Group communication considerations, staying in touch.
Last time we wet our feet in the ocean that is group communications, we touched on different digital modes to consider along with communication methods to reduce your radio frequency footprint. Today, we are going to forget about the possibility of our transmissions being intercepted and focus on making
sure we are able to maintain radio communications in any environment.
Baofengs, or any other similar handheld 2 band radio, will give you the ability to stay in contact with a person or group within roughly 6 miles on flat terrain. If you start to add buildings, forest, or hills to your communication environment your range will decrease to as little as a mile.
Let's talk about solutions to the limitations of a 5 watt handheld radio. Our first option is one that has been around for decades in the ham radio community and that is the use of a repeater. A repeater is simply another radio that when someone transmits on its receive frequency it takes that transmission and re-transmits on its transmit frequency. Usually, these repeaters are placed on a mountain top, or an antenna tower in the middle of a town. The use of a repeater can double, or even further extend, the range of your handheld radio, it can also solve environmental obstacles like mountains, allowing people on both sides of a mountain to communicate. A repeater does not have to be an expensive radio setup; it can consist of two Baofeng radios properly setup in a waterproof Pelican box connected to an antenna at the top of a hill. With the use of a Pelican box enclosure and solar panels, a setup like this could run on its own for a year or two without service. This option gives you a mobile repeater setup that can stay mobile or to be placed in an area before it is needed.
Far away. Let’s say you have friends or family that lives far beyond 6 miles, or even 30 miles, where a repeater could still possibly be used. You need to make contact with this person or persons on a regular basis but you have no usable cell service, internet, etc. This is where high frequency radio comes into the picture. HF radio is a whole new can of worms, so let's just touch on the basics first. HF radio differs from VHF/UHF radios in many ways, specifically two of the main areas; frequency and modulations. Though many HF radios allow for the use of AM/FM modes for long distance contacts, they mainly use sidebands as opposed to frequency modulation like handheld radios. In my opinion, the biggest difference between a handheld VHF/UHF radio and an HF radio is the frequency on which it can transmit. The HF frequency is the golden ticket to communicating at long distances. HF frequencies depending on the solar weather and time of day are able to reflect off the ionosphere multiple times allowing your transmission to make its way around the world one bounce at a time. Just having an HF radio and a good antenna won’t immediately give you the ability to reach anyone anywhere. There are many different factors that influence how far your signal is going to make it. The first is the sun; the solar activity will determine which HF frequency will reach the furthest. The time of day also plays a part as well, as if it is night when you are transmitting, you will be more likely to need to use lower frequencies like 7Mhz or 3.5Mhz. During the day, frequencies like 14Mhz or 28Mhz may get you the furthest reach. So now, let’s say you and a friend you need to reach both have your HF radios setup. Just calling their name into the microphone will probably not yield any useful results. Like with regular comms, you should always have a plan. Make sure you have a few frequencies you plan on making contact with planned out along with a schedule. An example would be at 16:00, I will transmit on 14.235.00 Mhz. If that frequency is in use, we will move to 14.244.50 Mhz at 16:05. Further, if this does not work, we will move to 7.141.00 Mhz at 16:10. Always ensure you have times and frequencies chosen far before communication is necessary. This will save a lot of time and headache while searching for someone in the sea of radio signals out there.
I would also highly recommend the comms person of your group earn, or at least study for, their ham radio technician class license, and their general class license, if possible. Having the knowledge required for a ham radio license will enable you to make your own antenna, understand how to navigate radios, and troubleshoot problems that may arise.
Lastly, now that you have an idea of what is possible with HF radio, let me add to that list. With HF radio, you can send emails or text-like chat using your computer and radio. You can send pictures using slow scan television modes, you can even listen in on pirate radio stations around 6.900.00 Mhz. In whatever you do that isn’t life or death dependent, remember to have a little fun.
Abbreviations and other term definitions.
Baofeng - A cheap but reliable Chinese handheld VHF/UHF radio
VHF - or Very High Frequency - is a classification of radio frequency, to most people it can be remembered as the 2 meter band or 144-148 Mhz frequencies used on a Baofeng or similar handheld radio
UHF - or Ultra High Frequency - also refers to the classification of radio frequencies, in this case anything above 300 Mhz, to most people you can remember it as the 420-450 Mhz radio spectrum on many handheld radios
HF- or High Frequency - a term used to encompass frequencies within 1.8-28 Mhz also the frequencies that are able to skip off of the ionosphere in the right conditions
AM - or Amplitude Modulation - an older mode still that still in use on CB [Citizen Band // "Trucker"] radios
FM - or Frequency Modulation - the mode used by most non-digital handheld radios
Author: E. Turner