On Wed, 22 Jun 2011 01:45:36 +0100, Graham. wrote:

It's a high intensity LED according to the datasheet. The device is
unlikely to have a relay switch but I suppose it is just possible.

I was also wondering if it has a poorly designed SM PSU that emits
hash when under load.

That was my thoughts as well. Now I know it's a "high intensity" LED,
that might not be fed with DC but with low duty cycle pulses running
at at few kHz but badly/not filtered so loads of RF noise.

The OP might want to place a MW or LW receiver tuned between stations in
the vicinity of the unit.

Yep.

--
Cheers
Dave.