The allure of detecting a police car with a scanner has captivated many. Driven by popular media and a desire for situational awareness, the question remains: how feasible is it to pinpoint a “Scanner Police Car” in the real world? This article delves into the complexities of radio frequency (RF) detection, separating fact from fiction in the realm of police scanner technology.
The Challenges of Active Detection
Traditional methods relying on signal transmission, like those employed by BearTracker or Close Call, face significant hurdles. These systems depend on the police radio actively transmitting, an increasingly rare occurrence with modern digital trunked systems. Even with proximity and a substantial financial investment (around $500), success is heavily reliant on luck. Police radios often operate in a receive mode, listening for dispatches rather than constantly transmitting. Moreover, when transmissions do occur, they are often brief data bursts for communication with towers, similar to a cellphone’s periodic check-ins. Investing double that amount for a rudimentary LoJack system with specialized antennas and an analyzer might offer a slight improvement by detecting Doppler shifts to approximate direction, but the infrequent transmission windows still pose a significant obstacle. Furthermore, officers engaged in traffic enforcement may not be actively transmitting radar signals, further reducing the chances of detection.
Exploring Passive Detection: A Costly and Complex Endeavor
While active signal detection is challenging, detecting a non-transmitting police radio is theoretically possible, albeit significantly more complex and expensive. Modern police radios, designed for durability and future-proofing, often incorporate robust shielding, making them difficult to detect from a distance. However, even in receive mode, a radio’s internal electronics generate faint noise at specific frequencies. Identifying these frequencies, coupled with knowledge of the agency’s radio make and model, could potentially reveal a radio’s presence. However, this approach requires sophisticated equipment like a precise spectrum analyzer and a high-gain directional antenna. The size of such an antenna, particularly for frequencies in the 30-100 MHz range used by police, presents practical challenges. Additionally, pinpointing a specific signal amidst the noise of numerous other government and commercial radio users on a statewide trunked radio system would be incredibly difficult. While technically feasible, this method demands extensive planning, expertise, and a considerable financial commitment for potentially minimal returns.
Conclusion: Separating Fact from Fiction
Detecting a “scanner police car” is far more challenging than often depicted. While active detection methods are limited by infrequent transmissions, passive detection, while theoretically possible, requires significant financial investment, specialized equipment, and advanced technical knowledge. The effectiveness of either approach is questionable, particularly given the advancements in radio technology and the complex RF environment. For those interested in further exploration of scanner detectability, the discussion on RadioReference.com forums offers valuable insights: Can scanners be detected? – The RadioReference.com Forums
