Topband: salt versus fresh water location

[Mike Harris]

G'day,

| BY FAR, the saltwater location is better!
| Do you have mudflats at low tide or is there water all the time?

It is interesting just how little salt water makes fresh water very 
conductive.

At the salt mine (11 metre dish earth station) we had to test a 100kVA 
generator by putting it on heavy load.  We placed a one inch copper tube, 
one for each phase, through a wooden form and into the top of a 45 gallon 
drum, one end removed, and filled it with fresh water.  Ran the genny up 
connected to the tubes and there was nil current.  Tipping about a gallon 
of sea water into fresh water in the drum brought the load up to 60+kW no 
problem.  The water soon got pretty hot.  The load increased with 
temperature.

Did a similar thing when we had to discharge a 200VDC battery bank (50kW 
UPS) for dismantling.  Only problem with DC was one of the tubes soon 
dissolved and the current fell off!

Regards,

Mike VP8NO