Build a Computer Controlled Radio Transmitter
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http://www.instructables.com/id/Build-a-computer-controlled-radio-transmitter/ Home Sign Up! Explore Community Submit Build a computer controlled radio transmitter by bmlbytes on February 4, 2007 Table of Contents intro: Build a computer controlled radio transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 step 1: Gather Supplies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 step 2: Which Oscillator? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 step 3: Wire some stuff up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 step 4: Wire up the oscillator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 step 5: Add antenna . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 step 6: Send some morse code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 File Downloads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 step 7: Receive some morse code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 File Downloads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 step 8: Congrats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Related Instructables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Advertisements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Customized Instructable T-shirts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Comments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Transcript of Build a Computer Controlled Radio Transmitter
http://www.instructables.com/id/Build-a-computer-controlled-radio-transmitter/
Home Sign Up! Explore Community Submit
Build a computer controlled radio transmitterby bmlbytes on February 4, 2007
Table of Contents
intro: Build a computer controlled radio transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
step 1: Gather Supplies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
step 2: Which Oscillator? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
step 3: Wire some stuff up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
step 4: Wire up the oscillator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
step 5: Add antenna . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
step 6: Send some morse code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
File Downloads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
step 7: Receive some morse code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
File Downloads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
step 8: Congrats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Related Instructables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Advertisements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Customized Instructable T-shirts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Comments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
http://www.instructables.com/id/Build-a-computer-controlled-radio-transmitter/
intro: Build a computer controlled radio transmitterThis will allow you to send morse code through radio waves to another computer. This could be used as a sort of chat program.
step 1: Gather SuppliesYou will need very few supplies:
-A crystal oscillator (will talk about which kind in the next step)-A 9 pin serial jack (D-SUB9)-A little bit of wire-Something to use as an antenna-A radio-A male to male audio jack (unless you know morse code)
step 2: Which Oscillator?To determine what kind of oscillator you want you will need to know what kind of radio you have.
Regular AM/FM radio - We will be using only the AM part. The numbers on the dial are frequencies in KHz. Most oscillators are marked in MHz. You will probally wantsomething in the .3MHz(300KHz)-1.5MHz(1500KHz) range.
Shortwave radio - Go with whatever frequency your SW radio can play. My radio has 3 bands. One is a KC (KHz or AM) band and the others are MC (MHz). I use a20MHz oscillator.
http://www.instructables.com/id/Build-a-computer-controlled-radio-transmitter/
step 3: Wire some stuff upYou will need to solder a wire onto pin 4 of the serial jack. This one should be red to make it easier to work with later but not nessesary.
You will also need to solder a (black) wire to pin 5 of the serial jack.
step 4: Wire up the oscillatorTake the red wire (from pin 4) and connect it to the pin directly above the black dot on the oscillator. Next, take the black wire (from pin 5) and connect it to the pin to theright of the black dot.
step 5: Add antennaNow add an antenna to the pin opposite the black dot. You can use pretty much any insulated wire as an antenna, just as long as it isn't too thick. I used a 25 foottelephone wire.
http://www.instructables.com/id/Build-a-computer-controlled-radio-transmitter/
step 6: Send some morse codeDownload the morse code program (linked below).Connect the serial jack into your computer.Start MorseCode.exeType some stuff in.Click the radio menu on the top.Click transmit.
-You may have to choose a different COM port from the "Com Port" menu.
-If your using a SW radio you can select the CW setting by clicking the radio menu and selecting CW
Your radio is now transmitting.
File Downloads
MorseCode.exe (1 MB)[NOTE: When saving, if you see .tmp as the file ext, rename it to 'MorseCode.exe']
http://www.instructables.com/id/Build-a-computer-controlled-radio-transmitter/
step 7: Receive some morse codeThere are to ways to do this.
-Learn morse code
-Use a computer: Find a radio.Tune to your freqency. Use a male to male headphone plug to connect the headphones part of the radio to the microphone jack in thecomputer. Download and install cwget.zip. When running it SHOULD (doesn't work well for me) start to decifer the morse code. Read the manual to figure out how.
File Downloads
cwget.zip (665 KB)[NOTE: When saving, if you see .tmp as the file ext, rename it to 'cwget.zip']
step 8: CongratsYour all done.
A few tips:-Get a good antenna. I heard about someone who did this with a 24.3MHz oscillator and a 10 meter antenna and sent his signal from California to Texas. I haven't triedtesting mine outside my house yet, but it works pretty well here.
-Get a higher frequency oscillator if possible. If you have a SW radio then you can to this, otherwise stick with AM. If you use AM though be warned that your messageswon't be private. Anyone can pick up an AM signal.
-Check your frequency. If your frequency is in an amatuer radio range then you will need a licence to run it. If it is in an AM range, you can only send your signal a fewblocks (I think it's a mile) without a licence.
Hope you can use this to send secret messages to far away friends.
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http://www.instructables.com/id/Build-a-computer-controlled-radio-transmitter/
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Comments50 comments Add Comment view all 71 comments
helzangel says: May 13, 2007. 8:37 AM REPLYwhere do you guys get your oscillators i can only find ones with 2 pins
greenbean says: Oct 4, 2008. 5:43 PM REPLYjameco.com
bmlbytes says: May 13, 2007. 5:45 PM REPLYHey I found mine in an old computer. They are typically used in comunication devices that need a specific frequency. Try a cordless phone or a PCI cardthat has an ethernet or serial jack on it.
xtank5 says: Feb 2, 2008. 10:39 AM (removed by community request)
bmlbytes says: Feb 2, 2008. 12:50 PM REPLYTOTALLY DOESN'T read other comments. I already said that it was from scitoys.com
greenbean says: Oct 4, 2008. 5:40 PM REPLYIt's way cheaper on jameco.com
xtank5 says: Feb 2, 2008. 3:28 PM (removed by community request)
JazzmanSA80 says: Feb 4, 2008. 4:52 PM REPLYunnecessary comments were unnecessary.
thanks for sharing this with us bmlbytes!
IdrisB says: May 25, 2008. 6:29 PM REPLYWhere did you get the oscillator? Ive been looking for weeks.
greenbean says: Oct 4, 2008. 5:38 PM REPLYYou can get a 1 mhz oscillator for $2.50 off of jameco.com
ultrastatic says: Aug 11, 2008. 12:58 PM REPLYDo you think this could be used to say... shut off the lights? Could you make it so that it will control power to several things through out a room?
http://www.instructables.com/id/Build-a-computer-controlled-radio-transmitter/
greenbean says: Oct 4, 2008. 5:27 PM REPLYYou should be able to send out a morse code like signal that has either on or off. The light switch would receive the signal, and if it was on, then the lightwould switch on and vice versa. The switch would be a simple circuit using a transistor and the radio receiver.
pyro14228 says: Sep 23, 2008. 2:19 PM REPLYI need to know if i could use this to send a continues transmission to space i no this is ganna sound crazy but i am trying to build a computer operated radiotransmitter to send a continues code like a sonar to see whats out there i am going to school right know to studie sounds from deep space if you guys knowwhat i mean
sam117 says: Aug 31, 2008. 1:54 PM REPLYwould it be possible to use this concept to control say a robot with a laptop?
botmaster 10 says: Sep 1, 2008. 1:09 PM REPLYY'know, i wanted to know the same thing. I want to build a topo. Have you heard of one? if not, google androbot. i could use some help
sam117 says: Sep 1, 2008. 1:22 PM REPLYwow thats a cool conceptim in the process of desining a robotic fish and i want to control it with my laptop
botmaster 10 says: Sep 1, 2008. 2:40 PM REPLYBut, can you help? no one else in R2 builders or androbot yahoo groups seems to want to help me. I am about clueless.
sam117 says: Sep 1, 2008. 2:59 PM REPLYidk if i can what are you clueless about?
botmaster 10 says: Sep 3, 2008. 2:05 PM REPLYBuilding a TOPO
sam117 says: Sep 3, 2008. 5:18 PM REPLYits called googleand read a couple of books
botmaster 10 says: Sep 4, 2008. 4:19 PM REPLYim entering the chassis in my science fair
tuane06 says: Aug 29, 2008. 6:25 PM REPLYcan i transmitte other code? why is morse code? can you help me?
The Nate Dawg says: Aug 31, 2008. 3:26 PM REPLYMorse code uses a signal that turns on and off in a series to make a short signal (dot) or a longer signal (dash). This gadget turns the signal on and off toform letters and numbers. Google it.
looking4ideas says: Aug 29, 2008. 7:36 PM REPLYi have seen this on scitoys.com years agoHereHere
helpseeker says: Aug 27, 2008. 9:56 AM REPLYwhat is male to male audio jack (unless you know morse code)
S1L3N7 SWAT says: Aug 8, 2008. 5:19 PM REPLYCool Instructable. Do you think this could be made to operate a servo attatched to a receiver running at 75 AM? It would be cool to control rc stuff from thecomputer.
http://www.instructables.com/id/Build-a-computer-controlled-radio-transmitter/
astro boy says: Aug 8, 2008. 12:18 AM REPLYhey if you need to find a One Megahertz Crystal Oscillator they sell them 4 $3.50 each here Scitoys.com Catalog it transmits at about the middle of am radio
jgeekw says: Jul 17, 2008. 8:05 PM REPLYcan you add a pic or diagram on where you added the blue LED?
the_mad_man says: Jun 21, 2008. 6:46 PM REPLYcan you make an oscillator with a crystal and some electronic stuff? coz i can't find a oscillator in my old dial up modem, only a crystal
davidprosser says: Feb 29, 2008. 2:35 PM REPLYWhere can I buy this ocillator in the UK, cos I can't find it anywhere! The only place I found STARTS their range at around 1.8 MHz, which is at the top of myam reciever, so I can;t pick it up unless reciever's tuner is at top, and the send/arial wires are around a cm a way! Where can I get it from!?
maguye007 says: Jan 7, 2008. 7:20 AM REPLYdude, cool device! I was wondering if i could send pics,music,e.t.c. Is there a program that i could download for that/ Rply please,man!
HOMEPIE64 says: Jan 6, 2008. 5:26 AM REPLYwait is it possible to use voice instead of morce code becuase you said something about a male to male audio jack and i would prefer using voice becuasemorsecode is kind of hard to translate while typing for an ametuer
Athlon says: Apr 7, 2007. 6:59 PM REPLYI can't find this oscillators with 4 pins, only with 2 :S Help pls!
bmlbytes says: Apr 10, 2007. 10:29 PM REPLYLook in old computers and desolder them. They will be found on cards that control things like serial ports, ethernet jacks, modems, etc.
locofocos says: Dec 29, 2007. 4:12 PM REPLYThey sell em in the catalog section of www.scitoys.com
Batas says: Nov 24, 2007. 11:49 PM REPLYCoolerPlay muzic, not morse code :D
J50Nunlimited says: Sep 20, 2007. 4:08 AM REPLYinteresting thing!just wondering if i can send music over it from my computerif it can, do i need to find a program that helps me transmit it? i just got the vvv toolkit and dont know if it will work (i dont know how to use it)this is where you can download it: http://vvvv.org/tiki-index.php?page=Downloadsor are there any other programs i can use?programming could be fun but i am only a beginner so i dont know muchi have a 2.4 MHz at hand, is it okay?so when i have the transmitter set with my computer, is the receiver the radio?that means i will have to find the right channel to hear music from my computer, right?thanks in advance!
static says: Jul 11, 2007. 1:56 AM REPLYSunspot activity is expected to be picking up coming out of a low heading towards a high. Unless you are licensed I would advise against using the 28 MHzmodules. When the band is open even these flea power transmitters can travel a ways. Some hams seak out weak signals to copy for the challenge. Theylike the challenge of tracking down bootleg signals as well.
robbtoberfest says: Feb 7, 2007. 10:49 PM REPLYIf you could hook this up to a hamm radio system you could make your own wimax network.
http://www.instructables.com/id/Build-a-computer-controlled-radio-transmitter/
static says: Jul 11, 2007. 1:42 AM REPLYWell there was/is; is/was a world wide computer network. Some areas quite robust, others not so quite so robust. I was viewing nexrad radar images andhad a weather bug like display long before this small town has local dialup.
Pepsi Supreme says: Feb 24, 2007. 8:10 PM REPLYMaybe this could be Modified into a really usefull thing. I was thinking of a morse code training device that would bring up on the computer what you codedin. Kinda like a really old keyboard. I've always wanted to learn morse code, but never had a cool way to do it. Sitting around looking at all those dashes anddots make my eyes hurt.
static says: Jul 11, 2007. 1:30 AM REPLYIn the event you are trying to learn the Morse Code, do yourself a favor and quit visualizing the dashes and dots, that will only slow you down. Visithttp://www.qrz.com/download/morse/index.html to download software to learn train, practice Morse Code.
HOMEPIE64 says: May 8, 2007. 6:23 PM REPLYdude i must say this is kikn @ss this a great instructable all around. 10 out of 10
wikityler says: Mar 26, 2007. 1:08 PM REPLYIf you're going to infringe on someone else's copyright the least you could do is credit him, and not change the license to a CC by-nc-sa.
fat_strat_cat says: Mar 10, 2007. 10:16 PM REPLYcan i do this with a usb (if so can you add it to the instructible) because i dont have the right port on my comp
epiphany_123 says: Mar 1, 2007. 1:01 PM REPLYthis is what I have whill it work?
bmlbytes says: Mar 1, 2007. 11:09 PM REPLYI'm not sure. I think that this is a plain crystal. You will need a crystal osscillator (like the one pictured above or the same only a square). They have 4pins and one of them is marked with a dot. The dot is the ground as is the pin that is by itself on your crystal. There would be no spot for an antenna onyours. Look for something that is simular to mine. It can be of any frequency as long as you have a radio that can recieve at that frequency.
ironmambob says: Feb 6, 2007. 4:21 PM REPLYThis project will only put out a few milliwats of power, so it will not interfer much with other services probably. Interfering with some services can be crime,however, so be careful.A "Hertz" is the unit of frequency, 1 cycle per second. It is capitalized because it is a proper name (of a physicist, Heinrich Hertz).Since the output of the oscillator is a square wave it will be full of even harmonics which can be enhanced by the length of the antenna. A "quarter wave" at agiven frequency will select what is radiated to some extent. for 1 mHz this is 1166 inches, 2 MHz 583 inches; 4 MHz 291 inches; 6 MHz 338 inches; 8 MHz291 inches; 12MHz 194 inches. A longer antenna will give you much more range but will cause more interference, and keying the oscillator this way will alsogenerate more interference.I have seen Morse code keyers that key off he game port, but I suspect these have gone the way of the dinosaur and serial port, too.
Ian01 says: Feb 25, 2007. 9:02 PM REPLYActually, hertz is not capitalized when used as a unit of frequency. See the bottom of Wikipedia's hertz article.
VIRON says: Feb 6, 2007. 8:15 PM REPLYHow did you calculate that? Did I goof? 1Mhz=300m wavelength300m/4 = 75m x39inch.p.m= 2925inches= (243 feet plus 9 more inches)
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