Many preppers turn to ham radio for grid down communications and for good reason. So long as you can generate power, you can create radio waves. There is no infrastructure to depend on although 2 meter and 70 cm repeaters may continue to work for a few days until their backup power systems run dry. The problem is privacy. Anybody with ham radio capability can listen in on your comms. Here are a few tricks and tips to make your comms a little more private. Keep in mind though that nothing is foolproof.
Low Power Operations –
Hams already know this. In fact it’s standard practice to use the lowest power possible to establish communications. Keeping a low power output means that your signal is not traveling huge distances. This is especially important for homestead or survival group communications. It would be great if you could set up a barrier that prevents radio signals from reaching outside of your desired area. That of course isn’t possible, but keeping radios on their lowest power setting can limit the distance.
Another trick is to wrap your hand around the antenna while transmitting. Keep in mind that we are talking about handheld radios here, DO NOT attempt this with 100 watts coming out of your HF rig!
Use Uncommon Bands –
Most preppers begin in ham radio with a typical dual band HT such as the Baofeng brand or less expensive HTs from Yaesu. These radios can be used to scan the frequencies and allow others to find and monitor your communications. However, there are HTs that are tri-band and also take advantage of the much lesser used 135cm band. Not a lot of preppers or even hams use this band or have equipment capable of using it, which limits the number of people able to intercept those signals.
Splitting Bands –
There are two ways of doing this with most common dual band HTs. If you are two people, the setup is simple. HT 1 will transmit on a VHF frequency and listen on a UHF frequency. HT 2 will do the opposite, transmitting on a UHF frequency and listening on a VHF frequency. Anyone listening on one band or another will only hear one side of the conversation.
If you are more than 2 people, you can assign a net controller. The net controller listens on one band (say VHF) and transmits on another (say UHF). Operators in the field program their radios to match those frequencies. Again, listeners will only get one side of the conversation. Just make sure that your net controller is aware of and working against the “broken telephone” phenomenon.
Rotating Frequency Sets –
Programming radios with a set of frequencies that are rotated on a regular basis is another technique that can confuse other who are trying to intercept your comms. Program 3, 4, 5 or more frequencies into memory and rotating them on a regular basis can be a great way to keep others in the dark. You can also make complex patterns in your frequency changes. Perhaps cycling through the odd channels then shifting to even channels or even more complex patterns. Make these changes happen at seemingly irregular intervals is another great idea. A code word inserted into a conversation could also be used to signal your group to change to the next frequency in rotation.
Regional Comms –
All of the above suggestions work great for local communications. But how can you go covert when trying to communicate with other groups or mags that aren’t close enough for the UHF and VHF bands?
Morse code is one way to do this. You can either learn the code and maintain proficiency through regular practice or use a laptop or tablet to convert typed text to code and send it out. HF bands are normally used for very long distances and with normal antennas, regional comms aren’t possible due to a skip zone. Try using an NVIS antenna, which sends the signal almost perfectly upward, which then gets bent back down to earth at a nearly vertical angle. A properly built NVIS antenna will allow for communications in the range of up to 200-300 miles and exclude the long distance signals. These radio wave are notoriously difficult to fox hunt as they appear to be coming from directly above.