usally this:

a device (usally a heavly modified FRS base station radio) that has been set up to jam frequencies in the FRS radio band, used to annoy little kids and to hold a channel for yourself. Some FRS jammers even add music to thier transmissions, which makes it all the more interesting.
"I can't hear anything on channel, that radio op's got his FRS jammer on again"
by IrishRepublicanArmy October 15, 2003
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