  A shape of the signals in proportional chamber with preamplification gap and
electron component extraction from proportional discharge has been
investigated. It was shown for Penning mixtures that in proportional discharge
besides the primary avalanches there is also the tail of secondary avalanches
caused by metastable and nonmetastable Penning effects. For different mixtures
of gases the duration of the signals caused by secondary avalanches are equal
to ~ n*10 microseconds (n = 1 - 10), the total charge of secondary avalanches
is comparable or larger than in primary avalanches.
