Somerset Sound listeners have been hearing "Voice of Russia", which transmits on the same frequency as the Taunton-based station.
A combination of the topography between the West Country and eastern Europe, a weak transmitter in Somerset and wet winter weather causes the problem.
From Tuesday, Somerset Sound is broadcasting on 1566AM to block out the Russian interference.
Voice of Russia transmits from Germany on the same frequency as Somerset Sound - 1323AM.
At times the Russian broadcasts are literally "dropped" on to Somerset, shadowing or completely obscuring the local station.
"In winter, particularly at night and in poor weather, our frequency is cut into," said Somerset Sound's senior producer, Max Cotton.
The same phenomenon means the Somerset station can be heard as far afield as Canada and Finland.
Rosie Sage is among listeners who are delighted by the change.
Studio move
"I am looking forward, and have been for a long time, to an improved frequency.
"Voice of Russia is quite dreary and nowhere near the quality of Somerset Sound."
The new frequency is the latest in a series of investments in the station.
In August, Somerset Sound moved to state-of-the-art studios from its cramped premises above a local cafe.