RF affecting USB ports...

[wavetar]

Anybody else here notice that USB ports, for some makes of laptops at least, are very susceptible to RF causing issues when connected to the unshielded MotoTRBO programming/interface cables?

We've recently been in-house testing with several different dispatch/GPS packages for MotoTRBO, and have experienced a lot of instances where the USB ports 'lock up' and become inactive...sometimes power cycling the radio connected to that particular port will restore functionality, but most times ALL USB ports get shut down (won't even respond to a USB stick plugging in) & only a computer reboot restores things back to normal. This occurs with several different laptop makes/models. At least one of the software providers has acknowledged it as an issue to me. Setting everything to low power and using dummy loads where possible minimizes the occurrences.

Granted, it's only really an issue when dealing with radios in close quarters. If you have a base radio in a building with your antennas on the roof and field radios miles away, you probably won't experience it. But in situations where customers are say doing GPS tracking in a command post vehicle where the antennas may be in close proximity to the radios, it becomes important. And indeed, it's proven to happen with some beta systems we have out there.

I custom made some shielded USB cables, since Motorola doesn't provide them, and they seem to help, at least some. Next step is to add a ferrite choke to see if that helps as well.

I'm wondering if a laptop such as a toughbook might be less prone to this?