The jammers were also directed against these programmes and so the broadcasts were re-arranged.
Of course, they will be needed for many years to deal with the stand-off bomber and the stand-off jammer.
Towed decoys which closely mimic engine heat and infra-red jammers can also be used.
The former may be a noise making jammer or a decoy providing a signal that looks like a submarine.
A fleet of 1930s red tour buses called jammers which were rebuilt in 2001 to run on propane or gasoline, offer tours on the road.
Jammers have an added effect of affecting radars along other lines of sight through the radar receiver's sidelobes ("sidelobe jamming").
Therefore, jamming can be seen in directions other than where the jammer is located.
One blocker can be designated as a pivot a blocker allowed to become a jammer in the course of play.
