Andreas, all,
The reason that the lamp dims or goes out when the secondary is approached is due to the "detuning" effect of the human body -or indeed any similar conducting object- in the vicinity of the oscillating secondary- which raises the capacitance secondary-to- ground ground capacitor "system" resulting a a decrease in the secondary resonant frequency; since the secondary is no longer resonant at the frequency at which it is being excited by the "generator" (i.e the primary tank circuit) less current circulates in it and is available to light the lamp. The same thing happens with an LED when the seconary is excited by an electronic "function" generator like Terry Fritz's reknowned "Tesla Coil Tuner" for the same reason albeit at lower i.e safer power levels.
JF Cox
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla