FM Trans and Charger not working together

Hi to everyone I have been readings everyones posts for a few weeks, I just bought a CF28 Ultimate Toughbook from Toughbook. This is one issue I have not come across and I have not found in the forum. I have a Monster FM Transmitter going through my headphone jack in my service truck with iTunes. It works as well as you can expect for a FM transmitter. The only issue is when I hook my Lind DC to DC charger into my CF28 there is so much engine noise (I am not sure what everyone calls it) even when the engine is off. I thought it was the Lind charger so I unhooked all connections but the only one that made a difference was unhooking it from the toughbook. After that no background (engine) noise and it works great. Is it the toughbook charger causing the noise if so what can I do because I do not want to carry more stuff. I already have the handheld company computer, company cellphone, company gps, my cellphone I do not want to have to drag my ipod with me to. Any help would be great.

 

Try taking the battery out - my old Samsung had a very noisy charging circuitry. Plus the noise also came whenever the hard drive was accessing data.. you could hear "ch chhhhchcchhc... ... chhchhhh." Getting an external USB audio card didn't help until I physically cut the shield on the USB cable... and then it finally worked. And then because the laptop was a P4m, heat killed it eventually.

 

At the moment i mean it is the step up converter, which works in a frequencerange, which i is not filtered backwards to the truck main power. Is this noise constant? Did u also tried with a normal powerchord with the original main supply? Is the sound hearable, if the fm-transmitter and laptop are connected to the charger but the audio from the laptop to the transmitter is disconnected? If this is not so, u need an audio transducer with two separate coils to disconnect the audio-ground to make the input from the transmitter electrical independence from the output of the laptop.