I just had to add my two cents to this six-weeks-ago thread that I just 
came across.  I, too, built one of these "idiot boxes" whilst in junior 
high school (late '60s).  I used NE-51's and it was powered from a 
(technically) "dead" 200 volt photoflash battery.  It ran for a year or two 
before I had to get another battery.  I probably ran it until I went to 
college, and I can't be certain I didn't have it there as well.  I keep 
hoping I will find it in the garage someday, since I never throw anything 
away.  Each lamp used a single resistor in the classic fashion.  I never 
had to replace a lamp.  Probable reason being that "200 volts always wins".

The number of lights was attributable to the number of junk TV sets I was 
able to locate.  Each chassis in the high voltage section would yield up 
one each 10 or 22 meg resistor, and a .1 at 400 volt mylar cap.   Then I 
could add another light to the box.  I ended up with 13 lights.

Barry

-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist