Arcturus (AC) 28 C
AC Amplifier Triode
1927

The (AC)28 C was a special indirectly heated tube with one end of the 15 volt AC heater connected to the cathode. This tube had screw terminals for heater connections on the sides of the base, this to allow for the connection of an AC harness sold by Arcturus. The tube carries the same markings as the regular (AC)28, but some of the boxes had a bottom sticker showing the C part number suffix.