SIGINT and the Guerrilla Radio


My note: I originally wrote this article for Spark31’s Signal-3, appearing in the SEP-OCT 2015 edition. I don’t know if it’s still in operation(?), but the ‘newsletter’ had some decent info while it ran it’s course. In any case, the authoring of this article led to the creation of this blog. The ‘video’ referenced in the opening paragraph is in reference to an Army presser vid from Afghanistan, where a couple of trigger pullers are running an AOR AR-8200 with a doppler antenna. While not as sophisticated, my own experience in Afghanistan using my personal and rather rudimentary equipment are contained here. Certain parts have been redacted by myself for PERSEC/OPSEC reasons, and additional notes have been added for emphasis.

A video was posted along along with a question to the [REDACTED] group in regards to an antenna array a soldier was using in Afghanistan. In short, it’s a [LLVI] SIGINT DF array hooked up to a scanner [AOR AR8200], to both capture enemy transmissions and DF them, so that troops on the ground can get an idea where the chatter is coming from. If they’re using this now, they’ll use it when things go kinetic at home.

The Taliban had a rather rudimentary but effective  communications system, anywhere from clapping pigeons, flashing lights in a sort of morse code between villages at night, to a VHF repeater system not unlike any standard domestic 2M repeater along the ridgelines. One of our missions was intercepting and dismantling this electronic network, which provided numerous challenges. Our AOR (area of responsibility) [REDACTED] was mostly open terrain interrupted by several mountain ranges which the Taliban relied upon for safety. At this point they knew ISAF SOF and conventional forces would attack in one of two ways- from vehicles or by air, both of which announce their presence long before they arrive on the objective. The last thing they expected was a small team roaming the mountains, and our tactics proved effective. Aside from the occasional tag-along SIGINT guys with dedicated equipment for those missions [NOTE: the SIGINT set referenced is roughly the same size as a standard SINGARS set, or Icom 7200 for those unfamiliar with military radios, along with a large sense antenna. The whole set together, with batteries to supply it for five to seven day’s mission, weighed over 60lb. That’s without water, calories, or any other team equipment. PT is pretty damn important, as is figuring out how to minimize load.] I carried my own receiver for a simpler purpose. Included in my own equipment was an old Radio Shack PRO-96, not to DF but rather to know when chatter happened or not, and use our  best judgement from that point, handing it off to the terp given the chance we had one with us (due to the nature of our mission set, we rarely did unless conducting a joint mission with [REDACTED]).

One particular point to note here is that the Taliban had very little radio discipline. They broke squelch everytime they saw anything and everything, and explained exactly what they saw (or thought they saw) over the net. We heard it all, and figured out their network based not always on what they were saying but when they were saying it. Due to this, we knew and worked off of what we gathered in the field [on the fly], often with my simple analog scanner. I’ll state that even though we gathered what we needed, it was largely ignored by the big Army battlespace owners. In short, the repeaters mostly remained.Maybe there was a larger plan at work. Who knows, it was outside my lane. But from the Taliban angle, a simple SALUTE/SALT report format and rotating net schedule could have done them wonders, even with their simple, analog, unencrypted system of chicom knock-off HTs.

Enough of the story…what does all this mean? If we used it then, potential OPFOR will definitely use it in the future. Careful observation goes a long way [for] everything your opponent does. I listened simply for increased chatter, to either make to either make our element aware that our presence was now known or at the halt scan for patterns in their communications. All the standard Vietnam-era LRP commo rules apply when conducting transmissions on the small unit level (brief transmissions, ever changing callsigns, creating team internal codespeak, etc) and is much more important than that shiny new rifle in the flavor of the month caliber. This works both ways. It’s not always what they’re saying but when and how long or frequently they break squelch. The name of the game is innovation. Conventional military leaders rarely think outside the dimensions of their equipment. As an occupying force becomes complacent, they rely upon the same methods over and over. If they follow a signal to it’s source, there’s a potential strategy. Waste no opportunity, and ignore nothing. The same patterning rule applies to FREEFOR…understand not to set a pattern, unless deliberate, and always follow PACE. Think outside the box, and stay frosty.

So the takeaways are that even with little discipline and unsophisticated kit, successful communications can be achieved, as well as Communications Intelligence with very, very simple equipment. That being said, someone is ALWAYS listening. With discipline, better gear, and improved knowledge (all goals emphasized by this blog) your network can and will be quite effective. The Taliban seemed to have little care that we were listening and re3acting to patterns they set, even when it often resulted in their ambush. They really are that ignorant, in more ways than one. Hopefully you’re not, but in the year since I wrote this, some in the “Liberty” movement give me serious pause to wonder. 

Seriously. But that’s another topic.

35 thoughts on “SIGINT and the Guerrilla Radio

  1. PSYOP

    once again, spot on analysis and simple reaffirmation of knowing ones kit, strengths and limitations….This is why one must regularly use/practice with their gear, in ideal conditions, and less than ideal conditions, such as weekend ftx’s, field days, or simple camping trips with the goal of being able to communicate and listen, off grid…

    Simply going out to (insert vendor/website/hamfest) and buying that shiny thing, and then placing it on the self, for when “it hits the fan,” and then somehow being able to automagically get set up is NOT going to happen for the vast majority of folks…there is a reason that the “communicate” piece is part of the “shoot, move…”

    Spending the money on good kit, augmenting with “disposable/loanable” kit, and more importantly actually using ones gear is paramount. It is better to have fewer good quality components and knowing how to use it, than having a bunch of lesser quality gear, just sitting there…

    I routinely scan for signals as i drive the region going from one IT gig to the next…I use two different uniden scanners, a plain analog bubba scanner and a portable trunk/digi unit….

    Add in an SDR platform, decent antenna, and one can have a nifty little home based, or mobile commo center….

    The one big takeaway from you, S31, DM76 and several others, is that RX truly is 2x more important than TX….

    After all, i really don’t think i’ll be talking to the left coast, Canada or even NYC, but will certainly want to listen in on my local/regional stuff and reach out to local/regional folks….

    That is my focus, local, local, local or my grid square, as a buddy of mine opined…

    Keep up the good work….

    1. s6cnrdude

      Great info NCSCOUT. Also, testing and using your equipment in a field environment is critical as mentioned above (remember RaDAR a couple of weeks ago?). QRP is the way to go. You may or may not be able to talk to stations in your regional area due to band conditions.

      Or even more sinister, I heard a report that the “coup” has shut down certain commercial stations and amateur stations in Turkey (that was reported on ARRL’s news line). I do not know what the current status is there as there were conflicting reports. Don’t think that can’t happen here. Again, think low profile QRP.

      Don’t assume you will be able to sit at home and operate your 100w rig with a huge beam on commercial power.

      1. everlastingphelps

        Their licenses have been suspended. That doesn’t mean that they are off the air. Even if the government came and confiscated all the transmitters, there are hams that can build another out of discrete components and scrap.

        Can’t stop the signal.

      2. Nope! You sure can’t stop that signal. Not when one has the skill. You can never take that away.

        Skills, and caches to support those skills.

  2. Another great article NCSCOUT. Radio discipline along with a Moxon antenna, as you wrote about on June 13, 2016 titled “DYI Moxon Antenna’s and LPI” is the name of the game. Because of your article I built a Moxon antenna last week for the 2 Meter band. (Go to the short article I wrote and pic’s at's/new/#new)

    With the Moxon antenna I was able to “ping” a repeater 30 miles away with my BaoFeng handheld radio putting out 5W of power.

    One night I played with trying to raise other hams by redirecting the antenna. I was able to pick up another ham ~100 miles away in Albany, NY. We chatted for a few minutes until he dropped off.

    One question I have that you or another reader might be able to answer is:

    For OPSEC purposes, could you record a message using a book code format (Page/Paragraph/Word) and send the stream of numbers at high speed, at a designated time, using the aforementioned Moxon antenna. The receiving party would record the message and then slow down the recording to decipher the message. This sounds time consuming however, it seems that it would be tough to DF the sending radio and of course they would not be able to decipher the message without the code book.


    1. You absolutely can, by a number of means.

      I say that with the caveat “no crypto on the Ham bands by law…”

      You can practice all you want on the license free bands though.

  3. everlastingphelps

    The one big takeaway from you, S31, DM76 and several others, is that RX truly is 2x more important than TX….

    I would say it is 2x for conventional forces, but 50x for asymmetrical warfare.

  4. mtnforge

    I have a question based on an observation.
    Can’t really say what was the intent of what I observed, but it sure was interesting and gave me pause to think of the possibilities, and it might be pertinent to the discussion here.
    I was working night shift on a mountain top mine, 4000ft elv, western spine of the Monogahela Mountains in WV. The view is unlimited up where we where working. Happened 2 years past on 3 nights of the new moon, stars are spectacular up there.
    I’m always looking up every chance I can spare, it’s just beautiful.
    Anyways, about 11:30pm, I look up and I see something I’m just blown away, an absolute perfect plan form sillouhette of a Predator Drone going over head. It looks like it is at most a dew hundred foot above where I’m standing. I say to a fellow miner I’m working with, look at that! And what was interesting, no engine noise except for a tiny but of turbine whine. We watch it till its too small to see. Wich was so easy cause the stars are so bright and so many, the drone is plain as day to see. We are always getting a birds eye view of various F15’s, A10’s, C-130’s and Hornets zooming over and around the ridge lines. So I’m hoping something else will fly over. About 20 minutes go by and here comes another drone, but its offset from it’s last pass by around a few hundred yards, this time somebody is on the CB, which all trucks and equipment in coal mining have. It’s quiet, we are on the far end of the strip, working on a wiggle wagon, theres about a dozen pieces of equipment sting near us and some of the CB’s are on. We hear the guys across the hollow working on a rib of coal talking about seeing this drone. (Turns out all night, for three nights, these drones, or only one, is making a grid pattern flyover over the ridge up there). I tell my wife the next mourning after seeing it, she says she saw it too when she went out for a smoke. We live at 3000 ft, lower end of the same general ridge line. I did a sat map estimate in straight-line from the house to the mine, it’s 34 miles.
    I’m thinking whats these drones doing up there? At night? Right? Up to gathering some kind of data if their doing a grid pattern for sure. Well the hillbilly grapevine around these parts is fast as grease lightning. Soon other miners are talking about seeing drones flying grid patterns over the mountain top mines. Talking mines separated by 50-60 miles. Another thing too. Working Hoot Owl you see all sorts of stuff at night up in these ridges and hollows. Wolves, Wild Cats, Boar’s. And two legged critters, in particular, two legged critters in brandy new blacked out crew cab Chevy’s and Suburban’s, traveling in caravan, 3-6 vehicles, nose to tail, going down these one lane dirt goat paths to nowhere, like 3 or 4am?
    This is what I’m thinking. The drones are mapping the electromagnetic spectrum. They are cataloguing what’s out there now so later they can reference a baseline map to see what out there in the future.
    The convoys are looking for water sources. I say that because up on this series of ridges are lines of hydraulic springs and spring fed ponds. The mountain top farms all shares these spring lines. I’ve followed and mapped them all along the 8 miles of ridge we live on. These are pure pristine water sources, the sources that are the start of unpolluted creeks. They run right on top of the Sewel Coal seam. Crystal clean water. We get our drinking H2O from our neighbors spring.
    But the drones, we even have seen them during the day. They will fly over, then hours later they come by from another quadrant.
    Any ideas anyone?
    I know most all electrical devices put out a radio signal of some sort, and it probably isn’t too much of a leap of logic to assume there is detection technology that can pick up what everyone is radiating.
    Make any sense to you guys?

    1. everlastingphelps

      Purpose reveals itself by what is different from the noise. In this case, mines. (Looking for water is plain.)

      They know the layout of the mines. They know where the mines are. This is all highly regulated. That means the mines are a known-known. If anything, I would expect less useful transmissions from the mines, because of the EM rules around explosives.

      So, my WAG would be that they are testing a new method of sensing voids in the earth, to find bunkers and maybe caches. Since the mines are known-knowns on layout and depth, they can compare the results of the sensor system to what they know the actual tunneling to be, and calibrated and hone their system.

      1. everlastingphelps

        OSINT of interest:

        From 1976, so this would be the SOTA at the time. Expect systems to be more sensitive, more precise, smaller, and more efficient since then, assuming that there isn’t an entirely new system. At the least, we know that this is considered to be valuable military intel, so development of these systems would have continued.

      2. everlastingphelps

        Another thing that just occurred to me — explosives are another thing that sets mines apart. This would be an even bigger clue if these are strip mines (which I didn’t consider originally but makes sense for coal.) They may be developing a sensor system to pick up the explosives themselves.

      3. Who really knows what is going on. It was such a remarkable sight watching those drones zoom back and forth. Obviously they had to be collecting some kind of data.
        Reading what you all talk about, it struck me as probable they are scanning the electromagnetic spectrum.
        The coal seams around these parts have better than a century of exploration, between core samples and seismic testing. The geology is very consistent. There is Marcellus shale gas, and I think it is Utica shale gas below everything. Pretty deep those are, like 150 ft to 1200 ft. Most strip mines put off at least one shot a day, never at night. Fairly low order brisience blasting agents, mostly Ammonium Nitrate and off road diesel. They use clusters of up to 6 booster charges for every 20-30 foot of hole to cause the amfo to fracture sandstone. But it is all sedimentary deposit geology from salt and fresh water oceans. Except for coal and gas, there are no there things to mine. All the old growth has been logged off. What else is of value as an extractable resource I don’t know. That is what caused me to wonder about EM spectrum scanning. But I’m literally guessing.

  5. Pingback: Brushbeater: SIGINT & The Guerrilla Radio | Western Rifle Shooters Association

  6. JustAroundTheBend

    Are digital comms, eg winlink, psk31, and others any better at escaping df snoops as they are low power xsmissions?

    1. Yes and no.

      Digi modes can be great for masking a transmission, ie using a mode for a sender/receiver in a place where not common (such as Olivia in an area where no one listens for Olivia) and being more efficient in the transmission itself. Many lines of data can be sent in a burst, so you’re transmission time is shorter than with SSB or CW.

      Less time transmitting+lower power= less chance of interception.

    1. So, I’ll begin by saying any and everything that transmits can be DF’d. Doesn’t matter what it is, anything, everything, every frequency. The keyword here it “can”. Doesn’t mean it will.

      Often it means unless they’re looking for you or listening for it, it’s gonna be tough to dedicate resources to it if it’s so obscure the gains diminish the returns. This also does not take into account the skill of those looking for you. If you’re constantly ahead of the curve, they’re constantly one move behind.

      Foxhunting (slang for DF) is very different and have different requirements when you’re talking HF vs. Line of Sight (VHF and higher), with HF requiring a Mag Loop to be practical, and VHF/UHF being done with either a much smaller loop or a Yagi.

      As far as QRP goes, there’s a reason I keep harping on using the lowest power possible. CW and Digital are both the most efficient, power wise, to sending information.

      Lowest power, shortest transmissions, and directional antennas. This is in contrast with what most “hams” do, but the technical knowledge can be applied in the same manner. Get a friend and practice- there’s also a reason I keep harping on getting a network going now, as this stuff is about as far from plug n’ play as it gets, and only working knowledge can overcome issues that are guaranteed to arise.

  7. Curious Beginner

    What is a recommendation for a good scanner to monitor others, more along the line of “disposable”? I know, if you buy once you only cry once, but my money is tied up at the moment.

    1. Read my section linked up top- “Signals Intelligence Resources”. Then search a few of my older posts. I’ve addressed this a few times. A lot of it depends on what you mean by “others”.

      If that’s simple “bubba detection”, meaning monitoring GMRS/FRS/MURS, etc, then a simple cheap analog scanner will do the trick. You can find them second hand for pennies on the dollar, sometimes at thrift stores or pawn shops.

      Baofengs can scan but they do it slow, and they’re not the greatest thing, quality-wise. But they are cheap. You get what you pay for.

      As you can afford/dedicate more money, you’ll wanna step it up, based on what’s already been recommended.

  8. Big Dozer

    I’ve recently come to western rifle shooters after hearing Matt bracken speak so highly of the work being done here. Nice to know there is a sizable amount of patriots constantly tuning their craft. I need to establish some form of listening ability now and learn all that I can for my family’s well being. I’m a firm believer once they hit the kill switch on the internet that current Intel will be crucial to our cause. Please help me get my act together and outline what equipment to start with and some further direction on usage. Thank You for what all of you do.

    1. Big Dozer, You’re in the right place. I greatly appreciate the kind words, and if there’s anything I can help with, feel free to ask.

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