  A tunable diode laser spectrometer has been employed to examine the overtone
absorption lines of $^{12}$CH$_4$ in the region around 12780 cm$^{-1}$ (780 nm)
at room temperature. The spectrometer sources are commercially available
tunable diode lasers operating in "free-running" mode. The measurement of the
line positions within 0.01 cm$^{-1}$ has been possible by the use of the
wavelength modulation spectroscopy and the second harmonic detection techniques
that permitted the observation of minimum optical absorbances of the order of
$\approx 10^{-6}$. The weakest observed lines of the band have absorption cross
sections of the order of $1 \times 10^{-25}$ cm$^2$/molecule, that is $\simeq
0.3$ km$^{-1}$/amagat. For some of them self-, air-, He- and H$_2$-broadening
coefficients have been obtained.
