Very strong QRM/interference on the 12 metre band

I recorded this awful noise on 12 metres this morning. It was obliterating all but the strongest signals in the CW portion of the 24 Mhz band. I wonder does anyone know what the likely source of this interference is? I have heard/seen it before, I think on 17 metres. It is not local. I have brought the interference to the attention of the Irish representative for the IARU Monitoring Service.

Update: I had a quick reply from the IARUMS. Apparently this interference is Over The Horizon (OTH) radar. 

Video of strange pulsating interference on 80m

I recorded this QRM on 80 metres last night. Anybody got any idea what it might be?

Plasma TVs cause massive interference on HF

Countdown timer: 9 weeks 6 days to go

I have not had time to study today due to work but might get 10 minutes in at lunchtime.

In the meantime, here is a warning to any HAM operator or SWL thinking of getting a new TV.

Avoid Plasma TVs like the plague. I got one a couple of years back and it causes 9db of interference on my HF radios. It affects especially the higher bands - 160M, 80M, 40M and 20M, but can be heard on all bands, even on a vertical antenna.

Here is a YouTube video demonstrating the effects of Plasma TV interference on 80 metres:



Always buy LCD.

I had a HF rig in the car for a few weeks not long ago, and the noise level would rise enormously as I pulled into the driveway. Even though my antennas for the home-base rigs are outside, away from the TV, it still causes huge interference. On 40 metres the noise blanks out any weaker signals so only the loudest can be heard - very annoying. I am planning to replace the TV with an LCD version at some stage which will hopefully eliminate the problem.