Dr Ronald Stiffler SEC technology

[Lidmotor]

erfandl---The inductor is 1000uh and a 3300uh.  I got the 3300uh (3.3 milihenry?) off the circuit board that came out of a 50w OptoLight led bulb.  The little transformer looking thing on the board (that is really just an inductor) also worked.  I can't remember what the value was. 
  I hope you try that 3 choke Exciter circuit that Slayer came up and put your spin on it to light up these 110v led lightbulb arrays.  What is happening in that circuit carries over to what we have been doing here---make light with as little power as possible.

Cheers---Lidmotor

[itsu]

Hi Itsu,

Very good, many thanks for everything.

I suspect the toroidal core starts saturating from the DC component of the collector current.  When you have time please measure the input current taken from the 12V battery.
Core saturation can cause the sine wave distortion we see across the tank (the yellow waveforms). And if you measure the variable capacitor pF value after it is set to the best tuned position, you may find it higher than what would be needed for tuning a 8.2 uH coil to 13.5 MHz, this would be a sure indication of certain core saturation which involves a less than 8.2 uH.

Trying to reduce core saturation, would you make the tap at the 3rd and / or at the 2nd turns instead of the present 4th? I know this may sound strange but I think it would be worth testing. This reduces the Amperturns for the core from the collector current point of view but also reduces the AC impedance for the collector, on which the transistor can amplify.  But the increased step-up transformation in the coil may partially compensate for that.   Try to set similar input current by the 100 kOHm trimmer pot when using the 3rd or 2nd tap, should it change but of course you can set it also for the highest output (maybe with some distortion returning...).

The spectrum of the waveform that drives L3 has many harmonics due to the suspected core saturation,  so energy is distributed rather than confined to the base frequency (13.5 MHz).
Okay on detuning the variable cap and the 40 MHz returns, we need not bother about it,  the loaded and detuned tank will have higher impedance for the collector nearer to 40 MHz than around 13.5 MHz, that is all. 

Two question if I may: Did you remove the capacitor from between the base and emitter?  Is the 22 pF or some other value is still needed between the collector and emitter for the oscillator to work?  (Switch the supply voltage on and of when the 22pF is changed or removed.)

Gyula

Gyula,

i have a hard time to accuratly measure the input current of this circuit at this frequency.
I normally use my current probe and match this up with a csr (1 ohm in this case), but they do not match up here.

So i then normally trust the csr over the current probe.

Here i have a 1 Ohm 1% inductionfree resistor in the minus line to the battery.
See screenshot for blue collector/emitter voltage and yellow the voltage across this csr.
So we seem to have 50mA rms input current (@ 12.5V = 625mW).

Video here:  https://www.youtube.com/watch?v=NjvnQNMkqos


Concerning the 22pF cap across collector / emitter, i can remove it and it still oscillates.
The variable cap at resonance with the 4.4uH toroid measures 50pF.

I will be playing with the tap later this weekend.

Itsu

[gyulasun]

Hi Itsu,

Thanks for the current measurements. I think you could pull out the crystal from the circuit and measure directly with a DC Ampermeter (DMM or analog) the non-oscillating input current, this would also be a kind of information for the current. And then try to plug in the crystal while the DC Ampermeter is still in the circuit to see how it changes.  By the way, what kOhm was the 100 k potmeter set to when you checked the input current?
I can see filter capacitors across the input 12.5V supply voltage, this is very good you use such. If you recall the Doc's SEC circuits he included a multistage LC filter in both supply rails between his oscillator and supply voltage source, so the RF energy going towards the supply was gradually blocked by the series L and parallel C members of the filter. I am not saying you need to build such LC filter of course and measure current behind the filter, I just mention this.
Would like to ask: when you measured the variable capacitor as 50 pF, was the 22 pF placed between the collector-emitter at the time you tuned the tank with the variable cap to maximum brightness? I assume no scope probe was attached to the collector or to the tank during this time.

Normally a 4.4 uH coil needs about 32 pF tuning cap to resonate at 13.56 MHz. A 50 pf cap involves having a 2.76 uH coil to resonate at 13.56 MHz. So if the 22 pF was present between the collector-emitter, then its capacitance was also in parallel with the tank via the low AC impedance of the battery and filter caps, hence probably there is no or only a little core saturion in that case.
IF the 22 pF was removed earlier than you checked the variable cap,  then the coil had only 2.76 uH inductance, this would indicate a stronger core saturation in that case.

Thanks,  Gyula

[NickZ]

   Gyula:   Here's a couple of pics (below) so that you and others can see what my crystal oscillator is looking like, at the moment. 
   I removed the AC filter and capacitor, just left the 0.1uf one, at the input. I installed a 221 choke, but I don't know it's value.
   I also made holders for both the crystal as well as the transistor. So that they can be easily swapped out. 
   The scope is on the 10x setting, as that is the probe that I'm using. But, the probe switch was on 1 instead to 10 times setting. Thanks for the tip.   C1850 transistor still runs ok on 4v, but still gets hot at 8v, and will melt at 12v input. I'll see about putting in a trim pot on the base. There are still two 1k resistors, and a small pot on the board, which I'm not using. Perhaps I should.

   Lidmotor: Thanks for the info on winding of the L3. However, your L3 seams a bit longer than the normal Doc's L3 coil that he uses.  How long is the Doc's L3, (just the windings), the Doc made L3 you have at home?  And I'll try to make one like that, first.

    The two scope shots are while running on batteries, first one is on 4v, and the second one on 12v.
    The last pic is the oscillator running on NO input, or better said, running a 4v input, but with no negative ground connected on the battery. Stray AC, perhaps.
   
   
   
   

[itsu]

Hi Itsu,

Thanks for the current measurements. I think you could pull out the crystal from the circuit and measure directly with a DC Ampermeter (DMM or analog) the non-oscillating input current, this would also be a kind of information for the current. And then try to plug in the crystal while the DC Ampermeter is still in the circuit to see how it changes.  By the way, what kOhm was the 100 k potmeter set to when you checked the input current?
I can see filter capacitors across the input 12.5V supply voltage, this is very good you use such. If you recall the Doc's SEC circuits he included a multistage LC filter in both supply rails between his oscillator and supply voltage source, so the RF energy going towards the supply was gradually blocked by the series L and parallel C members of the filter. I am not saying you need to build such LC filter of course and measure current behind the filter, I just mention this.
Would like to ask: when you measured the variable capacitor as 50 pF, was the 22 pF placed between the collector-emitter at the time you tuned the tank with the variable cap to maximum brightness? I assume no scope probe was attached to the collector or to the tank during this time.

Normally a 4.4 uH coil needs about 32 pF tuning cap to resonate at 13.56 MHz. A 50 pf cap involves having a 2.76 uH coil to resonate at 13.56 MHz. So if the 22 pF was present between the collector-emitter, then its capacitance was also in parallel with the tank via the low AC impedance of the battery and filter caps, hence probably there is no or only a little core saturion in that case.
IF the 22 pF was removed earlier than you checked the variable cap,  then the coil had only 2.76 uH inductance, this would indicate a stronger core saturation in that case.

Thanks,  Gyula

Gyula,

I just pulled out the crystal when in resonance and measure with an analoge DC amp meter the current in the
12V supply line to be 62mA.

Inserting the crystal (activating the leds) lowers the current on this meter to 50mA.

The 100K pot was and is set at 56K.

I only pulled out the 22pF cap at the very end to see if it still oscillates which it does, so the 50pF was
measured when this 22pF was still inserted as was the 8pF scope probe attached.

I did not see the distorted output signal as i showed in this post:
https://overunity.com/17249/dr-ronald-stiffler-sec-technology/msg523338/#msg523338
so indeed i think there was no or little saturation.

Not sure why i was not able to tune the thing to that situation, could be the inserted 1 Ohm csr
prevents this from happening.

Itsu