Radio oscillator/receiver?

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posted on Sep, 27 2012 @ 03:23 PM
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So all I got are: capacitors, paper clips, magnets, small-voltage electrical wires, small batteries, potentiometers, aluminium foil, switches and a small solder station.

Out of these I am trying to figure out how I can build an oscillator - a device which can produce radio waves. I am also trying to figure out how I can built a receiver - a thing which can receive this wave and make it a electrical signal. Nothing fancy, just send 1 kind of signal and receive it.

Any ideas?
edit on 27-9-2012 by swan001 because: (no reason given)




posted on Sep, 27 2012 @ 03:35 PM
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Check out YouTube videos of what you are interested in.



posted on Sep, 27 2012 @ 03:39 PM
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reply to post by RussianScientists
 


I also happen to be on dial-up. Videos take eternity to load as I have limited internet time.
edit on 27-9-2012 by swan001 because: (no reason given)



posted on Sep, 27 2012 @ 03:42 PM
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I recently purchased two very cheap IC's and a couple resisters to create a small radio link. Total cost was about £4.
What do you need it for - distance to cover etc?



posted on Sep, 27 2012 @ 03:45 PM
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reply to post by VoidHawk
 


I notice you dont mention semiconductors in the OP, but mention magnets, your not going to attempt one of those ancient vibratory things are you?



posted on Sep, 27 2012 @ 03:45 PM
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Originally posted by swan001
So all I got are: capacitors, paper clips, magnets, small-voltage electrical wires, small batteries, potentiometers, aluminium foil, switches and a small solder station.

Out of these I am trying to figure out how I can build an oscillator - a device which can produce radio waves. I am also trying to figure out how I can built a receiver - a thing which can receive this wave and make it a electrical signal. Nothing fancy, just send 1 kind of signal and receive it.

Any ideas?
edit on 27-9-2012 by swan001 because: (no reason given)


You need an amplifier component of some kind.. A common transistor( either npn or pnp or a vacuum tube but that entails
higher voltages and more parts; concept is the same though).

An "oscillator" in analog electronics can be created from any amplifier circuit; introducing a feedback loop;and using "tuned" (i.e.carefully chosen) capacitors and inductors or crystals to create a resonant filter in the feedback path determines the frequency of oscillation. There are plenty of single and double transistor transmitter schematics available online(Google is your friend).
Basic ones are Pretty simple;common circuits in general. Plenty of common integrated circuits incorporate oscillators like PLL's("phase locked loops") commonly used in fm receiver circuits.
common timer chips like 555's can be setup as "astable multivibrators"; (digital oscillators. Which tend to be used for timing and counting applications..).


It would help to have a basic understanding of capacitive and inductive "reactances" and how they react to frequency.

Capacitors oppose a change in voltage/Iinductors oppose a change in current. Capacitors pass higher frequencies more easily; inductors pass lower frequencies more easily and "impede" higher ones.

As for phase: "ELI THE ICE MAN"rules: You'll have to look up yourself (getting way a head there). Where these two components interact in frequency response; and how they are physically assembled; enables a frequency band to be passed or blocked very selectively.


en.wikipedia.org...
I'd imagine theres something to be learned starting here:
en.wikipedia.org...
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posted on Sep, 27 2012 @ 04:48 PM
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reply to post by swan001
 


well, without transistors (or valves) you are going to battle to make something decent. with a single transistor, a couple of resistors and capacitors you can make a simple transmitter.

However, you can make a spark-transmitter (and receiver) with the stuff you have, however, your neighbors are going to hate you, as those things transmit RF all over. You will jam all radios, TV's etc, etc ...... but it is a fun way of irritating neighbors, lol ...



posted on Sep, 28 2012 @ 01:09 AM
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Originally posted by swan001
reply to post by RussianScientists
 


I also happen to be on dial-up. Videos take eternity to load as I have limited internet time.
edit on 27-9-2012 by swan001 because: (no reason given)


Years ago I've been there and done that, and that is no fun. But... you can drive to McDonalds or other places and get fast internet access. That will help you out in getting faster internet access. Maybe you could just see if you can pick up free over the air access where you are at, have you tried that?



posted on Sep, 28 2012 @ 12:28 PM
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reply to post by RussianScientists
 


Air? Yeah, but it's password protected. I am not the kind of guy who will use Reaver just to get it neither...
edit on 28-9-2012 by swan001 because: (no reason given)



posted on Sep, 28 2012 @ 12:31 PM
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Originally posted by Hellhound604
reply to post by swan001
 


well, without transistors (or valves) you are going to battle to make something decent. with a single transistor, a couple of resistors and capacitors you can make a simple transmitter.

For reasons which I do not wish to disclose I can't use anything but what I described in my OP.


However, you can make a spark-transmitter (and receiver) with the stuff you have, however, your neighbors are going to hate you, as those things transmit RF all over. You will jam all radios, TV's etc, etc ...... but it is a fun way of irritating neighbors, lol ...


I don't think it'll be that powerful. I don't have a big battery, just 9 volts. I find this spark transmitter actually interresting. It's exactly what I'm looking for. You say it could send AND receive? And that I have all the ingredients?



posted on Sep, 28 2012 @ 12:32 PM
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Originally posted by VoidHawk
reply to post by VoidHawk
 


I notice you dont mention semiconductors in the OP, but mention magnets, your not going to attempt one of those ancient vibratory things are you?



Ancient vibratory thing? What's that.



posted on Sep, 28 2012 @ 12:40 PM
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Originally posted by swan001

Originally posted by VoidHawk
reply to post by VoidHawk
 


I notice you dont mention semiconductors in the OP, but mention magnets, your not going to attempt one of those ancient vibratory things are you?



Ancient vibratory thing? What's that.


the spark transmitter... You wire a coil, with a piece of magnetic metal completing the circuit. as soon as the coil magnetises, the coil attracts the metal, that breaks the circuit. The coil de-energises and that completes the circuit again..... So, you have a simple electro-magnetic oscillator. Depending on the inductance of the coil, you can have quite a high back emf developed across the coil, that generates a spark every time the circuit is broken. That spark is received by your receiver (and all other receivers in the area)..... Simple, that is how telegraph radios worked in the 1920's.

the receiver can be a simple diode, but in the olden days they used a glass tube filled with iron fillings. These fillings are magnetised by the H-field of your spark transmitter, and conduct electricity, that can be used by your galvanometer to show a decrease in resistance as it receives the pulse...... A lot simpler just to make a crystal receiver using a diode and a cap.
edit on 28/9/2012 by Hellhound604 because: (no reason given)



posted on Sep, 28 2012 @ 12:48 PM
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Originally posted by Hellhound604

Originally posted by swan001

Originally posted by VoidHawk
reply to post by VoidHawk
 


I notice you dont mention semiconductors in the OP, but mention magnets, your not going to attempt one of those ancient vibratory things are you?



Ancient vibratory thing? What's that.


the spark transmitter... You wire a coil, with a piece of magnetic metal completing the circuit. as soon as the coil magnetises, the coil attracts the metal, that breaks the circuit. The coil de-energises and that completes the circuit again..... So, you have a simple electro-magnetic oscillator. Depending on the inductance of the coil, you can have quite a high back emf developed across the coil, that generates a spark every time the circuit is broken. That spark is received by your receiver (and all other receivers in the area)..... Simple, that is how telegraph radios worked in the 1920's.


Hmmm.. could be done cleverly wiring a standard relay coil through one of its own nc contacts.But Some of those incorporate a diode acrss the coil to shunt(kill) the back emf "kick".
IMHO The transistor is easier and readily scrounge-able.."The professor"on Gilligan'sisland couldn't do it with cocoanuts and bamboo either. So "This is what I got"; may not get you there..
edit on 28-9-2012 by 46ACE because: (no reason given)



posted on Sep, 28 2012 @ 01:16 PM
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Originally posted by 46ACE

Originally posted by Hellhound604

Originally posted by swan001

Originally posted by VoidHawk
reply to post by VoidHawk
 


I notice you dont mention semiconductors in the OP, but mention magnets, your not going to attempt one of those ancient vibratory things are you?



Ancient vibratory thing? What's that.


the spark transmitter... You wire a coil, with a piece of magnetic metal completing the circuit. as soon as the coil magnetises, the coil attracts the metal, that breaks the circuit. The coil de-energises and that completes the circuit again..... So, you have a simple electro-magnetic oscillator. Depending on the inductance of the coil, you can have quite a high back emf developed across the coil, that generates a spark every time the circuit is broken. That spark is received by your receiver (and all other receivers in the area)..... Simple, that is how telegraph radios worked in the 1920's.


Hmmm.. could be done cleverly wiring a standard relay coil through one of its own nc contacts.But Some of those incorporate a diode acrss the coil to shunt(kill) the back emf "kick".
IMHO The transistor is easier and readily scrounge-able.."The professor"on Gilligan'sisland couldn't do it with cocoanuts and bamboo either. So "This is what I got"; may not get you there..
edit on 28-9-2012 by 46ACE because: (no reason given)


yep, if you use one of those old relay coils (without the snubber) or an old electromagnetic bell, it is the same. You jsut have to remember to remove the capacitor that snubs the spark, and will have to live with the fact that your contacts wouldn't last long before it is totally eroded by the spacks
.....

But I do agree, I played with the simple spark transmitter 40 years ago, and once I moved on to transistors (and valves) there was no going back



Now I know where you want to go with this .... You want to build your own Tesla-coils .... that is great fun!!!

edit on 28/9/2012 by Hellhound604 because: (no reason given)



posted on Sep, 29 2012 @ 12:00 PM
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reply to post by Hellhound604
 


The coil... can it be a spring? I imagine the magnetic metals goes at the end of this spring. One end of the spring is plugged to hot, and the metal piece to ground?

As for the receiver, I do have glass and bits of iron. But how do I magnetise them to my transmittor's H field? What's an H field in the first place.

I'll explore tube option before crystal option. Can't capacitors be used as diodes?

edit on 29-9-2012 by swan001 because: (no reason given)



posted on Sep, 29 2012 @ 02:28 PM
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reply to post by swan001
 


I really do suggest you read a very elementary book on electronics.



posted on Sep, 30 2012 @ 04:47 AM
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reply to post by Hellhound604
 


Most of them are explaining electronics in geek terms... It's hard to understand for a beginner. I am a bit familiar with electronics (I wire up my own electric guitars - not just pickup swaps: the whole thing, including the jack, the switch, the pots, capacitors values, couple pole on/on switch to create effect like parallel, out of phase etc.), but that I learned by myself over the years. And radio is a tiny bit different than that
.



posted on Sep, 30 2012 @ 11:41 AM
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I just wanna know if by "coil" you meant a wire of copper (which is hard to get but I could put my hands on this stuff) which looks like a doughnut, or if you meant a spring-like thing.

Like that?

edit on 30-9-2012 by swan001 because: (no reason given)



posted on Oct, 1 2012 @ 08:19 AM
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reply to post by Hellhound604
 


Hellhound? Are you all right?



posted on Oct, 1 2012 @ 09:06 AM
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reply to post by 46ACE
 


Okay. You. What do you think:

Originally posted by swan001
I just wanna know if by "coil" you meant a wire of copper (which is hard to get but I could put my hands on this stuff) which looks like a doughnut, or if you meant a spring-like thing.

Like that?

edit on 30-9-2012 by swan001 because: (no reason given)






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