I have had them on Oscilloscope, the first person ever to Public ally do this. See Hand Made Effective Jammers from $US 190 Posted. br Pointing one of these Awful devices at a $1400 ALP or $3,000 Stinger is like playing Russian Roulette, but with 4 or 5 , not One Cartridge in the 6 Chambers.The Odds of your Jammer surviving ARE that bad. br If I ever find a Safe 'Tester' i will be featuring it straight away.