According to
this (
Sony has no DCR-SX43 listed), the resolution is 720x480, thus it is already a "low" resolution.
The camcorder records in Standard Definition (SD) and not in HD and it uses an older compression algorithm, called the MPEG-2 codec.
There is not much you can get out of it. Maybe you can sell it and get a similar priced miniDV camcorder, as the image will not be as compressed as with the SX-43.
DV is short for Digital Video, and every frame gets recorded with DV capable cameras, which results in a "high" data rate of 3.125MB/s (128KB per frame with 25fps).
MPEG-2 compresses the image so much, that only every 15th frame is recorded and the rest is interpolated, thus you lose quality and information.
MPEG-4 camcorders are better at this, thus many HD camcorders use a variant of it for storing the video, for example AVCHD camcorders.