HAMnet LRN Toolkit - Learn the Basics

2023-11-13

NOTE: There are other communication options such as StarLink and satellite phones which we have not detailed as the sense is that in an SHTF scenario these options would likely not be functional.

Here are some videos that provide an overview of amateur (ham) radio:
Following is some basic info regarding the world of amateur (Ham) radio

General
  • the terms amateur radio and ham radio are interchangeable
  • licensed amateur radio operators are often called hams
  • amateur radio is defined as:

Radio Waves
  • Radio technology uses radio waves to propagate signals across distances.
  • Radio waves are part of the electromagnetic spectrum, which includes visible light, x-rays, gamma rays and microwaves.

Ham License
  • Generally speaking, you need a license to transmit on an amateur radio
    • However, you do not need a license to simply listen
    • The consequences of transmitting without a license, or the likelihood of getting caught, are not clear
    • Nonetheless, transmitting without a license is frowned upon by the ham community
    • The need for a license is suspended in a declared emergency
  • There are a couple of radio devices that do not require a license, namely:
    • Walkie-Talkies
    • CB Radios
    • These devices only work with each other, ie they cannot be used with each other.
    • However it is possible for amateur radios to be configured to listen in ??? on both Walkie-Talkies and CB Radio
  • There are a number of ways to get your license:
    • click here for more info on getting your license

Radio Types
  • There are basically 2 types of amateur radio based on the frequencies they use:
    • VHF and/or UHF radios (shorter range and relatively simple and inexpensive)
    • HF radios (longer range and more complicated and expensive)
  • Amateur radio configurations include:
    • handheld (HT for handheld transceiver)
    • mobile
    • base station
  • Amateur radios are also called transceivers as they can both transmit and receive radio signals as opposed to your standard radio (eg car radios) which can only receive.


Frequencies
Radio signals are measured in frequencies, usually denoted as Hertz (or Megahertz ie Mhz) or by the size of the radio wave, measured in meters.

In addition, the various frequencies assigned to the ham community are organized into 3 groups:
  • HF (High Frequency - sometimes called Shortwave - which is actually the lowest frequency range)
  • VHF (Very High Frequency)
  • UHF (Ultra High Frequency)

Here are the actual frequencies

HF Bands:
  • 160 meters (1.8 - 2.0 MHz)
  • 80 meters (3.5 - 4.0 MHz)
  • 40 meters (7.0 - 7.3 MHz)
  • 20 meters (14.0 - 14.35 MHz)
  • 15 meters (21.0 - 21.45 MHz)
  • 10 meters (28.0 - 29.7 MHz)

VHF and UHF Bands:
  • 6 meters (50 - 54 MHz)
  • 2 meters (144 - 148 MHz)
  • 70 centimeters (430 - 450 MHz)

HF Radios provide the broadest range as they can skip their signal off the ionosphere in order to get around the world. VHF/UHF Radios, which are usually less expensive, are for closer ranges.

CB
  • <info to come>

Walkie-Talkie
  • <info to come>

Handheld Radios
  • Handheld radios (HTs) are typically VHF and/or UHF.

Mobile Radios
  • <info to come>

Base Stations
  • <info to come>

VHF/UHF Radios

HF Radios
  • HF stands for High Frequency, which is actually a lower part of frequency than VHF and UHF
  • HF Radios are sometimes configured with VHF/UHF capability as well, often referred to as a 'shack in a box'.
  • HF is also sometimes referred to as Short Wave ???
  • The key considerations when determining which radio to get are as follows:
    • distance between parties
    • topography (line-of-site (LoS) vs non-line of site)
    • technical knowledge
    • budget
  • The key considerations when addressing distance and topography (ie range) are:
    • the bands (VHF/UHF vs HF)
    • the power of the radio (ie how many watts)
    • the configuration of the antenna
    • time of day and space weather
  • Range can be generally described as follows
    • Walkie-Talkies -  ??? kms
    • CB Radios -  ??? kms
    • Handheld Radios -  ??? kms
    • Mobile Radios
    • HF Radios (unlimited)

Shack in a Box

Power
  • All radios run on DC (direct current ie battery) power as opposed to AC (alternating current, which is what somes out of your electrical outlet)
  • HTs usually have a battery charger with a transformer which is then plugged into an AC electrical outlet
  • Mobile radios are usualy powered by the car battery, using the cigarette lighter socket
  • Base stations are usually run off a stand-alone car battery or a mobile power station such as the Jackery or EchoFlow, which can in turn be recharged using an electrical outlet, gasoline generators, solar panels or other sources of electricty
    • as amateur radios are often acquired for SHTF or grid-down situations, it is a good idea to have an independent source of power such as generators or solar panels to go along with your portable power station

Space Weather or EMPs
  • The effectiveness and range of a radio can be impacted by sun activity or EMPs (electromagentic pulses) which can be caused by a nuclear explosion
  • A key factor in longe range radio connections involves 'skipping' off the ionosphere:
    • The Ionosphere is part of Earth's upper atmosphere, between 80 and about 600 km where Extreme UltraViolet (EUV) and x-ray solar radiation ionizes the atoms and molecules thus creating a layer of electrons. the ionosphere is important because it reflects and modifies radio waves used for communication and navigation.
    • It is effected by space weather such as sunspots, flares and coronal mass ejections (CMEs) as well as cosmic radiation
  • In order to ensure that your radio will operate in these types of emergengy conditions, they should be protected by a faraday cage
    • click here for more information about faraday cages

Antennas
  • All radios require an antenna. The range achieved can usually be improved by upgrading the antenna
  • There are a number of antenna types:
    • fixed (as on Walkie-Talkies)
    • detachable (as on HTs – also called a Rubber Duckee)
    • vertical
    • dipole
    • end-fed
    • directional or yagi (looks like an old style TV antenna)
  • The last three types of antennas are primarily for use with HF radios and can be purchased or made from readily available materials. DIY antennas must be configured and tuned to achieve best results.

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