Re: Tesla Ground (fwd)

---------- Forwarded message ----------
Date: Sun, 18 Jan 1998 21:16:19 -0800
From: Bert Hickman <bert.hickman-at-aquila-dot-com>
To: Tesla List <tesla-at-pupman-dot-com>
Subject: Re: Tesla Ground (fwd)

Tesla List wrote:
> ---------- Forwarded message ----------
> Date: Sun, 18 Jan 1998 17:58:41 -0700 (MST)
> From: "Matt P." <ch038map-at-mode.lanl.k12.nm.us>
> To: Tesla List <tesla-at-pupman-dot-com>
> Subject: Tesla Ground
> All-
>         Today I (attempted) to construct an RF ground for my tesla coil I
> am building. Being the cheapskate that I am, I decided to use some scrap
> aluminum conduit that was laying around. I found a piece about 6' long and
> drove it  into the ground leaving about 6" sticking out of the ground to
> connect to. My question is this: will this poorly built ground be good
> enough for my coil? My coil is only about 3.25" and powered a tranny
> that is about 7Kv 30mA. I didn't know weather to connect the bottom turn
> of the secondary to the primary like some people do, or try to construct
> my own ground. Any comments, criticisms are appreciated.
>                         Matt P.


The aluminum RF ground should be OK for a while with your low power
coil. With time, however, the aluminum will corrode away to nothing in
the ground, so plan on replacing it with a copper-plated steel ground
rod. These are really not very expensive and will last for a LONG time. 

Do NOT connect the secondary to the primary when using a neon
transformer as a power source! In general, connecting the primary and
secondary is not a recommended practice, even when powering off
isolated-secondary transformers (i.e., pole pigs or potential
transformers), since if not done properly, it can result in high voltage
60 Hz power appearing at the top of the secondary! Also, this approach
will NOT work with neons due to the way that neons are internally
connected  - the HV center tap is tied to the case. 

Keep your primary tank circuit and the base of the secondary isolated.
You may want to connect the case of the transformer to the same RF
ground that you use for the base of the secondary... but make sure you
have a good RF ground connection first!

Safe Coilin to you, Matt!

-- Bert --