On an 800 MHz system, the shorter wavelength compared to VHF low or high allows easier penetration into vehicles. With wavelengths of only a couple of inches, small opening impingement is minimal. Conversely, a VHF high frequency with a wavelength nearing six feet struggles to pass through vehicle windows. Imagine driving through a long tunnel. FM stations (around 100 MHz) are usually audible throughout, while AM stations (1 MHz) are typically not. This demonstrates how smaller wavelengths at higher frequencies travel more easily into confined spaces.
Modern auto glass, often containing metal particles to block UV light, significantly hinders radio signal reception inside vehicles. This metallic content disrupts the passage of radio waves.
Antenna polarization also plays a crucial role. Since most Land Mobile Radio (LMR) systems in the US use vertical polarization, a scanner lying flat on a car seat, forcing the antenna into a horizontal position, can cause a 20dB signal loss.
In areas with strong signals, particularly 800 MHz systems, an internal scanner might suffice. However, in areas with weaker RF signals and lower frequencies like VHF, used often in remote tower sites, an external antenna mounted on the car, often referred to as a Scanner Car Mount Bcd, becomes essential for reliable reception. A scanner car mount BCD ensures proper antenna positioning and minimizes signal interference. Different BCD mounts offer varying features and compatibility with specific scanner models.
Consider the frequency of your local radio systems and the typical signal strength when choosing a scanner and antenna setup. In RF sparse environments or when using lower frequencies, a scanner car mount BCD paired with an external antenna significantly improves reception quality. Always remember the physics of radio wave propagation when setting up your mobile scanning system. A well-chosen scanner car mount BCD ensures optimal performance and clear reception while on the go.
