How much attenuation do window feed-throughs have?

The attenuation of window bushings in the amateur radio sector can vary, but is typically between 0.1 dB and 3 dB, depending on the type of bushing and the materials used. The thinner versions made from flat, flexible materials tend to cause the least attenuation, while thicker and more inflexible bushings tend to have more attenuation. In order to keep the attenuation as low as possible, you should pay attention to high-quality bushings with low resistance losses.