Why are UHF signals often more effective from inside buildings than VHF signals?

UHF signals are often more effective from inside buildings than VHF signals due to their shorter wavelength, which allows them to more easily penetrate building materials such as walls and windows. The shorter wavelength is better suited for navigating obstacles, which makes UHF frequencies generally more capable of maintaining signal quality in urban and indoor environments.

VHF signals, being of longer wavelength, tend to be absorbed or reflected more by typical building materials. This characteristic can lead to a significant loss of signal strength when trying to transmit or receive VHF signals indoors. As a result, in many cases, UHF is preferred in situations where communication needs to occur within complex structures, such as commercial buildings or densely populated areas.

The efficiency of antennas is not inherently a factor in why UHF signals perform better indoors; rather, it is a characteristic of the wavelengths themselves.