Many wifi and cell phone type jammers incorporate GPS jammers as well. These are to disable surreptitiously placed GPS based tracking devices which are often used by law enforcement as well as lawyers trying to catch cheating spouses.
Wifi (2.4G and above) usually operates well above GPS (1.2-1.3G; plus or minus a couple hundred MHz depending on which kind of equipment) and most cell phones, but any transmitter--especially one trying to jam -- and double especially one made in China -- generates all kinds of spurious signals and harmonics. And because it's a kinda pirated type of device to begin with there are not any form of universal frequency specifications or power level standards -- unlike normal cell phones, iPads, laptops, and the like.
Obviously this is illegal and dangerous aboard any aircraft with radio based navigation equipment and other electronics. And the possibility of knocking out onboard GPS (and other stuff) is most definitely there. Anyone trying such a stunt should be thrown in jail just like anyone else intentionally trying to harm an aircraft and its passengers.
Last edited by Shep69; 24th Apr 2017 at 19:45.