Re: Instrumental TC tuning

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: Esondrmn-at-aol-dot-com 

In a message dated 10/29/03 9:12:29 PM Pacific Standard Time, 
tesla-at-pupman-dot-com writes:

Chris,

I would suggest using 1.0" to 1.5" diameter copper pipe sections cut to 
about 2" or 3" in length.  Cut three of these using a tubing cutter which 
will bevel the ends inward.  Deburr the ends.  Mount them parallel to each 
other with each of the two gaps being .030" to .050".  At that low power 
level, you may or may not need a fan, wouldn't hurt anyway.  You will 
probably get several opinions, but that is what I would do.  For the 4 kv 
20 ma contest, I used one gap set at about .050"

Ed Sonderman

>Hi Ed
>
>You are correct in assuming a static gap (single gap of opposing
>tungston carbide cutting tips that are equalateral triangles with 15 mm
>side lengths and slightly rounded corners) which I set to ensure firing
>with no tank circuit present.  I do run a small fan between the gap
>which I will try turning off which should decrease the firing voltage.
>What would you suggest for a gap setting if using a 6kV/30 NST?  Note
>that my safety gaps on my filter were firing when I was setting my main
>gap also (I do have 1200 ohms of resistance in my filter which the
>safety gap is the first stage of).
>
>Chris,
>
>If your safety gaps are continuously firing with the coil in operation
>and
>they don't fire when connected only to the high voltage transformer,
>then
>you are experiencing 60 hz resonance in the primary circuit allowing the
>
>primary voltage to go way above what would be normally expected.  Proper
>
>setting of your main (static I expect) gap will fix this.  For a 15 kv
>neon
>sign transformer, I use .20" to .25" maximum.  Increasing your primary
>capacitance value by about 50% will also help.
>
>Ed Sonderman