These items are radio receivers and NO you wouldn't be allowed to use them on board. They have the potential to cause interference and it is impractical to expect the crew to have to assess the relative merits of each toy a passenger brings on board.
Certain electronic equipment may be permitted in accordance with rules pertaining to the timing of its use and always at the discretion of the aircraft commander but the use of radio receivers and or transmitters whatever their strength is never usually permitted on board exept where it is part of the aircraft architecture ( for example in flight phones ).
Taking it on board and switched off of course is not likely to be a problem.