Well, this is an idea I want to build. Yes I know it's 2013, people use media files (CD, DVD, memory stick, etc.) instead of the old FM radio, but you don't know where when it will come handy to have one.

So here is the basic idea:

I saw this on a DIY website and I thought, why not take this to another level?



This is USB so it would work with the N900 USB host for power, but not many phones can do that, so we need a self-powered FM transmitter. Also cables may get in the way, and the best method to replace cables is AD2P since every phone have it.

Now at this step we're going to get something like this:



This is a AD2P receiver with a 5V 140mah battery.

Now we open this up and get power for the stick above, then hook up the input of the stick to the output of the receiver, bound them together and you have your own wireless FM transmitter for any device with AD2P ready.

Now, the problem is that the USB transmitter above is very basic, it just broadcasts and you can't select frequency, and you need that so that's why I found this:



Now if we want a clean work we should search for more specific hardware:

And here is a Micro-USB powered FM transmitter:



and this Micro-USB AD2P receiver with keys:



And now they are just stand-alone, but if we're working with packs, even when charging we should use a pack, so we are going to hook the power trough a cable like this:



And here you have your own wireless FM transmitter.

I hope you will enjoy this!

If you search the forums and repos there are instructions and even a packaged app to boost the FM transmitter on the N900 to fill a whole room.
If you take most external FM transmitters you can jumper resistors or even overvolt the power to the amplifier chip, sometimes you need to add an antenna cut to length http://www.qsl.net/kb5wck/antenna.html
for the frequency you choose maybe also jumper a attenuator on the way to the antenna and you can get a few hundred meters of range on an open FM channel just watch out for the FCC.

I no longer have a N900, that's why I posted this in General, that package is useless for me now. I was just trying to find the best solution for a generic FM Transmitter that could receive data wireless.

This was the best solution until now.

I think I have a belkin FM transmitter from around 2002 with a 3 battery pack or USB power in and an added wire antenna I ge good whole house range. The trick is overvolting the amplifier, you can get the specs on the amp chip by web searching its part number.
FM is still the most universal way to send audio to any stereo home or auto.

And what was the price for it, back in 2002? I am still searching for the cheapest AD2P receiver, see it's specs and then analyze the competitors.

The point is that this will be hidden somewhere in my car, when I get in my car, the phone should connect to that AD2P receiver and transmit to the FM. I still care about sound quality, and also the transmitter has to have crystal clear sound.

Can you recommend anything?

I think it was something like $20 in '02, the quality is adequate for a tin ear like me to send music to a radio in the garden, probably not what I would call CD or MP3 line in quality though.

im looking all over my place for this FM transmitter, but no luck..



plan to use it with my N9..