Prepper Communications 101
This document is about using Ham Radio and Multi-Use Radio Service (MURS – no license required) radio transceivers to communicate in voice on a routine basis. This is especially useful when infrastructure dependent communications using cell phones and internet –for example- have failed. This actually happens more often than people may realize and does not necessarily require physical destruction of infrastructure. Cell phone networks have engineered into them a ‘selective availability’ program so that when the phone system is overwhelmed, for example when too many people get on their cell phones during a disaster, ‘high level’ users are allowed access to the phone networks while everyone else is blocked, and at BEST, might have severely limited ability to use their cell phones. Text messaging via phone is more reliable, but can also be disabled for ‘regular’ phone users. My wife and I found ourselves in this situation after an earthquake which did no significant damage, yet the cell phone system was overwhelmed by all of those “Did YOU feel THAT?” calls.
Be sure to check out the Communications S.O.I. ‘Quick Reference for the Communicator’ by John Jacob Schmidt for your communications binders.
Imagine what would have happened if there HAD been significant damage to infrastructure. We take communication for granted, but there ARE times when the cell phones stop.
All radio communication is not equal. I find it best to think of radio communication for emergencies in three layers: Tactical, Local and Multi-State. There is some overlap between these layers, as you will see, but the radio tools that are best suited for each layer are different.
1. Tactical Communication
> Ham ‘2 meter’ Handi-Talkie (Technician license required)-
or non-ham MURS Handi-Talkie (no license required)
> Stock “rubber duck” antenna.
By “tactical” I mean close range (0-2 miles), voice, on-the-move, quick, conversational type of communication. An example would be you and a few friends are driving together as a group in separate cars to rendezvous at a campsite. You can rapidly exchange bits of conversation, road directions and etc. using Handi-Talkies (“H/T”) when everyone in the group is driving within a couple of miles of each other. Once you arrive, you can use your H/Ts to coordinate with each other on-scene. This type of radio communication can be blocked by hills or too many buildings. FRS radios are not the same as MURS, license free radios and FRS radios have a much shorter range.
2. Local Communication
> Ham 2 meter H/T or mobile transceiver. (Technician license required)
or non-ham MURS H/T (no license required)
> External, Magnetically Mounted Antenna
Local, Mobile – No Repeater: (0-10 miles)
Suppose that your group is from several towns in different areas of the county and you have others back in town with roof mounted antennas who want to keep in touch. To maintain communication while on-the-move, to you could still use H/Ts but with external magmount antennas on top of the vehicles and perhaps even mobile transceivers in place of the H/Ts so that you can put out more power: 25-50 Watts instead of the 1-5 Watts of an H/T. The most important part is the external, magmount antenna. Power does not do as much as most people think. A roof top magmount antenna, though inexpensive, will give you very good range in open country as compared to an inefficient “rubber duck” antenna that comes on H/Ts. An H/T hooked into the roof mounted ‘real’ antenna will give you seriously improved performance, a maximum range of 8 – 15 miles not being unusual, even without using a repeater.
Local, Mobile or “Base” – Using A Repeater
>Ham 2 meter H/T or mobile transvceiver (Technician license required)
> Using standard “rubber duck antenna” or external magmount antenna, or base station antenna.
By using a ham ‘repeater’, even in flat terrain, we can usually cover a circle on the ground 40 miles across. If you are lucky enough to live within range of a mountain top repeater, you can literally have a 100 mile range using an H/T or mobile 2 meter transceiver. The higher the repeater is above ground level, the greater the range. Local ham repeaters provide serious communications capability that is not dependent upon commercial infrastructure as long as the repeaters have power/generators running and have not been heavily damaged. Some repeaters have back-up power systems for just such contingencies, including automatic back-up generators and solar recharging systems. Unfortunately, MURS (no license required) repeaters are not allowed per FCC regulations, so you are not allowed to extend the range of your MURS H/T using a repeater.
Local, Household – No Repeater
> Ham ‘2 meter’ H/T or mobile transceiver.
>or non-ham MURS H/T
>using a base station antenna.
Often there is a desire to have independent local communication that the basic H/T cannot provide while using the standard rubber duck antenna. By using the same radio, but hooking it to a base station antenna, mounted HIGH and in the clear, you will GREATLY extend your communication range. In general, you will want to use an antenna that transmits well in all directions; these are called “omnidirectional” antennas. (To keep this introduction simple, I will not discuss directional “beam” antennas.) House-to-house, it is easy to communicate 20 miles or more over flat terrain if both stations have base station antennas 25 feet or higher, with a clear path between them.
3. Multi-State Communication by HF Radio
When you want to communicate outside of your local, county sized area, “HF radio” (aka: shortwave) is ideal. It can also fill-in gaps NOT covered by repeaters and tie together your State with surrounding States. All HF radio requires a license. Ham HF radios are generally a bit bigger than a shoe box and often much smaller.
HF Ham Radio Transceivers come in many sizes shapes and ‘flavors’.
Ham Radio Tranceivers generally must have a dry place to be set-up. Most are “transportable” ; not used while walking. They require about one hour or less to be set-up by trained personnel such as our volunteer ham radio operators. Some, like the tiny Morse code only transceiver (pictured on the right) can be set-up almost anywhere in a few minutes and easily carried on long range backpacking trips and can be heard internationally – because Morse code is SO efficient! Many AmRRON hams currently have the capability to operate HF radio from their homes, cars and to set-up a station remotely. These radios must be hooked to an outdoor antenna, which in an emergency can often be little more than a wire strung into a tree or other support. Capabilities to communicate using this equipment would include many of the 3.5 million ham radio operators world wide, or resources such as county and State Emergency Operations Centers (EOC) and support agencies such as The Red Cross or The Salvation Army Emergency Radio Network (SATERN) by voice and data. Power required is high current 12 volt DC, provided by a power supply plugged into A.C. mains, generator or even by connecting the radio transceiver directly a 12 volt car battery for short periods of operation. (a few hours) Some stations have solar recharging capabilities.
Though large & expensive ham stations certainly do exist, it is not necessary for this type of communication for reliable communication out to at least 1,000 miles. The largest “base station” type of equipment we are interested in can be operated from a car battery using emergency, improvised antennas made from common house wire from a hardware store, erected on the spot, by trained personnel if necessary. HF ham radio even has e-mail over radio, when set-up to use a computer with appropriate software.
Why Does HF Radio Have Such Long Range?
Remember the discussion above about HandiTalkies? They work on radio frequencies which operate only “line-of-sight”, meaning that much like a car headlight, they only go so far then the curvature of the Earth gets in the way of ‘seeing the light’. The same as if there were hills or buildings in the way. Suppose however, that you had a giant mirror in the sky that would reflect your light beam back to Earth many miles away; that is how HF radio works. There is a layer of the upper atmosphere that ‘refracts’ HF radio waves back to Earth – like a mirror. So, your radio signal might be as strong ten miles away as it is 500 or a thousand miles away. You have friends in high places!
NVIS (HF comms with surrounding States)
> Ham HF transceiver
> Horizontal antenna (usually wire)
This is the most useful form of HF radio propagation for preppers because it allows reliable communication within your entire region! NVIS stands for Near Vertical Incident Skywave. This method can be used with ANY HF radio. It is ideal for preppers within 350 miles of each other (approximate) and excellent in mountainous terrain because it allows you to reliably communicate with stations from 0 to approximately 350 miles away, is NOT blocked by mountains, gets down into valleys. Antennas are usually made of inexpensive house wire and hoisted anywhere between to head height up to 30 feet, with little difference in received signals.
In fact, scientific studies were quite successful, some with with only 10 watts of power from a battery powered HF radio using a wire antenna only 10 1/2 inches off of the ground. I recommend installing antennas at least one foot above head height for many reasons, safety being one of them. Frequency selection and a low horizontal antenna are key factors for success. Vertical antennas are a POOR choice for NVIS because they radiate almost zero energy straight UP, which is where it’s needed for NVIS. Generally daytime frequencies should be between 5-7.5 Mhz and night frequencies from 1.8 – 5.5 MHz.
Remember: NVIS needs low bands and low (horizontal) antennas to work.
Medium Range (HF Comms to ~1,000 miles)
> Ham HF transceiver
> Horizontal antenna (usually wire)
or Vertical antenna
While a low NVIS antenna will probably allow you to contact stations much farther than 350 miles away, buy using higher HF ham bands, you can increase your ability to reliable work long distance by using the same equipment, but the antenna height needs to change. By raising the antenna from 6 feet to say 50 feet, a MUCH stronger signal will be received a long distance, say from Denver to Seattle. As illustrated below: an antenna up only 20-30 feet will tend to favor medium distances of under 1,000 miles while an antenna up HIGH and in the clear will favor longer distances.
A Basic Scenario:
A hurricane has struck our area, disrupting commercial infrastructure including electrical power, phones and internet. Some citizens are no longer able to stay at home safely and have relocated to emergency shelters. The county must pass reports, including the number of refugees, their names, contact information for next of kin, medical information and any needs for external assistance. Due to damaged local infrastructure, these reports cannot be distributed using internet or phones. Fortunately, HF communication with support organizations outside of the impacted area is easy and ‘nearly normal’ by sending a standard e-mail to their normal address, but in place of the damaged internet, it is transmitted using ham radio “e-mail-over-radio” capability – no internet required. Voice communications with relief agencies, hundreds and even thousands of miles away can also be done using HF radio.
Summary: We have the capability to communicate in voice, data, Morse and e-mail over HF radio with other ham radio equipped AmRRON members during a grid-down situation.
For Tactical and Local communication voice is usually the first choice. Quick, easy and requires only the Technician class license and simple equipment for entry. Voice is not good for sending a record of complex instructions, lists, maps and etc. but hams have methods to hook computers into their radios which allow sending any data from computer to computer that you can presently send via Internet, including e-mail, attachments, files, pictures and more. We do this as a hobby, yet it’s a powerful tool for emergencies.
For State and Multi-State communication voice is used for rapid exchange of ideas and coordination in a conversational manner. For exchanging e-mail, attachments, pictures, illustrations, maps & more, email-over-over radio is superb and well within our present capabilities as are some of our ‘chatroom like’ computer data modes such as PSK-31.
>>> We Need More Radio Volunteers!