system is 24volt
yes inverter is modified sine wave.
yes phone line is decidedly dodgy, I am at the outer limit to even get adsl.
5.5km to end of my road let alone the actual exchange. Phonline is completely underground and actually goes underground through a creek and they are constantly digging it up and messing with it. Phone line can get a bit noisy at times especially after rain.

The phone line as far as i can see is not connected to anything in the house, it comes straight from a pit box outside the house to the plug, this can be visibly followed as it is not in ceiling or walls, just stapled along the inside.

House has no distribution box or fuse box, just a home done string in ceiling that runs a half dozen lights and another string for some powerpoints, these join up and go through a fuse to terminate in a plug to plug directly into either inverter or generater. As the powerpoints are not where the computer or TV are setup, these are run directly from either inverter or generater(extension cords and power boards everywhere, basicly a mess)

The phoneline is the only outside service we have, water comes gravity feed from a permanant spring a couple of hundred metres up the hill in poly pipe. There are copper pipes for the hot water and gas but these are not underground.

I've got the phone company coming out today sometime(supposedly) so i'll see what happens then.

In the meantime i'll get out to the shed and try rustling up a galv rod or something and try to ground this thing better.

  What about just hooking up to a galvanized steel post that holds the house up?
  beams are wood,  but i doubt it goes in 3 feet.

Thanks all for advice,