A Possible Filter???
Two whips, 1/4 wavelength (69 mm), at a spacing of about 1 inch (25 mm), enclosed inside a drink can.
https://farm1.staticflickr.com/382/19056047500_e70e64498b.jpg
https://farm1.staticflickr.com/431/19056080338_b0ec120bf9.jpg
https://farm4.staticflickr.com/3948/19243673105_f911cd68d8.jpg