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David, Luckily I have 3-4 pairs of Tungsten rods but unfortunately only a 2 pairs of 3" high insulators. I'll have to see if I can find something like wood to temporarily mount them too. I'm assuming the more you have the closer they should be to have an over all gap of about 1/4" (i.e. 4 pairs should have 1/16" gap each to make an overall 1/4" gap total). But first I'll try the 2 I have in "series" set to 1/8" gap each and see if there is any significant improvement in spark length. I am moving in a couple of weeks so I wont be able to try it for a 2-3 weeks though. Thanks, Tim On Tue, Apr 7, 2015 at 10:22 AM, David <zipo@xxxxxxxxxxx> wrote: > Tim - It wouldn't hurt to try them in series, maybe even 3 or 4 gaps in > series and then adjust the total gap for best running. I believe you trying > and experimenting will tell you a hole lot and be very worthwhile. Without > some sort of elaborate ballasting it has been shown that two sparks in > parallel can't happen, as soon as one gap fires the other gap goes to zero > volts. And please let us know how the experiments go. > > to find the best answer you have to eliminate all of the bad answers first. > > > David > > On 4/7/2015 10:39 AM, Timothy Gilmore wrote: > >> David, >> >> When I bought the tungsten spark gaps and fan I received this email: >> >> *Most folks use them in series and reduce the gap width on each one. For >> example for a ¼ inch gap (a good place to start) they use two gaps in >> series set a 1/8”. I have had excellent results using them in parallel. >> For >> the amount of current you are using I would use two gaps in parallel both >> set at 1/4 inch. It works great and is easier to line up with the fan.* >> >> >> Should I be using them at 1/8" gaps in serial then? >> >> Tim >> >> On Tue, Apr 7, 2015 at 8:26 AM, David <zipo@xxxxxxxxxxx> wrote: >> >> Tim - Here is my take on spark gaps. First you say you have two gaps in >>> parallel, not series but parallel? Only one spark at a time can happen >>> in a >>> parallel gap set up, maybe it will switch back and forth from one to the >>> other but only one at a time. A single gap can provide the least >>> resistance >>> and more current in the primary circuit but does not quench and control >>> ring down very well. putting multiple gaps in Series seems to provide an >>> improvment in quenching and ring down control. To experiment with series >>> multiple gaps would seem to be a logical next step, two, four, maybe even >>> six gaps in series. A lot of people have had good results with the >>> Richard >>> Quick multi gap and is not to difficult to construct. The next step up >>> would be a sucker gap, a lot of people like these and they give real good >>> results, there are examples on the net. But I believe the best and most >>> difficult is the Sync Rotary gap. my recommendation would be to >>> experiment >>> with the progression of gaps above but keep an eye to words the sync >>> Rotary. Some thing I wish more people would do too, is cover your spark >>> gap, put a largish box over it to block the light from it and to quiet it >>> down a bit, doesn't have to be fancy, just a simple wooden box placed >>> over >>> it wile your running. Nasty gasses build up inside but for the length of >>> time most of us run our coil it will be ok. For a 15kv NST the max >>> voltage >>> it can handle is about 25kv +- a bit peak, so you want the largest cap >>> you >>> can charge to 25kv. The Geek group capacitor chart is very good at >>> appropriate cap values for a type of setup/gap being used. >>> >>> Thanks >>> David >>> >>> On 4/7/2015 8:00 AM, Timothy Gilmore wrote: >>> >>> David, >>>> >>>> 72" WOW as I have similar specs but only get 36-48" or so. >>>> >>>> >>>> Here are my specs: >>>> 15kv, 120ma <-- Same (2 15kv 60mA NSTs) >>>> >>>> 3 levels of 0.010uf in parallel for 0.030uf mmc (30kv) <--- Seems >>>> like >>>> your double of what mine is >>>> >>>> 2 parallel tungsten gaps "about" 1/4" separation each (with a squirrel >>>> cage >>>> fan blowing on them) <--- *Should these be tighter since there are 2 >>>> of >>>> them? (i.e. 1/8" inch each)* >>>> >>>> Secondary - 6"dia x 31"lg 1400 turns No. 24 >>>> >>>> Top load - 6" x 25" aluminum dryer ducting and foil pizza pans with foil >>>> wrapped cardboard between and nylon toilet bolt <-- NOT wrapped in 3" >>>> aluminum tape >>>> (Would wrapping this improve the length significantly). I have the >>>> materials for an 8" aluminum dryer ducting, aluminum tape, 17.75" x 1" >>>> circular wood table (to be wrapped in foil and then glued and possibly >>>> aluminum taped). *Should I just wrap the 6" more flimsy version or go >>>> with >>>> the bigger 8" more solid heavier version (to construct) - OR use both on >>>> top (wrapped/unwrapped in aluminum tape)?* >>>> >>>> Primary 0.25" copper refrigerator coil in single layer tapped at 12.5 >>>> turns >>>> >>>> I was thinking of the rotary gap motor version for the spark gap but >>>> have >>>> no idea where to even start on this. I was hoping to get everything the >>>> best I could first before and if I go down that route. >>>> >>>> *So what has the greatest impact on spark length - the rotary spark gap >>>> or >>>> the wrapped aluminum tape on the toroid - or are both necessary?* >>>> >>>> >>>> Thoughts? >>>> >>>> Tim >>>> >>>> >>>> >>>> >>>> On Mon, Apr 6, 2015 at 8:56 PM, David <zipo@xxxxxxxxxxx> wrote: >>>> >>>> Timothy, List - I too have recently put together a 15kv, 120ma coil. >>>> I'm >>>> >>>>> still tweaking for best out put. So far I'm getting 72" output and >>>>> based >>>>> on >>>>> the way it was running and the way it was tuned I believe it will do at >>>>> least 80" after it's fully peaked. I can only run outside so I'm having >>>>> to >>>>> wait for good weather. >>>>> Here is a brief over view: >>>>> 15kv, 120ma >>>>> .0625uf mmc >>>>> sync rotary gap @ 120 breaks/sec >>>>> secondary - 7"dia x 27.3"lg 1500 turns No.26 wire >>>>> Top load - 5" x 20" spun aluminum toroid >>>>> primary - 10 turn 2 layer spiral >>>>> Tesla equi drive circuit. >>>>> >>>>> There are two aspects of tuning and peaking that seem not to get the >>>>> attention that they should (in my opinion). >>>>> First is that if tuning with a signal generator and a oscilloscope you >>>>> need to simulate the added capacitance of the spark. Adding a piece of >>>>> wire >>>>> the length of the spark your expecting to the top load and then tune >>>>> with >>>>> sig gen and o scope. This seems to be overlooked a lot. Java TC shows >>>>> this >>>>> very well. If you ad an additional cylindrical top load, on JTC, >>>>> .02dia x >>>>> length of spark (JTC will point it straight up) you will see a marked >>>>> reduction in res. frequency. >>>>> Second is that the safty gap or static gap width has a large impact on >>>>> output. There are way of setting these gap for safest operation. >>>>> However >>>>> I'm guessing these gap widths get pushed a bit by savvy coilers but >>>>> don't >>>>> talk about it. At least on a sync rotary safety gap width has a big >>>>> bearing >>>>> on output. I would find it very interesting to hear what gap width >>>>> people >>>>> are using with what setup. And in full disclosure :) I have set both >>>>> of >>>>> my >>>>> safety gaps at .22 using rounded brass draw pulls for electrodes. >>>>> It just seems to take a lot of time to get every thing tweaked to >>>>> Perfection. >>>>> >>>>> Carry on >>>>> David >>>>> >>>>> >>>>> >>>>> On 4/6/2015 9:34 AM, Timothy Gilmore wrote: >>>>> >>>>> Has anyone put together any sort of a listing of others Tesla Coils >>>>> >>>>>> built >>>>>> with parameters listed such as: >>>>>> >>>>>> (for example): I have 2 NSTs (15kv, 60ma) each, 6" diameter, 31" high >>>>>> secondary, torroid is .... >>>>>> >>>>>> I am getting 3-4' sparks and wondering if I should be getting longer >>>>>> sparks. Is this normal? or should I add another NST or bigger Toroid >>>>>> (working on an 8" diameter ducting bigger one). How do I know since >>>>>> the >>>>>> Tesla Map software says I should get "ideally" 72.6 inch sparks and >>>>>> I'm >>>>>> getting about 1/2 to 2/3 of that. Just wondering if it's not tuned >>>>>> properly >>>>>> (but I think it is) - or making a larger toroid is worth the effort if >>>>>> I'll >>>>>> gain a foot or more sparks. >>>>>> >>>>>> How does one know they are getting close to the best they can get in >>>>>> spark >>>>>> length? >>>>>> >>>>>> I have attached my Tesla Map file of current settings. >>>>>> >>>>>> Thanks, >>>>>> >>>>>> Tim >>>>>> _______________________________________________ >>>>>> Tesla mailing list >>>>>> Tesla@xxxxxxxxxx >>>>>> http://www.pupman.com/mailman/listinfo/tesla >>>>>> >>>>>> >>>>>> _______________________________________________ >>>>>> >>>>> Tesla mailing list >>>>> Tesla@xxxxxxxxxx >>>>> http://www.pupman.com/mailman/listinfo/tesla >>>>> >>>>> _______________________________________________ >>>>> >>>> Tesla mailing list >>>> Tesla@xxxxxxxxxx >>>> http://www.pupman.com/mailman/listinfo/tesla >>>> >>>> >>>> _______________________________________________ >>> Tesla mailing list >>> Tesla@xxxxxxxxxx >>> http://www.pupman.com/mailman/listinfo/tesla >>> >>> _______________________________________________ >> Tesla mailing list >> Tesla@xxxxxxxxxx >> http://www.pupman.com/mailman/listinfo/tesla >> > > _______________________________________________ > Tesla mailing list > Tesla@xxxxxxxxxx > http://www.pupman.com/mailman/listinfo/tesla > _______________________________________________ Tesla mailing list Tesla@xxxxxxxxxx http://www.pupman.com/mailman/listinfo/tesla