In which frequency range is meteor scatter most effective for extended-range communication?

Meteor scatter is most effective in the low VHF range, specifically between 30 MHz and 100 MHz. This encompasses the popular 6-metre (50 MHz) amateur band, which is famous for this type of propagation. Frequencies below 30 MHz (the HF bands) are generally reflected by the standard D, E, and F layers of the ionosphere, so meteor trails are not needed for extended-range communication. At these lower frequencies, normal skip is far more reliable. On frequencies above 100 MHz, the meteor trails do reflect signals, but the duration of the reflection drops dramatically to mere milliseconds. The 30 MHz to 100 MHz range hits the 'sweet spot' where reflections are strong and last long enough to complete a contact.