[Pumblechook]

As I tried to say..  Bloke lights 200 lamps 10 miles away in 1890 when equipment was primitive and knowledge shakey.  Yeah right.  And no-one can do it now with all the stuff we have now and much greater knowledge??

 

[wolfekeeper]

It's not completely impossible.

Off hand, you could probably do it wirelessly if you had several hundred miles of wire.

For example, if you did it with resonant transformers, the main trick is that the diameter of the coils have to be about 1/3 of the distance, so 3 mile diameter coils, 10 mile range.

[Pumblechook]

Well,, it does work with a lot of energy wasted and the coils or aerials or whatever need to be a significant proportion of the distance you want to cover.  Wasn't some idiot at MIT pretending he had invented the idea and had 60 cm coils to cover 2 metres with 40% coupling plus significant 60 Hz to RF conversion losses and if he converted the RF at the receiving end to DC and them maybe 60 Hz would have further losses.  = WASTE of time and energy.   

[wolfekeeper]

30cm coils, and I think they did get slightly further distances than others had by running the frequency close to the diffraction limit for the equipment.

OTOH it unfortunately meant that they had more intense e-fields generated, and that meant that they failed the safety guidelines, for example, if they sat in the field for much longer than needed to take a photo, and it wasn't very practical in other ways either. AFAIK the productised versions would have to run at lower frequencies.

I don't think it was entirely a knock off of Tesla's tech; he mostly wanted to use capacitive coupling for power transfer anyway, although magnetic coupling over a rather smaller air gap was used IN his Tesla coils.