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Signals Intelligence Resources

Building your own Signals/Communications Intelligence(SIGINT/COMINT) capabilities is one of the cornerstone messages of this blog- trust me, you’re going to be doing a lot more listening, interception and analysis than you will be doing shooting.

Along the way, I’ve learned quite a bit about communications and communications intelligence, from a humble teenage beginning with a Radio Shack CB, K40 mag mount, and a RS Pro-96. Everyone starts somewhere.

Where to Begin

Listening is 2x more important than talking. Your first purchase should be a general purpose scanner. Poke around Radio Reference, searching your area code, to find out what type of modes local emergency services are running. If it’s digital, such as APCO/P25, you’ll need a digital scanner. Yes, they are kinda pricey. Poke around though, they can be found fairly affordably(~$200) if you look hard enough. Most of the models built in the past 10 years have a feature known as “close call”, which switches the receiver directly to the frequency transmitting closest to the scanner. This is a nice feature that definitely will come in handy. Don’t discount the older non-digital sets; they have plenty of uses for monitoring traffic other than emergency services, including the license free bands, Marine band VHF near water ways, and air traffic.

Have a Shortwave Receiver. Shortwave broadcasts sit sandwiched within the Amateur HF bands. They range from broadcasts from fringe elements to international news. If you didn’t already know, domestic US news is highly condensed and biased towards a marxist agenda, normally offering a “version” of events that are contrary to the facts. At the minimum, you’ll receive the other side of the story. The set pictured is the venerable GP-5, it receives both AM and SSB, the mode which most Amateur traffic is transmitted. The cost is about $80; you should have one. Have a look around HF Underground, a neat forum that logs Shortwave broadcasts, commercial, pirate, and numbers stations. These are clandestine broadcasts that send encrypted messages via OTP and are intriguing to listen to. For all of you that continuously refer to One Time Pads as the solution to every single crypto need, you’ll get an idea of how they’re done in the real world.

Getting more advanced- Field Worthy Kit

Invest in a Wideband Communications Receiver. These may seem redundant at first; they both scan and receive Shortwave traffic. Like any jack of all trades, they are a master of…well, a few. These are actually much more suitable to use in the field than either of the aforementioned devices. Sometimes referred to as bubba detectors, they’re great for monitoring common FRS/GMRS/MURS traffic used by the uneducated. Most on the market are fairly ruggedly built, and several higher-end HTs also include wideband receiver features, to varying degrees. Personally, I like having a separate device to listen with than communicate with.

The model pictured is an Alinco DJ-X11, which receives all modes including SSB, and has a hidden transmitter(“bug”) detector built in. Both AOR and Icom build compact models as well(AR-Mini and R5/6, respectively), that are both excellent values at around $160 new. The Alinco is around $320, but the addition of SSB reception means it can receive HF amateur traffic as well as Shortwave like the others can. I greatly value the ability of my gear to be as redundant as possible.

Other sets can serve this purpose adequately as well; the Yaesu 817 makes a decent enough receiver on its own. As I stated, I’m not a huge fan of putting all my eggs in one basket, but knowing that your equipment can wear many hats is always nice and becomes a force multiplier at otherwise inopportune times.

A portable Yagi Antenna.  Your signal collection team is not complete without one. Most folks use these to “beam” transmissions towards certain azimuths, and that’s a definite consideration for communications, but it also listens much better in the direction of which its pointed; giving a rough bearing on the direction of which a transmission is originating. 

This makes not only listening to bubba but finding out where bubba is much easier. Coupled with the directional communications capability, this is a piece of kit that a clandestine team should not leave the wire without. They’re also relatively simple to homebrew. On these notes, your individual kit is not complete without a compass; without the ability to get a decent bearing, you’re wasting your time. “Over yonder somewhere” ain’t gonna cut it in a formal intelligence report.

An all-weather notebook to write down what you hear and not have it get ruined if it gets wet. Without the means to copy what you hear, including call signs or other identification, type of traffic, type of voice or mode(male/female/CW/Digi, etc), and azimuth,you’re listening for nothing. Remember that this information will go into a detailed SALUTE report, and the more detail offered the better the results will be in the end. The more detail you can give to an analysis cell, the more effective your operations will be later on. Included in your notebook should be a simple band plan and detailed info on past positive ID’d signals; the ability to quickly identify signals, possible sources, and previous users will make life much easier on the interception end. In addition, information on antenna lengths and types should be included to help positive ID targets and their equipment. Again, the more details you can include, the better off the mission will be.

SIGINT/COMINT Teams in the Field

The Army’s Intelligence Units break down SIGINT guys into teams which collect signals known as Low Level Voice Intercept, or LLVI for short. This skill set is so important that Special Forces include what’s known as SOT-As, which like their LLVI cousins, collect signals intelligence in small teams on the ground, reporting their findings to an analysis cell. Both are typically composed of four men; two buddy teams switching off to keep continuous surveillance on a target. It’s boring and repetitive, but it’s critical, hence why it takes very disciplined soldiers to competently complete the tasks.

A clandestine setting, like an overt setting, postures a small team shadowing other elements for other purposes. Like cogs in a machine, they’re just one piece, but when they don’t function, the machine may not run. In addition, a lost or compromised signal team is a huge detriment; in addition to the lost time it takes to train, it also compromises your capabilities. Your men have to be among the best in your formation, bar none.

You should be doing this now-

Signals and interception training, unlike shooting or bushcrafting, can be done anytime, anywhere, and besides the cost of equipment, is free. It’s low profile, and likely no one is going to call the police if you’re doing it in public. The only way to get good at it is through practice.

You can keep hoping for miracles or begin making your own.

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