Potassium line data from observatories in Hawaii and Spain were used to establish the authenticity of complex solar oscillation signals. Combination of the two data sets yields precise frequency, amplitude and phase determinations. Analyses of individual lines indicate possible decay and excitation of individual modes and suggest lifetimes for the l1 modes of 85 days over the frequency range 2000 to 3800 micro Hz. The rotational splitting of the l1 modes appears less well resolved. The use of spatial filters could extend the range of l modes observable by a one dimensional solar spectrometer and, by specifically selecting the spatially simple sectoral modes, could prove to be a powerful way of determining rotational splitting.