The CV559 (commercially the 25Z6GT) rectifier consists of a pair of independent indirectly heated sections.
This construction offers a flexibility in circuit design. The CV559 can be used as a half wave rectifier with both sections in parallel or full wave rectifier by joining the cathodes or even as a voltage doubler.
The 300 mA heater is for series heater chains and on American 120 Volt mains a set HT of 250 Volts is possible in doubler configuration.
The two rectifiers side by side.
The front to back dimension is small with the face being wider to allow for more metal to radiate the generated heat.
The top mica showing the folded heater in the round cathode tube.
The wide glass tube envelope is 29 mm in diameter, and excluding the IO base pins is 68 mm tall.
