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Re: Mailing list names and other things

> I was thinking of posting the list of names on this list.

Feel free to include my name in your post.  I also think it would be 
worthwhile to include a person's city and state if you know it so other 
people can see who is local (me: Finksburg, MD and willing to host a 
regular get-together).

RE: Primaries, terminals, RF grounding, and power factor correction

Using my new series pipe gap, I seem to have maxed out my spark 
from my small coil at about 17" (infrequently to a non-grounded pointy 
thing).  When I increase my gap distance, I start to get inter-turn arcing 
on my secondary and arcing from my secondary to my primary (which 
is a vertical helix wound on a plexiglass form).  Even when I'm not 
getting arcs between the primary and secondary, the top turn of my 
primary gives off a pretty blue haze, which I presume is pure loss and 
isn't helping anything.  To get around this, I'm going to give my 
secondary a couple good coats of polyurethane and wind a flat primary 
from some copper ribbon that I have and give that a try.  The flat 
primary will also make it easier for me to vary the coupling.

After reading the posts from RIchard Quick (RQ), I decided that my next 
project is going to be a 6" x 24" (or 30") coil.  I found some 6" diameter 
flexible aluminum dryer pipe in our local "Ace" hardware store for $8 
that should work fine as the terminal capacitance.  To power this little 
puppy, I have a couple of 277V input, 15kV 60mA output neon sign 
xformers that I'll hook up in parallel.

Also after reading RQ's posts, I've decided that my grounding is not 
really all that good.  I'm just running the RF ground into the house 
ground (a no-no according to Richard), and now that I'm starting to get 
things powered up a little bit, it seems to be causing some trouble with 
my computer (keyboard locking up, sound card making funny noises, 
etc...)  Since I think have pretty good filtering on my low-voltage side, 
the only way I can think of for any interference to get through is the 
house ground.  One of my next projects will be to get some copper 
pipes and hammer them into the ground for my dedicated RF ground.

I've seen power factor correction caps mentioned for neon sign 
transformers a number of times, but I haven't really seen what to do 
with them or how to hook them up.  I'm assuming that they go on the 
primary side of the HV supply, but are they wired in series, parallel, 
etc...?  How do you tell if they're working (does your input power hit a 
minimum?)?  Are they useful for anything other than neon sign 
transformers?  Any information would be most helpful.


Steven Roys (sroys-at-radiology.ab.umd.edu)