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Silent jamming against British pirates ?

Posted: Mon Apr 28, 2008 19:13 pm
by Ray Lalleu
Silent jamming against British pirates ?

For a few days now, several British pirates seemed severely undermodulated for many hours. This is quite evident for Laser Hot Hits on 4032 and for Playback Int. on 6882 (though tx is abroad), maybe for Pandora on 3910, and who knows else?

That could be "silent jamming" : a strong blank carrier on the same frequency exactly can wipe out a small signal without making any noise, quite the opposite it makes silence in the receivers. Only high grade receivers are able to receive a sideband while filtering out excess carrier power. As you know, directive antenna are quite ineffective at these frequencies, but some parts of Europe (e.g. Finland) can escape a jammer distant from the station, acc. to ionosphere conditions.

Any advice ? Anyone able to monitor and locate the jammers ?

Posted: Mon Apr 28, 2008 20:43 pm
by Martin Scott
Hello, panic not. For a change it was not a jammer - it was low mod. The Laser techy bods tell me this was a transmitter fault which has now been fixed.

Regards

Posted: Mon Apr 28, 2008 22:01 pm
by Ray Lalleu
Transmitter fault for Laser 4032 : OK

Doesn't explain why Playback was "undermodulated" or un der a carrier in W. Europe and audible in Finland (at the same time) ?