What Frequency to Scan to Detect a GPS Tracker?

GPS tracker detection is an essential task to ensure the safety of your vehicles or assets. These devices, used to track location in real-time, can be difficult to find due to their small sizes and interval transmission capabilities. However, with the right equipment and knowledge about the frequencies they use, it is possible to locate these hidden devices. In this article, we will explain which frequencies to scan with a frequency detector to detect a hidden GPS tracker.

GPS Tracker Detector: How to Scan the Right Frequencies

Table of Contents

How Does a GPS Tracker Work?

To understand how to locate a GPS tracker, it is first important to know how a GPS tracker works . These devices use a combination of satellite signals and data transmissions to send the location information to a server or end user. In essence, the device receives the location through GPS signals (satellites) and then transmits this information over a communication network, which can be GSM, 3G, 4G, 5G, or even Wi-Fi and Bluetooth.

GPS uses a system of satellites orbiting the Earth to calculate the exact position of the device. To do this, the satellites send out radio signals containing information about your location and the exact time they were transmitted. The GPS device receives these signals and uses a mathematical process called trilateration to calculate your location.

However, it is important to note that GPS tracker detectors do not scan the GPS reception frequencies (L1, L2, L5) , as these are only for receiving information from satellites. Instead, what they scan are the transmission frequencies , which the tracker uses to send its location to the server or monitoring device.

Reception Frequencies vs Transmission Frequencies

The key to detecting a hidden GPS tracker is to understand the difference between receiving and transmitting frequencies. A GPS tracker receives signals from satellites on specific frequencies (such as L1, L2, and L5). These are receiving frequencies, which the device uses to calculate its exact location on Earth.

However, frequency detectors do not track these receiving frequencies. Instead, they focus on transmitting frequencies , which are what the GPS device uses to send its location to a server. Transmitting frequencies can vary depending on the type of network the tracker uses. These networks include GSM, 3G, 4G, 5G, Bluetooth, and Wi-Fi, among others.

Therefore, a frequency detector is designed to look for these transmitting signals, not receiving ones. For example, if the tracker is set to transmit data over a 3G or 4G mobile network, the detector will search those bands to detect device activity. Understanding this concept is crucial to using a detector effectively and ensuring that you don't miss any hidden devices.

Types of Transmissions to Detect

As mentioned, GPS tracker detectors do not detect the signals received by these devices from satellites, but rather the transmissions they emit to send location information. These transmissions are essential to identifying a hidden device. Below, we will explore the most common transmission technologies that you should scan for in order to detect a hidden GPS tracker.

GSM, 3G, 4G and 5G

GPS trackers frequently use mobile networks such as GSM, 3G, 4G and 5G to transmit their location. These networks operate on different frequency bands: 900 MHz and 1800 MHz for GSM, 2.4 GHz for 4G and up to 5 GHz for 5G. Devices using these technologies transmit data in real time or at scheduled intervals. Frequency detectors must be calibrated to cover these ranges, as these signals are the most commonly used by commercial GPS trackers.

Bluetooth and Wi-Fi

In addition to cellular networks, some GPS trackers may use short-range technologies such as Bluetooth and Wi-Fi to transmit data. These signals operate in the 2.4 GHz and 5 GHz bands, respectively. Devices that employ these technologies have a limited range, making them ideal for controlled environments. To detect these devices, a frequency detector must cover these bands, as hidden trackers may transmit over these networks intermittently.

RFID Frequencies

Some more sophisticated GPS trackers employ RFID technology to transmit data. Devices that use RFID operate on specific frequencies such as 125 kHz or 13.56 MHz, and while less common, they are effective at transmitting short-range information in specialized applications. Detecting trackers that use RFID requires scanning low frequencies, which is possible with high-precision detectors that cover a wide spectrum of frequencies.

Other Transmission Frequencies

In addition to GSM, Bluetooth and Wi-Fi, some trackers use low-power technologies such as LoRa or Sigfox. These technologies, which operate in bands such as 868 MHz, allow data transmission over long distances with low power consumption, which is ideal for GPS trackers that require long autonomy. To locate these devices, it is necessary to use detectors that include these frequencies in their scanning range.

How to Scan the Correct Frequencies?

To use a frequency detector effectively, it's crucial to know which frequency bands to cover. GPS tracker transmissions vary depending on the technology used. Here's how to adjust your equipment to scan the correct frequencies and maximize your chances of detecting a hidden device.

1. Identify the technology used: First, you need to determine whether the tracker uses GSM, Bluetooth, Wi-Fi, LoRa, or RFID, which will define the frequency ranges you need to monitor.

2. Set up the detector: Make sure the detector is set to scan the relevant bands. Some devices allow you to select specific ranges, which streamlines the process.

3. Continuous monitoring: The most advanced detectors can record and analyze signals to detect intermittent transmissions, which is essential for trackers that transmit at intervals.

Detecting Intermittent Transmissions and Burst Devices

Some GPS trackers are designed to transmit information at specific time intervals or only when the vehicle is in motion. These devices are difficult to detect because they do not emit signals continuously. Advanced frequency detectors are capable of recording these intermittent transmissions, but it is essential to know how to set up and operate the equipment so as not to miss these momentary emissions.

An effective technique for detecting these devices is to perform a motion test on the vehicle. By moving the car or causing a situation where the tracker must send its position, you increase the chances of capturing the signal. By driving through different environments, you can cause the tracker to transmit, allowing you to capture its frequency on the detector.

Additionally, some technologies such as LoRa or Sigfox, which are used by low-power devices, employ burst transmissions to send small amounts of data. These devices typically use bands such as 868 MHz, so it is important to tune the detector to cover these frequencies, otherwise the tracker could go undetected.

The Importance of Using the Right Equipment

Using the right detector is key to detecting transmissions from hidden devices. Not all equipment is designed to cover the wide range of frequencies that GPS trackers can use, from low RFID bands to 5G transmissions. Additionally, it is critical that the detector has the ability to record and analyze signals in real time, since many transmissions are emitted briefly or intermittently.

The most advanced detectors allow for detailed analysis of detected signals, providing information on the exact frequency, signal strength, and transmission duration. This is especially useful for identifying devices operating in low-power or burst modes, such as trackers using low-frequency networking technology such as LoRa or Sigfox.

Key frequencies for detecting GPS trackers

  • RFID: Between 125 kHz and 134 kHz or 13.56 MHz for short-range transmissions, mainly in geolocators or hidden tags.
  • GSM (2G): Between 900 MHz and 1.8 GHz, used by trackers that connect to the most basic mobile network.
  • 3G: Between 1.9 GHz and 2.1 GHz, ideal for more advanced hidden devices that transmit real-time position data.
  • 4G/LTE: Between 700 MHz and 2.6 GHz, increasingly used by GPS trackers and tracking beacons due to its extensive coverage.
  • 5G: Between 3.5 GHz and 6 GHz, being the most recent technology used in next-generation locators.
  • Wi-Fi: Between 2.4 GHz and 5 GHz, used by trackers that connect to local wireless networks to transmit data.
  • Bluetooth: Around 2.4 GHz, used in devices that synchronize data over short distances, such as hidden microphones or trackers.
  • LoRa/Sigfox: Between 868 MHz and 923 MHz, low-power, long-range technologies for transmitting data in short bursts.

The right detector should be able to scan frequencies from 125 kHz to 6 GHz or higher, covering all of the above technologies and allowing it to identify even the most advanced devices using the higher frequency bands.

Conclusions

Detecting a hidden GPS tracker requires proper equipment that can scan a wide range of frequencies. From GSM to RFID to Wi-Fi, each technology uses a different range of frequencies, making it imperative to properly configure the detector to cover all possible transmissions. Understanding how intermittent transmissions and devices that operate in bursts work is key to not overlooking any tracker. Advanced technology in frequency detectors allows not only to detect devices in real-time, but also to record and analyze signals to ensure that no device goes undetected.