Just a thought: It looks like a common base oscillator, it would be interesting to place a capacitor from the base to the ground. Interesting video, thank you.
Thanks for your comments. I have had several interesting comments and suggestions about modifying this circuit. So I modified the circuit and made another video. I thought this would help answer some question. There is the link. Oscillator Experiment Interesting Results Part II ruclips.net/video/l_yRTZ-YoPc/видео.html
Thanks for your comments. I have had several interesting comments and suggestions about modifying this circuit. So I modified the circuit and made another video. I thought this would help answer some question. There is the link. Oscillator Experiment Interesting Results Part II ruclips.net/video/l_yRTZ-YoPc/видео.html
Fun vid Rick. That little oscillator is really something. You turned me on to that with that one tramsmitter you made back when and I've enjoyed tinkering with it ever since.
Thanks for your comments. I have had several interesting comments and suggestions about modifying this circuit. So I modified the circuit and made another video. I thought this would help answer some question. There is the link. Oscillator Experiment Interesting Results Part II ruclips.net/video/l_yRTZ-YoPc/видео.html
Thanks for your comments. I have had several interesting comments and suggestions about modifying this circuit. So I modified the circuit and made another video. I thought this would help answer some question. There is the link. Oscillator Experiment Interesting Results Part II ruclips.net/video/l_yRTZ-YoPc/видео.html
Looks like a Colpitts oscillator with a transformer feedback instead of capacitors. You should be able to use a tuning cap across the secondary. It should also function as a frequency mixer/modulator if you apply a signal to the base through a cap.
Thanks for your comments. I have had several interesting comments and suggestions about modifying this circuit. So I modified the circuit and made another video. I thought this would help answer some question. There is the link. Oscillator Experiment Interesting Results Part II ruclips.net/video/l_yRTZ-YoPc/видео.html
TOTALLY AMAZED. My best guesses: -As there are two coils, where each one has self-inductance, it is a second order system. The mutual inductance between them contribute to positive feedback, but also the bridge collector-emitter of the transistor, which is supposed to invert signal 180 degrees, but in this case seems to act as a resistor(???), where the base provides a current to set the resistance and initiate the oscillation. -At 7:20 the oscillation stopped due to the some 10pF capacitance of the probe to the ground and that the feedback of the mutual inductance tends to be more negative than positive in this configuration (imagining dot convention now...).. Interesting that when inverting the collector coil it works the same, but when inverting the emitter coil, the oscillation stops if the base is measured. -The transformer also has in each coil a distributed capacitance, which form L-C tanks. In fact, I made a circuit few days ago and found that a 😂1:10 ratio 60Hz transformer has a different turns ratio at certain frequencies, which proves the existence of that capacitances. Even it has a resonant frequency at 12kHz, at which the apparent turns ratio is maximum, around 1:30. But it seems from the photos that the transformer used should have a very high resonant turns-ratio frequency.
Thanks for your comments. I have had several interesting comments and suggestions about modifying this circuit. So I modified the circuit and made another video. I thought this would help answer some question. There is the link. Oscillator Experiment Interesting Results Part II ruclips.net/video/l_yRTZ-YoPc/видео.html
It's been fifty years since I was in school but, my first thought are it doesn't matter if it's common base or common emitter as long as the base to emitter voltage varies. The phase shift must be inductive.
Thanks for your comments. I have had several interesting comments and suggestions about modifying this circuit. So I modified the circuit and made another video. I thought this would help answer some question. There is the link. Oscillator Experiment Interesting Results Part II ruclips.net/video/l_yRTZ-YoPc/видео.html
when you swap both your basicly just returning it to the same state as before, does the change in wave form have something to do with tap 2 on the secondary?
Thanks for your comments. I have had several interesting comments and suggestions about modifying this circuit. So I modified the circuit and made another video. I thought this would help answer some question. There is the link. Oscillator Experiment Interesting Results Part II ruclips.net/video/l_yRTZ-YoPc/видео.html
The metal strips in your breadboard are capacitance coupling the feedback to the base. The proof is lightly loading the base with the oscilloscope probe quenches the oscillation. Fun but not a mystery. The same circuit built dead bug style over a copper ground plane it will not oscillate.
I had thought of that. I had put the transistor and the 10K bias resistors on a separate small board. There was no change. It's hard to remember everything as you make a video. Here is part II. Oscillator Experiment Interesting Results II ruclips.net/video/MITyF5wX8SQ/видео.html
hanks for your comments. I have had several interesting comments and suggestions about modifying this circuit. So I modified the circuit and made another video. I thought this would help answer some question. There is the link. Oscillator Experiment Interesting Results Part II ruclips.net/video/l_yRTZ-YoPc/видео.html
Ciao, secondo te cosa accade per ottenere questa oscillazione?quale calcolo per progettare una frequenza di nostro piacimento? C'è una nuova teoria scienza sugli oscillatori? Grazie da italia(Italy).
Thanks for your comments. I have had several interesting comments and suggestions about modifying this circuit. So I modified the circuit and made another video. I thought this would help answer some question. There is the link. Oscillator Experiment Interesting Results Part II ruclips.net/video/l_yRTZ-YoPc/видео.html
Its looking like the high frequency o-scopes are quite difficult to find for $1000 or less (or even slightly above $1000. What did they use to test microwave circuits back in the day since the super expensive high frequency o-scopes are a relativly modern development? Or have these high frequency o-scopes always been around and just never come down in price and only available to large institutions? I wonder if its possible to build a high frequency o-scope? I built a metal cutting CNC machine and a chemical lab why not an o-scope.
Parasitic and a bigger influence is the ferric adjustable core. Looking at the lower left of the Oscilloscope screen the frequency varied from about 1.4 MHz to about 1.6MHz. It is small type.
Thanks for your comments. I have had several interesting comments and suggestions about modifying this circuit. So I modified the circuit and made another video. I thought this would help answer some question. There is the link. Oscillator Experiment Interesting Results Part II ruclips.net/video/l_yRTZ-YoPc/видео.html
Thanks for your comments. I have had several interesting comments and suggestions about modifying this circuit. So I modified the circuit and made another video. I thought this would help answer some question. There is the link. Oscillator Experiment Interesting Results Part II ruclips.net/video/l_yRTZ-YoPc/видео.html
Just a thought: It looks like a common base oscillator, it would be interesting to place a capacitor from the base to the ground. Interesting video, thank you.
I thought the same...
Thanks for your comments.
I have had several interesting comments and suggestions about modifying this circuit. So I modified the circuit and made another video. I thought this would help answer some question. There is the link.
Oscillator Experiment Interesting Results Part II
ruclips.net/video/l_yRTZ-YoPc/видео.html
Thanks for your comments.
I have had several interesting comments and suggestions about modifying this circuit. So I modified the circuit and made another video. I thought this would help answer some question. There is the link.
Oscillator Experiment Interesting Results Part II
ruclips.net/video/l_yRTZ-YoPc/видео.html
Observing the behavior of real world components is what attracts me to analog electronics in the first place. Thanks for showing and best regards!
Thank you, and your welcome.
Fun vid Rick. That little oscillator is really something. You turned me on to that with that one tramsmitter you made back when and I've enjoyed tinkering with it ever since.
Thanks Carl, it is fun experimenting. That is the best, Learn something and have fun doing it!
Interesting experiment Rick. Always learn something whenever I watch your videos. :)
Thanks Doug!
Wondering what would happen with a variable cap across the secondary. I liked the format of the presentation, thanks Rick
Thanks for your comments.
I have had several interesting comments and suggestions about modifying this circuit. So I modified the circuit and made another video. I thought this would help answer some question. There is the link.
Oscillator Experiment Interesting Results Part II
ruclips.net/video/l_yRTZ-YoPc/видео.html
That's a common base amplifier with positive feedback. Good examples for such use in RF oscillators.
Thanks for your comments.
I have had several interesting comments and suggestions about modifying this circuit. So I modified the circuit and made another video. I thought this would help answer some question. There is the link.
Oscillator Experiment Interesting Results Part II
ruclips.net/video/l_yRTZ-YoPc/видео.html
@@AllAmericanFiveRadio thank you for sharing.
Great video, can I ask the AM tx you built on another video, what would you need to change to make it LW ?
Thanks.
Use less capacitance in the variable capacitor in the tank circuit. It works,
Looks like a Colpitts oscillator with a transformer feedback instead of capacitors. You should be able to use a tuning cap across the secondary. It should also function as a frequency mixer/modulator if you apply a signal to the base through a cap.
Thanks for your comments.
I have had several interesting comments and suggestions about modifying this circuit. So I modified the circuit and made another video. I thought this would help answer some question. There is the link.
Oscillator Experiment Interesting Results Part II
ruclips.net/video/l_yRTZ-YoPc/видео.html
TOTALLY AMAZED.
My best guesses:
-As there are two coils, where each one has self-inductance, it is a second order system. The mutual inductance between them contribute to positive feedback, but also the bridge collector-emitter of the transistor, which is supposed to invert signal 180 degrees, but in this case seems to act as a resistor(???), where the base provides a current to set the resistance and initiate the oscillation.
-At 7:20 the oscillation stopped due to the some 10pF capacitance of the probe to the ground and that the feedback of the mutual inductance tends to be more negative than positive in this configuration (imagining dot convention now...)..
Interesting that when inverting the collector coil it works the same, but when inverting the emitter coil, the oscillation stops if the base is measured.
-The transformer also has in each coil a distributed capacitance, which form L-C tanks.
In fact, I made a circuit few days ago and found that a 😂1:10 ratio 60Hz transformer has a different turns ratio at certain frequencies, which proves the existence of that capacitances. Even it has a resonant frequency at 12kHz, at which the apparent turns ratio is maximum, around 1:30.
But it seems from the photos that the transformer used should have a very high resonant turns-ratio frequency.
Thank you!
Looking at the lower left of the Oscilloscope screen the frequency varied from about 1.4 MHz to about 1.6MHz. It is small type.
Wrangling electrons is a fascinating art, what software do you use to make the diagrams?
I use CorelDRAW Essential 2020, Photoshop Elements 2018 Editor, Adobe Premiere Elements 2018 and in that order.
Fun video Richard. Thank you for sharing it!
Thank you, and your welcome.
Akways fun and informative whenever you release a video!
Thanks for your comments.
I have had several interesting comments and suggestions about modifying this circuit. So I modified the circuit and made another video. I thought this would help answer some question. There is the link.
Oscillator Experiment Interesting Results Part II
ruclips.net/video/l_yRTZ-YoPc/видео.html
It's been fifty years since I was in school but, my first thought are it doesn't matter if it's common base or common emitter as long as the base to emitter voltage varies. The phase shift must be inductive.
Thank You!
Would that be a common base configuration?
Thanks for your comments.
I have had several interesting comments and suggestions about modifying this circuit. So I modified the circuit and made another video. I thought this would help answer some question. There is the link.
Oscillator Experiment Interesting Results Part II
ruclips.net/video/l_yRTZ-YoPc/видео.html
Thanks for the vidyo enjoyed it very much
Thank you.
How do you make the littke animations, is it a visio add on?
I use CorelDRAW Essential 2020, Photoshop Elements 2018 Editor, Adobe Premiere Elements 2018 and in that order.
when you swap both your basicly just returning it to the same state as before, does the change in wave form have something to do with tap 2 on the secondary?
Thanks for your comments.
I have had several interesting comments and suggestions about modifying this circuit. So I modified the circuit and made another video. I thought this would help answer some question. There is the link.
Oscillator Experiment Interesting Results Part II
ruclips.net/video/l_yRTZ-YoPc/видео.html
Old saying: If it doesn't oscil now it will oscil later.
Thank you!
Sure makes you think. Very good presentation.
Thank you, and your welcome.
The metal strips in your breadboard are capacitance coupling the feedback to the base. The proof is lightly loading the base with the oscilloscope probe quenches the oscillation. Fun but not a mystery. The same circuit built dead bug style over a copper ground plane it will not oscillate.
I had thought of that. I had put the transistor and the 10K bias resistors on a separate small board. There was no change. It's hard to remember everything as you make a video. Here is part II.
Oscillator Experiment Interesting Results II
ruclips.net/video/MITyF5wX8SQ/видео.html
Nice little experiment
hanks for your comments.
I have had several interesting comments and suggestions about modifying this circuit. So I modified the circuit and made another video. I thought this would help answer some question. There is the link.
Oscillator Experiment Interesting Results Part II
ruclips.net/video/l_yRTZ-YoPc/видео.html
Ciao, secondo te cosa accade per ottenere questa oscillazione?quale calcolo per progettare una frequenza di nostro piacimento? C'è una nuova teoria scienza sugli oscillatori? Grazie da italia(Italy).
Thanks for your comments.
I have had several interesting comments and suggestions about modifying this circuit. So I modified the circuit and made another video. I thought this would help answer some question. There is the link.
Oscillator Experiment Interesting Results Part II
ruclips.net/video/l_yRTZ-YoPc/видео.html
@@AllAmericanFiveRadio thanks very much!
Nice work, interesting.
Thank you!
Its looking like the high frequency o-scopes are quite difficult to find for $1000 or less (or even slightly above $1000. What did they use to test microwave circuits back in the day since the super expensive high frequency o-scopes are a relativly modern development? Or have these high frequency o-scopes always been around and just never come down in price and only available to large institutions?
I wonder if its possible to build a high frequency o-scope? I built a metal cutting CNC machine and a chemical lab why not an o-scope.
Yes you could build your own, but usually it does not save money. Most often it costs more and is not as accurate.
But what determine the frequency of oscillation without a capacitor or the parasitic one will do the job?
Parasitic and a bigger influence is the ferric adjustable core.
Looking at the lower left of the Oscilloscope screen the frequency varied from about 1.4 MHz to about 1.6MHz. It is small type.
Sir. I may be mistaken, but it appears that you have a emitter follower circuit through the transformer coils
Thanks for your comments.
I have had several interesting comments and suggestions about modifying this circuit. So I modified the circuit and made another video. I thought this would help answer some question. There is the link.
Oscillator Experiment Interesting Results Part II
ruclips.net/video/l_yRTZ-YoPc/видео.html
Looks like a blocking oscillator.
Thanks, that could be.
🤠
Thanks for your comments.
I have had several interesting comments and suggestions about modifying this circuit. So I modified the circuit and made another video. I thought this would help answer some question. There is the link.
Oscillator Experiment Interesting Results Part II
ruclips.net/video/l_yRTZ-YoPc/видео.html
That is cool
Thank you!