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Re: bargain or dead bird? (fwd)





---------- Forwarded message ----------
Date: Sun, 18 Jan 98 13:40:10 -0500
From: Adam <absmith-at-tiac-dot-net>
To: Tesla List <tesla-at-pupman-dot-com>
Subject: Re: bargain or dead bird? (fwd)


>as new coiler I just broke down my first coil which gave me 12-15"
>streamers from a 15 KV 30 mA NST, 24 windings primairy, 0.02 uF C(prim)
>Leyden jars and 13 pF top cap with a 2290 windings, 4.33" diam/ 33.7"
>lenght sec coilform. Way out of tune but startling results for me as
>beginner.

Your capacitor is too big for the transformer you are using.  Your cap is 
probably not charging to its full potential, and may be inhibiting the 
maximum performance possible from your system.  0.005 uF is the most you 
can theoretically charge with a 15kAV 30mA transformer.  I little bit 
more or less is fine, but 0.02 is definitely too much.  Losing some of 
the capacitor will allow you tune this small coil using a lot more of 
your 24 turn primary.

>kitchen (is this what they call 'flashing alu' ???). For higher voltage

Aluminum flashing comes in rolls from a hardware or building supply 
store.  It is used around roofs and windows, and is much thicker than 
kitchen foil.  

>I was offered tens of NST 8000 V varying from 30-50 mA for 13 U$ each

That's a pretty good deal.  Those will work fine in parallel.  Take the 
50mA units first!

>only. What about cascading them for higher voltage and switching them in
>parallel for higher current? 

Parallel is the only sensible way to connect them.  The insulation is not 
designed to survive a continuous two-times overvoltage condition.

>Isn't it so that when firing a coil in different place with different
>max. poweroutput of the partcular walloutlet and thus different settings
>of the variac->
>4)THE  CAPS and GAPS ALWAYS SHOULD BE READJUSTED WITH DIFF.
>VARIACSETTINGS?

If you plan to run/tune at low power, you may need to decrease the 
distance of the main gap *unless* you have resonance between the neon 
transformer and tank capacitor in which case it may not be necessary.  It 
will still run smoother if you do shorten the gap, which I would 
recommend.

>the static gaps described as build up with pvc tubes: are they just a
>PVC tube with several pieces of copper tubing stack up in a row through
>the pvc tube and
>5)ONLY USE THE FIRST AND THE LAST PIECE OF COPPER TO CONNECT THE GAP?

No.  Use any combination you need to get the best gap setting.  You 
connect the first and last pipe to the tank, and use short heavy duty 
jumpers to short out gap(s) from the whole.

>6) AND IS THE ALWAYS DESCRIBED FAN JUST BLOWING THROUGH THE PIPE TO
>QUENCH?

The fan mainly just clears ionized air from the gap.  If ions build up, 
the spark will shorten noticeably.  This does help quenching.

>7) CAN I  SIMPLE ADJUST GAPLENGTH BY CONNECTING 1 SIDE OF THE GAP TO THE
>FIRSTLAST OR SECONDLAST (ETC) COPPERPIECE?

Yes.

-Adam