Amplitude modulation tutorial & AM radio transmitter circuit

[Celiecinema1]

How about frequency modulation? Could you do a video on frequency modulation?

[Mrkirill578]

Great video! Is there going to be a video about LC filters in the near further?

[paliwp1]

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.

[0sakar0]

simplest and understanding video ever at youtube. lots of Thanks, you did a great job

[MisterAlexUk]

Thank you.

[uniqueandprosperous]

is there a way to key on & off 7.?? to 10.?? times per second whole number down to 2nd decimal & send that through a 144 klhz carrier wave ??

[FoulplayMFer]

would fap again



[FelixTheHouseFreak]

So glad you mentioned and gave credit to Nikola Tesla

[ivan3x]

duke nukem 3D !!! :) thanks for the clean instruction and tutorial :) Please go on with more complicated subjects like PID with opAmps. opAmps are my favorites. please more videos :)

[vetodnb]

pirate radio here i come ^^

[perazaroberto2]

His teachings are very clear and very good I owe you for your help to better understand the electronic mediocre classes I got here in Austin, Texas.

[perazaroberto2]

Thank you .

[FREEGARYMCKINNON]

THANKS FOR THAT. VERY CLEAR AND SIMPLE.

you are a very good conveyer of your information. thanks ; )

[gemis94]

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?

[Afrotechmods]

@gemis94 The phase should be the same.

[filipnis]

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

[Rk17]

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! ^^,

[MrEinstain]

Megadeth ^^

[highkoo98]

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?

[MrJonagikster]

Is it viable to use a BJT amplifier instead of an OPAMP? Are they able to amplify at sufficient frequency?

[Afrotechmods]

@MrJonagikster Of course

[MrJonagikster]

@Afrotechmods What about in the GHz and greater frequencies (e.g. 2.4GHz)? Switching speed is 100ns or somewhere around there from memory.

[Jhfgsjdcd]

Or u can connect it to ur dish and big house antennae

[Absalon2085]

Yea boy

[hoskhosrav]

Thanks! very very Usefull!

I was always wondering how I can teach carrier signals simply.

[saden007]

The one that disliked this video, thought that the dislike button stood for dis-i-like xD Nice video afrotech, as always!

[creatiph]

yay for duke nukem theme !

[blackmambe]

l Like alle your video's!!! :D

[megamarko94]

what software do you use to design pcb schematics????

[Koroistro]

i was wondering , it's possible to convert radiowaves in elettric current for , for example, turn on a LED o.O?

[L0wr4diation]

nice music :) megadeath duke nukem theme

[docfleed999]

6:36

How did you connect your mp3 audio to the circuit..??

thank you for the vids, I really liked them.

[courageous917]

duke nukem rocks

[sypha0x]

"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.

[sypha0x]

However, I do enjoy watching your videos great stuff thanks :)

[soundiscomforting]

What I don't understand is how changing the amplitude of the carrier frequency can reflect more than one frequency?

[florisvanvugt]

very cool, thanks!

[Afrotechmods]

@JoeDaaPlumber Yup

[rroge5]

is it possible to do this with general purpose low cost transistors? have you done it? will you do a youtube vid?

[GTXAbunada]

@Afrotechmods

Hey afro, I simulated this circuit on Multisim, however, it did not "modulate" my carrier but rather added the carrier to the input signal. Should'nt it multiply the signal, rather than adding it.

Cheers

[mattnedgus]

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...

[rome877]

Whats the range on this ?

[zerozio2u]

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.

[logankriete]

This is one of the BEST introduction tutorials I've ever seen on this topic. Thanks for making me finally understand amplitude modulation!

[Derpinguin44]

Duke Nukem.

[saden007]

I want more videos from you, you're Great man, keep it up!

[ShotecMusic]

Thank you so much for all this informations!!! I really enjoyed it!

[pcbheaven]

So cool video! Great work! I will feature it today in my site. Looking forward for your next work

[nlimchua]

Hi Afro -

Can you explain what the purpose of a BFO is in layman's terms? thx.

[leeYT321987]

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!

[mpampleki]

Afro u are the best beacouse u gives urs regarts for Stefa0719 for the help

few people do that!!!

[Cybergast1]

Now, how do you build an FM transmitter?

[skierplaterandy]

please do a video on resonance, i can't wait.

i was going to make some basic electronics videos, but my knowledge doesn't even come close to what you have here :D

[sciguy14]

very well explained - another excellent video!

[PopTheTheory]

Very nice vidoes Keep up the good work (y)

[pieznice29]

duke nukem soundtrack :D

[Serostern]

Five stars for Duke Nukem theme! =D

[spektrum1983]

This is relevant to my interests.

[oo131193oo]

Is it maybe possible to use a 741 op amp? does it really not work?

[Afrotechmods]

@oo131193oo Not a chance. The 741 is an old POS from the 70s and can barely do anything useful above 100kHz.

[bas12345654321]

@Afrotechmods

I just made a Colpitts Oscillator, that works too.

Just with a BC546, works fine for my.

[hasspol]

Your doing a great job ! keep doing it !

[fidely]

Awesome videos-how about something on "Bread Boards" Thanks

[36trooper]

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!!!

[dennisbauer65]

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.

[endesigner]

Love your videos!

[busybjorn]

That was AM, it seems very easy now (thanks !) but what are its (dis)advantages to FM?

Even better: Why are there two of such modulations?

[Afrotechmods]

@busybjorn There are dozens of modulation schemes, all with their pros and cons. AM is very susceptible to noise (ever notice how AM always sounds crappy in your car?) whereas frequency modulation is much less affected by noise. An AM receiver is very easy and cheap to build, but an FM receiver is a little more challenging. Overall for broadcasting voice and music short distances, FM is by far the better choice.

[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.)

[TheThievingBeggars]

@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.