HAM radios offer an extremely valuable means of communication in emergencies as much of their equipment can be self-contained, without a dependency on third party organizations such as network providers.
Although these devices are popular, they lack many security features allowing almost anyone to listen in to your transmission. At best, this leaving you vulnerable to having information compromised but at worst, can be used to locate your position. While the risk of being compromised is always present, there are many steps you can take to improve your security, including the use of a comprehensive communications plan.
How can HAM transmissions be traced?
The most common method used to trace a broadcast back to your radio transmitter is triangulation, which employs a series of directional-finding stations and navigational skills to locate your original location.
These stations may be either fixed or mobile, but in either case, once tuned to a broadcast frequency they can then scan an area to determine in which direction the signal in strongest.
Once this procedure has been repeated at least twice, it is possible to find the intersection of these headings to locate the position of the original broadcast. Although only two readings are needed, it is typically to take more as this helps narrow down on a precise location and ultimately reduces the search time, despite requiring more work initially.
This technique can work, but it is time-intensive as the process gradually narrows in on a specific broadcast location, and as a result, is much more effective against weaker antennas as the search area is already limited.
How easy is it to begin tracing HAM traffic?
As HAM radio tracing is a fairly exhaustive process, many amateur radio operators do not practice the skillset.
Although less popular, the equipment to start tracing is affordable with directional radios beginning at as little as $50, making it a great skill to start developing.
It can be difficult to find others interested in practicing, but regular competitions referred to as “Fox Hunts” are available for those interested. The ARDF-USA has some great resources as well as information regarding upcoming competitions available on their website.
Should I be concerned about tracing?
Although possible, the risk of being traced by a fellow radio enthusiast is arguably low. Even during an emergency, there are many more practical methods of finding other people, such as following smoke, tracks, and noise pollution back to a person’s camp.
While enthusiasts are unlikely to trace you, another potential group that may attempt to locate a broadcast location is law enforcement.
Under F.C.C. guidelines, it is possible to use HAM radios in an illegal manner, either through operating without a license or improper use of the radio. This was previously dealt with rapidly by law enforcement agencies, but with the amount of time required to triangulate a signal, they have become less responsive to these types of broadcasts.
Instead, these resources are now typically reserved for transmissions that either pose a direct security threat or interfere with critical frequencies (such as airport control or police radios).
What other risks are there to your position?
Triangulation is only one way in which your position may be compromised during HAM radio transmissions.
As amateur HAM radio transmissions are unencrypted, there is a significant likelihood of sensitive information (such as locations) being shared with third parties during normal transmissions if they are simply tuned into your frequency.
Alternatively, select modern radios (such as the Baofeng DM-1702) include GPS units which can be used to accurately locate your position.
GPS devices do not typically transmit your information, but this is a potential risk that should be considered if using stolen equipment, which is why you should always be careful where you choose to source your devices from.
How a good plan limits your traceability
Much like other communication methods, it is impossible to entirely secure your HAM radio traffic but there are steps you can take to improve your communications.
One of the most basic techniques you should employ is a detailed communications plan that you share with anyone in your family or network you are planning on connecting with.
As tracing requires your broadcast signal to be active over a significant period of time, using a pre-made plan will allow you to only transmit during short windows and therefore limit the risk of a transmission being triangulated.
Your transmission schedule should be unpredictable to limit the chances of third parties being able to listen in, but also not overly complicated in order to allow you to easily remember when communications should take place.
When transmitting, your windows of communication should be kept short again to limit your activity on a frequency. With sufficient planning, it is possible to convey all necessary information in only a few minutes before shutting off comms and waiting until the next window opens.
The amount of time your radio is active plays a key role in reducing the risk of your location being triangulated, but what you communicate should also be considered heavily.
Broadcasting specific details of your plans such as naming the location of your intended rally points is a guaranteed way to have your information compromised if someone is listening in on your traffic.
Instead, aim to pre-establish specific names of locations already agreed upon by your group. Plans never survive first contact with the enemy so there always the risk of having to share information explicitly but preplanning in this way limits the amount of information shared openly on a network.
How to use movement to your advantage
If we accept the risk that any communication broadcast on a HAM radio can be traced, the best alternative is to lead individuals to the wrong location, away from your home base or bug out location.
While this additional travel can be an inconvenience, it can substantially improve HAM radio capabilities.
By moving away from your base, you may be able to find more optimal broadcasting locations such as hilltops or away from buildings. These locations are able to increase your range by improving your line of sight to receivers, while also reducing the interference from large structures.
In a similar manner to varying your broadcast schedule, you should also aim to vary the location from which you broadcast. The amount you move is dependent on your needs, but alternating between three or four positions each broadcast at least a mile apart from one another is a good general rule.
How can distance limit your risk of tracking?
As triangulation works on a process of elimination to gradually narrow down on a location, another approach can be to increase your broadcast range and therefore increase the search area. This can greatly increase the time required to locate your broadcast position, therefore making it less likely your position will be compromised.
By using a relay station to boost your broadcasting distance, it is also possible to increase your anonymity to an even greater extent.
Many of these stations work through rebroadcasting an incoming transmission, ultimately meaning that any attempt to trace a signal back to you will lead an individual to the repeater station instead of your home base.
If someone is intent on tracking your broadcast, increasing the size of the area you transmit to will not stop them however likely will do much in the way of slowing them down.
HAM radios can be a great option for communications when things go south and we are left without our normal infrastructure.
With that said, the lack of secure end-to-end encryption on commercial units does pose a serious threat to operational security and could compromise the location of your home base or bug out location in a state of emergency.
Without this security, it is important to take steps to safeguard your network by having a solid and pre-established communications plan to limit the risk of having your broadcasts traced back to your position.
For more advice on HAM radios and how to get started with them, be sure to check out our comprehensive guide for beginners.