mp3 player transmitter

[zachtheterrible]

Hi there. I just got my truck and the license is coming in a few weeks, FINALY!! :lol:

Neway, my truck has a cd player, but is not mp3 capable, so its probably become apperent to you that I want to transmit my mp3 CD player to my truck radio :lol: .

My question is this: I want to transmit a stereo signal. Can a little two transistor "bug" transmitter with the mic amp taken off, and the signal fed directly to the oscillator transmit stereo?

 

[tansis]

Here you go Zach.
I does not show up well on the pic ..
the inductor L1 is 3 turns of .5 mm wire on a 5 mm ferrite core.

 

[zachtheterrible]

thanx tansis, but i would very much rather use my little transmitter like on the picture here if i could. mainly because i have all the parts and its very simple. would this work or not?

thanx :lol:

 

[Nigel Goodwin]

thanx tansis, but i would very much rather use my little transmitter like on the picture here if i could. mainly because i have all the parts and its very simple. would this work or not?

No, you need a stereo encoder!.

 

[zachtheterrible]

:lol: thats wut i thought, but it was worth a shot. ill try to find a circuit on the internet that consists of components i alredy have, but if not ill try yours tansis. btw tansis, how is the range on that thing? i would like it to be powerful enough to take over other car radios sitting next to me, just for fun :wink:

 

[tansis]

With a supply of a mere three volts the broadcast range will be fairly limited , a good antenna will help but don't expect much over fifty meters.

 

[audioguru]

Hi Zach,
Your simple mono FM transmitter also doesn't have pre-emphisis, the audio high frequency boost that FM radio stations use. So the FM radio will sound the same or worse than AM, like you have its treble control turned all the way down.
If the radio tunes stations by digital synthesis and the transmitter's frequency drifts (which it probably will) then the radio will reject it.

Sony makes a very good little FM stereo transmitter, for transmitting their Walkman sound to radios. It doesn't drift at all. Sounds great. It is almost as expensive as a new car radio/CD player/MP3 player.

 

[zachtheterrible]

tansis, thats all i want, id be taking people's radios over at a stoplight or somethin like that. i want to be able to hear wut im playing in my mp3 cd player over their radio, and i wanna see their reaction :lol: i wont do anything cruel though

are there any simple circuits that would require components that i already have? i bankrupted myself when i bought my truck, and i still owe some money to my mother dear :lol:

audio, like i said, i dont have any money right now, so buying something is OUT of the question :lol:

thanx :lol:

 

[TheOne]

Your biggest problem even if you could transmit in stereo is that the modern radios won't turn on it's stereo decoder if the received signal is too far off (+- 25kHz) the dial set frequency. If you want to transmit in mono that will be less of a problem. Stereo encoders could be made with a few CMOS logic chips, crystal and opamps. https://www.nrgkits.com/workshop/stereo_coder.htm

The MPX part gets fed into your transmitter to modulate.

 

[magickaldan]

You could try these they seem to contain only simple parts easily obtainable.
- 50-300mW FM Transmitter:**broken link removed**
500mW FM Transmitter **broken link removed**

 

[tansis]

Well Zach, I don't know what they call it in the states but over here in England we have a pastime known as "Skip Diving". Electronic scrap abounds, my amp an old but very servicable NAD3140 came from the dumpster of a local hi-fi store and a more recently aquired 17" monitor was left out for garbage collection (the NAD's former abuser had cooked it, managing to vapourise several inches of track from the pcb and the monitor was suffering from nothing more than a leaky HT cap!)
VCR's , older the better, more discrete parts and nice chunky motors.
Computers will always yield a good general purpose power supply and other goodies if you are lucky. Charity shops over here seem to have an inexhaustable supply of seven segment LED alarm clocks for around £1, grab them! for re-housed in a new box they look sleek, desireable and very saleable. Failing that with the addition of a suitable relay they make good single function timers for garden lights. Make your hobby pay for it'self!

 

[zachtheterrible]

sounds like stereo is gonna be a major pain in butt. i guess i'll just go with mono for right now.

tansis, im way ahead of ya :lol: i just inherited two old VCR's (finally got some dvd players), i have a box full of my old stereo boards and lots of other stuff, and then i just found this guy who used to work as a garbage man and he would collect electronics, now they're all laying on his porch, so im gonna inherit some old psu's, a moniter (yes!), some cell phones, answering machines, etc etc etc 8)

 

[kentken]

What you want is a FM transmitter for MP3 player, look around at computer, electronic suppliers.
Take a look at:
https://www.tigerdirect.com/applica...Sku=S750-4136&SRCCODE=GOOPROD&CMP=OTC-FROOGLE

This is one style, do a google search.
Kent

 

[audioguru]

Hi Ken,
The "spec's" for that cheap wireless gadget are too brief.
Does it transmit in FM? Or AM?
Does it transmit stereo? A stereo receiving system plays mono too, you know.
How much does its carrier frequency drift?
Distortion? Frequency response?

 

[vaineo]

If you want to make it a little easier rather than transmitting in stereo you could mix the signals and transmit mono, still get the left and right that way. Unless you have a really good system in the truck i don't think you would be too dissapointed.

 

[panic mode]

reading time

https://members.tripod.com/~transmitters/ck222.htm
https://members.tripod.com/~transmitters/njm2035_1.htm

 

[kentken]

I realy don't know much.
I think it transmits in FM
and I think it is stereo

Other then that ??

Kent

 

[zachtheterrible]

vaenio, that sounds interesting. when you say mix the two signals, do you mean have two transmitters or something?

As for all of the other chips and stuff, I think that that will come later (remember im broke, and owe my mother dear $475 for the truck :lol: )

 

[Nigel Goodwin]

vaenio, that sounds interesting. when you say mix the two signals, do you mean have two transmitters or something?

He means just join the left and right channels together, and transmit in mono.

 

[zachtheterrible]

AND ILL GET THE RIGHT AND LEFT!?!?! Thats what I was hoping that I could do all along!

What is the difference between true stereo and, um . . . "stereo mono?"