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Success!!!


Greetings,

Last night I finally got a tesla coil to work!  I used Gary Legel's
TCBA newsletter design (with a few modifications for currently available
materials).  I was getting streamers around 18" long from the top.
Now the next trick is to get them longer.  It's been so long since I started
to make tesla coils that I had almost decided to cut my losses and find
some other use for the transformers and capacitors that I had amassed.

I had initially built the coil to the specifications that Gary gave, 
except for one thing: I used solid #4 copper wire instead of 0.020"
copper strip.  I didn't think that there would be much difference between
the two primary coil designs.  His design called for 0.012uF capacitance,
so I hooked up two capacitors in series to achieve the 0.012uF called for.
When I tried tuning it, I got no more than a 1" spark between the end and 
ground.  Most discouraging.  This weekend my cousin was visiting from 
El Paso TX and I wanted to show him what I had.  For some reason I decided 
to try a larger capacitor (0.015uF).  I noticed a slight improvement when
I tapped at the outermost coil, so then I decided to try my 0.020uF cap.
After a little tuning, I started seeing streamers!  I had finally gotten
the thing to work.  

Last night I was playing around with the latest modifications: tapping
the primary from underneath, and a sheet of plexiglass separating the
secondary from the primary.  These two features seemed to help. 
However, I had two strange occurrences.  The first is that sometimes I
got a streamer coming off the top turn of the secondary, instead of the
top terminal.  The second is that after a longish run, my circuit breaker
on the variac tripped.  When I reset it, the coil didn't seem to power up
smoothly.  As I turned up the variac, I could hear the spark gap firing 
as it always has, but I would only get an intermittent streamer, and only 
when the power was turned up about 75%.   Before hand, I would get little 
1" hairs that would smoothly progress up to the full length as I turned up
the variac.  This last time, I would only get nearly full length streamers
in little bursts.

So, here are two questions for everyone: 
1) Does any one know why I am getting streamers from the top turn?
2) Does any one have any ideas why I am getting intermittent streamers?

Any ideas would be helpful.


>> Continuous duty microwave transformers:  I think they would have to 
be continuous duty because most microwaves can run for about 10min to 1 hr.
at full power.  I had a microwave that would give 99 minutes on its timer.

>> Series: I tried it without success on two neon sign transformers.
Perhaps I didn't play with it enough.  I am somewhat paranoid about 
neons because they short out so fast.  

Note: I know a guy in Loveland CO who just bought a rebuilt pole transformer
for about $200

Chip