SIGINT for the Small Unit

SIGINT: SIGnals INTelligence

The ability to listen to what’s going on around you. It’s a crucial skill on a number of levels, and can answer a number of questions based upon what you hear, such as:

1. How close is my OPFOR?

2. Are they OPFOR?

3. What is their level of Experience?

4. Do they have a higher echelon they are communicating with?

Just like physical observation from a hide site, listening to radio chatter from the observation target can be quite telling. The questions listed are simply an example to formulate a baseline. You should create your own list based first on Who, What, Where, When, Why, and How.


Believe it or not, this can be done as expensively or frugally as you wish. A decent SUT SIGINT package can be as simple as one of these:


Pictured in order of expense is an AOR AR-mini wideband communications receiver($150ish), Radio Shack PRO-96($40 or so on the used market, I bought it new a long time ago), and everyone’s favorite chicom set, the UV-5R with extended battery($40 or so with large battery and longwhip antenna). Each of these can receive a large number of common signals that you’re likely to come across at the SUT level, and each can run on AA batteries. Naturally, the more cash you spend and work you put into it the better the results will be. The AOR is a great piece of kit but sadly discontinued; the Icom R5/6 is almost identical and carries a similar price. Both are rugged enough to survive most field conditions.

The old Radio Shack has served me well for a long time; I used it extensively in Afghanistan and wrote an article about it in the current edition of the Signal-3 newsletter ( Mine survived crawling up and down southern mountain ranges in that hostile land, so while not rugged by design it works when care is taken to protect it. They’re cheap these days and they work…mine’s beginning to show it’s age and has some issues with desensitization; but it’s still getting it done. And if it quits tomorrow it’s more than served it’s purpose.

The last device is the omni-present Baofeng UV-5R. I’m not going into the whole debate over it; there’s better radios out there for sure. It does however listen fairly well for fairly little money, even more so with a bit better of an antenna. One of the attributes of the 5R is the battery life, and with the extended battery it will last some time just monitoring. It pushes 4-5w(depending on specific model) out of a small form factor like most HTs these days; compare this capability to the PRC-77 or even the ASIP for those who’ve humped it. Your back will thank you. Disable the stupid flashlight; that feature will get your patrol compromised fast. Program it with all of the common frequencies in use in your area; license free, licensed, public safety, whatever…you should be actively listening now to determine what these are. It scans slow but it works; so you should really be formulating a short list of active frequencies in use now in your AO to work around the limitations of your equipment.

Searching for the Frequencies

In the rural South, almost every family owns a police scanner of some kind, and it’s always on. It’s cheap entertainment, a form of jungle telegraph for the latest gossip, and a quick report on the local severe weather threat when warnings are issued from the Sheriff’s Deputies out looking for current conditions. Prior to the digital upgrades of equipment, everyone knew the frequencies by heart as well. These days it’s not quite as simple.

There’s two methods for searching the bands- Band Search and Point Search. As the name implies, a Band search sweeps the entire spectrum of a given band, and the Point Search narrows it down to a handful of frequencies. Band Searches take a lot of time; it should be the first thing done when arriving in a new area and done a few times a week. With your handy dandy notebook you carry everywhere with you, write down everything that breaks squelch and any data you gather. This is your information from which you develop your Point Search. Think lantern vs. penlight here.

These searches should be done before your Patrol ever steps off. You must know as much about your AO as possible before you move out if you want to survive contact. Before you’re knee deep in the bush you should know who and what breaks squelch and on what frequencies. Knowing this, now you can do three things; listen to the OPFOR, limit the OPFOR’s communications capabilities(electronic warfare, or jamming) to create chaos, and most importantly, communicate by methods they cannot.

Build Your Capabilities; Never Stop.

The better you build your capabilities now the easier it will become later one. Do it now. Even the most expensive Communication Receiver I’ve listed is not going to break the bank; quit smoking or drinking beer for a couple weeks and you’ll easily be able to afford it. In addition, use your gear on a regular basis. There’s no reason not to. Cut off the TV and switch on the scanner along with your brain.