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Old April 3rd 05, 05:33 PM
Asimov
 
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"Cecil Moore" bravely wrote to "All" (03 Apr 05 08:38:34)
--- on the heady topic of " Antenna wires and ferrite"

CM From: Cecil Moore
CM Xref: aeinews rec.radio.amateur.antenna:27837

CM Asimov wrote:
Speaking of odd antennas, how about using a long neon tube as an
antenna and what would eznec give as values then?


CM Back in college, we used to use a florescent bulb
CM to detect RF electric fields. What's the feedpoint
CM impedance of a neon tube?

I suppose the plasma looks like a DC resistance over a region of its
characteristic and maybe even negative at some point. It depends of
course if we are talking about a glow or an arc. With an arc the
current discharge is somewhat infinite and the huge noise makes it
impractical. I'm not sure about the noise with glow discharge on a
long neon tube but I'm assuming it is very low judging from some brief
measurements I made on a neon indicator bulb. BTW these make good UV
detectors wrapped in aluminium and biased at the conduction threshold.
I'm only guessing the long neon tube has a DC resistance of about 50
ohms per foot. Something 30 feet high would therefore be around 1.5K.
What are typical running voltages and currents for neon signs?
BTW don't know if running 1KW would it make a fabulous light show?
Shades of Nicolai Tesla!

A*s*i*m*o*v

.... Speeding doesn't kill people... Stopping really fast does!