A collaboration of several universities and scientific centres is studying the characteristics of a single pass FEL over a wide operating range. Optimum gain performance has been selected in a highly broadened regime for the range 2-20 μm, but higher harmonics will also be measured. The facility has been constructed using the 165 MeV Kelvin linac, modified to improve its properties as an FEL source. A new beam transport system matches electrons through the 65 mm period undulator and also incorporates an electron spectrometer system of high accuracy. The 5 m magnet has four independent, identical sections for experimental flexibility and is remotely controllable to high field strength. Following studies of the electron beam properties, including emittance and alignment, spontaneous spectra have been recorded and gain measurements are now being attempted.