  We investigated whether the predictions and results of Stanishev et al (2002)
concerning a possible relationship between eclipse depths in PX And and its
retrograde disc precession phase, could be confirmed in long term observations
made by SuperWASP. In addition, two further CVs (DQ Her and V795 Her) in the
same SuperWASP data set were investigated to see whether evidence of superhump
periods and disc precession periods were present and what other, if any, long
term periods could be detected.
  The results of our period and eclipse analysis on PX And confirm that the
negative superhump period is 0.1417 \pm 0.0001d. We find no evidence of
positive superhumps in our data suggesting that PX And may have been in a low
state during our observations. We improve on existing estimates of the disc
precession period and find it to be 4.43 \pm 0.05d. Our results confirm the
predictions of Stanishev et al (2002). We find that DQ Her does not appear to
show a similar variation for we find no evidence of negative superhumps or of a
retrograde disc precession. We also find no evidence of positive superhumps or
of a prograde disc precession and we attribute the lack of positive superhumps
in DQ Her to be due to the high mass ratio of this CV. We do however find
evidence for a modulation of the eclipse depth over a period of 100 days which
may be linked with solar-type magnetic cycles which give rise to long term
photometric variations. The periodogram analysis for V795 Her detected the
likely positive superhump period 0.1165d, however, neither the 0.10826d orbital
period or the prograde 1.53d disc precession period were seen. Here though we
have found a variation in the periodogram power function at the positive
superhump period, over a period of at least 120 days.
