The jammin in ROTJ was sensor jamming, not comms jamming.

<blockquote><strong><em>Quote:</em></strong><hr>"I get no reading on the shield, up or down."

"How could they be jamming us if they don't know we're coming?"<hr></blockquote>



Yackety shmackety . . .

Another point of note would be that the Rebels didn't know they were being jammed until they were unable to detect a shield.

. . .and they were only jamming the shield readings, not the enemy fleet that had manouvered in behind them, in holding sector 37, no less.


Which draws the question, Is jamming an all encompassing field that's thrown up like a blanket, or is it more of a focused weapon?

Trickster Jammer
this was the nickname given to the New Republic's repulsor-based gravitic countermeasures, used to disrupt the communications of a Yuuzhan Vong yammosk. These devices were developed using intelligence gathered by Jaina Solo and Danni Quee, and allowed the New Republic's naval forces to equalize the odds during battle. They were named for the Yuuzhan Vong goddess Yun-Harla, who was known as the Trickster, and whose guise was adopted by Jaina Solo in an attempt to goad the Yuuzhan Vong into rash actions.

220-SIG
this was the designation of Kuat Drive Yards' tactical combat jamming system. These incredibly powerful jammers were built for the Empire, which placed hundreds of them aboard both Death Stars to prevent sensor and communication usage in their vicinity.

Gravitic Amplitude Modulator
this piece of Imperial technology allowed a starship to modulate gravity in its vicinity. More sophisticated than the gravity well projectors used on Interdictor-class cruisers, the GAM was also much more expensive to develop. Thus, they saw little use onboard warships until the Galactic Alliance showed Imperial engineers how to reprogram it to jam the communications of a Yuuzhan Vong yammosk. This application of a GAM was used successfully at the defense of Borosk.

"Jam thier comlinks, center switch!"






WWWWWWWEEEEEEEEEEEEEEEEE!!!!!!!

Rectenna
this Fabritech communications and sensor array features active/passive scanners, jamming systems, ship-to-ship transmitters, and short-range targetting capabilities. The Millennium Falcon had one of these dish-like packages attached to its upper hull.

Silencer
this IntelStar communications jamming system allowed pirates, smugglers, and independent starship captains to block a nearby vessel's outside communications.

Silencer sounds like the most common form on TRF.