Radio Communication Basics

Overview

The lecture covers emergency radio communication options, radio frequency basics, legal considerations, equipment recommendations, and planning a practical radio communication strategy for disasters.

Radio Frequency Spectrum Basics

• The radio spectrum is divided into HF (high frequency), VHF (very high frequency), and UHF (ultra high frequency) bands.
• Lower frequencies (HF) allow longer distance communication, while higher frequencies (UHF) allow more data but shorter range.
• Common uses: FM radio (~100 MHz), aviation (120 MHz), WiFi (2.4 & 5.8 GHz), cell phones, and GPS.

Legal and Practical Radio Use

• Listening to radio transmissions is always legal; broadcasting has restrictions based on frequency band.
• FRS (Family Radio Service) and MURS (Multi-Use Radio Service) are license-free options in UHF and VHF for short-range use.
• CB radio operates on HF but with limited capability.
• Ham (amateur) radio requires a license and offers access to more frequencies and longer range.
• Itinerant business band frequencies are available for commercial use with a business license, allowing group use and encryption.

Radio Equipment Options

• Basic UHF-only radios (e.g., FRS) are cheap and suitable for short-range, low-power communication.
• Dual-band (VHF/UHF) analog radios (e.g., Baofeng) cover more frequencies but have limited privacy and range.
• Digital radios (e.g., DMR, D-STAR) offer improved range, error correction, and sometimes encryption (not allowed on ham bands).
• Mobile HF radios provide long-range communication but require more power, larger antennas, and technical skills.
• Software-defined radios and HF receivers are excellent for listening to a wide range of signals.

Radio Communication Planning

• Define your communication goals: local talk (tactical net), wider-area listening, emergency outreach.
• For short-range team communication, consider encrypted business band DMR radios.
• For wide-area and emergency listening, use multi-band or HF receivers.
• For long-distance contact, explore digital modes like JS8Call on HF bands.

Community and Coordination

• Build a trusted group for coordinated response and shared communication responsibilities.
• Research local EMS/EMA frequencies and foster connections for broader situational awareness.
• Collaborate with other local groups and amateur radio networks for disaster coordination.

Key Terms & Definitions

• HF (High Frequency) — 3–30 MHz band, enables long-range communication by bouncing off the ionosphere.
• VHF (Very High Frequency) — 30–300 MHz, used for FM radio, aviation, and some commercial and amateur uses.
• UHF (Ultra High Frequency) — 300 MHz–3 GHz, used for walkie-talkies, business radios, WiFi, and cell phones.
• FRS — License-free low-power UHF radio service for general public use.
• MURS — License-free VHF radio service providing better range than FRS.
• DMR — Digital Mobile Radio, offering efficient, encrypted communication (on business bands).
• Ham Radio — Amateur radio service, requires a license, allows for wide frequency and mode use.

Action Items / Next Steps

• Research JS8Call digital mode for long-range low-power text communication.
• Visit YouTube channels: Ham Radio Crash Course and OH8STN for further learning.
• Experiment with online software-defined radios (SDRs) like KiwiSDR.
• Identify and connect with local EMS/EMA groups and amateur radio organizations.
• Build and engage with your core, trusted communication group.