Re: First light
From: George W. Ensley Jr.[SMTP:erc-at-coastalnet-dot-com]
Sent: Friday, January 09, 1998 3:33 PM
To: Tesla List
Subject: Re: First light
>Sent: Thursday, January 08, 1998 7:24 PM
>Subject: First light
>I have been researching TC's for about a year now but have finally finished
>building my first Tesla coil. I am getting 49" streamers with seldom
>at 52". I would like to thank everyone on the list for their
>Although I have posted the list but a few times, I have always gotten
>The majority of my questions were answered from other posts and the search
>feature on the archives (Thanks Chip, good idea).
> What I would like to know is, how does my coil stack up against other
>with the same input power? Here are my coil's specs:
> Power supply: 2 15KV-at-60mA NST's
> no variac
> Filter network: Saftey gap, grounded center electrode
> 2 15KVDC doorknob caps in series to ground (each
> 1 3.5" toroid 25 turns #14 in series with
> 1 aircore inductor 2"o.d.x6" PVC wound with #28
> wire and a 50W 3K ohm resistor (each leg).
> 1 25A line filter (before NST's)
> Spark gap: RQ type in parrallel with HV bushings
> 11 electrodes 0.75x6"spaced 0.025" in 6" PVC (capped
> cut for air flow).
> 1 Vacuum cleaner motor
> Caps: 4 Rolled 0.011uF (2 series sets of 2, in parrallel)
> 3 20mil sheets 16"x96" of LDPE
> Al roofing flashing 12"x 91"
> Transformer oil (Texaco)
> Kraft paper between each
> Primary: 17 turns 0.25" copper tubing spaced 0.25"
> 15 degree bank
> Secondary: 8.5"o.d. (dried and sealed in and out)
> 34" winding length #20 magnet wire 1000 turns
> Top load: Toroid 4"x20" crafted from styro. and Al tape (looks
> Misc.: #6 sol. copper hookup wire for tank ckt.
> 0.05" wide brass strips for cap connections
> #14 HV wire for tap lead (neon sign shop)
> I am tapped at ~14 turns on primary for best spark. I know I need more
>and a larger wire for my tap lead but if someone sees something else I
>do to improve my coil, please let me know.
> Thanks again
> Rusty Duncan
Sounds like it's working pretty good to me.
Other than what you mentioned I would say up the size of the toroid to
6"x30" to raise the breakout voltage a bit. Then as a last resort up the Q
of the caps by going commercial.
As a reference I had a 6" coil with a 12kv 120ma xfmr. The long sparks were
at best 67" and average was 50"-60". Input to the neon was probably 130V.