Interested in learning about wireless power? Subscribers can get up to 80% off my course Wireless Power to the People - Wireless Charging 101 on udemy using the coupon code "UA-cam" www.udemy.com/wireless-power-to-the-people-wireless-charging-101/?couponCode=UA-cam
You all probably dont give a shit but does anyone know of a tool to get back into an instagram account..? I was stupid lost my login password. I love any help you can offer me.
I don't usually write youtube comments. Yet I have been looking for this kind of video for a very, very long time. Usually the videos similar to this do not explain much about the circuit - they just hand it to you. I have found many videos that explain AM, yet this is the one with many examples, so that I can clearly see what is going on. I really loved the part where you divide the big circuit into smaller parts. Liked the video. Subscribed. Did everything that is in my power. Cheers
As EE student, I must take many courses relate to digital communication, wireless communication, electromagnetic wave, analog circuit, etc. We have lab after lab to prove a ridiculous amount of theories and yet not a single lab like this. This is the first time I see all those theories we study come together nicely and do something useful in real life. I think the school should teach us how to walk properly down on the earth before they slap the Icarus’ wing to our back and demand us to fly high!
I want to thank you for this video. I'm a scientist (in comp sci) and have spent days looking through technical articles trying to understand basic RF concepts This video finally did it for me!
Thanks Afrotechmods, that's a terrific example of how to impose information into the carrier, thankyou, looking forward to more, people like you are pretty special for sharing your knowledge so others can learn. best wishes.
@Afrotechmods AM does pick up interference, but is much better for covering mountainous terrain than FM, which is strictly line-of-sight and will get blocked by terrain. I live in a hilly area between two major cities, and I have to keep switching my FM presets depending on which side of the mountain I'm on, whereas the AM stations from both cities can be heard equally well throughout the area. (Although this is mostly due to the frequencies used by the AM & FM bands, not the modulation method.)
Heads up to everyone making this with 12v, use a 10k from Vcc to the non-inverting side of the chip, and a 8.2k from the same pin to ground, hope this helps to those who need it, cheers
Look @3:04 - it's a "sort of" square wave that - as the frequency is turned up - is starting to collapse into a sort of trapezoid, then triangle because it's running near the max freq/slew rate of the opamp.
I'm an amateur radio extra class operator, but I really can't get enough of the fundamentals. You blew my mind when you said, "another spark appears." That did it for me. If I can explain this magic to my five and eight-year-olds, then the idea is rock solid for both of us. Kinda like I found that guy Uncle Doug (the guitar amp guru), I consider your stuff to be a "find." On that basis, I would LOVE to hear you explain radio receiver alignment concepts, what the BFO is and how it's tuned/zero beat. I suspect this is 'outside your ken' as it were--perhaps a bit too specific to the ham radio hobby and therefore of less interest to you. Anyway, that is my accolade and request for you today. Cheers.
+JC Haywire After two listens through, I have to say, this is a masterpiece. Sufficient for the Library Of Congress as an audio recording of "How Radios Work & What They Can Do." Perfectly scaffolded for basic listeners, yet peppered with unobtrusive bits of deeper technical rigor to hold the interest of experienced listeners. Woot.
This is Awesome! If you want to kill all the external radio noise you could line a box with aluminum foil and place all your supplies inside, when you put on the lid of the box (also lined with aluminum) a Faraday cage is created which will not allow electromagnetic interference into the box.
"A few years later? Nikola Tesla created Transmitters & Receivers"... correction, he invented the first radio. Also he didn't use Hertzian waves just for clarity.
Thanks for putting this up, I need to make a high frequency oscillator for an experiment I want to try, and this looks like it might work in my experiment.
@busybjorn FM can also transmit a greater range of audio frequencies making it better for transmitting music, whereas AM is more limited and is often used for transmitting speech.
great thx man your videos are really doing a great job! i am a newbies in electronics devices, but your videos are making them much more easier to be understood!
Are you going to do a video on LC filters and resonance as you say at 7:32 since I believe we are in the future with respect to the year you did this video ?
I absolutely love these videos! You're tutorials are very thorough and clearly explained. As an electrical engineering student I can tell these are going to help me out alot. I don't understand how that Fred idiot can get a billion subs and you've only got a few thousand. It should be the other way around. Cheers! BTW Megadeth kicks ass!!!
Great video Afroman! I believe another way possibly to get a bit more range would be to Attach the wire antenna to a telescopic antennae which has no insulation unlike wire. You are like another kipkay! lol I have a video request that could be interesting to some people if you are interested.
This is better than Stefan0719 because u explain it very good and the schematic is very clean. Can u put a schematic that i can put behind this for a little more power ? Keep up the good work !
If you use RF Hybrid (with its input connected to your output) and power it from battery (then connect its output to an antenna via matching circuit) you can amplify the output signal thus you can enable transmission of your MP3 player to a longer distance.
Interesting you would ask that, as using a crystal oscillator can simplify things a bit. However, they have some major disadvantages (large size, fixed frequency) and actually are likely to become replaced by tiny variable-frequency silicon (transistor-based) oscillators, like the one in this video, in the next few years.
Very impressive. I have an old truck, AM only, I would love to have a transmitter for it. Could you modify this to work in that setting? And would you be willing to write something up with a parts list and "Tab A" to "Slot B" type instructions for an old wrench turner like myself.
The carrier signal from the first TL072 (the 1MHz or so) feeds one of the second TL072's inputs. The audio (the modulation) from the mp3 player feeds the other input. If I'm understanding the circuit properly, the second TL072 essentially subtracts the two signals. When they are of equal amplitude but out of phase, there's no output. When in phase you get maximum output. See wikipedia under "modulation" for an animation
How I am understanding it is that he is essentially using the audio signal to dynamically distort the carrier wave. Kind of a brute force way to do AM and probably generating quite some harmonics. A simple subtractor/adder wont modulate anything. The bias circuit at the second TL072's noninverting input is simply determining the clipping level.
For my first radio circuit I used two 555 timer chips, one outputting a radio frequency and the other 555 turning first 555 on and off making a beeping noise that my am radio picked up
You explain electronics AWESOMELY!!! I'm been watching all your videos, and (especially as a beginner) I would like to offer my huge gratitude. Also, while most of your videos are all information, I always get a really good laugh when you add a joke or two. I wouldn't change anything about your videos, and please keep up the excellent work!
This is exciting, I have an Atmel board that has about 20 outputs pins on it. If I created a square wave toggling the pins on and off, could that still create a carrier wave? Also, If I created a neodymium core coil and fed analog audio trough that, could I use the coil to superimpose the audio onto the carrier wave? Not sure if the goal is to combine the two waves, but thinking this might still work.
Hello Afrotechmods, the second amplifier which is shown at 5 min and 35 seconds is powered exactly same as the first amplifier? Thank you for your time.
thanks afroboy! i love your videos man! please uplod more! you made me extremely happy! very easy to understand and interesting style of teaching! more power! ^^,
Keep up the good work my friend. If you find the time, can you produce a video on AM receivers? I know there are a few out there, but nobody explains it quite like you do. Thank you for your efforts, past and present.
Is it because even though its a summed output, its still a summed output at a specific frequency. Therefore when you set the AM radio demodulator at that specific frequency it demodulates it back into a carrier + signal. The demodulator also seperates and amplifies the signal and drops the carrier? Just a guest. Great Work Afrotechmods, how com you don't post any more videos? i wish you were in NYC so you can teach me first hand.
Hey, great video! Just watched a couple of your others. Nicely done. Did you ever put up an LC and resonance video? I've had a look but couldn't see...
From what I can tell, you're not really AM modulating the carrier frequency. Instead, the audio signal is changing the DC offset of the carrier signal, see 7:00. Because the carrier signal's amplitude doesn't change. So, the million dollar question is, why does it still transmit?
Iustinian P. If the components were ideal, nothing would happen. But any nonlinearity will mix the carrier frequency and the audio signal together and this is then transmitted.
you can also use a 27mhz rc car remote and a nine volt battery for it instead of two AAs and you will be able to do mores code over the cb radio but i dont think anyone far away will hear it and it is possible to be hered on the am radio band but it is realy quit unless you stick a screw driver to certon parts of the circuit board the remote i used was a newbright rc car remote
Great video!! But I've a question: at 1:35, what kind of opamp oscillator is it? Because I can't find it on my school book.... isn't it a Wien-Bridge oscillator, right? Thanks for the help!!
Love your videos, very helpful. I see that the circuit you show is slightly different than Stefan0719's. Is there any significance to these differences?
could you hook the output off the anttena to an hi fre amplifier and have the output of that go into a air core transformer and the other end off the transformer go to the anttena and ground?
Hi I really liked the video as the explanations made a lot of things clear. Just two questions: Looking at the oscillator I would suggest that it works that the opamp goes into saturation and charges the capacitor until it reverse saturates and keeps on continuing doing that. But that would give a square wave. Why do you get a sine wave? Can you also explain the second part? You have a signal on both inputs of the opamp and one terminal is dc biased. Why comes the wave out of this in such a controlled manner? Has it something to do with feedback?
Great video! Could you answer a couple of questions for me regarding the oscillator at 2m15? First, what kind of oscillator is it? It looks like a wein-bridge without the 'lead' part of the lead/lag circuit. Also how would you adjust the amplitude of the output in this circuit? I've done it by simply putting a voltage divider on the output, but that feels like cheating.
Thanks Afro for AM tutorial. I have a question about the Vo of the opamp. so, you power the opamp with 9 volt and gnd. however, your Vo also contain negative voltage, how does that work? Thanks.
Hi, great video. I'm an engineering student and I'm very intrigued by radio frequency communication. Could you please tell what I need to consider to gain more transmission range, about 5 to 10 km? You mentioned, in the video, that the circuit shown is low powered, what IC could I use for a more "powerful" circuit?
Much more simple method to make a real AM is to connect the 9 volt supply for the opamp through the primary of a low-power mains transformer, and feed the audio signal to the secondary. Maybe you will need a little audio ampliffier to drive the transformer. You'll get a better sound quality.
at 1:33 isn't it an op-amp relaxation oscillator? If so, how does it produce a sine wave carrier? I thought op-amp relaxation oscillators give a square wave. Thanks for your videos! These are so educational!
Are the source signal and modulation output around 90 degrees out of phase at 5:22? I mean shouldn't the amplitude of modulated signal be 0 when amplitude of source is?
Hello, great video. Can I ask if there is a way to generate 60Khz with this circuit? I have a RC watch but I leave in south hemisphere, and there are no radio broadcasting the syc signals. I'm looking to build a small radio at 6khz and feed with a computer + gps signal to broadcast a WWVB or JJY similar signal to sync my watch (just home range). Thanks for any advice!
First of all, i want to agree with leeYT321987. Your explaination is awesomely. I have build your circuit at the lab in the university and it works perfectly. I recognized that the oszillator ist an astable multivibrator (in german "astabile kippstufe") and it so for it generates many sine carrier signals (see: Fourier series). But no matter that. My Question is: Does the second OP-Amp multiply or add the two signals? I ask cause i can't see a multiplication circuit there. Confusing. Thanks.
Interested in learning about wireless power? Subscribers can get up to 80% off my course Wireless Power to the People - Wireless Charging 101 on udemy using the coupon code "UA-cam" www.udemy.com/wireless-power-to-the-people-wireless-charging-101/?couponCode=UA-cam
Thanks for the info, i will surely watch this!!
Nice video! Just wondering.. 7:16 if this counts as RF amplifier? Sorry for dumb question.. im new to electronics))
You all probably dont give a shit but does anyone know of a tool to get back into an instagram account..?
I was stupid lost my login password. I love any help you can offer me.
I don't usually write youtube comments. Yet I have been looking for this kind of video for a very, very long time. Usually the videos similar to this do not explain much about the circuit - they just hand it to you. I have found many videos that explain AM, yet this is the one with many examples, so that I can clearly see what is going on. I really loved the part where you divide the big circuit into smaller parts.
Liked the video. Subscribed. Did everything that is in my power. Cheers
this video was way ahead of its time.. Clean simple easy to follow. Didn't know until the end that this was posted 9 years ago.
As EE student, I must take many courses relate to digital communication, wireless communication, electromagnetic wave, analog circuit, etc. We have lab after lab to prove a ridiculous amount of theories and yet not a single lab like this. This is the first time I see all those theories we study come together nicely and do something useful in real life. I think the school should teach us how to walk properly down on the earth before they slap the Icarus’ wing to our back and demand us to fly high!
I want to thank you for this video. I'm a scientist (in comp sci) and have spent days looking through technical articles trying to understand basic RF concepts This video finally did it for me!
The best video on radio transmitter. Lot of easy to understand information, in a very short span.
probably one of the most informative videos I've seen on an actual application for modulation.
I'm still confused how modulation works but after watching this video, I got enlighten somehow. Thank you, sir, for this video.
this is the most informative and intriguing video i have ever seen
Thanks Afrotechmods, that's a terrific example of how to
impose information into the carrier, thankyou, looking forward to
more, people like you are pretty special for sharing your knowledge
so others can learn. best wishes.
Phenomenal video man, talk about making sense of black magic!
Oh, the old UA-cam layout, how we miss you.
@Afrotechmods AM does pick up interference, but is much better for covering mountainous terrain than FM, which is strictly line-of-sight and will get blocked by terrain. I live in a hilly area between two major cities, and I have to keep switching my FM presets depending on which side of the mountain I'm on, whereas the AM stations from both cities can be heard equally well throughout the area. (Although this is mostly due to the frequencies used by the AM & FM bands, not the modulation method.)
pretty awesome. i was looking for something like this several months ago, surprised i didn't stumble on this video then. thanks
Heads up to everyone making this with 12v, use a 10k from Vcc to the non-inverting side of the chip, and a 8.2k from the same pin to ground, hope this helps to those who need it, cheers
Look @3:04 - it's a "sort of" square wave that - as the frequency is turned up - is starting to collapse into a sort of trapezoid, then triangle because it's running near the max freq/slew rate of the opamp.
I came here to learn about amplitude modulation, and I have succeeded. Thanks!
I'm an amateur radio extra class operator, but I really can't get enough of the fundamentals. You blew my mind when you said, "another spark appears." That did it for me. If I can explain this magic to my five and eight-year-olds, then the idea is rock solid for both of us. Kinda like I found that guy Uncle Doug (the guitar amp guru), I consider your stuff to be a "find." On that basis, I would LOVE to hear you explain radio receiver alignment concepts, what the BFO is and how it's tuned/zero beat. I suspect this is 'outside your ken' as it were--perhaps a bit too specific to the ham radio hobby and therefore of less interest to you. Anyway, that is my accolade and request for you today. Cheers.
+JC Haywire After two listens through, I have to say, this is a masterpiece. Sufficient for the Library Of Congress as an audio recording of "How Radios Work & What They Can Do." Perfectly scaffolded for basic listeners, yet peppered with unobtrusive bits of deeper technical rigor to hold the interest of experienced listeners. Woot.
+JC Haywire Lol I think that might be a bit generous but I appreciate it thanks!
This is Awesome! If you want to kill all the external radio noise you could line a box with aluminum foil and place all your supplies inside, when you put on the lid of the box (also lined with aluminum) a Faraday cage is created which will not allow electromagnetic interference into the box.
"A few years later? Nikola Tesla created Transmitters & Receivers"... correction, he invented the first radio. Also he didn't use Hertzian waves just for clarity.
very well explained - another excellent video!
A decade old comment ❤️, how are you buddy?
@@taherpatrawala_ 😎
@@sciguy14 subscribed your channel keep uploading regularly 😃
This is just like the oscillator tutorial video I just seen tonight.
Thanks for putting this up, I need to make a high frequency oscillator for an experiment I want to try, and this looks like it might work in my experiment.
@busybjorn FM can also transmit a greater range of audio frequencies making it better for transmitting music, whereas AM is more limited and is often used for transmitting speech.
great thx man your videos are really doing a great job! i am a newbies in electronics devices, but your videos are making them much more easier to be understood!
Are you going to do a video on LC filters and resonance as you say at 7:32 since I believe we are in the future with respect to the year you did this video ?
I absolutely love these videos! You're tutorials are very thorough and clearly explained. As an electrical engineering student I can tell these are going to help me out alot. I don't understand how that Fred idiot can get a billion subs and you've only got a few thousand. It should be the other way around. Cheers!
BTW Megadeth kicks ass!!!
Great video Afroman! I believe another way possibly to get a bit more range would be to Attach the wire antenna to a telescopic antennae which has no insulation unlike wire. You are like another kipkay! lol I have a video request that could be interesting to some people if you are interested.
@Afrotechmods
I just made a Colpitts Oscillator, that works too.
Just with a BC546, works fine for my.
This is better than Stefan0719 because u explain it very good and the schematic is very clean.
Can u put a schematic that i can put behind this for a little more power ?
Keep up the good work !
If you use RF Hybrid (with its input connected to your output) and power it from battery (then connect its output to an antenna via matching circuit) you can amplify the output signal thus you can enable transmission of your MP3 player to a longer distance.
You make one of the most exceptional videoes on youtube.Thanku thanku and thanku
So cool video! Great work! I will feature it today in my site. Looking forward for your next work
Interesting you would ask that, as using a crystal oscillator can simplify things a bit. However, they have some major disadvantages (large size, fixed frequency) and actually are likely to become replaced by tiny variable-frequency silicon (transistor-based) oscillators, like the one in this video, in the next few years.
Very impressive. I have an old truck, AM only, I would love to have a transmitter for it. Could you modify this to work in that setting? And would you be willing to write something up with a parts list and "Tab A" to "Slot B" type instructions for an old wrench turner like myself.
The carrier signal from the first TL072 (the 1MHz or so) feeds one of the second TL072's inputs.
The audio (the modulation) from the mp3 player feeds the other input.
If I'm understanding the circuit properly, the second TL072 essentially subtracts the two signals. When they are of equal amplitude but out of phase, there's no output. When in phase you get maximum output.
See wikipedia under "modulation" for an animation
How I am understanding it is that he is essentially using the audio signal to dynamically distort the carrier wave. Kind of a brute force way to do AM and probably generating quite some harmonics. A simple subtractor/adder wont modulate anything. The bias circuit at the second TL072's noninverting input is simply determining the clipping level.
Afro u are the best beacouse u gives urs regarts for Stefa0719 for the help
few people do that!!!
This channel is super great.
For my first radio circuit I used two 555 timer chips, one outputting a radio frequency and the other 555 turning first 555 on and off making a beeping noise that my am radio picked up
You explain electronics AWESOMELY!!!
I'm been watching all your videos, and (especially as a beginner) I would like to offer my huge gratitude.
Also, while most of your videos are all information, I always get a really good laugh when you add a joke or two.
I wouldn't change anything about your videos, and please keep up the excellent work!
You sir are a master at teaching... #Respect!
It was J.C. Bose who did it first actually
This is a well produced video.
This is exciting, I have an Atmel board that has about 20 outputs pins on it. If I created a square wave toggling the pins on and off, could that still create a carrier wave? Also, If I created a neodymium core coil and fed analog audio trough that, could I use the coil to superimpose the audio onto the carrier wave? Not sure if the goal is to combine the two waves, but thinking this might still work.
Hey afroman. Are you the voice actor for Bird Person?
Amazing video sir, pls suggest any cheap oscilloscope
Hello Afrotechmods, the second amplifier which is shown at 5 min and 35 seconds is powered exactly same as the first amplifier? Thank you for your time.
thanks afroboy! i love your videos man! please uplod more! you made me extremely happy! very easy to understand and interesting style of teaching! more power! ^^,
Great video! Could you do a video on FM in the future?
This is by far the best electro-hobbist series I've ever seen.
Amazing audio visual presentation
Thanks
Keep up the good work my friend. If you find the time, can you produce a video on AM receivers? I know there are a few out there, but nobody explains it quite like you do.
Thank you for your efforts, past and present.
So glad you mentioned and gave credit to Nikola Tesla
Is it because even though its a summed output, its still a summed output at a specific frequency. Therefore when you set the AM radio demodulator at that specific frequency it demodulates it back into a carrier + signal. The demodulator also seperates and amplifies the signal and drops the carrier? Just a guest. Great Work Afrotechmods, how com you don't post any more videos? i wish you were in NYC so you can teach me first hand.
Hey, great video! Just watched a couple of your others. Nicely done. Did you ever put up an LC and resonance video? I've had a look but couldn't see...
Very interesting, clear information to understand...thanks a lot...
THANKS FOR THAT. VERY CLEAR AND SIMPLE.
you are a very good conveyer of your information. thanks ; )
Top notch tutorial. Subscribed.
This explanation was just amazing! Thank you very much!
Great video! Is there going to be a video about LC filters in the near further?
Awesome video man, nice work.
It actually worked, excellent video
Thanks for sharing
i wish i didnt do engg in college and instead did here :) love your tutorials
your video was informative and entertaining keep up the good work
Thank you very much. It is very clear to me now.
From what I can tell, you're not really AM modulating the carrier frequency. Instead, the audio signal is changing the DC offset of the carrier signal, see 7:00. Because the carrier signal's amplitude doesn't change. So, the million dollar question is, why does it still transmit?
That's a good question!
Iustinian P. If the components were ideal, nothing would happen. But any nonlinearity will mix the carrier frequency and the audio signal together and this is then transmitted.
You're totally right. Spent few minutes here thinking about it and yes, it should multiply both signals instead summing them.
you can also use a 27mhz rc car remote and a nine volt battery for it instead of two AAs and you will be able to do mores code over the cb radio but i dont think anyone far away will hear it and it is possible to be hered on the am radio band but it is realy quit unless you stick a screw driver to certon parts of the circuit board the remote i used was a newbright rc car remote
Great explanation! Thanks for sharing.
You did a great job explaining this. Cheers
Nice video!
Will you make some vid in which you can control something using this?
Great video!! But I've a question: at 1:35, what kind of opamp oscillator is it? Because I can't find it on my school book.... isn't it a Wien-Bridge oscillator, right? Thanks for the help!!
Love your videos, very helpful. I see that the circuit you show is slightly different than Stefan0719's. Is there any significance to these differences?
ur best.....you helped me a lot....thank you so much ...keep uploading.
could you hook the output off the anttena to an hi fre amplifier and have the output of that go into a air core transformer and the other end off the transformer go to the anttena and ground?
6:36
How did you connect your mp3 audio to the circuit..??
thank you for the vids, I really liked them.
Hi I really liked the video as the explanations made a lot of things clear. Just two questions: Looking at the oscillator I would suggest that it works that the opamp goes into saturation and charges the capacitor until it reverse saturates and keeps on continuing doing that. But that would give a square wave. Why do you get a sine wave? Can you also explain the second part? You have a signal on both inputs of the opamp and one terminal is dc biased. Why comes the wave out of this in such a controlled manner? Has it something to do with feedback?
Great video!
Could you answer a couple of questions for me regarding the oscillator at 2m15?
First, what kind of oscillator is it? It looks like a wein-bridge without the 'lead'
part of the lead/lag circuit.
Also how would you adjust the amplitude of the output in this circuit? I've done
it by simply putting a voltage divider on the output, but that feels like cheating.
Thanks Afro for AM tutorial. I have a question about the Vo of the opamp. so, you power the opamp with 9 volt and gnd. however, your Vo also contain negative voltage, how does that work? Thanks.
@Afrotechmods What about in the GHz and greater frequencies (e.g. 2.4GHz)? Switching speed is 100ns or somewhere around there from memory.
Hi, great video. I'm an engineering student and I'm very intrigued by radio frequency communication. Could you please tell what I need to consider to gain more transmission range, about 5 to 10 km? You mentioned, in the video, that the circuit shown is low powered, what IC could I use for a more "powerful" circuit?
Did you hook one input to the inverting input and the other to the non-inverting input of the second op-amp?
Thank you so much for all this informations!!! I really enjoyed it!
AM Radio 101! Every person going through High School needs to learn this like I did and stop calling it Ancient Modulation!
IT'S GIVING ME AND GOOD EXPIRIENCE
Much more simple method to make a real AM is to connect the 9 volt supply for the opamp through the primary of a low-power mains transformer, and feed the audio signal to the secondary. Maybe you will need a little audio ampliffier to drive the transformer. You'll get a better sound quality.
Is it viable to use a BJT amplifier instead of an OPAMP? Are they able to amplify at sufficient frequency?
why your modulated output is simply a sine wave without envelope? Which type of output was that DSB-FC, DSB-SC, or SSB
Is it maybe possible to use a 741 op amp? does it really not work?
Your doing a great job ! keep doing it !
at 1:33 isn't it an op-amp relaxation oscillator? If so, how does it produce a sine wave carrier? I thought op-amp relaxation oscillators give a square wave. Thanks for your videos! These are so educational!
Basically the output of the op amp can't keep up so effectively instead of square waves we are getting sine waves. .. slew rate manipulation
Hi Afro -
Can you explain what the purpose of a BFO is in layman's terms? thx.
why is it always 9v? why not 12v or 5v? excellent video.
Why are there two DC biases in the second stage (amplitude modulation of the oscillation)? Why not just combine them into one? Thanks
Why does the antenna have to be a meter long? Is it the frequency or is it that the voltage has more wire to work through making the signal stronger?
i was wondering , it's possible to convert radiowaves in elettric current for , for example, turn on a LED o.O?
You are awesome man!!!!!
This is what i wanted perfect!!!!!!!!
Are the source signal and modulation output around 90 degrees out of phase at 5:22? I mean shouldn't the amplitude of modulated signal be 0 when amplitude of source is?
Awesome videos-how about something on "Bread Boards" Thanks
Hello, great video. Can I ask if there is a way to generate 60Khz with this circuit? I have a RC watch but I leave in south hemisphere, and there are no radio broadcasting the syc signals. I'm looking to build a small radio at 6khz and feed with a computer + gps signal to broadcast a WWVB or JJY similar signal to sync my watch (just home range). Thanks for any advice!
First of all, i want to agree with leeYT321987. Your explaination is awesomely.
I have build your circuit at the lab in the university and it works perfectly.
I recognized that the oszillator ist an astable multivibrator (in german "astabile kippstufe") and it so for it generates many sine carrier signals (see: Fourier series). But no matter that. My Question is: Does the second OP-Amp multiply or add the two signals? I ask cause i can't see a multiplication circuit there. Confusing. Thanks.
However, I do enjoy watching your videos great stuff thanks :)