I have the first version of the Hulda Clark Zapper (the version without the 0.25 volts positive offset voltage). I pulled it out of storage after coming across an article about zapping, deciding to put it to some use again.
Because it wasn't used in a long time, I wanted to confirm that the thing still works. With a fresh 9 volt battery installed, it seemed to be putting out about 8 volts, but the current output seems to be very poor. If I simply short out the copper electrodes (1/2 inch copper pipe) by touching them directly with each other, the current draw was about 4.2 milliamps. When I grabbed the copper electrodes, one in each hand (dry hands), the current draw was 0.04 milliamps. Finally, when I wrapped the copper tubes in salty-wet paper toweling, the current increased to about 0.25 milliamps. I used an ad hoc approach when I made up my salty-wet paper toweling - I really should make up a specific solution to ensure the best conductivity solution.
One question I have is that several manufacturers claim that their zapper puts out 2 to 4 milliamps, is that confirmed or is that just estimated? Have others confirmed that their zapper is indeed putting out the current claimed?