FM Transmitter problem

[Zarniwoop]

G'day all,

Shortly after purchasing a PDA I found that I would like to play the MP3's stored on it through my car radio. Upon finding the manual for the radio, I discovered no auxiliary input for it, which made my task somewhat more difficult.

I then decided the easiest way to achive my goal is to build a small FM Transmitter and have it broadcast to the antenna in the car, in a sort of 'pass-thru' arrangement, similar to aftermarket CD Changer units.

Getting to the point, I purchased a Velleman-kit K1771 FM Oscillator hoping this would do the job. It seems that this kit is designed for an Electret microphone and not for the output of a PDA/MP3 Player/PC.

What needs to be done to the signal to make it appropriate for this transmitter? I can tune it in on a house radio, but the signal seems to be over-driven and comes out very distorted.

Cheers!
Grant

 

[Sebi]

Can i see Your circuit?

 

[Zarniwoop]

In the search for the online version of the circuit diagram, I found the revised manual, which is MUCH better than the one that came with it. The manual also contains the procedure for connecting a source such as CD player, mixer, etc. The solution is a 47K Logarithmic pot in the circuit as shown here.

**broken link removed**

Cheers anyhow!