Dr Ronald Stiffler SEC technology

[gyulasun]

Hi AG,

You may also need to vary the DC bias current for your transistor like Itsu did to have both crystals operate simultaneously.
And try to use other transistor types too, preferably with higher than 100 h_FE. Also, try to vary the supply voltage. These are some 'rules'... you may know some other ones too.  As I wrote earlier: each oscillator has a 'soul'.   

Superimposing waves, I can tell generally only: you can get twice the amplitude of two waves identical in amplitude, wavelength and phase.   

Try to play with these simulators below.  In the first one the wavelength of the 2nd wave is variable and see the sum of the red and blue waves:   http://physics.bu.edu/~duffy/HTML5/beats.html   
When you set 24 Hz for the blue wave, then it will be identical in phase and frequency to the red wave, so their sum becomes exactly twice all the way and harmonic-free, otherwise the nice sine wave gets distorted as you vary the blue wave frequency.
You can pause the process any time.
Here are some other simulations:
http://ophysics.com/w2.html          wave pulse interference and superposition
http://physics.bu.edu/~duffy/HTML5/interference.html         constructive and destructive interference
http://physics.bu.edu/~duffy/HTML5/interference_of_pulses.html       constructive and destructive pulse interference
http://physics.bu.edu/~duffy/HTML5/transverse_standing_wave.html       one wave goes to right the other to left, harmonics of the waves up to 6

I have not found an online wave simulator which would mimic the freak waves  i.e. letting vary the amplitude and the wavelength of 2 waves separately and let them collide. 

Gyula

[iQuest]

Mikrovolt: Thanks for the links, this is how I would summarize SRF and srf.  When a test connection is made to both ends of a coil the Self Resonant Frequency (SRF)
can be found.  But when a test connection is made to only one end of a coil, like Dr. Stiffler demonstrates in the videos you posted, the so called Spatial Resonant
Frequency (srf) can be found.  Not sure why Dr. Stiffler does not mention a standing wave, as the FG frequency is swept a quarter standing wave resonance would be
found with the setup that he demonstrates for the open end coils in these videos.  Thus I conclude, srf = quarter standing wave resonance, see additional info below.

Gyula: Appreciate the technical support info you continue to post and thanks for the links to the wave simulators. Regarding your comment "Superimposing waves, I
can tell generally only: you can get twice the amplitude of two waves identical in amplitude, wavelength and phase.".  I'm sure you know but would just like
to add that a wave reflected from the open end of a transmission line like an L3 coil (or Tesla coil) would meet this criteria.  In this application, the ideal would be
to tune to quarter-wave resonance to achieve maximum voltage magnification at the open end by way of a standing wave (quarter-wave resonator).

[AlienGrey]

Hi AG,

You may also need to vary the DC bias current for your transistor like Itsu did to have both crystals operate simultaneously.
And try to use other transistor types too, preferably with higher than 100 h_FE. Also, try to vary the supply voltage. These are some 'rules'... you may know some other ones too.  As I wrote earlier: each oscillator has a 'soul'.   

Superimposing waves, I can tell generally only: you can get twice the amplitude of two waves identical in amplitude, wavelength and phase.   

Try to play with these simulators below.  In the first one the wavelength of the 2nd wave is variable and see the sum of the red and blue waves:   http://physics.bu.edu/~duffy/HTML5/beats.html   
When you set 24 Hz for the blue wave, then it will be identical in phase and frequency to the red wave, so their sum becomes exactly twice all the way and harmonic-free, otherwise the nice sine wave gets distorted as you vary the blue wave frequency.
You can pause the process any time.
Here are some other simulations:
http://ophysics.com/w2.html          wave pulse interference and superposition
http://physics.bu.edu/~duffy/HTML5/interference.html         constructive and destructive interference
http://physics.bu.edu/~duffy/HTML5/interference_of_pulses.html       constructive and destructive pulse interference
http://physics.bu.edu/~duffy/HTML5/transverse_standing_wave.html       one wave goes to right the other to left, harmonics of the waves up to 6

I have not found an online wave simulator which would mimic the freak waves  i.e. letting vary the amplitude and the wavelength of 2 waves separately and let them collide. 

Gyula

Gyula; Thanks for info i will try that out later on when i can dig out a decent transistor, 

[TinselKoala]

Frankly I'm surprised that those of you using breadboards are getting consistent results. At the operating frequencies, solderless breadboards can cause problems due to diode-junction joints, interpin capacitances, loose connections and etc.

You might try one or another construction method like "dead bug" or "manhattan" styles.
Here's mine, built on a ground-plane slab of PCB material, and using a 74AC14 for output buffering:

[Lidmotor]

TK---Yes. It is amazing that those of us using breadboard setups for these RF circuits are getting such good results---unless the breadboard is actually part of the reason.  I did solder up an identical crystal oscillator circuit on a board and got the same results.  I was careful to keep the components in the same basic locations though.  Here is a 20 min. video I watched yesterday on the math involved with these tank circuits and all the sticky things you run into. This is all old news to many like you.  It is a lot come complicated than I thought.  Using a breadboard setup really stirs things up when one adds in the factors you mentioned.  Sometimes I solder up a quick 'dead bug' type setup on piece of cardboard to get away from it.  Just poke holes in the thin cardboard to hold the components and solder away.  Here is the 'back to school' video that helped me and might help others:
https://www.youtube.com/watch?v=vi24SpKYYoQ&feature=youtu.be

Gyula---I have really enjoyed the links you have posted.  Playing around with the wave forms on the simulators was fun but reminded me of sea conditions that make me seasick.  When the waves get together and 'stand up' like that my boat goes crazy and the motion is horrible.

erfandl---I built up your two paralleled crystal oscillators yesterday but did not get your results.  Both ran fine together or separately but the light output when joined was not double even though the amp draw went up.  I think that the waves are not joining up right to produce the double amplitude.  I will work on it some more today.

Cheers,
            Lidmotor