I'm licensed, but never even picked up a radio. Again, great video. You deserve more views.

@styrishrodrigues

2 жыл бұрын

Hii sir😍😍❤️❤️

@flymig29

Жыл бұрын

Yo bro hello

The best demonstration I have seen yet on how AM transmitting works. Thanks

Thanks. I'm glad you're liking them.

This is the only explanation in the whole of the youtube that made it understood so well (atleast for dummies of beginners as me). Tonnes of THANKS for this AWESOM'EST one.

Thanks Todd! My trick to keeping them short might be in the drawings - an animation is worth a thousand words. I'd still enjoy your 50 minutes though, and learn lots.

I'm glad you enjoy them! I was on vacation this past week but my videos will continue this week. Thanks for watching!

So very, very good, so clear an explanation. I was a University lecturer for too many years, now retired. I used to pride myself in my teaching ability and so I recognise a true educator. Excellent. Thank you I've learnt a great deal.

Thanks! I'm glad it was clear for you. I'll think about doing a frequency modulation one. The reason I did the amplitude modulation one was because I wanted to try transmitting to my crystal radio.

This is one of the most oustanding videos i've seen. Congratulations for the Job and explanation.

Thanks, Samimy! Good thing you mentioned a plane so that people can use it for parts! :) Looking forward to your next video. -Steve

Great breakdown Steve! Your instructions are very visual and easy to understand. Are you a ham radio operator by any chance?

EXCELLENT way of explanation of AM radio modulation. well done.

I mention that in the video where I show how to make the AM radio transmitter.

They're also good piezo crystals so that helps. The strikers and crystals are in small housings with a spring. You can see demonstrations of the sparkers in my videos "How to take Piezoelectric Igniter from Lighter for Spud Gun" and "How to get Piezoelectric Crystal from BBQ Igniter/Sparker". But even if you remove the crystal from the housing, tapping it against a solid surface like a tabletop gives a good 240 volt spike.

Oh cool. Playing around with vacuum tubes definitely appeals to me - very low level DIY. These days everythings at a super high level with feature-filled chips, but that stuff's fun too.

First video that i Completly understand the principle of AM Thanks a lot ❤️❤️❤️

I could see this video being shown in an introductory level undergraduate course. Nice job!

Thanks you Sir. cant be explained any simpler than this. Now I have clear understanding of AM. Step by step explanation is great.

It was fun to play with tubes and tube type transmitters back all the way to 1997 for me. I had a Collins 20V-3 Transmitter I had to use a main to keep the station on the air. Big 4-400 tubes that were the size of a softball, and the transmitter's weight was about 1,200 lbs. Now we use a small 1 KW Broadcast Electronics Box that is a 1,000 watt box the weighs only 80 lbs. Since I have been maintaining it, not tubes, no problems, it just runs and runs!

4 AA batteries produce some voltage based on the voltage of the batteries at the time they're used. When you buy a AA at the store it's voltage is higher than 1.5 volts. When I measured the voltage of the four battery together it was 6.3 volts.

Thanks Grant! I try to leave little to the imagination. Re ham radio, I picked up the ARRL Handbook a long time ago, and even pulled it off the shelf this week, but that's as far as I've gone. Are you a ham operator?

Thanks! I was thinking the same thing just this morning re if a joule thief could be used. The waveform's awfully spikey though. Also, when looking at it on a grounded scope like mine it looks all pos but I suspect it's put on the antenna pos and neg. It certainly is on the receiving side. Now that I've got the simplest transmitter out of the way, I should look into one with an oscillator circuit from scratch. Sounds like you have an itch to scratch with all your ideas. :)

Great video! Easy to understand. You should explain frequency modulation as well

Wow. That was an amazingly simple yet comprehensive explanation. Thank you so much for sharing, brilliant content mate

This is the best tutorial about radio.

I'm new in electronics and trying to learn by my self, thanks for the explanation it is very good.

Clear and concise information, thank you and happy holidays.

Perfect explanation of AM..i loved it

If it works and has a range of 2-3 meter then that's great! I'd say it's working. 108MHz is the top of the FM radio frequency range. If you were able to transmit long distance then you'd interfere with FM radio stations. I did a search and couldn't find anything useful about your chip, but since it's working I guess any problem isn't with the chip.

This is really useful, I've just bought an oscilloscope and this will help me learn how to use it.

It probably will be. Based on the comments I get from students and teachers I know my videos are used in classes quite a bit. And thanks!

I didn't know there were oscillator chip made that small these days. When I was a kid in the early 70s, you could by a kit a Radio Shack with springs to connect the wires into form a circuit like a Oscillator. Last time I had to work on an oscillator, it was in a tube type, 1948, Gates Radio Commercial Transmitter, whey the operating crystal used a oven to keep it warm. I never could keep that oscillator on frequency! That was back in the mid 90s.

Great explanation! This really amplifies (pun intended) your previous video on the subject!

I was thinking of doing that, instead of using my CD player, but that would have required making an amplifier circuit for the microphone so I skipped it for now. I'll put it on the todo list.

I'll add it to the list.

Thanks! I don't know the power but I deliberately keep the distance to a few feet or less. I wouldn't want to interfere with anyone's radio.

Thanks! Will do.

Awesome tutorial... Need tutorial for FM Modulation and FM Radio Transmitter.

Thank you for your efforts. Why did you use the crystal oscillator? You could send the sound in the am wave because the sound is in the am range

@RimstarOrg

4 жыл бұрын

The problem is with the receiving side. The receiving side needs a specific frequency to tune into and the original wave consists of many different frequencies. See the explanation of the problem in the video again starting at 0:31.

Awesome explanation Steve..as always ..

nice..very clear explanation...i just love what you do...keep going sir!!

Astonishing explanation as always. Very very interesting. I've just found your channel and I'm loving all your splendid videos. For that video I didn't understand just a thing: does the oscillator chip do something strange inside? The mixing process of the audio signal with the carrier wave that happens inside the chip is complex or is very simple? Does the chip just make the two waves join on the output connection? I'm wondering if I could reach the same goal using a simple, two pins oscillator, do you think is possible? Thank you again.

@RimstarOrg

10 жыл бұрын

I don't have the specs for the internals of the 4 pin oscillator, the specs for mine don't include it. You could probably reach the same with a 2 pin oscillator, but you'd need to add the extra functionality yourself. Unfortunately I don't have a schematic for that either. Sounds like an interesting project. Let me know if you get one working. And thanks. I'm glad you enjoyed the video, and all my others!

@EMandMORE

10 жыл бұрын

I made it!!! I built the Receiver almost the same as yours, with some amplification. For the Transmitter I used just a PIC which generates a 2.5 Mhz frequency. It plays and stops it with a frequency of 1 kHz. So on the Receiver I clearly hear the 1 kHz sound wave. So now I'm going to add a PIC also on the receiver so I can transmit and demodulate all kinds of commands!! I almost reached a 20 meters range of communication!! Thank you again for illuminating my mind on this subject, you're the best!!

@RimstarOrg

10 жыл бұрын

EMandMORE Cool! Congrats! Sounds like it was lots of fun. Just be careful not to transmit too far and interfere with others' communication.

Thanks. Much appreciated.

High school physics plus a first year university physics course. But mostly I've been an amateur scientist all my life, reading science and physics books and magazines, stuff online and more importantly doing things which means really having to understand the science behind them (well, I guess it doesn't have to mean that but I try to.)

Well put!

Thank you sir. You've helped me understand Modulation a bit more. 💥

How does DC power you connected to a transformer, which is works following AC principle?

@wfukfm

2 жыл бұрын

The tranny couples the AC audio to the oscillator output also AC . The DC is what the osc uses to produce the fixed carrier wave ( that we are gonna modulate to produce our 1000 khz " AM radio station" )

Yeah, I keep coming up with easier way to explain it and better animation ideas, but you gotta release the video sometime. I'd say I stopped when I had about a medium level of required background, at least for the last part.

Excellent Description of AM

Thanks my friend!

I havent' found any datasheet of my crystal so I wired it up as I saw in this video and it actually works,I can transmit at 108MHz (I'm using the 4th harmonic) but as I said before the output is very low so its range it's about 2-3 meters,I really can't understand what should I do.Anyway if you care the entire code of the oscillator is: XCL 27M000 OSC-P50-303 thank you so much for your help(If I wrote something wrong I'm sorry,it's because I'm 17 and Italian :) )

Thanks! Yeah, I have a problem showing how to make something with also explaining how it works. :)

about early 1920s or like that, how did they achieve Am without a continues wave by the old spark gap tesla coil configuration?

Great video! I always wondered how that worked, Now I think I could make an oscillator to do that! Ever seen a JT audio modulated and transmitting audio via radio? Exciters dont count... I've seen that a few times. But not with toroid core... That the signal goes all pos was news to me. Explains the mono though. Makes it easy(er) too :) 555 timer could probably do it too! I'm just using some for the first time in 20 years the last 2 weeks :)

I love your videos and look forward to them.

Yep. about 20-100 ideas a day, and time to try 2 if I'm lucky. If an idea works out half decent, I end up fiddling with it for a week... Going backwards fast.... Thinking about getting a PFY.... Still got 2 piezo speakers on the desk next to a high gain Jt coil and a hand made flyback........ Do those lighter sparkers have a cap and coil inside?

Wow! Thats a lot of volts! the striker must be fairly precise? Now you really have my curiosity.... Where did I put that flyback....

Brilliant! I'm unlocking so much information about energies!

How can this transformer step up 1 volt to arround 10 volts when out cd player output ha no yet voltage or current so high to full fill this requirement and secondaly our transformer is low frequency how does it can work on khz frequency?

Great video, I think amplitude modulation is a lot easier to understand than frequency modulation because unlike AM I don't understand how FM radio waves carry sound (audio) waves. Do you feel the same way about FM radio?

@RimstarOrg

10 жыл бұрын

Brandon Fisher I think conceptually FM is probably a little harder to understand, or picture. Looking at the original and the FM radio wave side-by-side, it's harder to see the original in the FM radio wave than it is if you had the original and AM side-by-side. In the AM case it really stands out.

After 5 hours of research i found the explenation i need

You need to mention that the crystal module generates so many harmonics that can interfere with commercial equipment.

I could almost hear the click in my head. Thank you.

I have a question. If the carrier wave is what is modulated and sent out, how exactly does single sideband transmission work? If you suppress the carrier wave, wouldn't that mean you have nothing left to send out? I'm sure that I'm just missing something simple, but SSB confuses me. Thanks!

wow. thats awesome power. Been thinking about vibrational energy in push bikes etc. Ball bearing in tube with piezo at bottom, should bounce like crazy..Lighter crystal might be good :) I got a ton of them too. Pulled one apart many years ago, made huge mess. couldn't work out what was going on in there. Should have another look now I have a better idea from watching your videos. I knew they had to be good for something more than "Nerve testing" my mates >:-)

I bought the things you said ( in AM radio transmitter video)...I have bought this oscillator chip.... It has only two wires/pins sticking out of it...How do i use it... I have sent you the mail

This is excellent!! Thank you for sharing.

Hey canu make a vid about about solar eruptions i don't really get what they are all i know are that they are magntic eruptions which happen in the sun and can be ten times larger than the earth

Can you explain how the oscillator adds the two waves together, why does it do it? Specifically, why just because the audio wave the carrier waves are added together, they form a new wave, why and how so?

@RimstarOrg

3 жыл бұрын

The answer to how is that the audio source's wave is on one coil of the transformer and induces a voltage on the other coil of the transformer. That other coil also has the voltage wave from the oscillator and so they add together. For the why, I explain that in the video starting at 0:37. You might also get some understanding of why from my video about how a crystal radio works kzread.info/dash/bejne/YmGEssOrg9DdpKg.html

@jupitersaturnuranusneptune2816

3 жыл бұрын

@@RimstarOrg Fantastic!!! Thank you very much

Nice video as always, I have a question though. I noticed the lack of lower band audio signal from the transmitted signal, as well as the use of square wave as carrier wave. I believe square wave takes a lot more bandwidth than sine wave, which may result in bad audio quality, is that true? Also, does the missing lower band signal matters at all in terms of audio quality?

@RimstarOrg

9 жыл бұрын

***** Thanks. Sorry, but I really don't have answers to your questions. This is a pretty basic transmitter though, so the quality is quite low anyway.

Hey, that was pretty good.

I've yet to understand single sideband myself.

Great tutorial, other than the fact that the frequency is not the distance between two waves. That is wavelength. The frequency is how fast waves pass a certain point. For instance, the faster waves move, the higher the frequency (usually).

@RimstarOrg

9 жыл бұрын

Shelly Gardner Hmmm... This is a case of hear what I mean, not what I say. :) In my head, as I was saying it I was processing the implication that if the frequency is the same than the wavelength is the same and therefore the distance between each peak is the same, or more likely I was processing that the same frequency implies the same distance between each peak - something automatic for me and you too I guess. So you're right, I shouldn't have said it that way. Sloppy. Good catch.

@DSimonJones

6 жыл бұрын

Do not use fast or faster in explanation of frequency as that implies the speed of the wave is changing. The speed of the the wave remains the same in the same medium. Frequency is best explained as the number of oscillations per second.

is there a way to use the earth as the antenna, or the connecting resonant frequency for two systems at a distance? Just an idea

Well, this video does make some assumption about how much electronics you know. I guess it's not a beginner level one.

Not that I know of... but that doesn't mean there isn't any.

how much power rf output this AM transmitter ?

@RimstarOrg

2 жыл бұрын

I didn't measure it so I don't know. You don't want it to be too powerful since you don't want to interfere with anyone's radio.

can you do a microphone for the transmitter? I planed to make some kind of walkie talkie

Woah! This video is awesome, thanks so much for making it. I was just wondering... if this is the modulator circuit - would a commerical radiostation theoretically just need to send this signal to their amplifier, and be able to transmit at a long distance?

@RimstarOrg

10 жыл бұрын

I'm don't know at which stage radio station sized transmitters do the amplification, before or after modulation.

@Project2025WILLRUINYOURLIFE

10 жыл бұрын

Ah ok, thanks anyway.

Nope, the lighter sparkers have just the piezo crystal and that's all. Very simple.

If I understand correctly, the receiver (crystal radio) uses an LC circuit to tune to the right frequency of the transmitter. Can't you just use the same LC circuit in the place of the crystal oscillator, for the transmitter as well ?

@RimstarOrg

2 жыл бұрын

I think so. You'd still need to power the LC circuit but an LC circuit can be used to generate an oscillating frequency, to be an oscillator.

@Ryan-lc4bl

2 жыл бұрын

@@RimstarOrg I'm not sure if it will be able to modulate the sound, in theory it should, but there's nothing to generate the continuous carrier wave ? (radio wave). This LC circuit was used in the early spark gap transmitters, and it was used to keep them at one frequency, but still didn't create continuous waves (CW), rather dampened waves. Maybe that's why it didn't work to transmitt sound.

@RimstarOrg

2 жыл бұрын

I was thinking that the LC circuit, i.e., tuned parallel capacitor and coil, would supply the continuous carrier wave. The audio wave would then be added to that just as is done by the audio source to the oscillator output in this video's circuit.

@Ryan-lc4bl

2 жыл бұрын

@@RimstarOrg I saw that another circuit (an amplifier) was needed together with the LC to keep the oscillations going, otherwise it would just drop quickly and become a damped wave. A quick search shows why it wouldn't work : "In a simple inductor-capacitor, LC circuit, oscillations become damped over time due to component and circuit losses. Voltage amplification is required to overcome these circuit losses and provide positive gain"

@RimstarOrg

2 жыл бұрын

Yup, that's what I meant in my original reply when I said you'd still need to power the LC circuit.

Thank you! Very impressive

I had never really understood modulation until now

Now we need to modify the crystal reciever to center that audio wave back to zero! :P

I am confused on what the transformer and oscillator chip do?

Awesome explanation as always. What are the components of the AM transmitter that control its range. i.e. how far its signals be received

@RimstarOrg

6 жыл бұрын

I prefer not to say since that would be a bad idea (plus I haven't tried it). Firstly, it would interfere with other broadcasts, secondly, it's illegal in many countries to broadcast, and thirdly, this simple circuit transmits on many frequencies besides the tuned one so it's even worse. So it's fun to play with for short range, but longer shouldn't be done. However, many countries have the ability to get amateur licenses if you want to pursue that sort of thing. It's very rewarding and you learn a lot. www.arrl.org/ham-radio-licenses

@osamabinladin4u

6 жыл бұрын

RimstarOrg thank you!!

does it matter that there is no reversed wave on the bottom?

@RimstarOrg

2 жыл бұрын

Which part of the video are you referring to? I can't find what you're asking about.

@WistrelChianti

2 жыл бұрын

@@RimstarOrg I mean that the wave being sent goes between 0 and some positive volts. I guess it probably doesn't since in the other videos you kinda subtract the bottom (negative section) with a diode anyhow

@RimstarOrg

2 жыл бұрын

That's right. At 3:13, I'm showing a measurement of what the oscillator is putting on the wire but the resulting electromagnetic wave's affect on the receiving radio's antenna is to make the electrons in the antenna oscillates back and forth.

@WistrelChianti

2 жыл бұрын

@@RimstarOrg I feel I should probably just try it and see what I find : )

@satltabur4597

2 жыл бұрын

This is actually an interesting question! At 3:29 we see the amplitude modulated carrier wave on oscilloscope. It is missing the mirrored bottom half of the signal below 0, which you normally get at amplitude modulation. What causes it to be missing?

Thank you very much Sir

What a class...

hi , dose that mean that the carrier frequency could be of any function ,, ie sine wave , square waves ,zigzag etc... cheers

@RimstarOrg

8 жыл бұрын

+Mustapha Alkhafaaf It would seem that way on the transmitting side, but the receiving side has to be able to do something with that carrier wave to get back the original audio wave.

@mustaphaalkhafaaf5512

8 жыл бұрын

so I understand from what you have said that as long as the receiver can be designed to demodulate the received signal according to the shape of the transmitted carrier wave , we are free to cheese any carrier wave ...

@RimstarOrg

8 жыл бұрын

+Mustapha Alkhafaaf Oh, now that you put it that way, I don't know if other waveforms than sinusoidal will work as electromagnetic waves propagating through space.

@mustaphaalkhafaaf5512

8 жыл бұрын

it depends how you know/see electromagnetic wave travels through space , some people see it as a sinusoidal wave others see it as ring circles just like the effect of stone in the water ... very confusing i must admit

@mustaphaalkhafaaf5512

8 жыл бұрын

Mohammed Al Sayegh First of All many thanks for the above explanation I really appreciate the time you spent to write this I am still not very clear why sinusoidal why could that not be of another form I do understand from the DSP point of view that all square waves are made up from the summation of sine and cosine waves (if we apply the Fourier transform ) but I am still not clear of the EXACT reason of the carrier frequency why it should be sine or cosine wave persay. If the physical property of the antenna only accept or “understands” sinusoidal waves then I would really like to know the exact reason for this , (if e look in the LC filter formula we see that there is the 2Pi times the Freq factor present ) and two pi element represents the unity circle of sine and cosine ... Now the question >.. is this the reason ????

Can I use a function generators 1 MHZ sine wave, instead of the 1 MHz crystal oscillator?

@RimstarOrg

2 жыл бұрын

I suspect so but I'm not sure.

@rentacowisgoogle

2 жыл бұрын

@@RimstarOrg Thank you! that's encouraging, I'll have to just try it and see! If it works, I wonder if I could even use the generator's bias control in place of the battery pack.

@wfukfm

2 жыл бұрын

I would think a sine wave being modulated would give a more natural sound than a square wave anyways.

it is the best observation.....

Are you sure you're wiring up your chip properly? Do you have documentation for your chip telling you what all the pins mean? They may be different from mine. Just a stab in the dark. You haven't given me much to go on.

hi can I use your simple am radio transmitter on my exam in school? but i don't know the circuit of it. can you give me?

@RimstarOrg

7 жыл бұрын

It's a common circuit. You don't need permission to use it. The circuit diagram is in the video and here on my website rimstar.org/science_electronics_projects/make_simple_am_radio_transmitter.htm. I don't have a version in schematic form.

@eamenaj14

7 жыл бұрын

RimstarOrg oh okay thanks 😊

Replied by email.

GREAT video! Thx

What did you use to record your audio? Sounds a little too cripsy for my ears.

@RimstarOrg

4 жыл бұрын

A Rode microphone but plugged into the camcorder (which adds some noise but is all I have). Then Audacity to clean it up, remove hiss and so on. And finally into Sony Vegas video editor where I do volume control and sometimes get rid of room and car sounds.

Did you record this before you had to catch a train?????

@ayo_dugge

4 жыл бұрын

Lmao

Naw, we'll just chop off the bottom half instead! :)

Nice. Thank you.