VK repeater jammed.. by headphones

Australia's telecommunications regulator ACMA has confiscated a consumer device that was wreaking havoc on an amateur radio 2-metre repeater.

The unit turned out to be a pair of wireless headphones, with a talk back-channel, designed to be used with a PC online.

The headphones carried a brand label Omni model WEP-910D. It turned out that they use the 2 meter frequency of 147.000 MHz to deliver audio to the headphones. This explains why radio hams in range of the repeater being jammed heard endless hours of whatever was being processed through the offending PC's sound card.

Now, here's the kicker. Not knowing that the unit was in a ham radio band, the users of these headphones complained that on some occasions they heard "voices talking to them" on their personal computer system.

As there may be more of these units in use anywhere in the world, radio hams need to keep an ear out for them. Most appear to operate on 147.000 MHz +- about 15 kHz, so users listening to repeaters on or near 147.000 MHz are
more likely to be affected by these units.

Source: WIA, ARNewsline