Dr Ronald Stiffler SEC technology

[gyulasun]

Hi Folks,

I am happy for your enthusiasm over ring modulators and indeed the 4 diodes involved in a ring modulator are in a series loop but normally two input frequencies are needed for a ring modulator (or ring mixer), no?

As I see from Lidmotor's video, he now uses 4 diodes to drive the LEDs and the middle point of the two-two diodes is connected to the plate of a capacitor, the other plate of the capacitor is driven from the L3 coil. 
This means the driving method is via capacitive coupling like was several times already in the case of using more than 4 diodes.
So here there is but one input frequency to the 4 diode 'ring' like earlier: why the ring modulator concept is mentioned? would like to understand.
For me a ring modulator has always meant mixing, manipulating two frequencies to get at least a new one (but in practice we get many new frequencies).
I am not against you: just wish to understand why you tend to endorse the Stiffle loop is a ring modulator. 

Gyula

[mikrovolt]

I recall a video showing probe in background PSEC running led board, looks like over-modulation.
Is it the probe, the background or both ?

https://youtu.be/pff8hqqCbWs

[Lidmotor]

All--I'm not sure now that a 'Ring Modulator' is like the 'Stiffler Loop'.  The Ring Modulator (like Gyula mentioned) is all about mixing two input signals.  We are dealing with just one here.  It was perhaps a trip down a rabbit hole. That was an interesting idea but maybe a waste of time to pursue that explanation.

Slider----Yep.  If Doc lights up an LED panel stuck in the ground more than about 6 inches away from the SEC----- I will be surprised also.

---Lidmotor

[NickZ]

Nick,  okay on the as high as even 100V from the crystal oscillator but let me ask: what DC voltage amplitude would be needed for your LEDs to get what you consider already as full brightness, did you check it too?  Your 10 LEDs in series may need say 31 - 33 V DC to operate with full brightness from a DC supply I would think and then the current draw would be say around 15-20 mA ? (If you check this, make sure to use a few kOhm resistor in series with the LEDs to protect them from extra current draw.)

Now I assume that when you use an L3 coil that creates the near field (rather than the choke coil in the collector), then you make sure that the L3 coil should be spot on the crystal frequency, otherwise the use of L3 has not much advantage. You surely know that anything near to L3 may detune it. And if you use a ferrite piece to fine tune L3 then the core material should have low loss at the crystal frequency. RF powder iron toroids could be used if you slip them close next to each other onto a piece of plastic or wooden rod. Such RF toroids I mean:
https://www.ebay.com/itm/282774499025  and data sheet http://toroids.info/T50-6.php
Of course these cores when you push them into an L3 coil, then L3 in itself should have already a higher resonant frequency than the crystal frequency so that the cores could reduce the original coil frequency. Also, when any so called 'top load' is connected to the floating free end of L3, it also reduces coil frequency, so the use of the cores should be considered accordingly, may be some turns should be removed. Sorry if you know all these fine tuning details though, and your thought on the match between the oscillator and L3 coil is correct.

The energy to light the LEDs should come from the RF field the L3 coil produces from the oscillator. Unfortunately, this is a lossy conversion process: one is the DC input to the oscillator (oscillator conversion efficiency), the other is (radiation efficiency of L3) the field of coil L3 is all over in its vicinity in quasi every direction in the near space i.e. the field is not concentrated solely for the LED boards and / or LED wires, it is spread over in quasi every direction, the strongest field being around the top end of the coil where the voltage maximum should be.

Itsu, Many thanks for checking the two loop currents, that is how I thought.

Gyula

   Gyula:  thanks for the suggestions.   I had blown the previous 400v transistor, so I'm using the MPSA42 at this time, which is a smaller version package but still with 300v capacity.   The 221 choke has been removed to your suggestion, and right now I am not using any choke or resistor on the collector.    The near field is now about one or two inches away from the L3 coil. However, when I let the oscillator run all night (as a night light), in the morning the near field effect has dropped. Not sure why, yet, and so has the bulb intensity. But, the voltage at the leds is still only 2.5v. And not ever any higher, no matter what I do. This low voltage is still the bottle neck in my circuit.   I have been trying different transistors, resistors, chokes, capacitors, etz... but still the low LED light levels remains, probably at about 1/4 normal lumin levels for my 10 led bulbs. That bulb fully turns on a 4v, but not at 2.5v. It's a flashlight bulb, meant for 4v input.
   I will try the same bulb on my HV kacher circuit, 4000v to 5000v, and see if it will light to full on, or not.    If this 2.5v limit is not breached, it will affect the output that we can obtain. Especially if the 2.5v, is all we are going to be able to get at the output using the Stiffler set up. As this led biasing idea, limits the output.   I agree that if the L3 is not tuned spot on, the effect will be less than if the L3 coil was not even present. However, this is not so easy to achieve, without the proper signal generator.  So, I guess it's adding or removing turns on the L3 to see any improvements. That is why some of us will need to know the exact turn count, size of mag wire, etz... to be spot on 13.5MHz. And every L3 that I've seen is different.  So... will the real L3,  please stand up...
   Any ideas are welcome. 

[gyulasun]

Hi Nick,

Sorry what I wrote was misunderstandable, unfortunately. I did not mean to replace the choke coil in the collector with the L3.
I was thinking on the field the choke creates is smaller than that of L3 (due to mainly the physical sizes) but to fully utilize the high near field of L3 it must be tuned correctly to the crystal frequency.
So please use the choke in the collector and drive the L3 from the common point of the collector and the choke via a single wire or via a series 10 or 22 or 47 nF capacitor to block DC (nF value is not critical). Now that the Doc showed in his latest video the use of 2 L3 coils: you can also use two such coils in series because they can enhance the resonant RF amplitude further on.
Please tell:

the 2.5 V voltage limit you mention is meant for across the flashlight bulb (and not across the series 10 LEDs)?  This flashlight bulb is what type? a single white LED? Else?

Regarding your finding the brightness dropped overnight: have you tried to carefully check L3 whether by fine tuning it with a piece of ferrite the brightness can be regained to its earlier intensity? Because if the oscillator input power did not change (DC voltage and current), then the next most sensitive component is L3.  Change in ambient temperature and / or in humidity level may easily influence its resonance.

I am afraid that there is not an easy way to bring L3 to resonance: only as you wrote by adding or removing the turns. Under the 3-4 MHz crystals the ferrite from the AM pocket radio is good for tuning L3 if the latter has a higher self resonance than 3-4 MHz. For crystals above 4-5 MHz and up to 13-14 MHz the powder iron material is preferable I mentioned above, they have less loss at these higher frequencies than the ferrite from the AM radio. Of course temporarily, you can use the latter too because it will help you for sure.

Gyula