MattBW
Here to help
Super Poster
Lifetime VIP Member
I have a little Electrosmog meter that does similar, depends on the frequency of RF being transmitted but if it interferes with the radio it can usually find it. That is how I found out my 12v usb chargers were awful. Sad to say most cheap Chinese tech is like that these days, corner cutting is the default approach over there sadly. I always give it a test and if its no good I return it.