Dr Ronald Stiffler SEC technology

[gyulasun]

You need not order both trimmer pots, only say the 220 kOhm and a 10 kOhm resistor you put in series with it.

Regarding the ferrite rod, I suggest to use more turns for the coil to make self inductance higher in itself so that the ferrite rod should not be needed to plug into the coil fully or even half way: just a little, say  only 2-3 mm to get the highest brigtness. I mention this because at 13-14 MHz, good quality ferrite material is needed, otherwise losses are inherently introduced into the coil and brightness suffers. Unless you are fully aware of your ferrite specifications, manufactured for the 10-20 MHz range. 

Gyula

[erfandl]

You need not order both trimmer pots, only say the 220 kOhm and a 10 kOhm resistor you put in series with it.

Regarding the ferrite rod, I suggest to use more turns for the coil to make self inductance higher in itself so that the ferrite rod should not be needed to plug into the coil fully or even half way: just a little, say  only 2-3 mm to get the highest brigtness. I mention this because at 13-14 MHz, good quality ferrite material is needed, otherwise losses are inherently introduced into the coil and brightness suffers. Unless you are fully aware of your ferrite specifications, manufactured for the 10-20 MHz range. 

Gyula

OK thanks. Yes, I'm just 2mm of ferrite core into the coil not all.

[Slider2732]

Just another +1 of congrats erfandl..that must have been a frustrating journey.
But now, that light output is well worth it and surpasses my own efforts with the Dollar Tree bulb easily.
I need a different bulb 

[erfandl]

Just another +1 of congrats erfandl..that must have been a frustrating journey.
But now, that light output is well worth it and surpasses my own efforts with the Dollar Tree bulb easily.
I need a different bulb 

thanks slider 
I test the lidmotor circuit from this video ( https://www.youtube.com/watch?v=tJhdZNIUOiI ) with 4 watt LEDs extracted from fillament light. the result is better than the first crystal circuit. the diodes is Germanium gold bonded AA119

voltage is 12 volt @ 51.5 mAh - 618mW

thanks to lidmotor and Gyula 

[gyulasun]

Hi Lidmotor,

Nice build for the "wiper" coil and it is unfortunate that it makes tuning very touchy (albeit it was expected due to the always huge field strength around the mainly air core coil). 
Maybe a 40-50 cm long piece of thread (yarn) kinked to the end of the wiper rod would reduce hand closeness by pulling the wiper with the thread... 

Just a sidenote but not important: you wrote Energetic forum in the text under the video: I mentioned this here at overunity forum. But again, do not bother, no problem.

Thanks, Gyula

Gyula -----I made one of those wiper coils for the crystal circuit and it worked.  It is very touchy because of how we are using it.  If you get your hand near it that changes the local capacitance which throw things off.  You have to adjust it in small increments then get away from it to see what happens.  Fine tuning can be done with a ferrite rod if you need to. 

https://www.youtube.com/watch?v=4ZjAKK38UIA

--Lidmotor