Why my radio bought from USA does not work well in Europe ?
Radio broadcasting have differences between USA and Europe. Because of that some radios bought form USA do not work well in Europe and in the other way. Thid document tries to clear out what are those differences.
North American FM broadcast channels are on the odd 200KHz frequencies: 99.5MHz, 100.1MHz, etc. In Europe, channels can be on any multiple of 100KHz, even or odd.
This means that a digital tuner from the USA will not tune European stations properly, resulting in distortion. Some tuner models are switchable between the two schemes, but these are rare. Frequency synthesizing tuners in Europe do their actual tuning in shorter steps (for example 25 kHz). With analogue tuners you have no such problem because they aren't stepped anyway.
Be aware that FM stations in Europe use a different pre-emphasis than those in North America, 75 and 50 microseconds respectively.
Same for AM, the difference is 10 kHz steps in the US vs. 9 kHz steps in Europe.