Wireless Audio Transmitter
Intro: Wireless Audio Transmitter
Hey world...
This is a instructable on wireless audio transmitter.In most of our day to day life we come across situation where we need a connect our iPod,mobile,laptop.....etc. to our sound system,but the major limitation is the cable that we need to connect.This probably happens if your sound system doesn't have a wireless connectivity option.i too had the same problem so i decided yo solve it...:-)
Basically its a adjustable FM transmitter that is designed to transmit sound waves to the radio receiver.We connect the transmitter to our device and use a old phone or FM receiver to connect to our sound system.This might seem odd as we are kinda broadcasting our-self but the range of the transmitter is limited to 800 meters only.The reason choosing this option is that it is very very CHEAP ..!!Also u can connect multiple sound systems at a time without any worries of sync.Hope this project helps you.!
STEP 1: Electronics You Need
Parts List :
Resistors :
R1 - 10k
R2 - 15k
R3,R4 - 4k7
R5 - 68E(68 ohms)
R6 - 2k2
R7 - 10E(10 ohms)
Capacitors :
C1 - 2.2uF/25v
C2,C3 - 10KpF(103)
C4,C5 - 10pF
C6,C7 - 1KpF(102)
Transistors :
Q1 - BC548
Q2 - C2570
Inductors (air core):
L1 - 4 turns (22 S.W.G Copper wire)
L2 - 4 turns (22 S.W.G Copper wire)
L3 - 6 turns (22 S.W.G Copper wire)
Miscellaneous:
Trimmers 1,2,3 - 22pf
Antenna - 30 cm
MIC (optional) - condenser MIC
Audio Jacks:
3.5 mm mono jack
3.5 mm female jack
6.5 mm mono jack (guitar jacks)
6.5 mm female jack
STEP 2: Tools You Need
Tools :
Soldering iron
Soldering wire
Multimeter
pliers
Wire stripper
Tester
Fevi-Col
De-soldering pump
PCB hand drill (if needed)
STEP 3: Schematics for the Transmitter
The above Image shows the transmitter Schematics you'll need to make the PCB.I have used a black zero PCB i.e. one that is used make a new prototype ;-).In the schematic instead of the MIC you can use a Mono jack. The pinouts for the jack are given above.Its has only two pins GND and Signal.The antenna can be replaced with a simple wire
STEP 4: After Building the Transmitter
You should get this after building the PCB. I've used a plastic box to place the circuit.The transmitter has a 2 basically a 2 stage transmitter having a V.H.F. oscillator and a R.F. power amplifier.R.F. output power is 100 milliwats. Frequency of the Transmitter can be set with in 88- 108 MHz band by adjusting the first trimmer and also by adjusting the distance between the coil.Adjust the other 2 trimmers for max radiation.Connect a 9 volt battery and thats about it..!
STEP 5: Applications
I had small speakers which I've connected to the speakers as radio receiver we can even use a FM receiver too. The tab is connected to the transmitter . So now whatever the tabs audio output is, it is being broadcast and received by the receivers.Also if you have to many transmitter in the at one place just change the frequency of the transmitter.
Here's a video of that.You can connect multiple sound systems now, by just getting a new receiver to each sound system.
STEP 6: Its Done..!!
Your done and hope fully the R.J. of your area .. ready to rock your neighbors..!!
21 Comments
supercapacitor 9 years ago
Nice build!
GerritW1 5 years ago
RusselL8 6 years ago
is it working for tv?
YuvrajJ3 7 years ago
chandra24 9 years ago
Scifiswapnil 9 years ago
Thats a good one .. but i think i have a solution....
for my solution you'll be needing two such transmitter's and two receiver's with some modification..
the idea is that ..in mono we send a single signal to the receiver but in case of stereo we need two outputs (the device generates two signals) to be sent...so we'll send those signals on two different carriers and receive them at two different receivers(on different frequencies) and connect them to one jack to get a stereo output.See in the image you'll see the stereo jacks have left and right signals ..
JelleV10 7 years ago
The image is incorrect, a 3 conductor jack does not contain a mic. it only has ground, left and right audio so the tip of the left jack is also audio out. The right jack is correct.
chandra24 9 years ago
I have bought all the parts. and going to make it but i need help so can i get ur fb id or whatsapp no so that i can contact you for help in realtime.
thanks.
my whatsapp no- 8126648064
mopswachtel 8 years ago
I can't find a place to buy that C2570 and I know to little to find something simmillar that I can use. I can't find the ones that Scifiswapnil posted neither :-/
Scifiswapnil 8 years ago
2SC2570 is an alternative for c2570.. try finding this one
mopswachtel 8 years ago
Yay! At least I found that one on Ebay. Looks like the usual big german electronic retailers are not too familliar with your choice of transistors :)
mopswachtel 8 years ago
Oh looks like the big retailers got them too, it's just that their site-search-tool sucks :)
RonE14 8 years ago
Is this type of circuit legal to operate? What is the range?
EdgarU1 8 years ago
How can I make this for a guitar?
Scifiswapnil 8 years ago
just replace the 3.5mm jack with 6.5mm jack
AnubhavR1 8 years ago
I did everything what was in the above steps.. But mine is not working.. The output is not coming
Scifiswapnil 8 years ago
did you tried changing the pot values, try doing this:
1) set a radio receiver to a fixed channel
2) now change the pot of the transmitter till you hear the sound on the receiver
chandra24 9 years ago
Scifiswapnil 9 years ago
try 2SC3512, 2SC2753, 2SC3128.But its more difficult to get these ic's ...!
chandra24 9 years ago