I decided to use an old case to do my testing before I went out and got a mini ITX - it's powered with an inverter - extremely ugly.

I did not want to work on the car audio during testing so I bought a modulator from target for $20. It worked super in the house, I was able to broadcast to every room with excellent quality, Very cool for parties where audio distribution is problematic. That was with the 2 batteries and a portable CD player. Quality has gone down since then.

The modulator pod as purchased has a 3 volt to 5 volt step up converter that drives the modulator chip. I just hacked in after the power switch flip flop (a 4013 !) and stuck in the 5 V. I suspect that the PC power supply is hammering the poor modulators B+ with lots of noise - probably the source of my less-than-perfect current sound quality. Since I took the time to mount it in a PC plate with a nice F-Connector. I might add some filtering before going DC.

It also seems like there is a slight impedance mismatch from the mother board audio-out to the modulator-in. I took out the 2 load resistors at the modulator input, but that did not seem to make any difference.

Here are a few shots of the test system on the bench:

mediacar menu.JPG	carputer fm xmitter.JPG	carputer.JPG
mediacar mp3 800.JPG	ant1.JPG