I have a nice pair of Amperex 7316/ECC186 audio tubes. Both were made in Holland and have the short plate halo getter. The Bugle Boy tested 89/97 and the date code is Ct1 delta 9D which is May 1959. The second tube tested 97/84 and the date code is Ct5 delta 3D which is April 1963. They were tested on a calibrated TV-7D/U with minimum of 56/56 so very strong tubes. $7.75 shipping.