Well The third build is absolute rubbish. The inner secondary is lucky to output half the power being sent to the primary. Also,no matter what the frequency,i cannot get that negative resistance effect-not even close.
This tells me that the inner core must be of a high permeability. I also believe that the higher the permeability of the outer core,the better the results will be-but i have a limit as to how high i can get the permeability of the outer core. The inner core is no problem,as it would seem that !off the shelf! ferrite cores are best for this design.
I have ordered a large ferrite core from Ebay,and will be trying again when that arrives. This will give me some time to experiment with different compounds for the outer core.
No again. This should simply confirm that winding the secondary all around the core is not efficient. The amount of outer coil impress would have to be so perfect to "push" output out of that inner coil will be too great with outer and inner core forces working for or against each other while the inner secondary is trying to output whatever it can.
For the impress to be activated by the outer primary, then amplified by the outer core that then exerts to the inner secondary before it can influence the inner core. Chances of that happening successfully on a first few trials basis is slimmer then winning the lotto let alone finding a new core material to favor the process. So many variables at play here. Traps will abound and only increase in the cancellation potential which you have already maximized by winding the secondary all around. Do the cores require rebiasing? So how can the outer primary and core rebias the inner core? If the inner coil is the output coil, what happens when the inner core is saturated and cannot reset (rebias)?
So what tests did you do with the inner core alone to find out how permeable that core is? It's very easy. You wind a 3 turn coil on the inner core and pulse it while you scope a second 3 turn coil on the same core that can slide closer or further away from the pulsed coil. This will tell you how far the pulsed coil can impress via the core to the second coil. If the second coil cannot pick up anything while it is on the opposite side of the inner core, this will confirm that a secondary wound all around is not good and that the impress to pickup has to be shorter runs, many few turn secondaries in parallel to exit the output before it gets cancelled.
So with your last build all I would want to know more then I know now is as follows.
Just short the secondary or put a pot on it. Put your CH1 scope on the primary since it will be the output and put the CH2 on the secondary. Take any separate coil and put it to your pulse generator and place that coil under your RT. Play with the FG that pulses that third coil and find the best frequency that will promote maximum waveforms in one or both RT coils. The idea here is to use the inner secondary as the primary and the outer primary as the secondary where the two cores become active via the inner coil and add together as active total mass that the outer primary can output. You may need to split the outer primary into halves or quads and see which ones output the most because for sure, even if a third coil can impress enough to the RT inner coil, since that coil is wound all around it will still always have dead spots.
The other option is as follows.
Put the FG onto the inner coil where you also take a separate coil that has a core and many winds on it and add this in series with the inner secondary on the negative side of the pulse. Play with the FG and see how the output is in the outer primary. Again you may need to split the outer primary into halves or quads. Then try the same but now on the outer primary and output the secondary.
Small tests man.
Also, yesterday my wife picked up a can of this stuff at Canadian Tire. It was 10 bucks instead of 40.
http://www.rustoleum.com/en/product-catalog/consumer-brands/specialty/magnetic@TinMan I know this is your show, your build, "your design" but man, do you want some help or not. Just say the word and I will no longer bug you. I will be putting up a new Half Coil Syndrome 2 youtube hopefully tomorrow, the contents of which should help clarify some of our most standard mistakes with pulsed coils. Every OUer needs to get this sunk into their heads. The game was never played by natures rules but forced by mans rules. hehehe
Listen man, learning is a two way street. One small side test on your part can save days of crap for many others and vise versa. We all spend time that hopefully saves time for others. The hours of trials I do on my bench to find the effects that help me make my videos is to open eyes and save years of hassles for others. If one shown effect can do that to only one guy that opens his eyes to an even newer effect, then the work gets compounded and that's how we all progress in this venue of illusion filled traps and misconceptions.
wattsup
PS: I have to say that your latest stint with @Erfinder was not cool. It does not cost anything to show some respect and the dividends in the long run could be worth it with just one new idea. You never know in advance from where that spark will come.