Hello!

Here is an odd one for the group to ponder.

I have a pair of Madiface USBs, which are connected to a Direct Out Technologies Andiamo unit.
The Madiface USBs take Clock from the Andiamo via 75ohn BNC
Madi is fed from the Madiface to the Andiamo via 75ohm BNC

When a 2way radio is used in the proximity of the Madiface, the RF interference is corrupting the USB Data from the computer to the Madiface. Playback from the computer still continues, however the audio in interrupted.

I experienced this at a gig. Depending on the channel used on the 2way radios would vary the severity of the interruption. On a particular channel I was able to stand over 5 meters away from the rack and completely stop all audio by simply transmitting from the radio.

We tried multiple computers, multiple USB cables, and we also had 2 Madiface USB devices, and all behaved in the same manor.

We also had available to us a Madiface XT and a HDSPe MADI card. We used these to determine if it was the Madiface USB or the Andiamo where the problems were.

Testing with the Madiface XT, we were able to reproduce the fault, but we had to wrap the USB cable around the antenna of the 2way radio to cause the fault to happen,

Testing with the HDSPe MADI card in a Thunderbolt chassis, and wrapping the thunderbolt cable around the antenna, we were not able to reproduce the fault.

Since the gig I have taken the system home, and am able to perfectly reproduce the fault utilising my hand held UHF radio.

Has anyone experienced anything like this or have any pointers on what to do next? The next steps I had in mind were to purchase some more expensive USB cables, and also purchase some ferrite chokes to place on the cables.