Hi Jim,I'm not in agreement with version 9.1 at all. That's really an old version and couping is not good if your talking about the primary "below" the secondary by 2.5". Things didn't get good in Javatc until version 10 ;-) . Upgrade!
I'm interpreting the primary as a 16 turn helical with an 8" diameter also has about an 8" height. The top of the primary would need to be at 3.3" above the bottom of the secondary winding for a k of 0.155.
I personally would recommend a coupling of 0.13 on this coil. Primary placement then is the top of the primary 2.5" above the secondary bottom turn.
I highly (HIGHLY) recommend updating Javatc to the latest version available at:
http://www.classictesla.com/java/javatc.htmlIt's not uncommon to run helical primary's low or even below the secondary. But in your case, you need to be a little above the secondary. To use all those turns you'll want to get the tank cap as close as possible for resonance (but keep an eye on the caps resonant value with the transformer as you should be above that value by about x1.5.
Doubt you'll be able to tune with the primary. Although there is more Cext with the helical versus a flat primary, the change in k is large with small changes in position. For minor tuning, you could use the top terminal height above the secondary or simply use some off axis inductance.
Jim Mora wrote:
Hello All, I have a 4" 24" acrylic secondary wound 23.25" for about 1150 turns (25 or 26awg). Furthermore, I have wound an 8" primary with 16 turns of .25" Cu tubing spaced .25" (poly rope) on a 14" high acrylic form. The coil can be moved up and down on the form as the outside is epoxied. If I am interrupting my old version (9.1) of JavaTC the secondary needs to be above the top winding about 2.5" to get a k =.155. Does that sound right?What about an ideal ground plane distance?I haven't played with a disruptive coil with a close solenoid primary before. If you are in agreement with my interpretation of the JavaTC run, what do you think about gluing a plexi disk about 3" from the top of the primary, affixing the secondary bottom to it, and adjusting the primary up and down to fine turn the coupling? The PSU is a static gap, forced air, 40-50ma 12kv repotted France neon. Am I interrupting the Java run correctly? Having the secondary above the top of the primary solenoid winding seems a bit weird. I would appreciate some feedback before I affix a base disk inside the primary tube a few inchesnear the top. Any corrections or suggestions welcomed.Thanks,Jim Mora_______________________________________________ Tesla mailing list Tesla@xxxxxxxxxxxxxx http://www.pupman.com/mailman/listinfo/tesla
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