OBSERVATIONS GM1SXX 18 October 2010
Weird Band Noise.
Tonight after work, I came home and worked a few European BPSK stations on 30M. Having a load of fun and then blam! A large chunk of the band was utterly obliterated by a signal unknown. You can see it nicely on the screenshot of the waterfall below, covering the whole (SSB) filter passband.
Out of interest, I also recorded the horrendous racket, since my FT102 was wired to the PC anyway. Here's a 30 second sound sample. Just click on the link to hear it.
Expect a horrendous racket! It's a very rough buzz with what sounds like the old-fashioned 'phasing' type sound effect superimposed on it. Not very pleasant. I'm sure it's a local noise source because it reads S9+10DB on the FT102!
I've been going around switching things off, but so far... no joy. Tried all the usual suspects, LCD TV, phone chargers, anything I could find that used a switch-mode PSU. Nothing. The interference has stayed constant, so I rather suspect that it is coming from a nearby property. Looks like I won't be working 30M again tonight. The racket is ongoing as I write this.
Many of the products that are sold in the UK are very shoddy indeed from an EMI point of view. Don't be fooled by 'CE Approved' stamps either. Many CE stamped products originating in China arrive here missing their RF filtering components, while the authorities (OFCOM), seem to turn a blind eye. I'm, sure they have better things to do than chase up radio interference. Still, for the moment at least, I can still operate on 20 & 17M.
A swish around the other bands shows them to be clear of this strong interfering signal... a good thing.
A tune around shows that the interference extends from 10.130 to 10.160Mhz and seems to be strongest around 10.135500(USB)
A strange one indeed. If any of our readers have suffered similar interference, I'd be glad to hear from you.
73 Al.
GM1SXX