Hi Steve, Stephen J. Hobley wrote:
This sounds correct from a fundamental standpoint of the tuner. Is this the Terry Tuner? I have one myself I built up and it certainly has come in handy for more purposes than Terry probably originally planed. My Tuner is a little modified from the original (mainly caps for frequency range of big low Fr coil and small high Fr coils). When I use it, I typically adjust for sec brightness and then take the tuner to the work bench and measure the "tuned frequency" right from the tuner. Primary is performed just as yours. Depending on the primary and secondary however, the tuner will work well on some and not so well on others (meaning your eyes can't distinguish brightness well and usually in the primary portion). As I said, some are easy to distinguish and others harder. Your performing the procedure correctly from what I read.This is the procedure that I use - I leave primary and secondary in place and connect the tuner in between the secondary base and ground. Turning the knob gives me a very definite lowest brightest point on the LED, way brighter than any of the others - I leave the knob set at that position.Then I remove the secondary coil, short out the spark gap and connect the tuner across the tank cap. I then take my primary tap and move it around the primary coil until I get the dimmest response from the led. This was at turn 11, and not between turns 8-9 as Teslamap said it should be. At this point I have assumed that the primary is resonating at the same frequency as the secondary. Can someone confirm if this is correct? Steve
But, realize that Teslamap or similar programs will get you only in the ball park. For some, a home run, for others, a base hit. Walls, height of coil above the ground plane, ceilings, and other objects near the vicinity affect the final result. Javatc has inputs for coil height above the ground plane, wall radius, and ceiling height, yet it still cannot account for the exact affect of external capacitances to the coil perfectly. There's certainly a better chance of a home run than the other programs out there, but there is also the chance of a base hit in some surroundings. That's just part of the fun I guess.
Use programs for ballpark design. Some programs are better than others for this. But in the end for performance, use your God given ability to distinguish performance and modifying the tap position to accommodate the best performance. An LED indication is nice to see and does indicate resonance. But, coils don't always run best at perfect resonance. Most of the time, the primary does best when it is slightly heavy on inductance (maybe 1/4 to 1/2 a turn heavy for a common coil). There are reasons for this but it isn't all black and white.
Take care, Bart _______________________________________________ Tesla mailing list Tesla@xxxxxxxxxxxxxx http://www.pupman.com/mailman/listinfo/tesla