Indirect glow triode. The years are different.
6C33C is a triode for operation as a control lamp in
electronic voltage stabilizers. It is also successfully used in
low-frequency amplifiers. It is in demand on Ebay among foreign amateur radio audiophiles, because having no foreign analogues allows you to get a wonderful tube sound.
Two heaters (filament) of the 6C33C-V lamp can be switched on in series (Uh=12.6V) or in parallel (Uh=6.3V), which undoubtedly adds operational convenience to this lamp.
Main technical characteristics:
Incandescent current (at Uh =12.6V) 3.3± 0.3 A
Incandescent current (at Uh = 6.3V) 6.6± 0.6A
Anode current 550±80mA
Reverse grid current <5mkA
Leakage current between the anode and the remaining electrodes <30mkA
Leakage current between the grid and the remaining electrodes <20mkA
Leakage current between cathode and heater <150mkA
The steepness of the characteristic is 40±10mA/V
Internal resistance 80-120 ohms
Vibration noise voltage (at Ra = 2K) <500mkV
Input capacity 30±7pF
Output capacity 10.5±1pF
Throughput capacity 31±7pF
Cathode-heater capacity <60pF
Operating time >750h
Weight 200g
The panel for this lamp is PLK7-1
