Re: LF: OT End of the BBC World Service on Shortwave

[Jacek Lipkowski <sq5bpf@lipkowski.org>]

On Mon, 31 Jan 2011, mal hamilton wrote:

> You are correct about the Internet being vunerable but you forgot to mention
> Broadcast JAMMING which is a regular occurance when your information is not
> wanted. This renders the transmitted information useless.
a local jammer doesn't work well - groundwave doesn't propagate far. the 
only way to jam is to bounce your signal off the ionosphere, but you need 
higher power for that, and the jammer has to be far away (usually in a 
different country). if the jammed stations work on multiple different 
frequencies, then you really need a lot of jammers, in different 
locations, to take varying skip zones into account etc.
we had Radio Free Europe etc jammed for many years, and somehow people 
were still able to listen to it :)
VY 73

Jacek / SQ5BPF