The majority of echoes is very fast and is in the noise. This echoes is not available on all frequency. He exists the low and high limits that depend on levels of ionization produces by the meteor. The speed of impact of the meteor and the mass condition the rate of ionization. For more scientific description see IMO web site .
Indication here is for Europe.
It is the frequencies presenting an interest in this type of monitoring. In East of Europe some countries use some exotic frequencies again for the FM broadcasting. As these frequencies are used little in Western Europe us have all leisure to do a monitoring without embarrass by the local emitters. It is possible to acquire a receiver FM capable to receive these frequencies while buying it in these countries or by correspondence. The meteor Scattering on 144 MHz and 432 MHz is a classic activity.