Articles on SHTF communications often dive right into super expensive systems allowing communication across the country – or the world. In my own personal efforts, I have been working on trying to set up a system for what I would refer to as a “local” communications network for my group. Ideally, we are talking 20 miles and less.
Many may hear this goal and consider it meager – “Hey – just connect to a Ham repeater.” While using a Ham repeater will allow 20 miles and much more I am looking for reliable independent communications. Efforts have been very frustrating and really not for this article. I have had some very good success lately and the retreat is currently set up for upwards of 10+ miles with no repeater. This is excellent for patrolling and inbound members. Longer range is just a matter of time.
The purpose of this article is to consider the perspective – in a world filled with cell phones, texting, Facetime, and other means of instant communication – if it disappeared today could you stay in touch with those heading up the street to check on a neighbor? That trip to the store or up the road to see Billy that used to be considered routine and no big deal post-SHTF might not be quite the same.
Although AM/FM and shortwave radios can bring in news and provide valuable information – they are both one-way communication methods which offer limitations.
Assuming that some form of SHTF situation has occurred – why would person to person communications be important?
- Assist in finding missing persons and pets.
- Announce rising flood waters to others in the area.
- Communicate direction of brush fires.
- Communicate with others in a hunting party.
- Perimeter patrols.
- Tactical operations and movements.
- Save time and energy to be able to relay information over distance rather than drive or walk to those you are wanting to communicate with.
- Warn of impending danger.
- Communicate observations of people moving through an area.
- Call of help or assistance while someone is not at home.
The list could go on and on.
Some considerations regarding a local communications network include equipping the home with some form of base station, vehicles with mobile units, and people with handheld transceivers(HT). Ideally, all could communicate with each other when within the boundaries of the local network area, however, that is not always possible when independent of any repeating system.
The exact components I have used and have had success with will come in a later article. Again the point of this article is to get you thinking. How far are you needing(not wanting) to communicate? This is an important question to answer before setting up your system. Know that generally the longer you want to be able to transmit and receive the more expensive it is.
Rourke
Easy calculation to see how far your signal will go: Height in feet of your antenna above the ground divided by .5736 =X, square root of X = distance to the horizon. For a person standing, that works out to about three miles. You don’t need your signal to get to the other radio, you need for your signal to meet another signal, Two team members could then talk at about six miles. You do get a little bend at the horizon, but not much. So it’s easy to see that if you can get your base antenna up high, you dramatically extend your range, even just using an inexpensive hand held radio. Use a fishing rod to toss a line over a tree, use the line to raise a very inexpensive J-pole antenna for 2 meters and 70 centimeters. Coax to your radio and your talking.
The calculation is easy- but having success has not been. The correct combination of antenna’s, correct mounting, antenna height, and power has led to good results. Getting to that point has been an effort in trial and error – with a lot more error. I’ve used antenna’s that were crap. Radio’s that worked well – and some that didn’t. Cables that were crap – and cables that worked well.
Hi I am a Amateur Radio Operator licensed for about 20 years. Not sure what you are using to operate. Some areas that are flat are easy to do 20 miles on VHF. Hand Held Radios are going to be a problem as you get further out. Directional Antennas will help. The Key to VHF is Height. I have talked 100 + miles with another operator with a 100 ft Tower and they had directional antennas or as we call them beams Antennas. They can be massive and you will need to be able to rotate. If your trying this with UHF it may be more difficult. But there may always be a few dead areas. I can think of one VHF dead Zone that for some reason. I cannot receive as I pass through the area regardless of which repeater I might operate. Height is the Key and you will most likely not get 100 percent coverage.
I have been working on what I call local communications for our group, like Natham stated 20 miles may be a problem with hand held but there are ways to increase the distance from someone in the field, a wire j pole pulled up as high as possible in a tree a bow arrow can be use to lunch a small strong line to pull up the j pole and coax. there are dead zones for a mobile unit but height should take care of that have that problem with my car but the pickup same area not so much.
I have a 70 ft tower with two 10 element beams co phase together on a 12 foot mask + an 2 meter /70 cm vertical at about 60 ft, I can reach most repeater with in my state with the vertical , base to similar base 100 miles no problem with the beams, have not been able top test further
Check out an All Band transceiver (UHF/VHF/HF) for the base/mobile units. Like commented on above, a good base setup with decent antenna height for the UHF/VHF will provide good coverage for personnel out and about (patrolling) using HT’s, while the HF (40-80 Meter bands) combined with a good NVIS antenna setup (G5RV in an Inverted “V”) will give you excellent coverage and reliability out to 200 miles. This would all but ensure anyone in a vehicle or packing a small portable HF in a pack outside of VHF range would have direct comms with the base. Just ensure you have a good battery back-up system, preferably connected to solar power to keep them charged.
If you have sight of the person you want to communicate with, even if they’re miles away on a hill or mountain or tall building, you could signal them visually using Morse Code. If you don’t have hours to spend to learn Morse Code, there’s an easier (but slower) code called Tap Code, which you can learn in a minutes or two, as many soldiers have. You can send messages by flashing a mirror or piece of glass or even aluminum foil to reflect sunlight to someone in the distance, even miles away as long as they can see the flashes. Or flash a light at night. Or tap on a wall or even blink, any countable signals. To send the letter of a word, first tap (or flash) through the letters A F L Q V, stopping at the one which is before the letter you want to send (or the same as it), then pause, then tap through the alphabet from that point. For example, to send the word “HELP”, you tap twice (A F), pause, tap three times (F G H) and the receiver writes down the H. Then you tap once (A), pause, then tap five times ( A B C D E) and he writes down the E. Then you tap three times (A F L), pause, and tap once (L) and he writes down the L. Finally you tap three times (A F L), pause, and tap five times (L M N O P) and he writes down the P. You can use X for a period and Q for a question mark. Use the letter C instead of K: asc. If you make a mistake and need to start a word over, tap eight times. Sometimes people have even blinked secret messages in Tap Code!
Appreciate your sharing DC. I had not heard of that method of communication before. Interesting!!