In article ,
(Yuri Tregubov) wrote:

Don't know is it true or not, but have read that hobbyist level
nonsophisticated 1W jammer shuts down GPS devices in an area of
hundred kilometres.

It's not true. The strength of a one watt signal just plain isn't
enough for such a thing to be true.

Whoever told you this knows *nothing* about RF other than the term
"watt."

--
cirby at cfl.rr.com

Remember: Objects in rearview mirror may be hallucinations.
Slam on brakes accordingly.