A. A. Volkov

Range of a radio communication in a range of metric waves within a large railway junction was defined also, as well as for a big city, on a Vvedensky's formula with the recommended multiplier of slackening r = 0,2 + 0,4 that has appeared inexact. Last years this range for a city began to define on attenuation of an electromagnetic wave, using the formula of Okumura - Hata. As this formula emperic on it, it is possible to specify a multiplier of slackening for Vvedensky's formula. For this purpose on it at r = 1 attenuation of an electromagnetic wave depending on distance which is compared with attenuation on the formula of Okumura - Hata at identical heights of aerials and lengths of waves is calculated. That these parallel curves coincided among themselves, it is necessary to put an slackening r = 0,1 multiplier in Vvedensky's formula that in (2 ÷ 4) time there is less than recommended. Practice of a railway radio communication confirms this value.