Sorry, Russell, I will write
   'If I ever go to New Zeland, I will vist the North Island and the South Islan
d'  50 times.   Incidentally, Radio New Zeland is one of my favorite stations in
 the evening on the US West Coast, with a very strong signal and excellent progr
amming.  My next project may be a PIC based frequency readout for my 1938 Zenith
 shortwave radio.  That (Italian) single PIC freq. counter program should fit th
e bill.

At 04:41 PM 4/9/99 +1200, you wrote:
>The NZ link mentioned uses two wires, one either polarity wrt ground.
>Each runs at about 300KV (!).
> ...        Russell McMahon
>
Also,
In the two wire HVDC systems, since one of the two wires is + with respect to gr
ound, and the other wire is - with respect to ground, if the loads are well bala
nced on the two wires, then there is no ground current between the stations.  Bu
t if one wire fails, then the ground current connection is there as a backup to
carry the load of the single wire that is left.
  Regards,
  Ron Fial