While I have been a "watcher" of the forum for some time this is my first post and I'm pleased to finally get involved. There is some great information offered and hopefully someone out there may be able to asssit with a little problem I am having.
I have an RF interference problem with my car computer system. I have been playing around with the system for some time, mainly for GPS use with OziExplorer. I am pretty happy with the current set up except for an RF interference problem. The system is a Dell C400 notebook in a docking station under the seat attached to a Xenarc 8.4” screen mounted in the dash. Plugged into the docking station is a USB GPS mouse, the USB cable from the monitor touch screen and a Compro wireless keyboard/trackball plugged into the PS2 ports. Power is from a DC-DC converter. The issues are as follows:
* There is interference through the monitor speakers and through the radio in the car sound system.
* There is no interference if I play a CD in the car sound system.
* The interference is only present when the monitor is switched to VGA mode. There is no interference in video mode.
* If I detach the VGA cable from the computer (audio cable still attached) the interference disappears.
* If I plug the audio cable into an alternate device the speakers in the monitor work fine.
* The RF interference also affects a portable radio – worse if I put the radio near the monitor but also to some extent if I put it near the computer.
* Unplugging the GPS, touch screen and wireless keyboard make no difference to the interference
* I have a dual battery system and it makes no difference which battery the system is powered from.
* It makes no difference whether the vehicle is running or not.
* The aerial cable is about 10cm from the back of the monitor which I am thinking is a problem for the radio.
I have read the information in the forum on interference and have attempted to earth the computer by running an earth cable to the VGA plug. Unfortunately that did not make any difference.
I would like to throw the problem open to other thoughts before pulling the system apart once again. The possible problems as I see them are as follows.
* The VGA cable runs fairly close to the audio cable from the computer to the speaker. Apart from separating the two is their any shielding that I should use around either or both?
* Would putting shielding around the aerial cable help? If so what is suggested?
* The monitor is not earthed. How is the best way to earth a monitor?
Any other suggestions with either problem appreciated.