Amplitude Modulation tutorial and AM radio transmitter circuit

This video covers the history of the discovery of radio waves, to the creation of simple oscillator based radio transmitters. Then I explain what modulation and amplitude modulation are, and show you how to build a low powered AM radio transmitter.

[notamage]

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 <3

[-Rishikesh]

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.

[dienthaily]

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!

[cosmiccastaway]

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!

[knowall]

The best video on radio transmitter. Lot of easy to understand information, in a very short span.

[balkey]

probably one of the most informative videos I've seen on an actual application for modulation.

[ronaldrosete]

I'm still confused how modulation works but after watching this video, I got enlighten somehow. Thank you, sir, for this video.

[muskhuan]

this is the most informative and intriguing video i have ever seen

[milesprower]

Oh, the old YouTube layout, how we miss you.

[Neurocidal]

Phenomenal video man, talk about making sense of black magic!

[dennisbauer]

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.

[arrowfitzgibbon]

pretty awesome. i was looking for something like this several months ago, surprised i didn't stumble on this video then. thanks

[vwestlife]

@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.)

[AdamEbelgccengineering]

This is just like the oscillator tutorial video I just seen tonight.

[FilipJelenkovic]

I came here to learn about amplitude modulation, and I have succeeded. Thanks!

[JCHaywire]

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.

[derivativ]

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

[mike]

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.

[catalin]

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 ?

[CoolDudeClem]

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.