The 25Z6GT is a pair of rectifiers in a single envelope with a common heater connection. This construction offers a flexibility in circuit design. The 25Z6GT can be used as a half wave rectifier with both sections in parallel. A full wave rectifier by joining the cathodes or as a voltage doubler.
Electrically the 25Z6GT is identical to the 25Z6 and 25Z5.
This exhibit features a metal base skirt and suggests an earlier manufacturing date to the later Bakelite base caps.
The Radiotron Brand and Made in USA.
The RCA logo.
The two sections with individual base pins for the cathodes. The heater passes through the cathode five times.
At the top the heater wires are joined by a horizontal tape welded to heater. It looks as if the tape has melted around the heater wire. This would suggest that the heater wire is tungsten.
The plastic base ring holding the pins. The wires from the glass envelope are soldered inside the pins.
The wide glass tube envelope is 28 mm in diameter, and excluding the IO base pins is 66 mm tall.
References: Data-sheet & 1040. Type 25Z6GT was first introduced in 1938. See also1938 adverts.
