  LEP precision measurements of the $Zb\bar{b}$ vertex coupling are
sufficiently accurate to see the non-oblique corrections from the heavy gauge
boson responsible for the large top mass in standard extended tecnicolour
models. If the ETC couplings are strong the techni-fermion condensate may be
enhanced by several orders of magnitude allowing a top mass of order 150GeV to
be obtained for large values of the ETC breaking scale sufficient to supress
the ETC contribution to the $Zb{\bar b}$ vertex. In this letter we investigate
the degree of fine tuning of the ETC coupling required in a realistic model. We
conclude that the fine tuning need only be of order $10\%$.
