Hello Fritz, We all have our methods for this and we vary slightly on some things.I personally would recommend taking the static gap and the NST to a table. Connect the static gap across the high voltage terminals of the NST and set the static gap to it's widest setting. Then power up the NST. The gap will likely not be conducting. Begin reducing the gap width until the gap conducts consistently each time you power up the NST. This will be a good setting for your gap. The reason I recommend this method is that electrode material, air pressure, and electrode size will change the gap distance requirements to fire at the NST's output voltage. By taking the static gap and NST alone and adjusting the gap, those basic items are accounted for and help ensure you don't set the gap too wide. Dr. R's values of 0.18 to 0.2 inch are right in the ballpark for most gaps, but because we don't know the electrode size, it is best to ensure a proper gap distance.
BTW, a proper gap distance for a static gap is as large a gap distance that can be obtained without risking over voltage of the MMC rating or the NST. The NST is usually the biggest concern.
A coil will fire a static gap at wider settings, but will cause excessive voltage to be felt back across the NST and can cause a high voltage short inside the NST on one of the internal coils. So to keep the coil operating within it's limits, this approach is best (IMO). It is important to provide a healthy air flow across the static gap when it's running in the coil. Failure to do so will result in the gap electrodes getting very hot. This will cause the gap voltage to conduct at lower voltages and results in a low coil performance.
Take care, Bart Fritz W. Egli wrote:
Dear Doc, dear all, How should the static gap (tank gap) to be concernet with in this process? Question from the Swiss alps... Fritz Re: [TCML] Setting up for the first time Set your total gap spacing to around .180" (180 mils), then, after tuning at low power (50% or less) with a variac, the set final gap to approx 0.200 (200 mils). Performance tuning includes both primary resonance tap point, and also elevating the sec coil to set the best coeff of coupling (k factor) as indicated by longest output spark length. Some 1/2 inch size scrap plywood works good for this exploration process. In many cases the sec coil can be elevated 1-2" above the horizontal plane of the pri coil to obtain longest spark output. Happy sparkin' Dr. Resonance 2008/7/17 Stephen J. Hobley <shobley@xxxxxxxxxx>:I'm getting close to firing up my very first Tesla coil. It uses a 12Kv NST, Terry filter, static gap, and MMC. When I begin, how should I set the gap? ...and then how should I measure performance and make adjustments for optimum discharge? Steve _______________________________________________ Tesla mailing list Tesla@xxxxxxxxxxxxxx http://www.pupman.com/mailman/listinfo/tesla_______________________________________________ Tesla mailing list Tesla@xxxxxxxxxxxxxx http://www.pupman.com/mailman/listinfo/tesla _______________________________________________ Tesla mailing list Tesla@xxxxxxxxxxxxxx http://www.pupman.com/mailman/listinfo/tesla
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