Filter networks for suppressing an arbitrary number of contiguous channels are supplied to order. For only a few channels, a series connection of individual channel deletion filters is used. For a large number of contiguous channels, a special network is used. Its components consist of a “Brickwall” lowpass and highpass filter and a pair of specially designed bandsplitters. For an intermediate number of contiguous channels, two single channel deletion filters establish the “Brickwall” ends while a less selective network deletes the middle of the specified stopband.