May 30, 2024

The following examples illustrate low-tech and unconventional uses of radio that are widely available. I am an unaccomplished civilian with no training on any of these topics and have little formal education of any kind. I am self-taught using the resources available in military manuals and on the Internet.

Avoiding RDF and Attacks by Drones: Remote TX

Since preppers are not militarily significant targets, it is unlikely scarce resources would be used to locate our low-power transmissions. That said, because drone technology is rapidly progressing and drones are now ubiquitous on the battlefield, we might anticipate that future drone swarms will evolve. They might be comprised of many kinds of drones, to be akin to a combined arms team. Some would be used for surveillance and some for attack, and so forth. We have yet to see what the cutting-edge Chinese drones are capable of on a future battlefield and how they will be used.

To avoid being located via Radio Direction Finding (RDF) and taking a direct hit from a drone or something else when threat conditions are high, we should not transmit using UHF/VHF/HF using groundwave propagation from a retreat or homestead if a drone might be in the area. If being DF’ed and targeted, the ‘cut’ only needs to be within a 500-meter square area for indirect fire to be effective. If the best RDF techniques are used by a SIRT team, a 10-meter square area can be identified making a a pinpoint attack possible. If this is the threat, the transmitter should be located at least 25 meters away from the hide, and a good E&E plan be in place. However, knowing that Low Level Voice Interception (LLVI) is exceedingly difficult to locate via RDF, we can be confident that our effort to avoid interception is possible if we practice proven techniques such as using very low power, directional antennas, and terrain masking. These same techniques can also mitigate an RDF effort by drones, as well.

Going Remote

There is a simple method to employ. It uses modern and inexpensive Commercial Off The Shelf (COTS) equipment, and it is based upon the time-tested techniques employed for the same reasons it was used by our military in the not-too-distant past. You can bet the Chicoms will use the latest drone technology against us. Fortunately, transmitting using a remotely located transceiver several miles away is relatively simple, if a remote and mobile station can not be used. I will assume that we will be short on manpower, and cannot send out a patrol at will, or establish a remote communications station. We can however improve our COMSEC by using a remote low powdered UHF/VHF transmitter and using either or both a directional antenna and terrain masking, and talk via a directional antenna into a cross band repeater located on a military crest, or elsewhere where terrain masking is possible. UHF is best as it does not propagate as well as high or low VHF in hilly terrain, and UHF antennas are one-third the size of high VHF antenna and are harder to see from the air.

One can use commercial telephones instead of field phones. Wire can be run from the retreat to a remote location and a commercial phone or field phone can ‘speak’ into the transceiver that transmits using its VOX function. Simply use duct tape to attach the earpiece to the front of the radio. This is referred to as ‘audio coupling’ or acoustic coupling. Or we can splice a 2.5mm jack onto the line and plug it directly into the microphone jack of the transceiver. The transceiver and phone can be well camouflaged, placed into a bucket with a tightly sealing lid, or placed inside an ammo can and buried with a large 12-volt DC battery that can operate the transceiver for a period of many weeks, if not months, without a solar panel. A coaxial cable can be run to an omnidirectional, or directional antenna that is also well camouflaged. Thin wire antennas can be covered and insulated with gray in color silicone that can be applied to the wire in a way that also breaks up the straight lines created by the antenna elements. It can then be spray painted using a nonconductive spray paint such as the Krylon brand. A patrol can routinely inspect the installation, or a MURS Dakota Alert Sensor can monitor the site, or a trip wire connected to the main phone wire leading to the transceiver can apply constant voltage that operates a buzzer at the radio shack, to determine if if the site has been disturbed.

To operate the remote transmitter, the radio attendant simply operates a toggle switch that energizes the line with 9 to 18vdc to power the commercial phones and a low-power relay that turns on the transmitter. In this way, a storage battery will not be drained of power by a transmitter that is not in use. This method can also be used with military field phones. Simply speaking into the phone is all that is necessary to operate the transmitter on the other end. We can hear the reply through the phone, or by monitoring the frequency at the communications center.

See:  1941 U.S. ARMY SIGNAL CORPS ” BASIC SIGNAL COMMUNICATION ” FIELD TELEPHONE SYSTEM SETUP 17134

This video provides the correct way to lay down field phone wire designed for the purpose. Light gauge copper wire can be used, though it is not strong enough to be suspended over waterways or roads alone, but only with another wire as its support. Copper wire is expensive, but it does conduct electricity 9 times better than steel wire of the same gauge, and can greatly increase the distance between two stations, or the distance between a communications shack and a transmitter, for a maximum of 3 to 4 miles using WD1A, to several times that distance using copper wire of at least 24 gauge.

Modern direct bury wire would be expensive, yet ideal. Military surplus WD1A is relatively inexpensive, but because of its age, it should be used above ground. This is because cracks in the insulation can cause a bad connection, or eventually a failure point that would be nearly impossible to locate, if buried.

If crossing a road or waterway is required, wire to be buried or submerged should be of the modern direct bury type that is spliced in. If enough WD1A wire is available, two wire pairs should be run to the same end point as a primary and alternate wire pair that ensures uninterrupted operation of a remote transceiver or field phone circuit in the event that one wire pair is damaged or becomes faulty. With 4 WD1A wires to the location 4 different wire pairs can be configured to repair the connection, or to serve as a field phone connection to an LP/OP.

Ghost Radio Networks and Drone Magnets

Another simple technique can be a valuable tool for deception or misdirection. It can be used as a diversion or to create false confidence, or confusion and doubt. This unconventional and low-tech Electronic Warfare (EW) can be useful in a variety of situations. It might be useful as an intentional drone magnet.

The equipment is common off the shelf technology. Only a small amount of ingenuity is needed to assemble an autonomous transmitter that is activated by a timer that supplies power to the transmitter and a playback device that could be a tape recorder. The timer is the common household type that is typically used to turn off and on lighting. The electronics can be fully contained and protected in a plastic 5 gallon bucket, and partly buried with the antenna inside the bucket, and otherwise camouflaged, or it can be installed in a building that has grid power.

When the timer switches on the power at the predetermined time, the tape recorder plays, and the VOX function of the transceiver causes it to transmit a recorded voice. Using one or more of these devices is possible, and one can also pretend to carry on a conversation with a device. For example, at several different times during a 24-hour period, several, or a single devices activates and calls the base station, something like the following sequence could be used:

Device: “LPOP 7, Central” (a real person response: “Central, LPOP7 go ahead…”)

Device: …”LPOP7/Central, we are 10-13. (real person: “LPOP7, Central”, copy, you are 10-13. Clear to Send )

Device: “Central, LPOP7 sending” (we then hear a prerecorded digital noise that sounds like a packet that is used for a report.)

When the timer switches on the power at the predetermined time, the tape recorder plays, and the VOX function of the transceiver causes it to transmit a recorded voice.

Using one or more of these devices is possible, and someone can also pretend to carry on a conversation with a device. For example, at several different times during a 24-hour period, several, or a single devices activates and calls the base station:

Device: “LPOP 7, Central” ( a real person response: “Central, LPOP7 go ahead…”)

Device: …”LPOP7/Central, we are 10-13. (real person: “LPOP7, Central”, copy, you are 10-13. Clear to Send )

Device: “Central, LPOP7 sending” (we then hear a prerecorded digital noise that sounds like a packet that is used presumably for a SALUTE report.)

Note that the signal strength can be stronger, and length of transmission from LPOP7 might be intentionally long to allow a rough bearing to be acquired.

This sort of deception technique can also be done using the Argent Data Systems Simplex Repeater. That is a digital voice recorder that is connected to a transceiver. It parrots what it hears. In other words, what it hears, it records and plays back. And it can be caused to store what it hears like a message machine, that anyone with the access code from a DTMF pad, can activate and control it. It can be used in several ways to similar effect of the aforementioned example. One can send a digital signal that the repeater repeats, or we can select one of many different prerecorded messages to simulate a conversation. The order in which the prerecorded messages are played back can be changed to create a different conversation. The repeater can also be set up and by a keypad command, can turn on and off a light to attract attention and create high confidence, or to signal using light. The repeater can be used in conjunction with the first type of ‘ghost’ station as well, and a low-power crossband repeater, located elsewhere.

Conclusion

The idea is to create an RF signature and chatter, and to make your unit appear larger than you are, or to create the illusion of being in one location rather than another so that we can employ other unconventional tactics. The combinations and opportunities are only limited by our imaginations and technical ability. Several fictitious LP/OPs or a FOB can report in, creating the illusion that you are part of a larger organization than you are, or to deceived your opponent that you are where you are not. We can also deliberately pass on false information over the air in the clear and cause the enemy to move at a time and in a direction that is tactically to our advantage, or even just to waste their time and resources, or to cause indecision and delay.