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Old 03-15-2009, 08:45 PM
DrStiffler DrStiffler is offline
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Join Date: Mar 2009
Posts: 948
Originally Posted by amigo View Post

I have rewound L2 to be an air coil and replaced the 10k with a carbon based resistor.

Following your suggestion, I made 1/4" plastic rings instead of a full length dielectric on the gate and put them in place.

Unfortunately this modification changed the gate's capacitance (lowered it) by ~4pf and threw the setup out of whack. After two hours of mucking around I could not get the same "strong" glow in the neon bulb, as I used to have. The neon bulb glows bright but appears not the same. Maybe because it's still daytime I'm having a problem with discerning the brightness.

Further more touching the neon bulb to the Ground cylinder does not always light it up even though the circuit appears tuned. The fluorescent will light up but for whatever reason neon bulb does not immediately, or at all.

My gate's capacitance (Collector - Ground cylinders) is about ~30pF right now with the plastic rings, while the previous gate had ~36pF.

I am going to look right now into other dielectric materials I can find around the house and see what kind of capacitance I get...
WOW! What a way to spend your Sunday?

Well its tuning, tuning, tuning.

My collector cylinder to ground cylinder capacity is so small it can not be measured with my meters. My Collector Cylinder to center (common) cylinder is 15.5pF as is the Ground cylinder to center (common) cylinder.

My current is <10mA and the transistor runs at ambient. I have included a picture of it running.

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