequencies have narrower bandwidth percentage
- 40-meter band: ~100-200 kHz useful bandwidth typical
- 20-meter band: ~50-100 kHz useful bandwidth typical
Antenna Tuners
Purpose of Antenna Tuner
An antenna tuner (or "transmatch") provides impedance matching:
- Matches antenna to transmitter (usually 50Ω)
- Reduces SWR on transmission line
- Allows single antenna on multiple bands
- Loss in tuner reduces effectiveness
Types of Tuners
- L-Network: Simple, uses inductor and capacitor
- T-Network: More complex, better matching range
- Pi-Network: Low-pass filter function, reduces harmonics
- Balanced Tuner: For ladder line feeders
Antenna Feeding
Feed Line Selection
| Type | Impedance | Best Use |
|---|---|---|
| 50Ω Coax (RG-8) | 50Ω | Standard for most stations |
| Ladder Line (open wire) | 300-600Ω | Multiband dipoles, low loss |
| Parallel Feeders | ~450Ω | Balanced feeders for balanced antennas |
Velocity Factor
Cables have velocity factor (VF) - speed of propagation relative to speed of light:
- Solid dielectric coax: ~0.66
- Foam dielectric coax: ~0.78
- Ladder line: ~0.95
Multi-Band Antenna Strategies
Single Wire For Multiple Bands
- End-fed wire can work on multiple bands
- SWR varies by band
- Requires tuner for good match on all bands
Trap Dipoles
Use LC traps (resonant circuits) to block current flow at higher frequencies:
- Single physical antenna works on multiple bands
- Trap loss reduces efficiency
- Popular for limited space
8. Test Equipment & Measurements
Essential Test Equipment
Multimeter
- Measures: DC/AC voltage, current, resistance
- Essential for all troubleshooting
- Choose range carefully (analog or digital)
SWR and Power Meter
Measures:
- Forward power (what you're transmitting)
- Reflected power (SWR indicator)
- SWR ratio directly
Frequency Counter
- Verifies transmit frequency accuracy
- Required if rig frequency is uncertain
- Can measure harmonics
RF Power Meter
- Measures actual RF power output
- Uses directional coupler or dummy load
- Important for verifying transmitter calibration
Dummy Load (RF Load)
- 50Ω non-reactive resistor
- Dissipates transmitter power safely
- Allows testing without radiating
- Must be rated for your power level
Spectrum Analyzer
- Shows frequency domain (amplitude vs frequency)
- Useful for measuring harmonic content
- Expensive but professional tool
Basic Measurements and Tests
SWR Measurement Procedure
- Connect SWR meter between transmitter and antenna
- Set meter to "FWD" (forward)
- Key transmitter (low power)
- Adjust SWR meter to full scale (Set)
- Switch to "REF" (reflected) to read SWR
- Try different frequencies to find lowest SWR
Power Output Measurement
- Connect dummy load to transmitter
- Attach power meter to dummy load port
- Transmit at desired frequency
- Note power reading
- Adjust transmitter output as needed
Receiver Measurements
Sensitivity Testing
Receiver sensitivity can be measured using:
- Signal generator with attenuator
- Measuring minimum signal for 10dB SNR
- Typical HF receiver: 0.5-2 μV for 10dB S/N
Receiver Selectivity
Tests the receiver's ability to reject adjacent channel signals.
Oscilloscope Usage
What an Oscilloscope Shows
- Voltage vs time (waveform display)
- Can show modulation patterns
- Useful for measuring frequency and amplitude
Common Oscilloscope Measurements
- Peak voltage
- Peak-to-peak voltage
- Frequency (from period)
- Phase relationships
- Modulation quality
Smith Chart Usage
Reading the Smith Chart
- Center represents 50Ω match
- Horizontal line = purely resistive
- Vertical lines = purely reactive
- Circumference = constant SWR circle
Practical Applications
- Finding impedance from SWR measurement
- Designing matching networks
- Visualizing transmission line behavior
- Quarter-wave and half-wave transformers
9. Advanced Safety Considerations
RF Radiation Exposure Limits (Detailed)
FCC Exposure Limits Table
| Frequency Range | Occupational/Controlled (mW/cm²) | General Population/Uncontrolled (mW/cm²) |
|---|---|---|
| 0.3-1 MHz | 100 | 100 |
| 1-30 MHz | 100 | 100 |
| 30-300 MHz | 50 | 10 |
| 300-1500 MHz | 50 | 10 |
| 1500-100,000 MHz | 50 | 10 |
RF Power Density Calculation
Power Density = Power (Watts) ÷ Area (cm²)
For a rough field estimate (near an antenna):
E² = (P × 3770) ÷ d² (E in V/m, P in Watts, d in feet)
For a rough field estimate (near an antenna):
E² = (P × 3770) ÷ d² (E in V/m, P in Watts, d in feet)
Antenna Safety
High Voltage Hazards
DANGER: HF antennas can develop high voltages (kilovolts) even with low power transmitters!
- High impedance mismatch creates high voltages
- End-fed antennas particularly dangerous
- Never touch antenna during transmission
- Towers and guy wires can be energized
Antenna Tower Safety
- Towers require proper engineering and installation
- Self-supporting towers typically require deeper footings
- Guyed towers need proper spacing and strength
- Regular inspection for rust and damage
- Lightning protection essential
Power Supply Safety (Advanced)
High-Voltage Power Supplies
Tube equipment and some amplifiers use kilovolt power supplies:
- Can kill instantly - treat as lethal
- Capacitors hold charge even when powered off
- Discharge through load resistor (never short)
- Use insulated tools only
- Never work alone on high voltage circuits
Measuring Voltage Safety
- Unplug equipment from AC
- Wait for any internal capacitors to discharge
- Ground yourself with wrist strap
- Use insulated probe on meter
- Measure voltage carefully
- Verify power is off before touching
Transmitter Interlock Systems
Purpose
Interlocks prevent RF transmission when someone might be exposed to harmful RF:
- Door interlock: Disables transmitter when cabinet open
- Cage interlock: Prevents transmission in antenna work area
- RF detection interlock: Senses high RF and disables
Grounding and Lightning Protection
Proper Grounding System
- All equipment grounded together
- Antenna mast bonded to ground
- Copper strap or #6 wire minimum
- Ground rod(s) 8+ feet into earth
- Multiple ground rods for large installations
Lightning Arrestor
A lightning arrestor on the antenna feed line protects equipment from direct lightning strikes:
- Installed as close to mast as possible
- Properly grounded to ground rod
- Multiple types: gap, tube, semiconductor
- Must handle full transmit power safely
Disconnection Switch
- Allows disconnecting antenna feedline
- Typical setup: Coax switch at entry point
- Allows grounding antenna to earth during storms
RF Burn Prevention
Common RF Burn Hazards
- Touching antenna during transmission
- Contact with high-impedance feeders
- Loose cable connections heating up
- End-fed antenna tuning
RF Burn First Aid
- Immediately disconnect RF source
- Cool burn area with cool (not cold) water
- Remove any tight clothing or jewelry
- Do not apply ice directly
- Seek medical attention for significant burns
- Cover with clean, dry cloth
Chemical Safety in the Station
Common Chemicals and Safety
- Battery acid: Neutralize with baking soda, seek medical help for contact
- Flux and solder fumes: Use ventilation, avoid breathing
- Cleaning solvents: Use in well-ventilated area, wear gloves
- RF shielding paint: Follow manufacturer's safety guidelines
Emergency Procedures
Station Emergency Plan
- Keep first aid kit accessible
- Know location of fire extinguisher (Class C for electrical)
- Have emergency contact numbers posted
- Never transmit during emergency unless authorized
- Emergency nets should follow established protocols
Practice Questions for General License Exam
This section contains representative practice questions covering all topics on the FCC General license exam. Study these carefully and review the explanations.
FCC Rules - General Class
1. What is the maximum transmit power for a General class licensee?
Answer: 1500 watts PEP
General class has the same maximum power as Technician: 1500 watts Peak Envelope Power on most authorized bands.
2. What is the primary advantage of General class license over Technician?
Answer: Access to HF bands for worldwide communication
The General class license grants access to HF bands (1.8-30 MHz) which enable long-distance worldwide communication through ionospheric propagation.
3. On what HF band do General class operators have phone privileges starting at 3.775 MHz?
Answer: 80-meter band
The 80-meter band spans 3.5-4.0 MHz, with General phone privileges from 3.775-3.890 MHz (SSB mode).
4. Which of the following frequencies is in the General CW portion of the 40-meter band?
Answer: 7.050 MHz
General CW privileges on 40 meters extend from 7.025-7.125 MHz. Phone privileges start at 7.150 MHz.
HF Propagation and Bands
5. During the day, which HF band would provide the best long-distance communication?
Answer: 20-meter band
The 20-meter band (14.0-14.35 MHz) is the most reliable daytime band for worldwide DX communication. It remains open during daylight and provides consistent long-distance propagation.
6. What is the primary cause of the "skip zone" in HF propagation?
Answer: Too short to use ground wave, too far for direct wave
The skip zone exists between the maximum ground wave range and where the skywave signal returns. Neither propagation mode works effectively in this area.
7. What does MUF stand for and what does it indicate?
Answer: Maximum Usable Frequency - highest frequency ionosphere will reflect
The MUF is the highest frequency that the ionosphere will reflect back to Earth at a particular time, location, and solar activity level.
Antenna Systems
8. Calculate the length of a half-wave dipole antenna for 14.150 MHz (20-meter band center).
Answer: Approximately 33 feet (33.1 feet)
Using the formula: 468 ÷ frequency (MHz) = 468 ÷ 14.15 = 33.08 feet. This is typical for a 20-meter dipole.
9. What is the primary advantage of a quarter-wave vertical antenna?
Answer: Omnidirectional pattern with low-angle radiation for DX
A vertical antenna radiates equally in all directions (360°) and with a low takeoff angle ideal for long-distance skywave propagation.
10. How many radials are recommended for a quarter-wave vertical antenna?
Answer: At least 32 radials, ideally 120
More radials provide a better ground plane and improved performance. Minimum acceptable is 4 radials, but performance improves significantly with more.
Circuits and Components
11. What is the primary advantage of SSB over AM transmission?
Answer: More efficient power usage and narrower bandwidth
SSB suppresses one sideband, saving power and reducing bandwidth from ~10 kHz (AM) to ~2.7 kHz, plus better spectrum efficiency.
12. What does Carson's Rule define?
Answer: The bandwidth of FM signal = 2 × (deviation + modulation frequency)
Carson's Rule calculates FM bandwidth. For ±5 kHz deviation and 3 kHz audio: BW = 2 × (5 + 3) = 16 kHz.
13. Which of these digital modes has the narrowest bandwidth?
Answer: PSK31 (~31 Hz)
PSK31 operates at 31.25 baud with extremely narrow bandwidth, making it excellent for weak-signal work. FT8 is also narrow but larger than PSK31.
Measurements and Equipment
14. What does an SWR meter measure?
Answer: Forward and reflected power, allowing calculation of SWR
The SWR meter compares forward and reflected power. SWR ratio = √(Fwd/Ref) or can be read directly from a calibrated meter.
15. What is the purpose of a dummy load in transmitter testing?
Answer: Safe dissipation of transmitter power without radiating signals
A dummy load (50Ω resistor) allows testing and tuning without broadcasting unintended signals. Essential for responsible RF operation.
Additional General Questions
16. Which HF band is best for night-time long-distance communication?
Answer: 80-meter band
The 80-meter band (3.5-4.0 MHz) provides excellent night-time propagation at longer distances. 40 meters is also good but 80m often better for DX.
17. What does LSB stand for and on which bands is it typically used?
Answer: Lower Sideband, used on 160m, 80m, 40m, and below 10 MHz
LSB is used on lower frequency HF bands. USB (Upper Sideband) is used above 10 MHz. This is a standardized convention.
18. Calculate the wavelength of a 7.150 MHz signal (40-meter phone).
Answer: Approximately 41.6 meters
Using: Wavelength (m) = 300 ÷ Frequency (MHz) = 300 ÷ 7.15 = 41.96 meters. This confirms the band is called "40-meter" band!
19. What is the characteristic impedance of standard coaxial cable used in amateur radio?
Answer: 50 ohms
Most amateur radio equipment is designed for 50-ohm coaxial cable. Matching impedances minimizes reflections and power loss.
20. What does FT8 stand for and what is its primary advantage?
Answer: Fast Turnaround 8-FSK, designed for weak-signal work with rapid exchanges
FT8 uses 8-FSK digital modulation with 8-second transmit/receive cycles, enabling quick DX contacts even with weak signals.
21. What is "gray line" propagation and when is it best?
Answer: Propagation along the sunrise/sunset terminator, excellent for DX
The gray line (boundary between day/night) provides unique propagation with low D-layer absorption and F2-layer reflection, making it ideal for long-distance DX.
22. What is an antenna tuner (transmatch) and when is it used?
Answer: Impedance matching device used when antenna impedance doesn't match transmitter (50Ω)
An antenna tuner provides impedance matching, reducing SWR and allowing single antennas to work on multiple bands effectively.
23. What is the frequency range for the General class CW portion of the 20-meter band?
Answer: 14.025-14.150 MHz
General class CW privileges on 20 meters are from 14.025-14.150 MHz. Phone privileges extend to 14.350 MHz.
24. What is the primary disadvantage of a Yagi antenna?
Answer: Requires tower/rotor, wind loading, expensive installation
While Yagis provide excellent gain and directivity for DX, they require substantial infrastructure, rotor, and maintenance.
25. What is an "A-index" and what does it indicate about propagation?
Answer: Overall planetary magnetic disturbance; lower is better for propagation
The A-index ranges 0-400. Lower values (0-30) indicate stable ionosphere and good propagation. Higher values indicate geomagnetic storms with poor conditions.