We have some wireless microphones set up with the receivers in a confined space. After adding some HDMI cables (for streaming purposes) we now have an interference problem.
While the transmitter is switched off, the receiver now locks in to an extremely loud and unpleasant signal which comes from HDMI cables running about 15 cm below the receiver. We first decided to just "live with it" keeping the mic muted until the transmitter is switched on. However, it also starts to kick in at other random times, maybe when the batteries of the transmitter start to run low or so. In any case, it almost blasts everyone's ears off and could potentially damage our speakers or our sound engineer's heart when he panics to find the mute button :-)
We have put some small boxes under the receiver to enlarge the distance to the HDMI cables and that seems to help a little, but we cannot make a larger gap.
The wireless microphones operate at around 650.000 MHz.
We tried inserting some aluminium sheets underneath the receiver to shield it, but it does not seem to do much.
Is there a way to shield the HDMI cable, or is there something we can put under the receiver to shield it from the interference? Or is there a way to make the receiving antenna more directional?
