AMATEUR RADIO EMCOMM BASICS
PLANNING TO COMMUNICATE
This paper is intended to teach hams how to plan to communicate in an emergency. This could be an individual ham, or EMCOMM group.
Most emergency communication events are LOCAL. What is LOCAL? Your city, county, & state. Keep this in mind. This alone may determine what antennas and frequencies you use. Does your local ham radio group have a communications plan with listed frequencies? That's a good place to start in emergency communications planning. Make sure you can communicate on those frequencies. How about your state plan? Can you communicate across your state on HF?
VHF / UHF Voice Communications:
You need to be able to communicate on every 2M or 70CM frequency in your county, and the counties adjacent to your county. Does this mean have everything programmed into your HT? Well, maybe. Your HT is a good tool, but limited on what it can do. You need a mobile rig, capable of 35 – 50 watts, with a good mobile antenna (for mobile) or good base antenna (for base). If a base antenna, it should not be the highest antenna on your farm. It should be placed to reduce the possibility of being hit by lightning.
HF Voice Communications:
You need to be able to communicate LOCALLY on HF. That means from the next county, to 500 miles away. Your wiz bang DX antennas are probably NOT going to work. They are designed for 500 miles or greater communications. So, what do you need for an antenna?
There is a concept called “NVIS” or “Near Vertical Incidence Skywave”. Basically, this refers to an antenna that radiates almost straight up. Huh? Yep. DX antennas radiate outward toward the horizon, and bounce signals far away off the ionosphere. NVIS antennas make use of very short hops off the ionosphere. What is an NVIS antenna? A dipole placed 0.1 – 0.25 wavelength off the ground. It can be a multi band dipole, such as a trapped or “fan” dipole. A 40 / 80M trap dipole will work well on 20, 40, and 80 meters (which happens to be where all emergency communications take place). A multi element “fan” dipole with legs for 20, 40, and 80 meters will also work. It can be built as a fan, or with the legs hanging under each other. You will need a “good” antenna tuner.
You can also increase the effectiveness of an NVIS dipole by placing a wire on the ground under the dipole. This makes it act more like a beam antenna, providing a reflector for the “driven” element, the dipole.
Why do emergency communications on HF happen on 20, 40, and 80 meters? Two reasons: propagation and established frequencies. Propagation on each of these bands serves different purposes. 80 meters works well for short range HF, say state wide. 40 meter works well region wide, say 4 or 5 states. 20 meter works well for longer range communications.
Does your local group have some type of digital communications system? Great. If you plan to utilize it, you have to do two things. Learn how to use it, then USE IT! If you go through training to use the system, then plan to wait until you need it to use it, then don't bother training. Seriously. You need to be fluent in digital communications to be an effective communicator.
There are a lot of hams that put down and berate WINLINK. WINLINK is a digital email communications system. Why do you need it? Say your internet at your home, or in your area goes down. Say cellphone networks go down. WINLINK utilizes Radio Message Servers across the US, Canada, and other countries. Simply put, you send an email formatted message using digital modes with your HF radio to a RMS station in another location where the internet is working, and your message sent via HF radio gets delivered via the email to it recipient. That recipient can also reply back to you, and you pick up the message via radio.
Here again, this is a system you will have to train on and use to be proficient enough to rely on it when you need it.
Sounds like you are going to have to spend a lot of money to do emergency communications. NOT SO! You can build HF antennas. You do not need to BUY them! A good fiberglass VHF / UHF antenna can be had for $50. Every digital communications system has FREE software. You might need to buy an interface for your radio, at no more cost that $125. You can build that if you wish.
Knowing the basics presented here should be the basis you use to set up your emergency communications system. However, knowing HOW TO COMMUNICATE will take training and practice. On the air operating is key to learning how to communicate. One thing to remember about communication... You have two ears and one mouth. You were designed to listen twice as much as you talk (at least). Keep that in mind... listen much, talk little.
Having a backup power source:
backup power source can be one or more of several things,
on your perceived need. If you live in an area where power
are frequent and extended, by all means, consider a generator.
for some, having a back up battery to power equipment may be all
need. Practice good safety in your installation. Look for sealed
batteries, and power supply / chargers designed to do what you
Install generators according to electric codes.