  We present high-speed, three-colour photometry of the eclipsing dwarf nova
PHL 1445, which, with an orbital period of 76.3 min, lies just below the period
minimum of ~82 min for cataclysmic variable stars. Averaging four eclipses
reveals resolved eclipses of the white dwarf and bright spot. We determined the
system parameters by fitting a parameterised eclipse model to the averaged
lightcurve. We obtain a mass ratio of q = 0.087 +- 0.006 and inclination i =
85.2 +- 0.9 degrees. The primary and donor masses were found to be Mw = 0.73 +-
0.03 Msun and Md = 0.064 +- 0.005 Msun, respectively. Through multicolour
photometry a temperature of the white dwarf of Tw = 13200 +- 700 K and a
distance of 220 +- 50 pc were determined. The evolutionary state of PHL 1445 is
uncertain. We are able to rule out a significantly evolved donor, but not one
that is slightly evolved. Formation with a brown dwarf donor is plausible;
though the brown dwarf would need to be no older than 600 Myrs at the start of
mass transfer, requiring an extremely low mass ratio (q = 0.025) progenitor
system. PHL 1445 joins SDSS 1433 as a sub-period minimum CV with a substellar
donor. These existence of two such systems raises an alternative possibility;
that current estimates for the intrinsic scatter and/or position of the period
minimum may be in error.
